Assessment of HELCOM Hot Spot No. 10 Agricultural runoff to the Archipelago Sea with the view to delete the Hot Spot by 2027 Maria Laamanen (edit.) SNELLMANINKATU 1, HELSINKI PO BOX 23, 00023 GOVERNMENT, FINLAND government.fi julkaisut.valtioneuvosto.fi ISBN pdf: 978-952-383-470-5 ISSN pdf: 2490-0966 Publications of the Finnish Government 2025:XX Päätosikko P U B L I C AT I O N S O F T H E F I N N I S H G O V E R N M E N T 2 0 2 5 : 8 1 Assessment of HELCOM Hot Spot No. 10 Agricultural runoff to the Archipelago Sea with the view to delete the Hot Spot by 2027 Maria Laamanen (editor) Ministry of the Environment, Regional Centre for Economy, Transport and Environment of South-West Finland, Natural Resources Institute Finland, Finnish Environment Institute and Ministry of Agriculture and Forestry Finnish Government Helsinki 2025 Publications of the Finnish Government 2025:81 Finnish Government Ministry of the Environment CC BY-SA 4.0 ISBN pdf: 978-952-383-470-5 ISSN pdf: 2490-0966 Layout: Government Administration Department, Publications Helsinki 2025 Finland Publication distribution Institutional Repository for the Government of Finland Valto julkaisut.valtioneuvosto.fi https://julkaisut.valtioneuvosto.fi/ Description sheet 28 August 2025 Assessment of HELCOM Hot Spot No. 10 Agricultural runoff to the Archipelago Sea with the view to delete the Hot Spot by 2027 Publications of the Finnish Government 2025:81 Publisher Finnish Government Editor(s) Maria Laamanen Group author Ministry of the Environment, Regional Centre for Economy, Transport and Environment of South-West Finland, Natural Resources Institute Finland, Finnish Environment Institute and Ministry of Agriculture and Forestry Language English Pages 111 Abstract This report assesses Finland’s only remaining site on the Baltic Marine Environment Protection Commission (HELCOM) hot spot list, Hot Spot No. 10 Agricultural runoff to the Archipelago Sea. The objective is to apply for the deletion of this hot spot from the list by the end of 2027. The report evaluates progress towards meeting the deletion criteria. Advances have been made in water protection in the Archipelago Sea area, with 17 out of the 23 HELCOM criteria currently fulfilled. The fulfilled criteria include the hot spot boundaries, goals, nutrient load management plan, monitoring, funding, crop cover, application of soil amendments, restoration and nutrient recycling. The criteria not yet met relate to issues such as the ratio of land available for manure spreading to livestock numbers, the implementation of manure storage and spreading, ammonia emissions, and trends in the agricultural nutrient loads to the Archipelago Sea. The status of the unmet criteria will be reviewed regularly. Once the deletion criteria are met, this report can be updated and used as part of the deletion application. Applying for the deletion does not require an improvement in the marine environmental status of the Archipelago Sea. The state of the marine environment is influenced not only by nutrient loading but also by climate change and other human activities. Keywords Baltic Sea, agriculture, water protection, eutrophication, nutrient recycling, protection of the Archipelago Sea, nutrient loading ISBN PDF 978-952-383-470-5 ISSN PDF 2490-0966 URN address https://urn.fi/URN:ISBN:978-952-383-470-5 https://urn.fi/URN:ISBN:978-952-383-470-5 Kuvailulehti 28.8.2025 Maataloudesta Saaristomereen päätyvää kuormitusta koskevan HELCOM Hot Spot nro. 10:n tilannearvio tarkoituksella, että Hot Spot -status voitaisiin poistaa viimeistään vuonna 2027 Valtioneuvoston julkaisuja 2025:81 Julkaisija Valtioneuvosto Toimittaja/t Maria Laamanen Yhteisötekijä Ympäristöministeriö, Varsinais-Suomen elinkeino-, liikenne- ja ympäristökeskus, Luonnonvarakeskus, Suomen ympäristökeskus ja maa- ja metsätalousministeriö Kieli englanti Sivumäärä 111 Tiivistelmä Raportissa tarkastellaan Suomen ainoaa Itämeren suojelukomission (HELCOM) hot spot -listalla olevaa kohdetta, kohde nro 10: Saaristomeren valuma-alueen maatalouden kuormitus. Tavoitteena on hakea hot spot -statuksen poistoa vuoden 2027 loppuun mennessä. Arviointiraportissa tarkastellaan poistokriteereiden täyttymistä. Maatalouden vesiensuojelussa on Saaristomeren alueella edistytty ja HELCOM:n asettamista 23:stä kriteeristä 17 täyttyy. Täyttyneet kriteerit koskevat mm. hot spotin aluerajoja, tavoitteita, kuormituksen hallintasuunnitelmaa, seurantaa, rahoitusta, peltojen kasvipeitteisyyttä, maanparannusaineiden käyttöä ja vesistökunnostuksia sekä ravinteiden kierrätystä. Täyttymättömät kriteerit koskevat mm. lannanlevitysalaa suhteessa eläinmääriin, lannan varastoinnin ja levityksen toteutusta, ammoniakkipäästöjä ja Saaristomereen päätyvän maatalouden ravinnekuormituksen kehitystä. Täyttymättömien kriteereiden tilannetta aiotaan tarkastella säännöllisesti. Kun poistokriteerit täyttyvät, tämä raportti voidaan päivittää ja hyödyntää osana poistohakemusta. Poiston hakeminen ei edellytä Saaristomeren meriympäristön tilan paranemista. Tilan kehitykseen vaikuttavat ravinnekuormituksen ohella ilmaston muuttuminen ja muu ihmisen toiminta maalla ja merellä. Asiasanat Itämeri, maatalous, vesiensuojelu, rehevöityminen, ravinnekierto, Saaristomeren suojelu, ravinnekuormitus ISBN PDF 978-952-383-470-5 ISSN PDF 2490-0966 Julkaisun osoite https://urn.fi/URN:ISBN:978-952-383-470-5 https://urn.fi/URN:ISBN:978-952-383-470-5 Presentationsblad 28.8.2025 Lägesbedömning av HELCOM hot spot nr 10 om jordbrukets belastning på Skärgårdshavet med avsikten att senast år 2027 avlägsna Hot Spot -statusen Statsrådets publikationer 2025:81 Utgivare Statsrådet Redigerare Maria Laamanen Utarbetad av Miljöministeriet, Närings-, trafik- och miljöcentralen i Egentliga Finland, Naturresursinstitutet, Finlands miljöcentral och jord- och skogsbruksministeriet Språk engelska Sidantal 111 Referat I rapporten granskas Finlands enda objekt på den hot spot-lista som HELCOM upprätthåller, belastningen från jordbruket i Skärgårdshavets avrinningsområde. Ett mål är att ansöka om att ta bort hot spot-statusen före utgången av 2027. I rapporten granskas hur kriterierna för borttagande uppfylls. Man har gjort framsteg kring Skärgårdshavet, och 17 av HELCOM:s 23 kriterier uppfylls. De kriterier som uppfylls gäller bl a. gränserna för hot spot-området, mål, plan för hantering av belastningen, övervakningsprogram, finansiering, växttäcke på åkrarna, vattenskyddsåtgärder, såsom användning av jordförbättringsmedel och restaurering av vattendrag samt återvinning av näringsämnen. De kriterier som ännu inte uppfylls gäller bland annat gödselspridningsareal i förhållande till antalet djur, genomförande av lagring och spridning av stallgödsel, ammoniakutsläpp och utveckling av näringsbelastningen från jordbruket i Skärgårdshavet. Situationen i fråga om de kriterier som inte uppfylls kommer att granskas regelbundet. När kriterierna för borttagande uppfylls, kan denna rapport uppdateras och användas i samband med ansökan om borttagande. Ansökan om borttagande förutsätter inte att den marina miljöns tillstånd i Skärgårdshavet förbättras. Utvecklingen av tillståndet påverkas förutom av näringsbelastningen också av den globala uppvärmningen och den mänskliga verksamheten på land och till havs. Nyckelord Östersjön, jordbruk, vattenskydd, övergödning, återvinningen av näringsämnen, skyddet av Skärgårdshav, näringsbelastning, nutrient loading ISBN PDF 978-952-383-470-5 ISSN PDF 2490-0966 URN-adress https://urn.fi/URN:ISBN:978-952-383-470-5 https://urn.fi/URN:ISBN:978-952-383-470-5 Contents Executive summary.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1 Introduction.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.1 Finland’s only remaining Hot Spot, the agricultural runoff to the Archipelago Sea Hot Spot No. 10.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.2 Criteria for deleting a Hot Spot from the HELCOM list. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 The Archipelago Sea and its catchment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.1 Description of the area.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.2 State of the Archipelago Sea.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.3 Agriculture in the Archipelago Sea catchment.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.4 Nutrient loading to the Archipelago Sea. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3 Formal definition of the geographical unit of the Hot Spot.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4 Long-term environmental goals.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.1 Goals for nutrient load reductions to the Archipelago Sea.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.2 Secondary preliminary goals for nutrient load reductions from the pilot areas.. . . . . 39 5 Assessment of the Archipelago Sea Hot Spot against HELCOM’s agricultural pollution related hot spots’ deletion criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.1 Legislation, policies and programmes providing the framework for measures. . . . . . 41 5.2 Archipelago Sea Programme and the Roadmap for agricultural water protection. 44 5.3 Measures of the Roadmap to reduce agricultural load to the Archipelago Sea. . . . . . 50 5.4 Monitoring programme.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 5.5 Demonstrated adequate funding.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 5.6 Fulfillment of the conditions of Annex III Part 2 of the Helsinki Convention.. . . . . . . . . . 64 6 How far are we from fulfilling the requirements for deletion?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 7 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 7 Publications of the Finnish Government 2025:81 E X E C U T I V E S U M M A RY Finland’s only remaining Hot Spot on the HELCOM’s list of the biggest polluters in the Baltic Sea region is the Hot Spot “Agricultural runoff to the Archipelago Sea” (ID number 10). The national Archipelago Sea Programme has the goal to enable the deletion of this Hot Spot by the end of 2027. This report provides an assessment of the status of the Hot Spot and an analysis of the extent to which the Hot Spot deletion requirements by HELCOM have been met. Extensive work is ongoing to enhance nutrient recycling in the Archipelago Sea catchment and to reduce agricultural nutrient loading to the sea. The Archipelago Sea Programme and its Roadmap for agricultural water protection measures lay out the measures necessary to improve the state of the sea and delete the Hot Spot from the list. Due to the significant scale of different financing possibilities, especially through the national CAP plan, it is possible to conclude that the 18 M € per year cost estimate of implementation of the Archipelago Sea Programme’s Roadmap for agricultural water protection measures has been covered in recent years and it will be covered in the following years at least up to 2028. According to the analysis, 17 out of the 23 requirements for the deletion of the Hot Spot from HELCOM’s list were fulfilled. The Archipelago Sea Programme and its Roadmap for water protection in agriculture serve as a non-point source pollution reduction plan required in hot spot’s deletion criteria. There are long- term environmental goals, declining total loads of both nitrogen and phosphorus, signs of decreasing agricultural phosphorus loading, a monitoring programme and sufficient financing for measures in place enabling us to meet deletion criteria. The criteria for wintertime crop cover and pollution reduction measures, such as application of gypsum on fields, as well as the requirements for the design and location of animal houses and nutrient recycling, have also been met. The six (in fact only five, since one unmet criterion repeats five other non-met criteria) criteria which have not yet been met all relate to livestock production and manure management and there are challenges especially in regions with intensive livestock production and high soil phosphorus content. The exemption on manure 8 Publications of the Finnish Government 2025:81 spreading of the Phosphorus Decree hampers meeting the criteria. It was also observed that a data repository of plot level soil nutrient data could improve the implementation of water protection measures and permitting procedures. In conclusion, the Archipelago Sea agricultural pollution Hot Spot is not yet ready for deletion and an application to HELCOM is not timely. Nevertheless, most of the deletion criteria have already been met and good progress is underway and contributing to decreasing the non-point source agricultural pollution to the Archipelago Sea. The Archipelago Sea catchment has all the possibilities to become a pioneering region of nutrient recycling and achieve a continuous decline of nutrient loads from agriculture of the catchment. However, to maintain this trend and to reach the preliminary load reduction targets of the Marine Strategy, determination and further action is needed to reach the goal. This gaps in meeting the criteria as well as the state of nutrient loading will be reviewed annually and this report updated until it can be concluded that the criteria have been met and it is possible to submit the deletion application to HELCOM. This report is intended to provide the justification to the eventual deletion application. 9 Publications of the Finnish Government 2025:81 1 Introduction In 1992, the Baltic Marine Environment Protection Commission, HELCOM, established a list of 162 significant pollution sites around the Baltic Sea called HELCOM Hot Spots. A major focus of the Hot Spots programme is to support measures to bring about a decisive reduction of pollution to the Baltic Sea from land-based sources according to the provision of the Helsinki Convention which require the Contracting Parties to: “…take all appropriate legislative, administrative or other relevant measures to prevent and eliminate pollution in order to promote the ecological restoration of the Baltic Sea Area and the preservation of its ecological balance.”1 Hot Spots were initially designated according to the seriousness of their impact on the environment and human health. Out of total 162 HELCOM Hot Spots, 40 (25%) are still active and 122 (75%) had been cleaned up by December 2020 when HELCOM last assessed their status. Most of the original Hot Spots were industrial Hot Spots, and altogether 17 agricultural Hot Spots were included. In this document we assess the status of Finland’s last remaining Hot Spot, agricultural runoff to the Archipelago Sea, against deletion criteria provided by HELCOM. The aim is to provide the information needed to decide on whether Finland is ready to apply for the deletion of the Hot Spot. 1.1 Finland’s only remaining Hot Spot, the agricultural runoff to the Archipelago Sea Hot Spot No. 10 Initially, ten Hot Spots were established in Finland, seven of them were industrial, one municipal, one agricultural and one concerned fish farming. The only remaining Hot Spot in 2025 is the Hot Spot “Agricultural runoff to the Archipelago Sea” (ID number 10). 1 Final-report-on-JCP-efficiency-1.pdf (helcom.fi) https://helcom.fi/wp-content/uploads/2019/08/Final-report-on-JCP-efficiency-1.pdf 10 Publications of the Finnish Government 2025:81 HELCOM has not provided any description of the Hot Spot. In the report on the implementation of the Hot Spot programme in 2013, HELCOM stated that the only remaining Hot Spot of Finland is agricultural runoff to the Archipelago Sea and it is not proposed for deletion within the coming years due to the low effect demonstrated with measures undertaken so far. In general, agricultural Hot Spots are characterized by intensive agriculture and livestock farming and there are nutrient losses to the Baltic Sea, which threatens coastal ecosystems. The sites included in the Hot Spot list have many livestock in relation to the arable area or deficiencies in agricultural water protection measures. Photo: Sari Luostarinen 1.2 Criteria for deleting a Hot Spot from the HELCOM list To guide the process of deleting Hot Spots, HELCOM has provided “Criteria for Inclusion and Deletion of Hot Spots: Procedures and Guidelines for Inclusion and Deletion of Hot Spots”2. 2 Document (helcom.fi) Criteria-for-inclusion-and-deletion-of-hotspots.pdf https://helcom.fi/wp-content/uploads/2019/08/Criteria-for-inclusion-and-deletion-of-hotspots.pdf 11 Publications of the Finnish Government 2025:81 For deleting agricultural Hot Spots HELCOM gives the following criteria: “An agricultural Hot Spot or subdivision thereof, may be considered for deletion, provided that the Hot Spot unit has been formally defined by the co-operating government on the basis of administrative and/or drainage basin/sub-basin boundaries, long-term environmental goals are established for the area, and it fulfils the following criteria: (i) an agricultural non-point source management plan has been prepared, which includes an appropriate monitoring programme, and there is demonstrated funding which will be adequate for a sustained incremental programme of on-farm activities including improved agricultural practices, investments in manure, urine and slurry handling, and the establishment of buffer strips; (ii) the management plan will result, through a series of phased actions, in all relevant provisions of the Helsinki Convention Annex III being fulfilled; (iii) farms within a watershed with an animal density higher than [1.5] livestock units per ha or large animal farms with more than 250 livestock units have demonstrated that fertilisers and manure are adequately stored and are applied on an appropriate area and according to official national or regional fertilisation guidelines; and (iv) if located in a vulnerable area that requires special measures according to national considerations, the management plan will support a series of activities to fulfil these requirements.” HELCOM has provided general procedures for agricultural Hot Spot deletion: Step 1: Quantify pollutant loadings and downstream water quality Implementation of the management plan for the area would support a series of farm-level interventions that over the medium and long term would result in a high and/or significant reduction of amounts of polluting substances released via rivers or directly to Baltic Sea marine and coastal waters, including wetlands, lagoons and semienclosed basins. https://helcom.fi/about-us/convention/annexes-to-the-convention-2/annex-iii/ 12 Publications of the Finnish Government 2025:81 Step 2: Compare monitoring results against relevant HELCOM Recommendations and Annexes or other relevant international agreements The management plan for the area is technically sound and adequately funded to allow for a phased series of farm-level activities that are consistent with Annexes of the Helsinki Convention (especially Annex III), and relevant HELCOM Recommendations, or other international agreements relevant to countries in the Baltic Sea catchment area, if HELCOM Recommendations are not available and/or applicable. Step 3: Assess management plan, performance indicators and monitoring programme Assess whether the management plan will fulfil objectives for the reduction of non-point source pollution from agriculture. Review the adequacy of the monitoring programme with regard to information on farm-level interventions and longer-term environmental benefits through pollution load reductions. In addition, HELCOM recommends that recognizing the slow response times of interventions for the control of non-point source pollution from agriculture, countries should provide satisfactory information concerning the types of management plans, monitoring programmes, funding commitments and their implementation status, as the basis for deleting an individual management unit. 13 Publications of the Finnish Government 2025:81 2 The Archipelago Sea and its catchment 2.1 Description of the area The Archipelago Sea in the Southwest of Finland is a relatively shallow sea area with a unique mosaic of islands, skerries and marine water (Figure 1). In the south, the sea area is delimited to the boundary of the Finnish coastal waters (1 NM from the baseline as in the MSFD) and in the west to the waters of the Åland Islands, an autonomous region of Finland. The number of islands is over 40 000. Water depth is 23 meters on average with the deepest site being 146 meters. Coastal waters are shallower, usually less than 10 meters deep. Water salinity varies between 5.5 and 6.5 PSU. The archipelago can be divided into inner coastal, middle and outer archipelago according to the share of islands and skerries in relation to water surface and biota. The marine environment of the Archipelago Sea provides conditions for diverse communities of plants and animals. Underwater life consists of species of both marine and freshwater origin. Large parts of the area have been designated as a national park and also have a Natura2000 status. 14 Publications of the Finnish Government 2025:81 Photo: Maria Laamanen The marine area of the Archipelago Sea is large and there are a number of major rivers flowing into it, such as the rivers Mynäjoki, Aurajoki, Paimionjoki and Uskelanjoki. These rivers are large and impacted by the high clay content of the soils of the catchment. They are also classified to a poor or moderate ecological status according to the Water Framework Directive. 15 Publications of the Finnish Government 2025:81 Figure 1.  The Archipelago Sea is located in the Southwest of Finland and has a large catchment area with several rivers. 2.2 State of the Archipelago Sea In addition to the HELCOM targets, the goal for all EU Member States is to achieve a good status of all coastal waters as required by the Water Framework Directive (WFD) and of the marine environment as required by the Marine Strategy Framework Directive (MSFD). According to the WFD assessment of ecological status in 2019, the Archipelago Sea is mostly in a moderate ecological status (Figure 2). The main problem is eutrophication manifested by algal overgrowth and blooms, hypoxic and anoxic sediments as well as changes in species composition towards species that favor less transparent and warmer water. The MSFD assessment report in 2024 ‘State of the marine environment 2024’ also defines eutrophication as the major problem.3 3 Suomen meriympäristön tila 2024 https://www.ymparisto.fi/fi/luonto-vesistot-ja-meri/meri/suomen-meriympariston-tila-2024 16 Publications of the Finnish Government 2025:81 Photo: Maria Laamanen The waters in the inner archipelago closest to the coast are in the worst condition, often classified as poor. None of the water bodies in the Archipelago Sea are classified as being in a good status. 17 Publications of the Finnish Government 2025:81 Figure 2.  The ecological status of the Archipelago Sea (Syke 2022) is based on biological, chemical, and hydrological quality factors in comparison to its natural state. The greater the human impact, the lower the ecological quality of the water body. In addition to the nutrient loading from the catchment, the status of the marine waters, especially in the outer archipelago, is affected by nutrients from the neighboring, severely eutrophicated sea areas, the northern Baltic Sea and the Gulf of Finland (Figure 3). Nitrogen also enters the system via atmospheric deposition. In addition, the eutrophicated state partly persists due to historical loading and inability of the sediments that are impacted by anoxia to withhold and permanently bury the nutrients which results in so called internal loading4. Benthic anoxia and thus also internal loading, however, is seasonal. This means that phosphorus released from anoxic sediments to the water during summer-late summer can be 4 MAAMERI-hanke – Vaikuttavaa merentutkimuksen yhteistyötä Saaristomeren parhaaksi (2).pdf C:\Users\03022541\Downloads\MAAMERI-hanke - Vaikuttavaa merentutkimuksen yhteistyötä Saaristomeren parhaaksi (2).pdf C:\Users\03022541\Downloads\MAAMERI-hanke - Vaikuttavaa merentutkimuksen yhteistyötä Saaristomeren parhaaksi (2).pdf 18 Publications of the Finnish Government 2025:81 partially adsorbed back to the particles in the water column settling to seafloor and also sediment surface when the sediment oxygen conditions improve along with cooling waters, breaking of the seasonal thermocline and enhanced vertical water exchange. 19 Publications of the Finnish Government 2025:81 Figure 3.  In the upper panel the share of phosphorus fluxes from different sources as a percentage of total loading, (point sources, catchment, bottom sediment, open sea) based on FICOS-model calculation5) of phosphorus and nitrogen and in the lower panel total phosphorus (P, µmol/g) release potential from bottom sediment in the outer, middle and inner Archipelago Sea. Size of arrows in the upper panel is proportional to nutrient flux, also presented as percentage in number. Green circle in the middle of panels shows the algal biomass as concentration of chlorophyll-a in μg/L in the different parts of the Archipelago Sea as calculated by the FICOS model. It is to be noted that FICOS-model calculation represents overall balance of nutrient sources available to planktonic algal biomass growth. Processes driving phosphorus fluxes from and to the sediment are dynamic and seasonal; phosphorus released from the sediments during seasonal anoxia can be adsorbed back to particles in the water column and the sediment when the sediment returns to oxygenated state after summer period. 5 Fleming, V. & al. (2021): Rannikkovesiemme vedenlaadun ja rehevöitymistilan tulevaisuus ja sen arvioiminen. Valtioneuvoston selvitys- ja tutkimustoiminnan julkaisusarja 2021:14. http://urn.fi/URN:ISBN:978-952-383-111-7 http://urn.fi/URN:ISBN:978-952-383-111-7 20 Publications of the Finnish Government 2025:81 2.3 Agriculture in the Archipelago Sea catchment The largest rivers in the catchment of the Archipelago Sea are the Rivers Paimionjoki, Aurajoki, Kiskonjoki and Uskelanjoki, along with numerous smaller rivers that flow from the catchment into the sea. The terrain of the area is relatively flat, and the surface soil consists mainly of layers of clay (even in the order of 80 % of all soils) and silt deposited on top of basic moraine. There are no large lakes in the catchment. The high clay content of the soil makes them susceptible to erosion, which decreases the quality of the river waters. The share of arable land in the Southwest of Finland is relatively high compared to the rest of the country as over 10% of the Finnish agricultural and horticultural enterprises are in Southwest Finland. Nearly one-third of the total land area of the Archipelago Sea catchment, about 240,000 hectares, is farmland. Farms producing different plants make up 80% of the farms. Grain, especially wheat, and special crops such as sugar beet, pea and rapeseed are cultivated in the area. The region's livestock farming focuses on pig and poultry production. About two thirds of all laying hen and 20 % of broilers are reared in Southwestern Finland (within or in close proximity to the Archipelago Sea catchment), while the share of all pigs is 28 %6. Cattle production is significantly smaller, only 3 % and 8 % of all dairy cows and suckler cows, respectively, are reared in the area. This also explains the small field area for grass production. 6 https://www.luke.fi/fi/tilastot/kotielainten-lukumaara https://www.luke.fi/fi/tilastot/kotielainten-lukumaara 21 Publications of the Finnish Government 2025:81 Photo: Sari Luostarinen The animal density in Southwest Finland is 0.45 LSU/ha (average in Finland 0.40 LSU/ha)7. However, the livestock production and hence also the manure nutrients in the Archipelago Sea catchment are highly concentrated in the western and northern parts of the area and the animal density for the whole catchment does not give a representative picture of the situation (Figure 4). The higher the number of livestock is, the higher the amount of manure nutrients available for fertilization and the higher also the risk of leaching to waters in case the manure is not sustainably managed and used. Most of the manure produced in the area is directly applied on fields on or close to the livestock farms, while little is processed or transported to be used elsewhere. 7 Eläinyksiköiden suhde hehtaareihin maakunnittain | Taloustohtori https://taloustohtori.luke.fi/tuotantorakenne/aikasarja/elainyksikoiden-suhde-hehtaareihin-maakunnittain/ 22 Publications of the Finnish Government 2025:81 Figure 4.  The amount of manure phosphorus produced per field area (ha) per municipality in Southwest Finland. Average Finnish amount of manure phosphorus per field hectare was 6.7 kg/ha in 2023.8 In addition, most of the ammonia emissions causing atmospheric deposition of nitrogen to the sea originate from manure management. The quantity of emissions to the air thus also follows the number of animals within the region (Figure 5). 8 http://urn.fi/URN:ISBN: 978-952-380-612-2 http://urn.fi/URN:ISBN: 978-952-380-612-2 23 Publications of the Finnish Government 2025:81 Figure 5.  Ammonia emissions (t/km²) from agriculture by municipality in 20239. Due to the long agricultural history of the Archipelago Sea area, previous high use of fertilizers in all agricultural production and regionally concentrated intensive livestock production, phosphorus content of the field soils is rather high in the area (Figure 6). This reduces the need for phosphorus fertilization in the region. The higher the soil phosphorus content is, the higher also the risk for phosphorus losses from the fields to the waters. The highest average soil phosphorus content is usually in municipalities and sub-catchments with high animal density and/or production of special plants such as sugar beet, potato and pea. High manure use in fertilization has been one reason for persistently high phosphorus content of soils when the overall use of phosphorus fertilizers is not balanced against the needs of plants. 9 Suomen ympäristökeskuksen ilmapäästötietojärjestelmä/Juha Grönroos 2025 24 Publications of the Finnish Government 2025:81 Photo: Sari Luostarinen 25 Publications of the Finnish Government 2025:81 Figure 6.  Average soil phosphorus content (soil test P; mg/l) per municipality in the fields of Southwest Finland. Average soil phosphorus content in Finnish field soils is 11 mg/l.10 When comparing the amount of manure phosphorus and the need for phosphorus fertilization (taking into account the soil phosphorus content and plants produced) per municipality in the Archipelago Sea area, a surplus can be identified in the municipalities with higher animal density (Figure 7). While noticing that this comparison assumes manure phosphorus is applied on all field area benefitting from phosphorus fertilization, and that mineral phosphorus fertilizers are also used, it shows there is an overall need to reduce phosphorus fertilization in the area and improve allocation of manure nutrients between the livestock and plant producing farms. 10 http://urn.fi/URN:ISBN: 978-952-380-612-2 http://urn.fi/URN:ISBN: 978-952-380-612-2 26 Publications of the Finnish Government 2025:81 Figure 7.  Regions of surplus and deficiency in the availability of manure phosphorus (kg/ ha) in comparison to phosphorus fertilization needed in crop production per municipality in Southwest Finland. The fertilization need for an area is calculated considering soil phosphorus content, crops produced and crop-specific needs for phosphorus fertilization11. 2.4 Nutrient loading to the Archipelago Sea The eutrophication of the Archipelago Sea is caused by long-term land-based nutrient loading from the catchment, direct point source discharges, transport of nutrients from the neighboring sea areas and atmospheric deposition. In addition, anoxic sediments release nutrients, especially phosphates, that have accumulated in the sediments over time. 11 http://urn.fi/URN:ISBN: 978-952-380-612-2 http://urn.fi/URN:ISBN: 978-952-380-612-2 27 Publications of the Finnish Government 2025:81 Point source pollution from municipal wastewaters and fish farming started to remarkably decrease already in the 1980s first related to phosphorus and only later related to nitrogen. The Urban Waste Water Treatment Directive from 1991 (revised in 2025) significantly improved the municipal wastewater treatment and reduced the discharge12. Nowadays, the largest source of nutrients to the Archipelago Sea is agriculture. It causes 50 % of loading of nitrogen and 67% of phosphorus even when natural leaching of nutrients is accounted for (Figure 8). This is due to intensive farming activities, and concentrated livestock production, in combination with slowly impacting or insufficient water protection measures in western and northern parts of the area. The high clay content of the field soils and the lack of lakes that could retain nutrients make the catchment area prone to land-based nutrient loading. 12 https://vesi.fi/aineistopankki/yhdyskuntien-jatevesien-kuormitus-vesiin/ https://vesi.fi/aineistopankki/yhdyskuntien-jatevesien-kuormitus-vesiin/ 28 Publications of the Finnish Government 2025:81 Figure 8.  The share (%) of sources of nitrogen and phosphorus loading to the Archipelago Sea from local sources (the catchment area and islands in the archipelago area) as an average of years 2010–2019. Data from Finnish Environment Institute Syke. 2 % 0 % 3 % 0 % 67 % 4 % 1 % 0 % 23 % Phosphorus (480 ton/a) Municipal waste waters Industry Fish farming Peat production Agriculture Scattered dwellings Forestry Storm waters Natural leaching 5 % 0 % 2 % 0 % 50 % 2 % 1 % 0 % 7 % 7 % 26 % Nitrogen (8 800 ton/a) Municipal waste waters Industry Fish farming Peat production Agriculture Scattered dwellings Forestry Storm waters Air deposition Shipping Natural leaching 29 Publications of the Finnish Government 2025:81 Nutrient loading to the sea has decreased over the years and there is a statistically significant decreasing trend for total loading of both nitrogen and phosphorus over 1995–2023 (Figure 9). The decrease is mainly a result of improved wastewater treatment and fish farming methods. Diffuse loading, mainly (ca. 89%) from agriculture, has also decreased in a statistically significant way when it comes to phosphorus, but diffuse loading of nitrogen shows no sign of a decrease (Figure 9). Photo: Sari Luostarinen The decrease in diffuse loads was detected in flow-normalized inputs, whereas no such decrease was observed in non-normalized inputs. Flow-normalized load estimates decrease the impact of variation in water flow on the nutrient load and they better show the effects of load-reducing measures. Noteworthy is that currently there are large gaps in the coverage of monitoring, which increases the uncertainty in estimating trends in nutrient loads (see Chapter 5.4). 30 Publications of the Finnish Government 2025:81 Figure 9.  Land-based loading (tons per year, t/a) of nitrogen (N) and phosphorus (P) to the Archipelago Sea (excluding the Åland Islands) in 1995–2023 with point source and diffuse (ca. 89 % agricultural) loads as well as natural leaching presented for both nutrients with bars, and for nitrogen atmospheric deposition is also included. The total and diffuse loads are also denoted with a waterflow normalized line as well as with a linear trend when the trend is statistically significant (P>0.95). Data from Syke. 0 2 000 4 000 6 000 8 000 10 000 12 000 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 20 13 20 14 20 15 20 16 20 17 20 18 20 19 20 20 20 21 20 22 20 23 tons/a Nitrogen load Di�use load Atmospheric deposition on lakes Point source load Natural leaching Total load (normalised) Di�use load (normalised) Lin. (Total load (normalised)) 31 Publications of the Finnish Government 2025:81 0 100 200 300 400 500 600 700 800 900 1 000 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 20 13 20 14 20 15 20 16 20 17 20 18 20 19 20 20 20 21 20 22 20 23 Phosphorus load Di�use load Point source load Natural leaching Total load (normalised) Di�use load (normalised) tons/a Lin. (Total load (normalised)) Lin. (Di�use load (normalised)) 32 Publications of the Finnish Government 2025:81 3 Formal definition of the geographical unit of the Hot Spot HELCOM requires the Contracting Party or its cooperating government to formally define the Hot Spot based on administrative and/or drainage basin/sub- basin boundaries before it can apply for Hot Spot deletion. The Archipelago Sea agricultural Hot Spot No. 10 covers the whole drainage basin or catchment of the Archipelago Sea as shown on the map (Figure 1). The drainage basin has been defined based on the geographical boundaries of the catchment area and some administrative boundaries. Within the national Archipelago Sea Programme, aiming at improving the state of the sea and deleting the Hot Spot status (see: Chapter 5), three pilot areas have been defined (Figure 10). They are two river basins within the catchment, the Rivers Aurajoki and Paimionjoki, and an island with its surrounding marine area, Kemiönsaari. The pilot areas are subject to intensified measures and higher activity to reduce agricultural nutrient pollution. They have been selected due to their significant nutrient loading in comparison to most other areas. In addition, the inclusion of an island with its surrounding marine area into the set of pilot areas will enable measures taken in the sea as well. 33 Publications of the Finnish Government 2025:81 Figure 10.  Three pilot areas of the Archipelago Sea catchment: river basins within the catchments of the Rivers Aurajoki and Paimionjoki, and an island with its surrounding marine area, Kemiönsaari. 34 Publications of the Finnish Government 2025:81 4 Long-term environmental goals 4.1 Goals for nutrient load reductions to the Archipelago Sea One of the prerequisites for the Hot Spot deletion is setting long-term environmental goals for the Hot Spot. These goals need to be aligned with internationally and nationally set goals. For Finland, the goals for the status of marine and surface waters are set in the national Marine Strategy13 and River Basin Management plan for the area14. Nutrient load reduction goals are given as environmental goals of the National Marine Strategy15. Overall, it is evident that the total nutrient load to the Archipelago Sea from the catchment must be reduced considerably to achieve a good state of the marine environment and a good ecological status of coastal waters. The preliminary nutrient load reduction targets presented in the national Marine Strategy show the long-term reduction targets required to achieve a good ecological status of marine waters. The targets were updated in 2024 for the period 2024-2030. These targets for the whole Archipelago Sea are -140 tn P/year (-30 %) and -750 tn N/year (-10 %) of total nutrients in comparison to the average loads of the years 2012–2021. The National Marine Strategy includes also updated goals for nutrient load reductions in certain sectors. The preliminary reduction goals for agriculture in the Archipelago Sea catchment area are exactly the same as the general goals above. This is relevant since the anthropogenic loading is mostly diffuse loading from agriculture. 13 Taustaraportti Hyvän tilan määritelmät 2024.pdf 14 Kokemäenjoen – Saaristomeren – Selkämeren vesienhoitoalueen vesienhoitosuunnitelma vuosille 2022–2027. Osa 1: Vesienhoitoaluekohtaiset tiedot. 15 Tausta-asiakirja Merenhoidon ympäristötavoitteiden tarkistaminen 2024_0.pdf https://www.ymparisto.fi/sites/default/files/documents/Taustaraportti Hyv%C3%A4n tilan m%C3%A4%C3%A4ritelm%C3%A4t 2024.pdf https://www.doria.fi/bitstream/handle/10024/184724/Raportteja 15 2022.pdf?sequence=7&isAllowed=y https://www.doria.fi/bitstream/handle/10024/184724/Raportteja 15 2022.pdf?sequence=7&isAllowed=y https://www.ymparisto.fi/sites/default/files/documents/Tausta-asiakirja Merenhoidon ymp%C3%A4rist%C3%B6tavoitteiden tarkistaminen 2024_0.pdf 35 Publications of the Finnish Government 2025:81 Photo: Riku Lumiaro Even though nutrient loading is decreasing, reaching a good status of the Archipelago Sea marine environment will take a long time. It is also influenced by additional factors such as climate change. Reaching a good environmental status is not a prerequisite for deletion by HELCOM. The long-term environmental goal Finland sets for the deletion of its HELCOM Hot Spot is a decrease of N and P loads from agriculture towards the preliminary reduction targets of Marine Strategy. When considering reaching the goal, the delaying effects of climate change and other potential factors that may hinder the achievement of the objective will be taken into account. Nutrient loading will be monitored using data from the Archipelago Sea monitoring programme and modeling. This is in line with the hot spot deletion approaches used by some other HELCOM countries. 36 Publications of the Finnish Government 2025:81 Figure 11.  Agricultural nitrogen and phosphorus loading in tons/year (bars, non- normalized; dotted line, flow-normalized and dashed line, statistically significant trend of flow-normalized) into the Archipelago Sea from 1995 to 2023 together with the level of loading at the preliminary nutrient load reduction target for total nitrogen and total phosphorus set in the updated of the Marine Strategy (2024). Data from Syke. 0 1 000 2 000 3 000 4 000 5 000 6 000 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 20 13 20 14 20 15 20 16 20 17 20 18 20 19 20 20 20 21 20 22 tons/a Agricultural nitrogen load Agricultural load Normalised agricultural load Target load for agriculture (preliminary) 20 23 37 Publications of the Finnish Government 2025:81 No deadline for achieving the preliminary targets has been set because the underlying data and modeling information are not yet considered sufficiently reliable to do so. The goals will be reviewed according to the regular six-year cycles of the Marine Strategy and new data and modelling will be used to set the goals. The goal is to achieve a continuing decrease of the loads towards the targets, preferably in the 2030s, and subsequently to a level allowing a good ecological status to be reached. The goals are based on an estimate made by modeling how much the nutrient load into the Archipelago Sea will decrease if all the measures included in the River Basin Management plans for the Archipelago Sea catchment area for 2022–2027 are implemented in full. According to a study, which used modeling of needed reductions to reach a good status of the marine environment as a starting point, reaching a good status for summertime eutrophication indicators would require a 68 % reduction of loading of both N and P. These reductions would equal to the maximum loadings of 0 100 200 300 400 500 600 700 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 20 13 20 14 20 15 20 16 20 17 20 18 20 19 20 20 20 21 20 22 20 23 tons/a Agricultural phosphorus load Agricultural load Normalised agricultural load Target load for agriculture (preliminary) Lin. (Normalised agricultural load) 38 Publications of the Finnish Government 2025:81 1 794 tn/year of N and 126 tn/year of P16. These results, however, were not considered sufficiently reliable to be used as a basis for setting the load reduction targets of the Marine Strategy due to perceived uncertainties in modelling and unknown or not well understood factors related to internal loading, among other things. Hence, the preliminary less ambitious reduction targets were set, and they will be reviewed regularly as further knowledge is accumulated. Photo: Susa Niiranen HELCOM, on the other hand, has used a slightly different approach to estimating load reductions necessary for reaching a good status of marine waters in terms of eutrophication. Their method focuses on the open sea and is based on the reduction needs of eutrophication in the open sea areas, while the focus in our approach is on the eutrophication of coastal waters. HELCOM estimated the reduction needs and input ceilings of the Archipelago Sea in 2023 (Technical NIC background report, HELCOM 2023). According to those estimates, the need to 16 Rannikkovesien ravinteiden kuormituskatot ja kuormituksen vähentämisen keinoja – Loppuraportti https://julkaisut.valtioneuvosto.fi/bitstream/handle/10024/165047/VNTEAS_2023_45.pdf?sequence=1&isAllowed=y https://julkaisut.valtioneuvosto.fi/bitstream/handle/10024/165047/VNTEAS_2023_45.pdf?sequence=1&isAllowed=y 39 Publications of the Finnish Government 2025:81 reduce phosphorus load would be about the same or slightly lower than Finland's nationally defined goal in national Marine Strategy. The slightly lower nitrogen load reduction needs would have already been reached with current loading. To reach a good status of the coastal waters, higher load reductions are necessary compared to the open waters, where the effect from open sea sources, e.g. transboundary pollution from other countries and legacy pollution is higher and the task of reducing the loading is divided among the coastal countries (HELCOM system of County Allocated Reduction Targets). On the other hand, Finnish load reduction goals will have a greater impact on the near shore coastal waters, where the external pollution is largely of national origin, and the effect of external transboundary pollution is less17. In addition to national approaches, the subject of this report, international cooperation and action by other countries to reduce nutrient loads according to the HELCOM Baltic Sea Action Plan and its nutrient load reduction system is highly necessary but is not the subject of this paper. Although a lot of focus has recently been put on phosphorus loading, nitrogen loading is just as important to reduce. Internal loading of phosphorus from the sediments due to anoxia poses a challenge both in coastal and open waters but its level can mainly be brought down by reducing external loading of both nitrogen and phosphorus. Nitrogen is the main nutrient driving spring blooms which are the main pelagic biomass peak settling as particles to the sediments and consuming oxygen as they decompose. Anoxia drives internal loading of phosphorus from the sediments and the continuous vicious cycle of eutrophication. Similarly, coastal annual filamentous algae, which give many coastal environments a slimy appearance are driven by nitrogen and their decomposition also consumes oxygen. 4.2 Secondary preliminary goals for nutrient load reductions from the pilot areas In addition to the main long-term environmental goals of the Hot Spot, preliminary nutrient load reduction targets have been set for each of the three nationally chosen pilot areas within the Hot Spot area (see: Chapter 3). The method for setting the secondary goals is the same as for the priority goals, i.e., they are based on an 17 Hyytiäinen, K., Huttunen, I., Kotamäki, N., Kuosa, H. and Ropponen, J. Good eutrophication status is a challenging goal for coastal waters. Ambio (2023). https://doi.org/10.1007/s13280-023-01965-7 https://doi.org/10.1007/s13280-023-01965-7 40 Publications of the Finnish Government 2025:81 estimate made by modeling of how much the nutrient load into the Archipelago Sea will decrease if all the measures included in the River Basin Management plan, when accounting only for the pilot area, are implemented in full. The preliminary load reduction targets for the pilot areas are in the order of 13–16 % from the average level of 2012-2021 loading for nitrogen and 34–36 % for phosphorus (Table 1). These reduction levels are higher than those for the whole catchment since the pilot areas are sources of higher loading per unit area in comparison to most other areas. These goals are preliminary and indicative in nature, and they provide a reference point for the efforts to reduce loads. No timetable has been set for these reductions. Table 1.  The level of current loading (tn/year) and preliminary load reduction targets (tn/year and %) of total nitrogen and phosphorus for each of the three nationally chosen pilot areas within the Hot Spot area. Area Nitrogen Phosphorus Average 2012–2021 loading (tn/year) Reduction target (tn/year and %) Average 2012–2021 loading (tn/year) Reduction target (tn/year and %) River Aurajoki 590 -90 (-15 %) 52 -19 (-36 %) River Paimionjoki 800 -130 (-16 %) 93 -33 (-36 %) Kemiönsaari 290 -37 (-13 %) 19 -6 (-34 %) 41 Publications of the Finnish Government 2025:81 5 Assessment of the Archipelago Sea Hot Spot against HELCOM’s agricultural pollution related hot spots’ deletion criteria Already for long, Finland has been and is currently taking measures to reduce nutrient loading to the Archipelago Sea to improve its state. The legislation, policies and programmes contain norms, obligations and incentives to agricultural water protection measures. In 2021, Finland also launched an Archipelago Sea Programme with the aim to achieve a clear decrease of agricultural loading through more effective cooperation and implementation of intensive measures in the area and with the ultimate goal to delete the Hot Spot status preferably by 2027. 5.1 Legislation, policies and programmes providing the framework for measures Much of the national legislation listed above stems from EU legislation and policies, such as the Water Framework Directive (2000/60/EC), Marine Strategy Framework Directive (2008/56/EC), Nitrates Directive (91/676/EEC) and EU CAP (EU/2115/2021 ja EU/2116/2021). The Programmes of Measures for years 2022-2027 under the River Basin Management Plan for the Western Finland18 and the national Marine Strategy19 provide the framework for further measures targeted at improving the state of the Archipelago Sea. The aim of these Programmes is to achieve and maintain a good status of the marine environment and a good ecological status of surface waters. Agricultural water protection measures have been implemented and financed since the last millennium, primarily through the CAP. There is a number of measures under the CAP that are obligatory to receive the funding. In addition, there are 18 Varsinais-Suomen ja Satakunnan vesienhoidon toimenpideohjelma vuosille 2022–2027. 19 Suomen merenhoitosuunnitelman toimenpideohjelma vuosille 2022–2027 https://www.doria.fi/bitstream/handle/10024/184006/Raportteja 44 2021.pdf?sequence=1&isAllowed=y https://julkaisut.valtioneuvosto.fi/bitstream/handle/10024/163704/YM_2021_30.pdf?sequence=1&isAllowed=y 42 Publications of the Finnish Government 2025:81 water protection measures in the national CAP plan that are voluntary. More precise guidance for nutrient use in fertilization and manure management is given also in the legislation. The whole of Finland has been designated as a nitrate vulnerable zone, meaning that the Nitrates Directive is applied throughout the country. The Nitrate Decree sets out practices for the storage and spreading of manure and fertilizer products to reduce nitrogen emissions into water bodies, soil, and air from the use, storage, and handling of fertilizers. The Fertilizing Product Act, Decree on Fertilizing Products and especially the Decree on the use of phosphorus fertilizers, including manure, have recently set stricter rules and boundaries for all fertilization in agriculture, horticulture and landscaping. The most important national legislation, policies and programmes regulating and supporting the protection of marine and surface waters and water protection measures in agriculture include: Environmental legislation especially related to waters − Environment Protection Act (527/2014) and the relevant related Government Decrees − Water Act (587/2011) − Government Decree on Urban Waste Treatment (1303/2004) − Waste Act (646/2011) and Government Decree on Waste (978/2021) − Act on the Environmental Impact Assessment Procedure (2017/252) − Nature Conservation Act (9/2023) − Water Resources Management Act (2004/1299) − Government Decree on Water Resources Management Areas (1303/2004) − Government Decree on Water Resources Management (1040/2006) − Government Decree on the Organization of the Development and Implementation of the Marine Strategy (2011/980) − Government Decree on the Granting of Assistance for Projects to Improve the Use and Condition of Water Bodies and the Aquatic Environment (2001/688) − Government Decree on State Grants to Non-Profit Organizations and Foundations for the Promotion of Health and Social Well-Being (1552/2016) 43 Publications of the Finnish Government 2025:81 Photo: Sari Luostarinen Legislation related to agricultural policy and subsidies affecting on water protection − Government Decree 867/2024 on requirements related to good agriculture and environmental conditions related to EU and national farmer subsidies − Government Decree 1278/2023 on statutory management requirements related to EU and national farmer subsidies − Government Decree 78/2023 on environmental compensation − Government Decree 28/2025 on decoupled direct payments from agricultural production 2025 − Act on the Management of the Common Agricultural Policy Strategic Plan (1324/2022) − Act on Direct Payments to Farmers in the European Union (1332/2022) − Act on Certain Rural Development Compensation Measures (1333/2022) − Act on the Implementation of Certain European Union and National Agricultural Supports (1334/2022) − Act on Supporting Rural Development in the 2023–2027 Funding Period (1325/2022) − Decree of the Ministry of Agriculture and Forestry on Environmental Protection Requirements for Subsidized Construction (606/2023) 44 Publications of the Finnish Government 2025:81 Legislation on fertilizing products and their use − Nitrate Decree, the Government Decree on the Restriction of Certain Emissions from Agriculture and Horticulture (1250/2014) − Fertilizing Product Act (711/2022) − Decree of the Ministry of Agriculture and Forestry on Fertilizing Products (964/2023) − Decree of the Ministry of Agriculture and Forestry on the Operation and Supervision of Fertilizing Products (965/2023) − Plant Protection Products Act (2011/1563) − Government Decree on the Use of Phosphorus-containing Fertilizing Products and Manure (64/2023) National Programmes and subsidies for agricultural water protection measures and nutrient recycling and relevant related legislation − Finland’s CAP Strategic Plan 2023–2027 − National Marine Strategy 2022–2027 − River Basin Management Plans 2022–2027 − Ahti programme for Water and Marine Protection 2024- − A strong and committed Finland: Programme of Prime Minister Petteri Orpo's Government 20 June 2023, including its chapter on the protection of the Archipelago Sea and the Ahti Programme for protection of waters and the marine environment − Operational grants for nutrient cycles (Government Decree 81/2024) − Nutrient Recycling Pilot Programme (Government Decree 382/2016) − Nutrient Recycling and Urban Waste Water energy efficiency, RAKI Programme 2020–2026 (657/2020) 5.2 Archipelago Sea Programme and the Roadmap for agricultural water protection The state of the Archipelago Sea has been of concern for a rather long time and measures to improve its state have also been carried out for quite some time. In 2010, in the high-level Baltic Sea Action Summit20, the Finnish government committed to effective action to reach a good state of the Archipelago Sea by 20 The President of the Republic of Finland: Press Releases and News https://www.presidentti.fi/halonen/public/defaulte3b4.html 45 Publications of the Finnish Government 2025:81 2020. In another commitment in 2010, the government agreed to make Finland a model area of nutrient recycling21. Since then, several governments have prioritized nutrient recycling and measures to improve the state of the Baltic Sea and Finnish surface waters, directing funding to research, development and innovation projects and investments related to these topics. In April 2021, due to increasing public pressure and a certain lack of progress related to the state of the Archipelago Sea, the Finnish government (2019-2022) decided to initiate a specific Archipelago Sea Programme22 with the aim to reduce pollution to the sea in such a way that the area could be deleted from the HELCOM list of Hot Spots by 202723. The Programme (Figure 12) has since been further detailed and elaborated and the current government has laid out the main objectives of decreasing pollution and improving nutrient recycling, as explained in its Government Programme (2023–2027). The need to fully and effectively implement the Programme was further accentuated by the Finnish National Audit Office in 2024, which highlighted shortages in the effectiveness of agricultural water protection measures in Finland in its 2024 report24. 21 Suomesta ravinteiden kierrätyksen mallimaa – Valto 22 Saaristomeri-ohjelma – Saaristomeri – ELY-keskus 23 Puoliväliriihessä turvattiin luonnonsuojelun rahoitus, päätettiin Luontolahjani Suomelle -kampanjan jatkosta ja Saaristomeren tilan parantamisesta – Valtioneuvosto 24 Vesien- ja merenhoidon ohjaus, rahoitus ja tuloksellisuus – Maatalouden ravinnekuormituksen vähentäminen – Valtiontalouden tarkastusvirasto https://www.presidentti.fi/halonen/public/defaulte3b4.html https://www.ely-keskus.fi/web/saaristomeri/saaristomeri-ohjelma https://valtioneuvosto.fi/-/1410903/puolivaliriihessa-turvattiin-luonnonsuojelun-rahoitus-paatettiin-luontolahjani-suomelle-kampanjan-jatkosta-ja-saaristomeren-tilan-parantamisesta https://valtioneuvosto.fi/-/1410903/puolivaliriihessa-turvattiin-luonnonsuojelun-rahoitus-paatettiin-luontolahjani-suomelle-kampanjan-jatkosta-ja-saaristomeren-tilan-parantamisesta https://www.vtv.fi/julkaisut/vesien-ja-merenhoidon-ohjaus-rahoitus-ja-tuloksellisuus-maatalouden-ravinnekuormituksen-vahentaminen/ https://www.vtv.fi/julkaisut/vesien-ja-merenhoidon-ohjaus-rahoitus-ja-tuloksellisuus-maatalouden-ravinnekuormituksen-vahentaminen/ 46 Publications of the Finnish Government 2025:81 Figure 12.  Logo of the Archipelago Sea Programme. Both the ministers of the Environment and Climate as well as Agriculture and Forestry have been actively involved in promoting the Programme since its establishment. The stakeholder meetings organized by the ministers to promote the implementation of the Programme have involved relevant ministries, farmer associations, main food enterprises with production or other activities in the Archipelago Sea catchment area, nature protection NGOs, foundations working on protection of the Baltic Sea and academia. In February 2025, minister of the Environment and Climate Sari Multala set up an Archipelago Sea monitoring group to follow-up and boost the implementation of the Programme until the end of 2027. The regional Centre for Economic Development, Transport and the Environment in Southwest Finland (ELY Centre) was put in charge of coordinating the Programme under the guidance of Ministry of the Environment and Ministry of Agriculture and Forestry. The ELY Centre set up a regional collaboration group to widely engage regional and national stakeholders in the work. 47 Publications of the Finnish Government 2025:81 In 2021, the general status of the Archipelago Sea agricultural Hot Spot was assessed for the first time and a report25 presenting the gaps in relation to deletion criteria was published. The report concluded that there is no single integrated management plan for agricultural water protection and management in the Archipelago Sea catchment, which would be fully in line with the HELCOM criteria, but the legislation, water and maritime management plans and the parts of the national CAP plans promoting water protection together form a management plan. The strong regional concentration of livestock farming in the South-West Finland poses challenges for manure spreading, which means that manure processing and transportation opportunities should be developed. Some shortcomings were identified in fulfilling Annex III of the Helsinki Convention. The second phase of the Programme assessed bottlenecks in the implementation of agricultural water protection measures. The report26 concluded that one of the most significant challenges of agricultural water protection is targeting the measures in areas where they can bring the greatest benefits in terms of water protection. In the Archipelago Sea catchment, especially the vegetation cover should be targeted in areas where the risk of erosion and nutrient leaching is greatest. The region's concentrated livestock farming is a challenge, and measures should be taken to enhance the utilization of manure nutrients. Phosphorus stored in the soil, the so-called legacy phosphorus, makes it more difficult to reduce nutrient loads and the report suggested enhanced utilization of soil fertility data in fertilization. It was also concluded that the lack of economic viability of the farming operations reduces the interest and capacity of farmers in implementing water protection measures. The complexity of the subsidy system makes it challenging for many farmers to find measures best suited to their operations resulting in a need for targeting guidance which should be resolved to overcome this bottleneck of agricultural water protection. 25 4714b10e-dfe7-5024-cdef-989daffa5e8c (Removing the agricultural loading to the Archipelago Sea catchment area from the Baltic Marine Environment Protection Commission’s (Helsinki Commission – HELCOM) hot spot list) 26 6e4f4626-0ef3-5ed2-82d0-331cafe8369e The Archipelago Sea Hot Spot Road Map Project: bottlenecks of agricultural water protection https://www.ely-keskus.fi/documents/43571093/43606083/Hotspot_arvio_en.pdf/4714b10e-dfe7-5024-cdef-989daffa5e8c?t=1641986952002 https://www.ely-keskus.fi/documents/43571093/45562867/Pullonkaulat_tiivistelm%C3%A4_en.pdf/6e4f4626-0ef3-5ed2-82d0-331cafe8369e?t=1641985896453 48 Publications of the Finnish Government 2025:81 Photo: Lentokuva Vallas / Image bank of the Ministry of the Environment Based on the prior assessment steps, in 2022, a Roadmap for agricultural water protection in the Archipelago Sea catchment was published27. It was developed with the participation of various stakeholders, including farmers, associations, municipalities, companies, and research institutions. The Roadmap outlines measures still needed to fulfill HELCOM Hot Spot deletion criteria and estimates the reduction of N and P load to the Archipelago Sea enabled by each measure (Figure 13). In addition, it provided a timeline for implementation of the measures and their likely effects during the period of 2022–2028. Challenges in implementing the measures were identified as needs for funding, further specification of the measures and turning the measures into action. The measures, when fully implemented, were estimated to reduce phosphorus loading by 100–150 t P/year which is a good match to the preliminary load reduction target of 140 t P/year. Nitrogen loading was estimated to be reduced by 629 t/year, not fully covering the preliminary reduction target of 750 t N/year. 27 Saaristomeriohjelma : Maatalouden vesiensuojelun tiekartta – Doria https://www.doria.fi/handle/10024/185530 49 Publications of the Finnish Government 2025:81 Figure 13.  Measures in the Roadmap for agricultural water protection in the Archipelago Sea catchment (2022) together with timing of implementation and effects, expected challenges and estimated reductions in N and P loading. In 2023, the government gave the Archipelago Sea Programme even higher priority by including a number of measures in the Government Programme. The need to enhance nutrient recycling was amplified by a request to make the Archipelago Sea catchment a model region for nutrient recycling. Since the Government Programme further defined the priorities of the Archipelago Sea Programme and the measures in the Roadmap needed to be turned into concrete action, a Work Plan for the implementation of the Programme for 50 Publications of the Finnish Government 2025:81 2024–2027 was prepared in May 202428. The Work Plan further defines what will be done to implement the Programme as a whole and the Roadmap for agricultural measures more specifically, where, by whom, when and with what funding. The Work Plan will be updated as the work proceeds, and the implementation of the Plan is expected to reveal how it needs to be adapted and further specified. The measures included in the Archipelago Sea Programme, its Roadmap and Work Plan for the years 2024–2027 constitute the agricultural non-point source management plan required by HELCOM deletion criteria. 5.3 Measures of the Roadmap to reduce agricultural load to the Archipelago Sea The measures included in the Roadmap for agricultural measures are largely enabling measures that have needed further specification to be turned into action. Below is a short description of the measures and more specific plans for turning them into action as outlined in the Work Plan for the implementation of the Archipelago Sea Programme in 2024–2027. Compiling existing information: Creating a data repository of water protection targets and measures for the Archipelago Sea catchment level Planning of measures at all levels should be based on existing information on goals and targets agreed and measures already ongoing and planned. Currently, there are challenges related to the availability of information which is spread out to different actors and authorities at different levels (national, regional, county, municipality) or is limited due to e.g. privacy reasons. The information needs to be made more efficiently available to operators to enhance project coordination of different actions and to reduce work in compiling the information. To promote information sharing, a voluntary data repository of water protection targets and already implemented measures will be compiled at the Archipelago Sea catchment level. This repository will facilitate catchment-based planning and effective targeting of measures by collecting existing research data, water protection plans, and spatial data at the catchment level onto one platform. 28 Saaristomeri-ohjelman työsuunnitelma 2024–2027 https://www.ely-keskus.fi/documents/54370442/54985027/Saaristomeri-ohjelman+ty%C3%B6suunnitelma+2024-2027.pdf/4187ff48-05d0-a6a9-ba05-f12de93e4813?t=1715664030610 51 Publications of the Finnish Government 2025:81 Promotion of Manure Relocation The livestock production in the Archipelago Sea catchment area is regionally concentrated to the western and northern parts of the area. In areas of intensive production, there is a high ratio of manure phosphorus to phosphorus fertilization needed, while in areas of less livestock, the need for phosphorus fertilization surpasses the phosphorus available in manure. This imbalance necessitates promotion of relocating part of the manure from livestock farms to fields with lower phosphorus content, often in use of plant producing farms. According to a previous rough estimate, recycling part of the manure phosphorus to nutrient- deficit areas within and/or outside the Archipelago Sea catchment could enable the removal of approximately 500 tons of phosphorus from the catchment reducing the phosphorus load to the Archipelago Sea by about 20 tons. To promote manure relocation, efforts will be made to facilitate manure processing into more easily transportable forms, increase the use of manure in biogas production, enhance the knowledge of livestock farmers and landowners, and increase the availability of contracting services for manure transportation and application. To promote manure relocation, a new impact-based funding form, nutrient recycling subsidy (2024–2026) has been set for biogas plants digesting manure and/or plant biomasses from nature restoration and processing the digestate into more transportable fertilizing products29. The amount of subsidy received is coupled with the amount of phosphorus in manure or plant biomass digested in the plant. Regions with intense livestock production, such as the Southwest Finland are given priority in the selection of beneficiaries. A technology neutral version of the funding instrument is also under development. Promotion of Organic Fertilizer Use Promoting the production and use of organic fertilizers can reduce the use of mineral fertilizers and enhance nutrient recycling in the Archipelago Sea catchment. To promote the use of organic fertilizers, their production and use needs to be publicly supported before achieving market-driven profitability, including promotion of research related to their use. Investment support for necessary technologies and structures, and incentives for the use of these recycled products, are essential for achieving circular economy goals. Farmers should be provided more efficiently with information and guidance on the use of these products. Both 29 Operational grants for nutrient cycles – Maa- ja metsätalousministeriö https://mmm.fi/en/bioeconomy/good-use-of-nutrients-and-energy/operational-grants-for-nutrient-cycles 52 Publications of the Finnish Government 2025:81 the Ministry of Agriculture and Forestry and the Ministry of the Environment have provided grants to promote nutrient recycling of nutrient-rich biomasses, including manure,30 since 2012. Development of Fertilization: Establishing a plot-specific soil nutrient data repository To reduce nutrient loads, fertilization rates should be decreased, especially in areas with high soil phosphorus content. Fertilization could further be refined by considering intra-plot variability with precision fertilization and split fertilization. While the farms need to analyze soil phosphorus content (minimum every five years; CAP) and take it into account when planning phosphorus fertilization (Decree 64/2023), the resulting plot-specific soil fertility data is not available for environmental authorities and research due to privacy reasons. Solutions for sharing farm data, while securing data ownership are needed. That would contribute to more precise planning and targeting of cost-effective measures which has also been pointed out in a recent report by the Finnish Audit Office on the cost- efficiency of measures to decrease nutrient loading from agriculture31. A field plot-specific soil nutrient data repository, accessible to both authorities and researchers, will be developed on a voluntary basis to support more precise fertilization. Farmers will be trained in various fertilization methods, and the use of soil analysis results and existing fertilization calculators. Additionally, research on the fertilization needs of different plant species will be promoted. Improving Water Management on the Fields Improving the water management on fields in the Archipelago Sea catchment is essential. Climate change increases extreme water conditions. Flooding and increased overland flow results in increased soil erosion and nutrient leaching, and high riverine flows increase nutrient transport to the sea. Flooding but also drought and water shortage are a challenge to farmers. Water management may be improved through nature-based drainage solutions, such as restored or constructed 30 Good use of nutrients and energy – Maa- ja metsätalousministeriö 31 Steering, financing and effectiveness of the management of water resources and marine environments – Reducing nutrient loading from agriculture – National Audit Office of Finland https://mmm.fi/en/bioeconomy/good-use-of-nutrients-and-energy https://www.vtv.fi/en/publications/steering-financing-and-effectiveness-of-the-management-of-water-resources-and-marine-environments-reducing-nutrient-loading-from-agriculture/ https://www.vtv.fi/en/publications/steering-financing-and-effectiveness-of-the-management-of-water-resources-and-marine-environments-reducing-nutrient-loading-from-agriculture/ https://www.vtv.fi/en/publications/steering-financing-and-effectiveness-of-the-management-of-water-resources-and-marine-environments-reducing-nutrient-loading-from-agriculture/ 53 Publications of the Finnish Government 2025:81 wetlands and floodplains with two-stage ditches, which can reduce flood and drought risks. Additionally, promoting the environmentally friendly maintenance of ditches, controlled drainage, and sub-irrigation are necessary. To improve the overall structure and condition, including water flow conditions of fields, landowners will be informed about available support. Local drainage associations, a traditional communal way of working of the landowners, will also be activated, and landowners will be assisted with drainage planning. Increase of Field Vegetation Cover Increasing vegetation cover on fields reduces soil erosion and nutrient and carbon runoff into water bodies. The area of wintertime vegetation cover and cover crops will be increased in the Archipelago Sea catchment as part of the CAP. Increasing vegetation cover can help retain phosphorus bound to soil particles, and to improve soil structure. In previous years, CAP support for increasing buffer zones and wintertime vegetation cover has been available for use anywhere in the country. Since the implementation of a new data-based approach, a more effective and result-oriented spatial targeting of buffer zones has been in use. With this measure, data and information based spatial targeting of the wintertime vegetation cover of the fields will also be tested to improve water protection using the RUSLE2015 erosion model. When increasing vegetation cover in the fields, attention will also be paid to the removal of plant biomass, thereby removing phosphorus bound to it from the field. Increasing the Use of Soil Amendments Gypsum, structure lime, and pulp and paper industry fiber sludge, when spread on fields, function as soil amendments by enhancing the binding of nutrients to soil particles and improving soil structure and thus reducing the runoff of phosphorus and particulate matter into water bodies. Soil amendments can also enhance crop yields and reduce crop losses due to weather conditions. The soil amendments are derived from side streams of fertilizer production (gypsum) and pulp and paper industry (fiber) and structural lime is either prepared from lime (high greenhouse gas emissions) or as a side stream of lime production (so called LKD lime, near zero emission but low availability)32. 32 A-Competitive-and-Efficient-Lime-Industry-Technical-report-by-Ecofys_0.pdf https://www.eula.eu/wp-content/uploads/2019/02/A-Competitive-and-Efficient-Lime-Industry-Technical-report-by-Ecofys_0.pdf 54 Publications of the Finnish Government 2025:81 Gypsum spreading has been going on in the Archipelago Sea catchment since 2020, and the goal is to apply gypsum to altogether 50 000 hectares. In September 2024, gypsum had been applied to about 27 000 hectares, and it had been estimated to have reduced phosphorus loading to the sea by 49 tons since the start of spreading in 2020. Altogether, it has been estimated that applying gypsum to the whole suitable target area could reduce phosphorus loading by approximately 90 tn/year. The effect of gypsum is quick, and it can reduce phosphorus load by almost half. The effect of application lasts for about five years, and it does not preclude the need for general and longer-term soil condition improvement measures. Photo: Tero Pajukallio / Image bank of the Ministry of the Environment Promoting the spreading of gypsum involves ensuring the continuity of activities and effectively marketing gypsum to farmers in the area. Farmers voluntarily accept and order gypsum which is organized and spread to their fields by the gypsum project of the state. Farmers should be provided with information about the impact of gypsum on phosphorus availability and yield to dispel some of the misconceptions. 55 Publications of the Finnish Government 2025:81 In addition to gypsum structural lime and fiber sludge from pulp and paper industry have been applied in a similar manner to test their use. The effects of the tests are being monitored and a project testing and monitoring impacts of joint use of the three soil amendments is being carried out in 2023–2025. The ministries are exploring funding possibilities and options for supporting their use in the coming years. Implementation of Water Stewardship Commitments Water stewardship refers to a company's sustainable use of water, where the company takes responsibility for its water impacts and manages the water risks it causes33. Many companies, also those having activities in the Archipelago Sea catchment area, have scope for more sustainable water use and better management of their impacts on aquatic environments. The water stewardship model allows companies' water impacts to be examined at the catchment area level, considering the entire supply chain. The water stewardship commitments are further developed in collaboration with local entrepreneurs and their adoption of promoted. The aim is that enterprises would widely take on and implement the water stewardship commitments. Especially those food industry companies which have contract-based production in the Archipelago Sea catchment area are in focus. Development and Implementation of Impact-Based Financing Models Impact-based financing as a concept shifts the focus from procuring narrowly defined outputs or actions to making purchases or payments based on results and impacts34. This could be a cost-effective way of providing public and private financing to improving the state of the sea. To enhance water protection in agriculture, it is important to even out the differences in soil phosphorus content across fields. On fields with high phosphorus levels, phosphorus fertilization should be reduced, and on fields with low phosphorus levels, it should be increased. One example of an impact-based financing model is the nutrient EIB (Environmental Impact Bond), which supports the spreading of manure on low-phosphorus fields based on phosphorus content, utilizing biogas as an intermediate step. To implement impact-based financing models, related research and pilot work will continue. 33 Water Stewardship Commitment | Vesi.fi 34 gaia_report: Saaristomeren vaikuttavuusinvestointiselvitys, December 2022, Gaia Consulting Oy https://www.vesi.fi/en/water-topics/responsible-water-use/ https://www.ely-keskus.fi/documents/10191/175661/Saaristomeren+vaikuttavuusinvestointiselvitys%2C+loppuraportti+2022.pdf/fc31da43-12af-e5d6-142c-4a772d53ca3e?t=1671714988836 56 Publications of the Finnish Government 2025:81 Since the adoption of the Roadmap, an impact based funding system has been employed for phosphorus entering biogas plants. Ministries of the Environment and Agriculture and Forestry are collaborating to start a pilot project for testing impact-based public funding for lowering the soil phosphorus content in the fields of the Archipelago Sea preferably in 2025–2026 and exchange on the matter has been initiated with DG COMP of the European Commission. Sea-based Nutrient Removal The eutrophication of the Archipelago Sea can also be reduced by removing nutrients directly from the sea or from lakes within the Archipelago Sea catchment area. Nutrient removal can be done by extracting nutrient-containing biomass from the water, e.g. through removal of fish or aquatic plants. Another option is to prevent the nutrients in the bottom sediment from entering the water or to remove them. Significant development work is still needed for the utilization of marine nutrients, for example, regarding the use of fish and the harvesting of common reed. Sea-based removal is much more costly than prevention of nutrient loading to the sea. 5.4 Monitoring programme The prerequisites for the Hot Spot deletion include the preparation of a monitoring programme to be included in the agricultural non-point source management plan. Monitoring will be used in evaluating the effects of the measures taken to eliminate the Hot Spot. The monitoring programme of the Archipelago Sea Hot Spot consists of two parts: 1. Monitoring of the implementation of the measures and their effects and/or effectiveness and 2. Monitoring of nutrient loading and its impacts on the Archipelago Sea. A framework for monitoring the implementation of agricultural water protection measures and their effects and/or effectiveness in the Archipelago Sea catchment has been prepared. It includes annual reporting on the progress of implementing the measures by different actors in the catchment. The information will be (as of 2025 for 2024) annually compiled into a report. This monitoring combined with the monitoring of nutrient loads and their destiny in the sea described below allows the assessment of the effectiveness of the measures. 57 Publications of the Finnish Government 2025:81 The state of the Archipelago Sea and the nutrient load entering the sea are monitored using different methods. The basis of the monitoring is the regular monitoring of water quality and biological variables carried out by the Finnish Environmental Institute Syke and the ELY Centre funded by the Ministry of the Environment (Figure 14). It produces regular information on the state of coastal waters, rivers, lakes and groundwater and it is also part of the monitoring of River Basin Management planning and the National Marine Strategy. Figure 14.  Water quality monitoring in the Archipelago Sea area and in the rivers of its catchment area. The monitoring frequency at different sites is categorized as follows: “high” (annually 10–20 samples in the sea, over 20 samples in rivers per year), “basic” (annually 2–6 samples in both the sea and rivers), and “low” (monitoring every 2nd or 3rd year in the sea, or every 3rd year in rivers, with 2–4 samples per year). Automatic meters measure water quality every half hour. 58 Publications of the Finnish Government 2025:81 Photo: Maria Laamanen A programme for monitoring of riverine material export was started already in the 1970s and currently it includes four biggest rivers (River Kiskonjoki, River Uskelanjoki, River Paimionjoki and River Aurajoki) draining into the Archipelago Sea, covering 39% of the total catchment area. In the updated monitoring programme (2025 onwards) the spatial coverage of the present monitoring will be remarkedly improved. Five new intensively monitored (at least 20 annual water samples) rivers will be included in the updated monitoring programme. This will increase the coverage of the monitoring to 61% of the Archipelago Sea catchment area and thus, decrease the uncertainty in riverine load estimates. In addition, five new monitoring stations in smaller rivers with intensively cultivated catchments and five stations in catchments with big animal farms will be established. This will enable more reliable estimation of changes in loads originating from agricultural activities. Investments will also be made in the development of flow measurement, and new flow measurement stations will be established in connection with the new load monitoring points. 59 Publications of the Finnish Government 2025:81 In addition, the largest rivers flowing into the Archipelago Sea have automatic water quality stations, which provide real-time information on the nutrient and suspended solids content of the water. The stations measure water quality practically continuously, so they provide more detailed and accurate information about water quality than traditional monitoring based on water samples and laboratory analyses, which they however complement well. The effects of gypsum application on load reduction are monitored in three rivers of the Archipelago basin and in one reference river. The most important measuring stations and stations located in the pilot catchments (River Aurajoki, River Paimionjoki, River Uskelanjoki, River Savijoki) will be renovated to better correspond to modern measurement techniques and to increase their reliability. Monitoring stations that measure the effects of gypsum and other soil amendments will be converted into permanent stations, and the measurement of diffuse pollution from agriculture will be developed further, especially in the River Savijoki catchment. The water quality and nutrient load model of the Finnish Environment Institute (VEMALA) is used to estimate the origin of nutrient loads, their export to watercourses and the effectiveness of the water protection measures. The VEMALA model is an operational, national scale nutrient loading model for Finnish watersheds35. It simulates nutrient processes, leaching and transport on land and in rivers and lakes. The model simulates nutrient gross load, retention and net load from Finnish watersheds to the Baltic Sea. Background data related to agriculture and the part of the model dealing with agriculture aspects (ICECREAM) will be updated and improved in 2025-2026 with funding provided by the Ministry of the Environment. In the monitoring of the Archipelago Sea area, in addition to the monitoring stations of the environmental administration, monitoring paid for by license holders (wastewater treatment plants, industrial plants, fish farms) plays a key role. Through that monitoring, the effects of the plants’ operations on the state of the sea are monitored. 35 Huttunen, I., Huttunen, M., Piirainen, V., Korppoo, M., Lepistö, A., Räike, A., ... & Vehviläinen, B. (2016). A national-scale nutrient loading model for Finnish watersheds – VEMALA. Environmental Modeling & Assessment, 21, 83–109. 60 Publications of the Finnish Government 2025:81 Monitoring is also carried out in coastal waters. In 2022, the monitoring program was renewed to a source-to-sea type. The main focus of the monitoring is on the climate and eutrophication parameters of the water column and sediment, on the monitoring lines from river mouths to the open sea. The main objective of source- to-sea monitoring is to produce observational data for assessing the effects of eutrophication load and climate change in the land-sea continuum. Finland's coastal waters are under pressure from land and the open sea, and the effects of the reduction measures are not directly visible in time or spatially. The renewed monitoring produces essential information for the needs of coastal models, strengthening the knowledge base on the resilience and internal load of coastal areas. Satellite images (Sentinel-2, Landsat) are also used to assess the state of the sea area. Satellite observations are used to calculate monitoring station- and water- specific observation data. Station-specific satellite observations are collected from the locations of the environmental administration's monitoring stations. Status database. There is a total of 48 such stations in the Archipelago Sea area. In addition, statistical data based on daily observations is calculated for almost all water bodies in the Archipelago Sea, e.g. chlorophyll a, turbidity and temperature. Linear observations from the river discharge point to the open sea will also be added to the current satellite monitoring. These observation lines for turbidity and total phosphorus illustrate the dispersion and impact areas of the most essential river waters in the surface layer of coastal waters. Satellite observations will be further refined with new high-resolution satellite images. In addition, continuous monitoring stations have been installed at the mouths of three rivers (Halikonlahti, Paimionlahti and Mynälahti) in 2024, which measure water turbidity, electrical conductivity and a-chlorophyll every half hour. Their results are also used to develop satellite image interpretation. 5.5 Demonstrated adequate funding The HELCOM Hot Spot deletion criteria require there to be demonstrated funding which will be adequate for a sustained incremental programme of on-farm activities including improved agricultural practices, investments in manure, urine and slurry handling, and the establishment of buffer strips. 61 Publications of the Finnish Government 2025:81 The cost of full implementation of the Roadmap for water protection measures in agriculture of the Archipelago Sea Programme’s Roadmap for agricultural water protection measures was estimated to approximately 72 M € between 2024 and 2027 (roughly 18 M € per year). With the Archipelago Sea Programme, increasing funding has been directed to the implementation of the Archipelago Sea Programme. Most of the funds are state aid or grants targeted to measures by farmers, entrepreneurs, associations and citizens. A minor fraction of the funding is used for coordination and administration of the Programme. Most of the funding is not earmarked to the Archipelago Sea catchment but can be applied for anywhere in mainland Finland. Many funding programmes providing state aid or grants have nevertheless given preference to funding projects and activities in the Archipelago Sea catchment area. Due to the voluntary nature of applying for funding and carrying out projects it is possible to estimate only afterwards the spending on the Archipelago Sea Programme. The only earmarked funding allocated by the government for the period of 2024– 2027 is 15 M € for the Archipelago Sea Programme. This funding is used to support local actors in implementing the measures and to a lesser degree for financing of state agencies or entities, such as the Regional Centre and Syke for monitoring of the environment and nutrient loads, an management and administration of the Programme. 62 Publications of the Finnish Government 2025:81 Photo: Maria Laamanen In addition to the earmarked Archipelago Sea Programme financing, the Ministry of the Environment estimates that up to 10 M € can be allocated to actors in the Archipelago Sea catchment as state aid or grants in 2024–2027 through the national Ahti Water and Marine Protection Programme, the final figure depending on uptake. The funding includes support for actors to implement water protection 63 Publications of the Finnish Government 2025:81 measures, including fully state paid gypsum application to fields, grants for enhancing R&D and investments for nutrient recycling, aid to aquatic restoration projects and implementation of water protection structures. The funding from the Ministry of Agriculture and Forestry includes significant financing possibilities through the national CAP plan and other national funding programmes. A total of approximately EUR 345,4 million will be available in 2023– 2027. The uptake of these funds is voluntary and dependent on the willingness of the local actors in the Archipelago Sea catchment. For CAP measures, including agricultural start-up and investment grants and environmental payments, organic production, advisory services and non- productive investments, a total of approximately EUR 328.7 million will be available in the CAP Plan period 2023–2027. These measures respond in many ways to the need for measures in the Archipelago Sea. They include several water protection measures, such as riparian zones, winter vegetation cover, catch crops, good soil management, accurate use of nutrients and promotion of recycling. In addition, advisory (Neuvo2030), funded by CAP plan, will increase knowhow on the importance of implementing the measures. The experimental Pilot Programme for Nutrient Recycling extensively supports biogas production, manure processing, nutrient recycling and carbon sequestration activities from testing innovations and product development to production scale activities. A total of EUR 8.4 million will be available in 2024–2027. Operational Grant for Nutrient Cycles is granted based on competitive tendering. The grant is targeted for biogas plants digesting manure and/or plant biomasses from water restoration. The idea is to promote recycling and further processing of phosphorus into recycled fertilizer products on a commercial scale, in particular to encourage the transfer of nutrients from nutrient surplus areas to deficit areas. The total funding for the support in 2023–2026 is EUR 9 million. In addition, there are various subsidies granted by the Ministry of Agriculture and Forestry for the use and improvement of the aquatic environment and for water management and flood protection as well as funding for development of fisheries, logistics and product development contribute to efforts to improve the state of the Archipelago Sea and the utilization of marine nutrients. 64 Publications of the Finnish Government 2025:81 Due to the significant scale of different financing possibilities, especially through the national CAP plan, it is possible to conclude that the 18 M € per year cost estimate of implementation of the Roadmap has been covered in recent years and it will be covered in the following years at least up to 2028. In addition to public finance, there are private investments and initiatives that enhance nutrient recycling in the catchment. Public-private cooperation is expected to bring in increasing private funding. As the first step agri-food sector companies active in the Archipelago Sea catchment are asked to take on Water Stewardship Commitments and be involved in water protection. The two involved ministries are also developing new financing tools, e.g., by piloting impact and results-based state financing in the Archipelago Sea catchment with the objective of extending to private sector in the future. As described above, competitive tendering is already used for supporting the use of manure in biogas plants and a similar funding model is under preparation for the use of manure with other nutrient recycling technologies. The private sector is planned to be increasingly involved also through direct donations to certain activities. An Archipelago Sea Programme Implementation Monitoring Group established by Minister of the Environment and Climate Sari Multala in January 2025 and involving numerous enterprises as members will start looking into this in 2025. In addition, there is an increasing interest in the start-up community to contribute to the protection of the Archipelago Sea and a new entity A’Pelago Accelerator has been set up to enhance these activities36. 5.6 Fulfillment of the conditions of Annex III Part 2 of the Helsinki Convention The Annex III of the Helsinki Convention concerns criteria and measures for the prevention of pollution from land-based sources. Part 1 concerns prevention of pollution from industry and municipalities and Part 2 under consideration here concerns prevention of pollution from agriculture. To delete an agricultural Hot Spot, the requirements in Part 2 should be fulfilled. Below is an assessment of fulfillment of each of the regulations and criteria in Part 2 for the Archipelago Sea catchment area. 36 A’Pelago https://helcom.fi/about-us/convention/annexes-to-the-convention-2/annex-iii/ https://www.apelago.fi/ 65 Publications of the Finnish Government 2025:81 Regulation 1: General provisions “In accordance with the relevant parts of this Convention, the Contracting Parties shall apply the measures described below and take into account Best Environmental Practice (BEP) and Best Available Technology (BAT) to reduce the pollution from agricultural activities. The Contracting Parties shall elaborate Guidelines containing items specified below and report to the Commission.” Status This criterion has been fulfilled. Explanations Annex II of the Helsinki Convention determines the criteria for BEP and BAT in the HELCOM context. BEP is described as the application of the most appropriate combination of measures, while BAT includes the latest stage of development (state of the art) of processes, facilities or methods of operation which indicate the practical suitability of a particular measure for limiting discharges. In addition to this Regulation 1 in Annex III, HELCOM has prepared a new Recommendation on Best Available Technology (BAT) and Best Environmental Practice (BEP) to reduce nutrient inputs and greenhouse gas emissions from manure. Other BAT/BEP documents for agriculture are not available. Finland was active in the preparation of the Recommendation. Finland is a member of the European Union