Impression Platformsession, October 11th 2022 (Large Shallow Lakes and Lagoons)

Lake Pyhäjärvi

Kristina Vuorio (Finnish Environment Institute) shared that over the years the water quality of the Finnish lake Pyhäjärvi has deteriorated, where an increase in chlorophyll causes almost yearly occurring bacterial blooms. Winter time runoff and water temperatures of the lake have also increased, largely due to climate change. What stands out is that 56% of the phosphorus that enters the lake, remains there because it settles at the deeper parts or is being eaten by fish. Measures currently in place to improve the water quality consist of managing the external nutrient load, for example with ponds and wetland, sand and lime filters and buffer zones along the lake and catchment areas. Long term biomanipulation, by extracting nutrients from the lake through fishing (yearly 500,000-700,000 tons), help to manage the internal nutrient load on the long term.

Lake Peipsi

Külli Kangur (Estonian University of Life Sciences) gave a presentation on lake Peipsi, the largest transboundary lake in Europe, located in the basin of the Gulf of Finland. Over half of the lake and a large part of the catchment area is located in Russian territory. Covid-19 and the increasingly tense relationship with Russia prevents activities such as monitoring and control of (over)fishing on the Russian side. Changes in the water level (not regulated) are the main factor influencing the functioning of all levels of the lake’s ecosystem. Research shows that accelerated eutrophication periods have appeared in warm and dry years, possibly enhancing the internal nutrient load. The lake is of socioeconomic importance for commercial and recreational fisheries, with over 90% of inland fish catches coming from the lake. An increase in warm temperature extremes due to climate change and eutrophication (decrease of oxygen availability) have led to a radical restructuring of fish species in the lake system and an increase in toxic cyanobacterial blooms. More warm water species have been noticed since the 1980s.

Curonian Lagoon

The Curonian lagoon is a mostly freshwater lagoon located in the west of Lithuania, tells Arturas Razinkovas-baziukas (Marine Research Institute). The lagoon is of importance to migratory birds and is an important spawning area for several fish species. In summertime the amounts of inorganic nitrogen cause water quality issues (such as cyanobacterial blooms) and fish killing events, which are problematic for recreational and commercial fishing. Heatwaves cause temporary stratification, which increases the chances of fish killing events, turning the problem into a vicious cycle. Next to climate change issues, sectorial conflicts, such as bird protection versus fisheries or recreation versus natura protection are of influence on the lake’s ecology. One example given was the conflict between fisheries and agriculture in the Nemunas Delta. Fish spawn in the polders, benefitting fisheries, but farmers want the polders to be drained as soon as possible.

Oder/Szczecin Lagoon

Miriam von Thenen (Leibniz-Institute for Baltic Sea Research) presented about the Oder/Szczecin Lagoon, located in the east of Germany. The main human pressures are fishing, shipping and tourism. Eutrophication is a large problem and causes blue algae blooms and hypoxia. The system is largely influenced by a large catchment area, of which the nutrient input is strongly influenced by agricultural emissions. A large part of the catchment area lies in Poland, where agricultural activities have intensifies. To deal with eutrophication, research is being done into possible internal measures to improve water quality. One example that has been looked into, the effectiveness of mussel farming, is not suitable due to the large scale at which this would have to take place. However, locally it can be an effective measure. Climate change will mostly have negative effects, such as an increased risk of pathogens and water shortages. Improvement of the ecological state will help the system become more resilient to these changes.

Afternoon program

The afternoon focused on the possibilities and challenges for further enhancement of cooperation on large shallow lakes.

Jimmy Darren (European Regional Advisory Consultants) presented the possibilities of coming to European funding for a large shallow lakes network.

After this presentation participants brainstormed on how to get to enhanced cooperation in four sub-groups and presented a first action they would be able to take.

1. Education and knowledge

• First action: exploring the possibility of setting up an EU network with doctors and other young professionals (applied sciences) focused on lowland lakes and lagoons, to increase transboundary knowledge sharing and to think outside of the box to be able to deal with climate change. Action holders: Marcel, Annette and Harm.
• Important to get subsidies for 10-15 young professionals to set up this network.

2. Cooperation, governance and stakeholder involvement

• First action(s): visit all European lakes and lagoons and discuss how governments are organized and how stakeholders are involved. Give a presentation in Gdansk on her findings on the best practices. Organize a water challenge in Gdansk. Action holder: Flos Fleischer
• Important to evaluate hard ecologic use of lakes and lagoons and soft social matters:
  • Where are governments helping and where are they frustrating us?
  • How can we strengthen cooperation, exchange of data collection, experiences on the long term?

How are stakeholders involved in different lakes and lagoons? What are the best practices?

3. Human factors

• First action: combine all data of monitoring/ research that has been conducted on Lake Ijsselmeer and look at which data is currently lacking. Action holder: who feels responsible in the network agenda of AIJG 2050?
• Creating a better understanding of different pressures on the system can be improved through dialogue.
• Look into physical and social-economic data. Data sharing across communities is necessary.

4. Ecology and ecological changes

• Work on creating a platform where all the data sets with base information on different lakes (and thus on different pressures, etc.) can be found.
• Create an overview of the similarities and differences on issues in the lakes and lagoons.
• Create an overview of large events in the past years that created a shift in the ecological system, weather extremes such as warm summers.
• Compare effect of similar events (weather extremes) on the reactions of the lakes (triggering factor, what really happened?).

Important to talk these plans over with the action holders of the sub-group education and knowledge.

Finally

Thanks to the international guests and the input of the attendees the event was a success. The event showed the similarities between lakes and lagoons and the importance of increased cooperation, due to the complexity of management issues.

Jimmy Darren will conclude the report on possibilities of funding on a European scale.

Another step to improve international cooperation is within the BALLOON network, which is part of EuroMedLag. Arturas shares that EuroMedLag, set up to disseminate and promote ecological culture, is positive about increasing the cooperation with relevant people from different lakes. A next step to set this up will follow shortly. He also invites everyone who is interested to join the next BALLOON conference on the 19 of June 2023 in Gdynia, Poland, to continue the cooperation.