Scientists will plant eelgrass in the sea bed

Scientists of the Estonian Marine Institute are planning to plant 384 eelgrass plants into Estonian coastal sea bed to help marine ecosystems recover and to improve the condition of marine habitants.

On 8th June, world’s ocean day is celebrated. It is important to pay attention to the condition of the sea because seafaring has become a burden to many marine ecosystems and in turn caused irreversible changes. Among other things, new facts have become evident about the effects of human activity such as debris and underwater noise.

“One of the most notable examples of the seriousness of the situation is the loss of marine predators. There is only 5% of predatory fish and marine mammals left from their initial population. This, in turn, means less seafood for humans but also an impact for the socio-economic and cultural well-being,” said UT Marine Ecosystems leading researcher Henn Ojaveer. Ojaveer gave an example of ring seals, whose number in the Baltic Sea has suffered a noteworthy decrease due to hunting and marine contamination and as a result, the species have reached a danger zone. Another example he brought was about a low point in the cod stock: “Because cod stock is in a low point, it has caused a situation where there is no cod in our waters anymore. The reason for this is nature itself but also excessive human activity.”

In order to improve the situation, scientists of the Estonian Marine Institute are participating in European Union Horizon 2020 project “Marine Ecosystem Restoration in Changing European Seas” (MERCES; 2016-2019), where one of the scientists’ tasks is to look into recovery possibilities with the eelgrass plants in the Baltic Sea. “Eelgrass fields are one of the most valuable and most endangered marine habitants over the world. Eelgrass increases the diversity of habitats by providing good conditions for shelter and nutrition for many other plant and animal species. Attention is being paid to them globally because the eelgrass coverage area has decreased or even disappeared in some regions. In Estonian coastal sea, only the tall eelgrass, Zostera marina, which is a key species in soft sandy grounds, spreads” Liina Pajusalu, the Marine Biology Junior Research Fellow summarised one certain role of the University of Tartu scientists in the project.

For the project, scientists carry out fieldwork in Estonian coastal sea in Tagalaht and Soela Väin to develop a suitable method for recovering the eelgrass habitats. 384 Zostera marina plants will be planted on two different test areas with the size of 25 m x 25 m. Samples will be taken from the test areas, and different environment factors will be monitored over three years (2017-2019). The same activities are planned to be carried out in a larger scale when the tests will succeed.

European Union Horizon 2020 project “Marine Ecosystem Restoration in Changing European Seas” (MERCES; 2016-2019) comprises activities related to the conditions of Baltic Sea, the North Sea, and the Mediterranean sea and the environmental, socio-economic and legal aspects of the recovery of marine ecosystems is being researched. University of Tartu and University of Turu are involved in the Baltic Sea part of the project.

More information:

Henn Ojaveer, Lead Research Fellow in Marine Ecosystems in UT, 443 4456, henn.ojaveer@ut.ee
Liina Pajusalu, Junior Research Fellow in Marine Biology in UT, 671 8908, liina.pajusalu@ut.ee