The brackish waters of the Baltic Sea have a unique combination of marine and freshwater species and habitats developed for the special environment. In order for the marine ecosystems to be resilient and able to adapt to changes it is very important to preserve the biodiversity of the Baltic Sea. The goal that has been set within HELCOM is to "reach favourable conservation status of biodiversity" and good "ecological and good environmental status."
What does biodiversity mean? And why is it so important?
Biodiversity can be defined as the variety of all forms of life, from genes to species, through to the broad scale of ecosystems. An ecosystem with a bigger variety of life form is more likely to be stable than one with a smaller variety. In an ecosystem with a big biodiversity, even if one form of life is disturbed, i.e. increases or decrease, there are other forms of life that cover for the change. The balance is moved a little bit within natural variations and does not necessarily lead to severe consequences. Hence, loss of biodiversity leads to more vulnerable ecosystems that are less resistant to other types of impact, such as climate change and ocean acidification.
Loss of biodiversity also has economic an impact as it leads to reduction of many essential services to human societies. One example of such service is seafood. The reason for this being that when the balance of an ecosystem is disturbed, at a certain point, the system reaches a "tipping points", in which ecosystems shift to alternative, less productive states from which it may be difficult or impossible to recover.
Bladder kelp – example of a Baltic Sea key species
There are of course species that are more important to the stability than others, so called key species. If a key species is extinct it will affect the entire chain of organisms in the ecosystem. An example of a key species in the Baltic Sea is the seaweed “bladder-kelp” (Macrocystis pyrifera). The bladder-kelp constitutes the base of the nutrient web. It transforms sunlight to energy at the same time as it binds nutrients, i.e. nitrogen and phosphor, and also carbon dioxide. Many small animals have their hiding places among the thick leaves of the seaweed, where they are feeding on microorganisms living from the weed. These small animals becomes pray for bigger animals. If the bladder-kelp were to disappear from the Baltic Sea, it is very likely that there would be an ecosystem shift. The environment would change in such a drastic way that many other organisms would be affected and even extinct.
Technical areas for preserving biodiversity
There are many threats to the biodiversity in the Baltic Sea. In fact all threats to the Baltic Sea environment are also threatening the biodiversity. However, looking strictly at measures that can decrease the disturbance on biodiversity as such, Sea of Inventions has focused on two technical areas. These technical areas are:
• Bycatch reduction
• Treatment of ballast water