Fish farming has both direct and indirect environmental impacts. Nutrients, chemicals or organisms leaking from fish farms are direct impacts, while indirect impacts result from transportation and the use of energy and natural resources (such as raw materials for infrastructure and fish feed).
In cage systems, nutrients, fish feed residues and excrement are released into the water. An increase in nutrients promotes production in the water (e.g. by phytoplankton such as cyanobacteria). Sedimented material may cause problems for plants and animals on the seabed, and also contribute to the release of nutrients from the sediment. Anoxic environments may develop under fish farms. However, this all depends on several factors, such as the depth, topography and flow conditions of the site. Location management can reduce direct environmental impacts. However, currents still spread nutrients and particles further in the water mass.
Part of nutrient loading from fish farming originates from the feed used to feed the fish. The raw materials for the feed may come from the Baltic Sea or they may be imported from outside the Baltic Sea catchment, mainly from the Atlantic, which means that nutrients are imported from outside the area. Although feed products have improved significantly over the past 20 years, some of the nutrients that they contain end up in the surrounding sea from the cage systems used for fish farming.
Objective of the measure:
An important part of this work is to promote sustainable fish farming within the framework of the HELCOM collaboration by implementing the new recommendation on sustainable aquaculture adopted by the Baltic coastal states at the beginning of March 2016.
The Environmental Office, the Fisheries Office, fish farmers and, where necessary, Åland’s environmental and health protection authority (Ålands miljö- och hälsoskyddsmyndighet, ÅMHM) have negotiated together continuously for years. They have discussed suitable sites for fish farming, fish feed and new more sustainable recirculating systems as well as compensation measures.
The cooperation group must continue to address the following issues:
– New innovative measures to promote sustainable aquaculture, such as new techniques, feed development, circular economy aspects and measures to increase the use of low-phosphorus feed
– Investigate opportunities offered by compensation measures and improvement surplus (förbättringsöverskott), such as possibilities to locate fish farms in more suitable areas.