Fish stock work guides sustainable fishing
Each year, our research scientists travel to Finland’s sea areas in the Baltic Sea to investigate the condition of Baltic herring and sprat populations. Annual fishing quotas are defined based on the data obtained from these surveys. The quotas serve to guide the fishing of Baltic herring so that fish stocks are not endangered in the long term.
The surveys are conducted on Aranda, a research vessel of the Finnish Environment Institute (Syke), by scanning a pre-defined route using a sonar. The data collected is primarily used by the International Council for the Exploration of the Sea (ICES). It issues scientific recommendations based on population estimates for the maximum sustainable catch volumes, based on which the European Commission issues annual fishing quotas for different countries.
In recent years, Baltic herring and sprat have accounted for 50–80% of Finland’s fishing quota. Determining threshold values for the sustainable fishing of the Baltic herring population in the Gulf of Bothnia using the ICES standard methods has been more difficult compared with other fish populations being evaluated. Baltic herring and sprat quotas started to decrease during the latter half of the 2010s, and in 2020 and 2021, Baltic herring individuals were found to have become slimmer.
In 2023, the European Commission proposed a full ban on the fishing of Baltic herring in the Gulf of Bothnia and the Baltic Proper in 2024. The survey conducted in 2023 showed that populations had grown significantly stronger which is why Luke’s research scientists did not find the full ban necessary.
The fishing of Baltic herring also produces benefits in the eutrophic Baltic Sea, as the fishing of Baltic herring and sprat is the most effective individual method to remove nutrients that have already reached the sea. Fishmeal made from Baltic herring is also used in rainbow trout farming with the aim of decreasing the nutrient pollution caused by rainbow trout in the sea through an internal nutrient cycle.