The herring spawning stock in the main basin of the Baltic Sea and the Gulf of Finland amounted to approximately 838 000 tonnes in 2017, which was over2 times that of the year 2000. In the Gulf of Riga, the spawning stock amounted to approximately 97 000 tonnes in 2017.
The herring population of the Bothnian Sea has been growing since the 1990s, and the latest estimate of the spawning stock was 433 000 tonnes in 2017. The herring population of the Bothnian Bay appears to have begun to grow in the 2010s.
The spawning stock of sprat was estimated at 1 303 000 tonnes in 2017. It has been declining gradually since the record-breaking year of 1996. The high figure in the 2014 indicates at least a temporary turn for the better once more.
The cod population has begun to grow again after a few poor years. The extremely large number of sprat born in 2014 and the saline pulse that brought a large volume of salty, high-oxygen water from the Atlantic at the end of 2014 and the beginning of 2015 changed the situation and produced in 2015 the highest number of cod born in decades.
Data on the status of fish populations
The Natural Resources Institute Finland carries out regular inventories of the Baltic Sea’s herring, sprat, and cod populations and produces estimates and forecasts of the status of fish resources. In addition to evaluating fish resources, the studies help to accumulate biological data on fish populations and factors that affect them, as well as the ecosystem of the Baltic Sea.
Regular evaluation of fish populations is one of the performance targets set by the Ministry of Agriculture and Forestry for the Natural Resources Institute Finland, and it is based on international conventions. The EU’s fisheries policy also requires Member States to evaluate their fish resources.
Annual estimates are produced by working groups of the International Council for the Exploration of the Sea (ICES). ICES issues recommendations specific to each fish population or regulated region to the European Commission, which agrees the national fishing quotas for each species with the Member States and Russia.
Picture on top of the page: Plugi