Lake Inari is a prime example of the fulfilment of fishery obligations in regulated waterbodies

The fishery obligation required by regulations on Lake Inari and the monitoring of its fulfilment are the most comprehensive in Finland. The stocking obligation fulfilled by the Natural Resources Institute Finland (Luke) and the monitoring of stocking results lead the way and act as a benchmark for other waterbody obligations.

In addition, the “Lake Inari model” defines how any adverse impact caused by regulations on fishery should be offset. There are numerous fishery obligations laid down in lake regulations in Finland, and they are mainly fulfilled by means of fish stocking, as in Lake Inari.

Fish stocked from original populations – regular replacement of parent fish maintains diversity

The fish produced for the Lake Inari stocking obligation – brown trout, European whitefish and Arctic char – come from the region’s original fish populations.

The parent fish used in the production of stocked fish are replaced regularly every three to four years to maintain natural genetic diversity in the stocked populations. As a result, the regional adaptation of the original fish populations in the waterbody can also be protected. Roe production of parent fish is also based on the tagging of individual parent fish, DNA analyses and the REALVAL tool in reproduction management and parent fish maintenance.

Monitoring studies guide stocking and fishing regulations

Luke supports annual monitoring studies related to the Lake Inari obligation that produce diverse high-quality information especially about the state of brown trout, European whitefish and Arctic char based on catch samples. The rivers that discharge into Lake Inari are home to vital migratory lake trout populations that withstand fishing based on regulations as the only waterbodies in Finland.

The monitoring results provide the fishery authorities with the information required to modify stocking-based fishery obligations and guide fishery areas in regulating fishing volumes. In addition, the monitoring results guide the fulfilment of obligations in the selection of the stocking size, place and time for various species. Relationships between the stocked species can also be altered as approved by the fishery authorities in accordance with the principles of the adaptable fulfilment of obligations introduced in the 1990s.

Luke tags all fish stocked in Lake Inari. Tagging helps obtain accurate information about age distributions in fish catches and identify the year when stocking was productive and when not, as well as the percentage of stocked and natural fish in catches. Luke has developed effective serial tagging methods especially for Lake Inari to identify stocked fish.

The monitoring results also indicate any changes in fishing activities in Lake Inari and the state of naturally reproduced fish.

Luke fulfils the Lake Inari fishery obligation as assigned by the Centre for Economic Development, Transport and the Environment for Lapland.