Impact of a large-scale translocation program as a way to increase American eel spawners production

Session: 08b. - Restoration of Native Fishes

David Stanley, Ontario Power Generation, [email protected]
Guy Verreault, Ministère des Forêts, de la Faune et des Parcs, [email protected]

Abstract

A large-scale American eel (Anguilla rostrata) translocation program was initiated with glass eels / elvers (0+) starting in 2006 in the upper St. Lawrence River and Lake Ontario as a way to reverse the decline and increase spawners escapement. First seaward migrants appeared in the St. Lawrence estuary four years after initial translocation exhibiting exceptionally fast growth. Numbers increased annually during downstream migration but translocated female eel length was 250-300 mm less than naturally-recruited eels, raising questions on their ability to travel 4000 km to reach oceanic spawning grounds. Size gradually increased and now after 10 years, translocated eels exhibit a similar size distribution to naturally recruited eels at migration. In 2017, sampling of the Quebec silver eel fishery found that translocated eels constituted 33.5% of migrating eels, the highest proportion found. For 2017, we estimated that 36,000 eels originating from the translocation program migrated thus contributing to increase the reproductive potential of the species. We expect that their occurrence will increase further over the next few years as a larger number of translocated eels are expected to reach maturation and migrate. The impact of this program will be discussed in the context of the species recovery.

1. Keyword
fish management

2. Keyword
migrations

3. Keyword
St. Lawrence River

4. Additional Keyword
American eel

5. Additional Keyword
translocation/stocking