Abstract
The Detroit River connects Lake Huron and Lake Erie of the Laurentian Great Lakes. The river once supported a substantial lake whitefish (Coregonus clupeaformis) fishery until the early 1900s, when habitat loss, pollution, and overfishing contributed to the collapse of the fishery and loss of spawning populations in the river. In the early 1970s, efforts were initiated to improve water and habitat quality, and in December 2005 a spawning male lake whitefish and viable eggs were collected; the first documented evidence of spawning since 1916. Researchers have tracked the spawning magnitude of the lake whitefish population in the Detroit River since 2005 by assessing the number of eggs deposited on egg mats. Genetic analysis of larval fish hatched from eggs collected in the field between 2005 and 2018 was used to determine the relative contributions of Lake Erie and Lake Huron to the resurging population. Over 80% of the hatched larvae had parents originating from Lake Erie in all the years sampled. The estimated number of full-sibling families sampled at Belle Isle was the same in 2010 and 2014 and varied between 2009 and 2016 at Fighting Island. The estimated number of lake whitefish parents at Fighting Island decreased in the most recent collections possibly due to loss of habitat on spawning reefs due to sedimentation. Our results provide additional evidence that restored spawning habitat in the Detroit River is again being used by lake whitefish and continued reproduction at these sites may improve the Great Lakes portfolio of ecological and genetic diversity.
Funder
Great Lakes Restoration Initiative
Great Lakes Fish and Wildlife Restoration Act
Reference54 articles.
1. Spatial extent of contemporary lake whitefish spawning in western Lake Erie
2. Specific microsatellite loci for brook charr reveal strong population subdivision on a microgeographic scale
3. Auer NA (Ed.). 1982. Identification of Larval Fishes of the Great Lakes Basin with Emphasis on the Lake Michigan Drainage. Special Publication 82-3. Great Lakes Fishery Commission, Ann Arbor, Michigan. http://www.glfc.org/pubs/SpecialPubs/Sp82_3.zip
4. Baldwin NA, Saalfeld RW, Dochoda MR, Buettner HJ, Eshenroder RL. 2009. Commercial fish production in the Great Lakes 1867–2006. Great Lakes Fishery Commission, Ann Arbor, Michigan. http://www.glfc.org/commercial/commerc.php
5. Diverse portfolios: Investing in tributaries for restoration of large river fishes in the Anthropocene