Miraculous Rediscovery of Shortnose Cisco, Thought to be Extinct

In what could be considered a reality that surpasses the imagination, an indigenous Great Lakes whitefish—Long assumed extinct, has been serendipitously found again by researchers, albeit in an unexpected location. Specifically speaking, it is the Shortnose Cisco, which was believed to have gone extinct around four decades ago, has now emerged in a different Great Lake. Predominantly thriving in the Great Lakes, rising threats from overfishing and proliferation of non-native species, like the sea lamprey, zebra and quagga mussels, alewives, and round gobies, have led to a reduction in their population and disruption of their natural habitat.

A report released by the Great Lakes Fishery Commission in 2016 detailed the once-flourishing masses of the Shortnose Ciscos in the Great Lakes of Michigan, Huron and Ontario. The report further noted that despite meticulous sampling at specific locations and depths, the last recorded presence of this species was in 1964 for Lake Ontario, 1982 for Lake Michigan, and 1985 for Lake Huron. Given its continuing absence through this period, the expert consensus was that the Shortnose Cisco was extinct.

Shortnose Cisco is a member of the coregonine class of fish, which comprises up to eleven different species of cisco and whitefish indigenous to the Great Lakes. The Fishery Commission’s documents unveiled that these coregonines once densely populated each lake a century earlier, with a variety of habitats ranging from rivers and bays to the lake’s deepest areas. Certain species played a crucial role as prey primarily for lake trout and burbot, thereby aiding the sustenance of a Great Lakes fishing industry now worth $7 billion per year.

However, amongst coregonines, numerous cisco species observed a precipitous decrease in their numbers between 1920 and 1970 due to a sustained period of overfishing, the arrival of intrusive species, and rapid loss of native habitats. As a consequence, at least two species, including the Shortnose Cisco, have been declared extinct, and several other species now seem conspicuously absent from multiple lakes.

Utterly resistant in comparison, the species of whitefish have also begun to witness their numbers dwindling over the last two decades, according to executives from the Fishery Commission. Systems involving bottom trawler nets and gill nets further up the water column have been utilized by researchers in Lake Superior to capture coregonines for study over several years, both regarding their morphology as well as their attributes determined by genetics.

Learning about the diversity of cisco species present in the lake is now a more realistic goal, thanks to progress being made in the field of genetics. During one of these scientific expeditions that took place in July 2022, three juvenile Shortnose Cisco were surprisingly identified among the fish that were caught in trawl nets around the Keweenaw Peninsula.

Researchers confirmed the genetic and physical traits of the Shortnose Cisco specimens, marking this finding as a rediscovery of the species in Lake Superior, after its presumed extinction over a century ago. Rehabilitation of indigenous cisco species may be a key step in overturning the detrimental impact on the Great Lakes ecosystem, caused by generations of invasive species, changing nutrient dynamics, and other pressure factors.

Since 2018, Michigan’s Department of Natural Resources (DNR) has been involved in harvesting gametes – fertilized eggs – from a surviving wild population of cisco near Drummond Island located in the far-north of Lake Huron. Having been raised at a hatchery run by the U.S. Fish and Wildlife Service situated at Jordan River in Antrim County, a massive one million juvenile fish were released into Saginaw Bay, both in spring and fall—a location where the cisco used to dominate but had been decimated.

Experts underscore that the odds of catching a cisco in Saginaw Bay nowadays are quite high due to stocking. Recognizing their survival in hostile environment characterized by a higher density of predators like walleyes and the lack of prey fish have proven to be encouraging revelations.

Recent observations of the juvenile, stocked cisco fish reaching the adult stage and adapting to the new habitats pleasantly surprise the officials. Detection of successful reproduction will certainly be a significant milestone in the coming years.

Experts believe that the endurance and adaptability of these native fish across such varied habitats and conditions prove them to be versatile. Their strategic reintroduction into the ecosystem could result in not just increased stability for the Great Lakes presently but also fortifying them against future adversities.