The Search for Lake Michigan’s Elusive Cisco
BY KATIE STEIGER-MEISTER, EXTERNAL AFFAIRS REGIONAL OFFICE
In the early morning hours of a chilly winter day, all is quiet in Two Rivers, Wisconsin save for a flurry of activity at the Susie Q Fish Market dock. Two commercial fishing vessels, the Peter Paul and the Susie Q, are being readied by crew and U.S. Fish and Wildlife Service fish biologists from the Midwest Region for a full day of trawling on Lake Michigan.
Winter swells and bitterly cold air temperatures on the water cannot deter Service personnel from their mission. Eight miles out from shore and hundreds of feet below the surface of the water a small silver fish, commonly known as the bloater, is reproducing.
“Most people only see bloaters in deli counters labeled as ‘smoked chub,’” said Mark Holey, Project Leader of the Green Bay Fish and Wildlife Conservation Office. “They have no idea of the importance this fish holds in tying the Great Lakes food web together.”
A type of deepwater cisco, the bloater is an important part of the Great Lakes food web providing important nutrients to native predator fish such as lake trout. Yet their populations are low, if not completely extinguished, in much of the Great Lakes due to over-fishing, invasive species and habitat degradation. An effort by the U.S. Fish and Wildlife Service at the request of the state of New York and the province of Ontario aims to restore bloater populations in Lake Ontario, which will help to support growing populations of lake trout and Atlantic salmon. The lessons learned as part of this effort will help to guide cisco restoration efforts in other parts of the Great Lakes.
“Species recovery in the Great Lakes is a priority for us,” said Todd Turner, Assistant Regional Director of the U.S. Fish and Wildlife Service’s Midwest Fisheries Program. “With invasive alewife populations in significant decline, we now have a great opportunity to restore the native bloater back into its historic niche.”
An hour after leaving the dock, the rear doors on the Peter Paul and Susie Q are opened in the predawn light and machinery begins to hum as the bottom trawl nets are readied and deployed in the water. For one hour the nets will be in the water, slowly pulled across the bottom of the lake to collect spawning bloaters.
Ongoing bloater restoration efforts require the Service to chart new ground in deepwater fish propagation techniques and necessitates both muscle and expertise from numerous National Fish Hatcheries and Fish and Wildlife Conservation Offices located across the Midwest Region. In 2015, the goal is to collect two million fertilized bloater eggs. The goal is ambitious in light of previous efforts never yielding more than half a million eggs in a season.
The challenge is that bloaters only reproduce for a month in the heart of the winter in more than 300 feet of frigid water. A narrow time window for peak collection is complicated by winter weather and ice conditions on Lake Michigan, and the many unknowns surrounding the life cycle and behaviors of bloaters.
“Another distinct challenge to this restoration project is the lack of knowledge we have in the culture requirements for this species,” explained Roger Gordon, project leader at Jordan River National Fish Hatchery in Elmira, Michigan. Every week for a month or more, Gordon and members of his team make the drive to Two Rivers to assist with egg collection efforts. “Up to this point,” Gordon continued, “no significant studies have been done on the large scale propagation of this small fish.”
The Service and its partners, including the Ontario Ministry of Natural Resources and the U.S. Geological Survey, are currently carrying out multiple early life rearing trials to fill in the gaps in information.
Back on the boats, the sun finally rises over mercifully calm winter waters as the trawl nets are hauled from the deep. Aboard the Peter Paul and Susie Q the trawl nets are opened, depositing piles of bloaters across enclosed decks. The bloated appearance of the fish, and the inspiration for their name, is the result of air rapidly expanding in their bodies when they are quickly pulled from the bottom of the lake to the surface. In females, the expanded air in their swim bladders will push many of the ripe eggs out of the fish and into the lake before fish biologists have an opportunity to collect them. This poses yet another complication on the road to bloater propagation and recovery.
After the fish are removed from the trawl net, commercial fishermen and Service fish biologists kneel side-by-side as they sort the fish into bins. At a makeshift work table next to the sorters, fish biologists begin examining each bloater. Eggs are taken from ripe females and testes are removed from males. Every set of harvested eggs is fertilized with sperm from one or two male bloaters. Spawned fish are then packaged and labeled for later work in the lab, which will include genetic sampling and ageing. The process is repeated over and over again until all the fish are gone from the bins. The trawl nets are placed back in the water and the cycle is repeated three more times before the Peter Paul and Susie Q return to the dock later in the afternoon.
At the dock the fertilized eggs from the two boats are measured to estimate total take for the day. The day was a success, with nearly 200,000 eggs collected. The eggs are packaged for the next leg of their voyage where they will be overnighted to New York Department of Environmental Conservation’s Cape Vincent Fisheries Station or the U.S. Geological Survey’s Tunison Laboratory. When sent to the Department of Environmental Conservation, state fish biologists transport the eggs to the Canadian border where the eggs are received by the Ontario Ministry of Natural Resources for transport to the White Lake Fish Culture Station.
“This year we have already collected more than 1.2 million eggs for this reintroduction effort,” said Dale Hanson, a fish biologist from the Green Bay Fish and Wildlife Conservation Office. “Most of
the fish that hatch from these eggs will be stocked into Lake Ontario as yearlings, but several thousand will be retained at the White Lake Fish Culture Station and reared to maturity where they will be used as a future source of eggs to support large-scale stocking operations.”
Thus far, the eggs harvested by the U.S. Fish and Wildlife Service on Lake Michigan have resulted in more than 92,000 bloater yearlings stocked into Lake Ontario.
Now in its sixth year of winter egg collection and bloater research, the U.S. Fish and Wildlife Service’s Midwest Fisheries Program is at the forefront of bloater research and recovery in the Great Lakes. A return of bloaters and other ciscoes throughout the Great Lakes is an important step to restoring balance in the Great Lakes’ food web, one that will support the growing populations of important predator species including lake trout and Atlantic salmon.
The sun is beginning to drop as gear is hauled off the Peter Paul and the Susie Q. After another grueling day on the winter water, one thing is clear. Commitment to the cause is high. It is only a matter of time before countless hours on the water and in the lab results in the return of bloaters to the Great Lakes.
Want to see more? Check out the complete photo set on Flickr. The only thing missing is the smell of fish and the sound of a diesel engine.