Ashland FWCO Assists in Cisco Spawning Survey on Lake Superior
BY MIKE SEIDER, ASHLAND FWCO
In early November, the Ashland Fish and Wildlife Conservation Office (FWCO) contributed to an assessment of cisco populations in the Apostle Islands region, Lake Superior. The objective of the study was to estimate the density of spawning cisco and evaluate multiple capture methods. Sampling included gill netting (on the bottom and up in the water column) by the Wisconsin Department of Natural Resources (DNR) and hydro-acoustic sampling and mid-water trawling by United States Geological Survey (USGS). Ashland FWCO fisheries biologist Mike Seider assisted staff from USGS with data collection and processing aboard their research vessel the R/V Kiyi.
Cisco stocks throughout Lake Superior began to recover during the 1980s following several decades of low abundance likely caused by over exploitation and exotic species. The lake wide recovery was spurred by large but sporadic year classes that recruited to the adult population. As the stocks in Wisconsin recovered, commercial fisheries also expanded due to the value of cisco roe. Although cisco stocks appear to be healthy, biologists remain concerned about the sustainability of the increasing fishery exploitation, especially in light of highly sporadic cisco recruitment.
Thus the Wisconsin DNR, with assistance from partner agencies initiated a three year study to evaluate spawning cisco stocks and the viability of a multi-gear survey. The survey will be conducted in other locations within the Apostle Islands region in subsequent years. Data collected will aid managers in not only evaluating the status of spawning stocks but also in developing the most efficient methodology to sample those stocks in the future.