Developing methods of blocking and removing invasive fishes, while allowing the passage of desirable fishes (selective fish passage) is becoming an issue of great importance to fisheries managers in the Great Lakes. We propose to assess the potential for selective fish passage with currently operated trap-and-sort fishways used to remove invasive Sea Lampreys (Petromyzon marinus) and pass desirable fishes. Trap and sort fishways consist of sequential downstream and upstream compartments.
Cisco have played an important role in Great Lakes fisheries and ecosystems, particularly in Lake Superior. While some Lake Superior cisco stocks have recovered from declines in the last century, recent increases in fishing effort have raised concerns. Currently the quantitative tools available for informing cisco fishery management are limited. Given the importance of cisco, the development of informed harvest management strategies is critical to avoid stock collapses and subsequent ecological and fishery repercussions.
Currently the GLFC manages the impacts of sea lampreys through a combination of trapping, barriers, and lampricides. Over the next several years, the GLFC faces potentially elevated control costs due to pressure to remove barriers that currently prevent sea lamprey access to large areas of productive habitat, in the absence of alternative long-term, cost-effective options. Modern genetic technology could provide such an option.
The lampricide, 3-trifluoromethyl-4-nitrophenol (TFM), selectively targets larval sea lampreys (Petromyzon marinus), which have a lower capacity to detoxify and eliminate TFM through its conversion to TFM-glucuronide than non-target fishes. Although non-target fish mortality is relatively uncommon, juvenile lake sturgeon (Acipenser fulvescens) are vulnerable to TFM-induced mortality, particularly when smaller than 10 cm, and they appear to be more susceptible to TFM toxicity in waters of higher alkalinity.