I LIKE TO STUDY FISH AND WATER; APPLIED ECOLOGY AND MANAGEMENT GETS ME EXCITED

Featured research below:

ROLE OF FOOD WEB CONFIGURATION IN THE RESTORATION OF NATIVE PELAGIC SYSTEMS

Invasive species are a global concern, particularly for aquatic ecosystems.  It remains unknown how food web configuration plays a role in the restoration of native pelagic systems and in the mitigation and control of invasives. We will be conducting two whole-lake experiments to test the hypothesis that food web configuration (i.e., presence or absence of a predator) influences interactions between native and invasive forage fishes.  To accomplish this, we will be stocking native cisco (Coregonus artedi) into Crystal and Sparkling lakes, which are currently dominated by invasive rainbow smelt (Osmerus mordax).  Crystal contains no predator and Sparkling will receive supplemental walleye (Sander vitreus) stocking.  We hypothesize greater rainbow smelt control and cisco reintroduction success in the system with predators (Sparkling) than without (Crystal). This study will have implications for future reintroduction and control efforts.

PALLID STURGEON DRIFT

Anthropogenic modifications on the Missouri River have resulted in a cooler thermal regime and altered water flows (slower water velocities) for the federally endangered pallid sturgeon (Scaphirhynchus albus).  We quantify the effects of temperature and water velocity on larval energy use, behavior, and mortality.  We show that these variables have a strong influence on growth, energy use and survival of pallid sturgeon larvae and discuss the implications that habitat modifications may have to the development and survival of endogenous S. albus larvae.

WISCONSIN WALLEYE HYPERSTABILITY

In Wisconsin, walleye are a highly valuable economic, cultural, and recreational resource that is shared among different stakeholders (e.g., recreational anglers and tribal spearfishers).  We characterized the size distribution and mean length of harvested walleyes, harvest, exploitation rate, and catch and harvest rate for both fisheries during 1990–2015.  Then, we evaluated catch and harvest rates in relation to adult density to test for self-regulation or hyperstability in each fishery.  Size distribution and mean length of harvested walleyes in both fisheries were biologically similar. Anglers harvested significantly more walleyes, and the mean exploitation rate was greater in the angling fishery. Spearfishers had significantly higher mean harvest rates compared with angler catch rates. Catch and harvest rates followed an asymptotic relationship with adult density, with the spear fishery showing more hyperstability than the angling fishery.  Due to the hyperstability observed in each fishery, active management and monitoring of the joint walleye fishery should continue given recent declines in natural recruitment and production observed in the Ceded Territory of Wisconsin in order to maintain walleye populations in a “safe operating space.”

 

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