Evaluation of a Power Plant Reservoir As A Holding Area For Paddlefish Brood Stock

Twenty paddlefish (Polyodon spathula) released into the Big Stone Power Plant boiler make-up reservoir were monitored to determine growth, condition, and food habits. In addition, fish and zooplankton populations were sampled and chemical and physical parameters measured to determine the potential of the reservoir as a holding area for paddlefish brood stock. Paddlefish captured during the first year after their release into the boiler make-up reservoir averaged 2.2 kg body weight increases and 59 mm eye-fork length increases. Condition factors of captured paddlefish also increased during this period from 1.26 to 1.49. Paddlefish food in the reservoir consisted almost entirely of crustacean zooplankton. Cyclopoid copepods were the most abundant food item found in stomachs sampled, making up over 60% of the total food organisms consumed by numbers. Volumes of food in paddlefish stomachs sampled ranged from 0 to 90 ml. Feeding activity was greatest during April, May, and July. Feeding occurred at lower levels or ceased during June, August, September, October, and November. Cyclopoid copepods had the highest mean selectivity index and Diaptomus spp. the lowest mean selectivity index. Mean selectivity values of other food items were all near 0, indicating that paddlefish had no preference for or against them

Lake Characteristics Influencing Spawning Success of Muskellunge in Northern Wisconsin Lakes

We determined the physical, chemical, biological, and land use characteristics that distinguish northern Wisconsin lakes with self‐sustaining populations of muskellunge Esox masquinongy from lakes where stocking is required to maintain populations. Lakes that supported self‐sustaining muskellunge populations were characterized by fewer shoreline alterations and by spawning habitats with softer, organic‐nitrogen‐rich sediments. Lakes that required stocking had extensively developed shorelines. The direction of water level change during the spawning period, percentage of spawning area sediment covered by woody debris, number of deadfall trees per kilometer of shoreline, and percentage of shoreline that was totally developed were the most important variables for classifying the level of muskellunge reproduction a lake could support. A linear discriminant function correctly classified 83% of the lakes with self‐sustaining muskellunge populations and 89% of the lakes requiring stocking to sustain or enhance muskellunge populations. Lake managers wishing to use muskellunge stocking programs to reestablish self‐sustaining populations should critically review each candidate lake by considering our model and that of Dombeck et al. (1986).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141695/1/nafm0834.pd

Variation in Species Composition of the Larval Assemblage in Four Southwest Michigan Lakes: Using Allozyme Analysis to Identify Larval Sunfish

Many of Wisconsin’s native populations of muskellunge Esox masquinongy exhibit declining reproductive success and failing natural recruitment. As a result, self‐sustaining populations of muskellunge are diminishing. This study focused on spawning habitat factors that influence egg development and survival and, consequently, the reproductive success of muskellunge. Muskellunge spawning habitat characteristics in lakes with self‐sustaining populations were compared with spawning habitat characteristics in lakes that were once self‐sustaining but are now maintained by stocking. The hatching success of artificially fertilized eggs was assessed under natural lake conditions. Spawning sites were typically marshy areas in water less than 1 m deep. Characteristics of the spawning habitat influenced successful reproduction. Spawning areas in stocked lakes had low dissolved oxygen (DO; 1.2–5.4 mg/L) at the substrate–water interface, whereas self‐sustaining lakes had more variable DO (0.5–9.6 mg/L) with some microhabitats having high DO. Organic carbon content, texture of spawning substrate, and water temperature at the substrate did not differ between self‐sustaining lakes and lakes supported by stocking. Fallen logs, stumps, and other wood in spawning areas may increase egg survival. Muskellunge egg survival over natural substrate was low (0.0–1.3%), even in lakes with self‐sustaining populations. Collections of eggs and observations of fry indicated that major mortality occurred after egg deposition but before fry reached nursery habitats several weeks after hatching.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141740/1/tafs0995.pd

A Multidisciplinary Approach to Probing Enthalpy–Entropy Compensation and the Interfacial Mobility Model

In recent years, interfacial mobility has gained popularity as a model with which to rationalize both affinity in ligand binding and the often observed phenomenon of enthalpy-entropy compensation. While protein contraction and reduced mobility, as demonstrated by computational and NMR techniques respectively, have been correlated to entropies of binding for a variety of systems, to our knowledge, Raman difference spectroscopy has never been included in these analyses. Here, non-resonance Raman difference spectroscopy, isothermal titration calorimetry, and x-ray crystallography were utilized to correlate protein contraction, as demonstrated by an increase in protein interior packing and decreased residual protein movement, with trends of enthalpy-entropy compensation. These results are in accord with the interfacial mobility model, and lend additional credence to this view of protein activity