Recruitment dynamics of walleyes (Stizostedion vitreum) in Kansas reservoirs: generalities with natural systems and effects of a centrarchid predator

2003 ◽  
Vol 60 (7) ◽  
pp. 830-839 ◽  
Author(s):  
Michael C Quist ◽  
Christopher S Guy ◽  
James L Stephen
Keyword(s):  
Abiotic Factors ◽  
Water Clarity ◽  
Water Levels ◽  
Stizostedion Vitreum ◽  
Manipulative Experiment ◽  
Natural Systems ◽  
White Crappie ◽  
Zooplankton Density ◽  
Pomoxis Annularis ◽  
Biotic Effects

Knowledge of factors influencing recruitment dynamics of walleyes (Stizostedion vitreum) in different systems and regions is important for developing a better understanding of walleye ecology. Therefore, we investigated associations among walleye recruitment and climatic, water-level, and biotic characteristics in four Kansas reservoirs during 1985–1999. Walleye recruitment was positively related to spring storage ratios and temperatures and negatively associated with spring water levels and abundance of 130- to 199-mm white crappies (Pomoxis annularis). The influence of juvenile white crappie predation on larval walleyes was examined by conducting a manipulative experiment. Regardless of zooplankton density or water clarity, mortality of larval walleyes resulting from white crappie predation was over 90%. Based on our empirical and experimental results, we propose a biotic–abiotic confining hypothesis (BACH) to explain abiotic and biotic effects on walleye recruitment dynamics. Specifically, high variability in walleye recruitment was observed during years with low densities of 130- to 199-mm white crappies and likely resulted from the effects of abiotic factors. When white crappie abundance was high, walleye recruitment was low and exhibited little variability, suggesting that white crappies can have an overriding influence on walleye recruitment regardless of abiotic conditions.

Biotics: Competition, Herbivory, Predation, Parasitism and Symbiosis

2017 ◽  
Author(s):  
Christer Brönmark ◽  
Lars-Anders Hansson
Keyword(s):  
Population Dynamics ◽  
Ecosystem Function ◽  
Theoretical Basis ◽  
Abiotic Factors ◽  
Biological Interactions ◽  
Natural Systems ◽  
The Many

If biological interactions, such as competition and predation, have any effect on population dynamics, or if abiotic factors alone determine which organisms, how many of them do we see in a specific ecosystem, was for long a controversial question. This chapter aims at providing the basis for the understanding of biological interactions, as well as showing ample examples of how important those interactions are in shaping both population dynamics and ecosystem function of natural systems. In addition to the many examples, the reader is introduced to the history and the theoretical basis for biological interactions.

Mortality of First-Feeding Postlarval Walleye (Stizostedion vitreum) in Culture Ponds

1993 ◽  
Vol 50 (9) ◽  
pp. 1835-1843 ◽  
Author(s):  
Thomas A. Johnston ◽  
J. A. Mathias
Keyword(s):  
Critical Period ◽  
Mortality Rates ◽  
Predation Pressure ◽  
Stizostedion Vitreum ◽  
Exogenous Feeding ◽  
Natural Lakes ◽  
First Feeding ◽  
Zooplankton Density ◽  
Food Concentrations ◽  
Order Of Magnitude

We examined mortality rates of postlarval walleye (Stizostedion vitreum) at the onset of exogenous feeding in extensive culture ponds. Food concentrations (≥49 zooplankters∙L−1) were apparently sufficient to support successful first feeding, and no critical period of starvation mortality was evident at this stage of life. The highest observed mortality rates were associated with interspecific or intraspecific predation pressure. At low predation pressure, mean survival from stocking to the 12-mm stage was 87% in 1988 and 90% in 1989, and instantaneous mortality rates were an order of magnitude lower than those reported for postlarval walleye in natural lakes. Mortality rates calculated over the early postlarval period (stocking to 12 mm; 9–11 d) were similar to those calculated over the entire culture period (88–107 d) when predation pressure was low. At low predation pressure and 49–159 zooplankters∙L−1, there was no significant relationship between postlarval mortality rates and zooplankton density. The condition of first-feeding postlarvae captured from the pond with the lowest mean zooplankton density (49∙L−1) was significantly higher than that of postlarvae deprived of food for 48 h. Starvation is probably not a major cause of postlarval morality when zooplankton densities are ≥50∙L−1.

Influence of wind, wave, and water level dynamics on walleye eggs in a north temperate lake

2015 ◽  
Vol 72 (4) ◽  
pp. 570-581 ◽  
Author(s):  
Joshua K. Raabe ◽  
Michael A. Bozek
Keyword(s):  
Water Level ◽  
Wave Energy ◽  
Wind Wave ◽  
Abiotic Factors ◽  
Critical Factor ◽  
Fine Sand ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Egg Survival ◽  
Wave Velocities

Walleye (Sander vitreus) populations are cyclic because of biotic and abiotic factors, and wind activity, wave energy, and water levels may be influential given walleye spawn close to shore. We installed an anemometer and tridirectional velocimeter on a spawning reef in Big Crooked Lake, Wisconsin, in 2005 to determine wind–wave relationships and wave energy exceedance of critical velocities of both egg (affecting transport) and substrates (affecting abrasion or burial). To evaluate egg movement, we delineated egg locations at adhesive, postspawn, and black-eyed stages and surveyed on-shore for stranded eggs. We monitored water level with a staff gauge. Wind and wave velocities were significantly (p < 0.01) correlated, and wave velocities were significantly higher (p < 0.01) nearshore (2.0 m) than further from shore (4.6 m). Mean nearshore wave velocities were often sufficient to initiate movement of nonadhesive eggs (45% of records) and fine sand (39%) during egg incubation. Surveys indicated waves moved eggs closer to shore and some onto shore. Water level fluctuations (range = 2.4 cm) likely did not strand or desiccate eggs. We documented that wind and wave activity transports eggs and substrates and should be considered a critical factor in annual walleye egg survival and year-class strength.

Indirect effects of zebra mussels (Dreissena polymorpha) on the planktonic food web

2003 ◽  
Vol 60 (11) ◽  
pp. 1353-1368 ◽  
Author(s):  
Erik G Noonburg ◽  
Brian J Shuter ◽  
Peter A Abrams
Keyword(s):  
Food Web ◽  
Indirect Effects ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Abiotic Factors ◽  
Zebra Mussels ◽  
Trophic Groups ◽  
Planktonic Food ◽  
Zooplankton Density ◽  
The Impact

The exotic zebra mussel (Dreissena polymorpha) has caused dramatic reductions in phytoplankton density in lakes with dense mussel populations. However, the indirect effects of this invader on other trophic groups have been inconsistent and difficult to interpret. In some lakes, zebra mussels appear to have had little effect on zooplankton density, despite decreasing the abundance of their phytoplankton prey. We analyze food web models to test hypothesized mechanisms for the absence of a strong effect of dreissenids on zooplankton. Our results suggest that neither reduced inedible algal interference with zooplankton filtering nor reduced phytoplankton self-shading is sufficient to explain the insensitivity of zooplankton populations to dreissenid competition. Instead, we show how the impact of benthic filter feeders can be influenced by the rate of mixing within a basin, which limits phytoplankton delivery to the benthos. We explore the predictions of a simple spatially structured model and demonstrate that differences in abiotic factors that control mixing can result in large differences in direct and indirect effects of zebra mussel filtering.

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