Degree-day accumulation influences annual variability in growth of age-0 walleye

作者：Uphoff Christopher S^*; Schoenebeck Casey W; Hoback W Wyatt; Koupal Keith D; Pope Kevin L

来源：Fisheries Research, 2013, 147: 394-398.

DOI：10.1016/j.fishres.2013.05.010

• Age-0
• Degree-day
• Growth
• Reservoir
• Walleye

The growth of age-0 fishes influences survival, especially in temperate regions where size-dependent over-winter mortality can be substantial. Additional benefits of earlier maturation and greater fecundity may exist for faster growing individuals. This study correlated prey densities, growing-degree days, water-surface elevation, turbidity, and chlorophyll a with age-0 walleye Sander vitreus growth in a south-central Nebraska irrigation reservoir. Growth of age-0 walleye was variable between 2003 and 2011, with mean lengths ranging from 128 to 231 mm by fall (September 30th-October 15th). A set of a priori candidate models were used to assess the relative support of explanatory variables using Akaike's information criterion (AIC). A temperature model using the growing degree-days metric was the best supported model, describing 65% of the variability in annual mean lengths of age-0 walleye. The second and third best supported models included the variables chlorophyll a (r(2) = 0.49) and larval freshwater drum density (r(2) = 0.45), respectively. There have been mixed results concerning the importance of temperature effects on growth of age-0 walleye. This study supports the hypothesis that temperature is the most important predictor of age-0 walleye growth near the southwestern limits of its natural range.

• 出版日期2013-10