Department of Fisheries and Allied Aquacultures, 203 Swingle Hall, Auburn University, AL 36849, USA.
J Fish Biol. 2009 May;74(7):1580-93. doi: 10.1111/j.1095-8649.2009.02231.x.
Effects of river discharge on growth of redbreast sunfish Lepomis auritus were investigated in nine rivers in Georgia, U.S.A. Fish were aged and annular total length increments (L(Tinc)) estimated from measurements from sectioned sagittal otoliths using the generalized regression model that held for the effects of decreasing L(Tinc) from annual age (X): L(Tinc)=b(o)-b(1)(X) +/-b(i)(D), where b(o), b(1) and b(i) were the regression coefficients for the intercept and slopes and D, discharge, was either a single or multiple measurements of annular or seasonal flow volume or variation in flow volume. For eight of nine rivers, higher or greater variation in flows from April to June was associated with greater L. auritus growth; in the last river, higher flows from January to March were associated with greater fish growth. Across all rivers, L. auritus growth increments were 22, 45 and 36% greater in a wet year v. a dry year at ages 1, 2 and 3 years, respectively. Based on the results of this study, increasing water withdrawals by an additional 30% in five Georgia rivers would reduce the predicted number of L. auritus recruiting to 203 mm (angler preferred size) by 19-62%.
本研究在美国佐治亚州的 9 条河流中调查了河川径流量对红腹太阳鱼（Lepomis auritus）生长的影响。通过对矢状耳石切片测量的分析，采用通用回归模型估算了鱼的年龄和环形总长度增量（L(Tinc)），该模型考虑了 L(Tinc)随年龄（X）减少的影响：L(Tinc)=b(o)-b(1)(X) +/-b(i)(D)，其中 b(o)、b(1)和 b(i)是截距和斜率的回归系数，D 是环形或季节性流量或流量变化的单一或多次测量值。在这 9 条河流中，有 8 条河流的 4 月至 6 月的流量较高或波动较大，与红腹太阳鱼的生长较大有关；在最后一条河流中，1 月至 3 月的高流量与鱼的生长较大有关。在所有河流中，1 岁、2 岁和 3 岁时，湿润年份 L. auritus 的生长增量分别比干旱年份高 22%、45%和 36%。基于这项研究的结果，如果在佐治亚州的 5 条河流中再增加 30%的取水量，预测到 203 毫米（钓鱼者偏好的尺寸）的 L. auritus 数量将减少 19%至 62%。
