VARIABLE GIZZARD SHAD RECRUITMENT WITH RESERVOIR PRODUCTIVITY: CAUSES AND IMPLICATIONS FOR CLASSIFYING SYSTEMS
VARIABLE GIZZARD SHAD RECRUITMENT WITH RESERVOIR PRODUCTIVITY: CAUSES AND IMPLICATIONS FOR CLASSIFYING SYSTEMS
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不同砂囊鲥鱼补充量与油藏产能的关系：分类系统的原因和意义
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
R. Stein
中科院分区：
文献类型：
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作者：
Mary T. Bremigan;R. Stein
实现可持续的捕食性鱼群，以支持捕食性鱼类种群，是渔业管理者面临的一项根本挑战。在中西部和东南部(美国)的水库中，为了促进捕食者的生长，已经广泛放养了石斑鱼。然而，这些长袜对运动鱼产生了高度不同的影响，部分原因是高度不同的鱼鳞鱼补充。为了确定是否可以利用水库生产力来分类水库，我们沿着中营养化到高富营养化的生产力梯度量化了鱼鳞鱼的补充量。我们在1993年5月至6月期间对12个水库进行了采样，以评估幼虫取食成功率和存活率随着水库生产力的增加而增加的假说。孵化丰度和仔鱼存活率与总磷浓度呈正相关，总磷浓度是水库生产力的一个指标。15 mm(全长)的幼体鳞鱼幸存者的丰度，一个0岁年龄级强度的指标，在不同的TP浓度下增加了两个数量级。随着首选的小型浮游动物猎物的可获得性，幼体鱼的觅食成功率增加。然而，小型浮游动物的丰度并没有随着水库TP浓度的增加而增加，幼虫的存活率也没有随着觅食成功而增加。这些结果从机理上解释了中营养化水库中相对缺乏鱼鳞鱼的现象，以及高营养化水库中鱼鳞鱼的优势地位。在富营养化水库，通过减少分水岭的磷负荷，可以缓解鲤鱼对运动鱼的负面影响，这表明一个分水岭方法可以解决这个渔业和水质问题。
Achieving sustainable prey fish assemblages that support sport fish predator populations is a fundamental challenge to fisheries managers. Among Midwestern and Southeastern (USA) reservoirs, gizzard shad, Dorosoma cepedianum, have been widely stocked to improve predator growth. However, these stockings have yielded highly variable effects on sport fish, due in part to highly variable recruitment of gizzard shad. To determine whether reservoir productivity can be used to classify reservoirs according to recruitment of gizzard shad, we quantified gizzard shad recruitment along a mesotrophic to hypereutrophic productivity gradient. We sampled 12 reservoirs during May through June 1993, to evaluate the hypothesis that larval gizzard shad foraging success and survival increase with reservoir productivity. Both hatch abundance and survival of larval gizzard shad correlated positively with total phosphorus concentrations (TP), an indicator of reservoir productivity. Abundance of 15-mm (total length) larval gizzard shad survivors, an indicator of age-0 year class strength, increased by two orders of magnitude across TP concentrations. Larval gizzard shad foraging success increased with availability of preferred, small zooplankton prey. However, abundance of small zooplankton did not increase with reservoir TP concentrations, and larval survival did not increase with foraging success. These results provide mechanistic understanding for the relative lack of gizzard shad in mesotrophic reservoirs, and the dominance of gizzard shad in hypereutrophic reservoirs. In hypereutrophic reservoirs, negative effects of gizzard shad on sport fish may be alleviated by reducing phosphorus loading from the watershed, suggesting a watershed approach to this fishery and water quality problem.