Stunz G W., Minello T J.
Fishery Ecology Branch, National Marine Fisheries Service, Southeast Fisheries Science, Center, Galveston Laboratory, 4700 Ave. U, 77551, Galveston, TX, USA
J Exp Mar Biol Ecol. 2001 May 31;260(1):13-25. doi: 10.1016/s0022-0981(01)00248-9.
We examined the patterns of habitat-specific mortality for newly settled red drum (Sciaenops ocellatus) using an experimental mesocosm approach. Experiments were designed to analyze prey vulnerability and fish rearing-type (wild-caught or hatchery-reared) in estuarine habitats of varying structural complexity including marsh (Spartina alterniflora Loisel), oyster reef (Crassostrea virginica Gmelin), seagrass (Halodule wrightii Aschers), and nonvegetated sand bottom. We used two different predators, pinfish (Lagodon rhomboides Linnaeus) and spotted seatrout (Cynoscion nebulosus Cuvier). For both predators, vulnerability of wild-caught red drum was significantly lower in structurally complex habitats such as seagrass and oyster reef; the highest vulnerability was associated with the nonvegetated bottom. This habitat effect was not apparent for hatchery-reared prey. In trials using a combination of both rearing-types, there was no significant habitat effect on prey selection, but hatchery-reared red drum suffered higher overall mortality than wild-caught fish from pinfish predators. In these trials, spotted seatrout did not select for either prey type. Differences we observed in prey vulnerability were likely caused by behavioral differences between wild-caught and hatchery-reared red drum. Our results reinforce the conclusion that structural complexity in estuarine habitats increases survival of newly settled fishes. Our data also suggest that hatchery-reared red drum may be more vulnerable to predation than natural fishes, and that survival of stocked fish may be enhanced through habitat-related behavior modification.
我们采用实验性中宇宙方法，研究了新定居的红鼓鱼（眼斑拟石首鱼）在特定栖息地的死亡模式。实验旨在分析不同结构复杂性的河口栖息地（包括盐沼（互花米草）、牡蛎礁（弗吉尼亚牡蛎）、海草（赖特氏二药藻）和无植被的 sandy 底）中猎物的易损性以及鱼类的养殖类型（野生捕捞或孵化场养殖）。我们使用了两种不同的捕食者，尖吻鲈（菱形牙汉鱼）和斑点海鲈（云斑尖塘鳢）。对于这两种捕食者而言，野生捕捞的红鼓鱼在海草和牡蛎礁等结构复杂的栖息地中的易损性显著较低；最高易损性与无植被的底部相关。这种栖息地效应在孵化场养殖的猎物中并不明显。在同时使用两种养殖类型的试验中，栖息地对猎物选择没有显著影响，但孵化场养殖的红鼓鱼总体死亡率高于被尖吻鲈捕食的野生捕捞鱼。在这些试验中，斑点海鲈对两种猎物类型均无选择性。我们观察到的猎物易损性差异可能是由野生捕捞和孵化场养殖的红鼓鱼之间的行为差异造成的。我们的结果强化了这样的结论：河口栖息地的结构复杂性提高了新定居鱼类的存活率。我们的数据还表明，孵化场养殖的红鼓鱼可能比天然鱼类更容易受到捕食，并且通过与栖息地相关的行为改变可以提高放养鱼的存活率。
