Consumption of discards and interactions between Black-browed Albatrosses (Thalassarche melanophrys) and Kelp Gulls (Larus dominicanus) at trawl fisheries in Golfo San Jorge, Argentina
Consumption of discards and interactions between Black-browed Albatrosses (Thalassarche melanophrys) and Kelp Gulls (Larus dominicanus) at trawl fisheries in Golfo San Jorge, Argentina
复制标题
阿根廷圣豪尔赫湾拖网渔业的丢弃物消耗以及黑眉信天翁 (Thalasarche melanophrys) 和海带鸥 (Larus dominicanus) 之间的相互作用
DOI：
10.1007/s10336-011-0657-6
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发表时间：
2011
影响因子：
1.3
通讯作者：
P. Yorio
中科院分区：
文献类型：
--
作者：
Diego González;P. Yorio
我们评估了与阿根廷圣豪尔赫湾拖网渔船相关的海带鸥 (Larus dominicanus) 和黑眉信天翁 (Thalasarche melanophrys) 的丢弃物消耗量，并评估了它们的摄食行为、猎物大小偏好和觅食效率的差异。在无须鳕（2007 年 1 月）和捕虾船（2008 年 11 月）上进行了观察。海带鸥和黑眉信天翁是两个渔业中最常见和最丰富的海鸟，而阿根廷无须鳕 (Merluccius hubbsi) 在丢弃物的构成中占主导地位。海带鸥和黑眉信天翁消耗了 91% 的实验性废弃无须鳕 (n= 1236)。在鳕鱼和虾类渔业中，海鸥捕食的猎物平均尺寸分别为 22.4 和 23.7 厘米，而信天翁捕食的猎物平均尺寸分别为 28.5 和 31.3 厘米。在这两个渔业中，海鸥选择了较小的猎物（在鳕鱼和虾渔业中分别<25和<30厘米），而黑眉信天翁选择了较大的猎物（在鳕鱼和虾渔业中分别>25和>30厘米）。海带鸥和黑眉信天翁的种内和种间盗贼寄生现象分别明显高于预期。信天翁的抢劫效率明显高于海鸥。在这两个物种中，直接捕获的猎物尺寸明显小于被盗的猎物尺寸，并且盗贼寄生率随着猎物尺寸的增加而增加。海鸥偷走的猎物比信天翁小得多。海带鸥的猎物选择受到与黑眉信天翁相互作用的影响，这两个物种使用丢弃物的程度似乎取决于所考虑的渔业、提供的食物以及根据海鸟物种特定偏好选择的猎物大小。
We evaluated discard consumption by Kelp Gulls (Larus dominicanus) and Black-browed Albatrosses (Thalassarche melanophrys) associated with trawlers operating at Golfo San Jorge, Argentina, and assessed differences in their feeding behaviour, prey size preferences and foraging efficiency. Observations were made onboard hake (January 2007) and shrimp vessels (November 2008). The Kelp Gull and Black-browed Albatross were the most frequent and abundant seabirds at both fisheries, while Argentine Hake (Merluccius hubbsi) dominated the composition of discards. Kelp Gulls and Black-browed Albatrosses consumed 91% of experimentally discarded hake (n= 1236). Mean sizes of prey consumed by gulls were 22.4 and 23.7 cm in the hake and shrimp fisheries, respectively, while those of prey consumed by albatrosses were 28.5 and 31.3 cm, respectively. In both fisheries, gulls selected the smaller prey available (<25 and < 30 cm in hake and shrimp fisheries, respectively) while Black-browed Albatrosses selected the larger prey available (>25 and >30 cm in hake and shrimp fisheries, respectively). Intraspecific and interspecific kleptoparasitism were significantly more frequent than expected in Kelp Gulls and Black-browed Albatrosses, respectively. Robbing efficiency was clearly higher in albatrosses than gulls. In both species, sizes of prey consumed by direct capture were significantly smaller than those stolen, and the rate of kleptoparasitism increased with prey size. Gulls stole significantly smaller prey than albatrosses. Prey selection by Kelp Gulls is affected by the interaction with Black-browed Albatrosses, and the degree at which discards are used by both species appears to depend on the fishery considered, the food on offer and the selection of prey sizes according to seabird species-specific preferences.