Effects on benthic scavengers of discards and damaged benthos produced by the beam-trawl fishery in the southern North Sea
Effects on benthic scavengers of discards and damaged benthos produced by the beam-trawl fishery in the southern North Sea
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DOI：
10.1006/jmsc.2000.0914
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发表时间：
2000-10-01
影响因子：
3.3
通讯作者：
Fonds, M
中科院分区：
文献类型：
--
作者：
Groenewold, S;Fonds, M
捕捞比目鱼的桁拖网渔业产生大量垂死抛弃物以及受损和受干扰的底栖生物。这些食物来源的重要性，以清除底栖物种进行了调查。为了确定表现出食腐行为的底栖物种，并检测它们的食物偏好，在北海南部的14个地点部署了以不同种类的腐肉（鱼类、甲壳类动物、软体动物、棘皮动物、多毛类动物）为诱饵的陷阱（共370个）。食腐动物主要有长齿石首鱼、贝氏寄居蟹、红海星、蛇形目和小鳕类，而端足类主要以甲壳类腐肉为食。估计的吸引力领域是最大的鳕，寄居蟹，梭子蟹。通过在拖网带中重复取样，观察到鱼类和梭子蟹迁入实验拖网区。拖网捕捞（摄食活动，食物生态位宽度，资源分配）之间的差异选定的鱼类物种的反应。Limanda limanda，Pleuronectes platessa，Merlangius merlangus，Calliamus lyra和Eutrigla gurnardus都表现出强烈的反应，使用不同的喂养策略。对暴露在海底的被丢弃死鱼的就地清除率进行了估计。丢弃物和垂死的底栖生物在几天内就被吃掉了。梁拖网渔业生产的食物量和潜在的食腐动物消耗的食物量之间的平衡被翻译成梁拖网调动的食物hows模型。一般来说，额外的食物资源对食腐动物种群的直接重要性被认为相对较小。然而，食腐鱼类的重要性可能相对大于无脊椎动物。据估计，在单梁拖网后，约1.27 g m（-2）无灰干生物量，或每单位面积大型底栖动物年次级生产量的6%至13%，将突然可供食腐动物和碎屑食物链使用。有人建议，梁拖网导致营养关系的捷径，因此可能会提高次级生产。(C)国际海洋考察理事会。
The beam-trawl fishery for flatfish produces large amounts of dying discards as well as damaged and disturbed benthos. The importance of these food sources to scavenging benthic species was investigated. To identify epibenthic species showing scavenging behaviour and to detect their food preferences, traps (370 overall) baited with different kinds of carrion (fish, crustaceans, molluscs, echinoderms, polychaetes) were deployed at 14 locations in the southern North Sea. Liocarcinus holsatus, Pagurus bernhardus, Asterias rubens, ophiurids, and small gadoids were the main active scavengers feeding on different kinds of food, while lyssianid amphipods (Orchomene nanus, Scopelocheirus hopei) fed mainly on crustacean carrion. Estimated attraction areas were largest for gadoids, hermit crabs, and swimming crabs. Immigration of fish and swimming crabs into experimentally trawled areas was observed by sampling repeatedly in a trawled strip. Differences in the response to trawling (feeding activity, food niche breadth, and resource partitioning) between selected fish species are described. Limanda limanda, Pleuronectes platessa, Merlangius merlangus, Callionymus lyra, and Eutrigla gurnardus all showed strong responses, using different feeding strategies. In situ clearance rates of dead discarded fish exposed on the sea floor were estimated. Discards as well as moribund benthos were consumed within a few days. The balance between the amount of food materials produced by beam-trawl fishery and the amount of food consumed by potential scavengers was translated in a model of the food hows as mobilized by beam trawling. In general, the direct importance of the additional food resource for populations of scavengers is considered to be relatively small. However, the importance may be relatively larger for scavenging fish than for invertebrates. It is estimated that after a single beam trawling about 1.27 g m(-2) ash-free dry biomass, or 6% to 13% of the annual secondary production of macrobenthos per unit area, would suddenly become available to scavengers and to the detritus food chain. It is suggested that beam trawling leads to shortcuts in trophic relationships and therefore may enhance secondary production. (C) 2000 International Council for the Exploration of the Sea.