Deep-water fisheries at the Atlantic Frontier
Deep-water fisheries at the Atlantic Frontier
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DOI：
10.1016/s0278-4343(00)00121-7
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发表时间：
2001-05-01
影响因子：
2.3
通讯作者：
Gordon, JDM
中科院分区：
文献类型：
--
作者：
Gordon, JDM
深海通常被认为是一个寒冷、黑暗和均匀的环境，鱼类生物量低，其中大部分鱼类高度适应食物匮乏环境中的生命。虽然生活在水体中的中上层鱼类可能是这样，但生活在不列颠群岛（大西洋边界）周围大陆斜坡底部或接近底部的底层鱼类肯定不是这样。这些鱼目前正在进行商业开发。越来越多的证据支持这样一种观点，即底层鱼类群落的成功取决于垂直和水平冲击陆坡的中上层或底层食物来源。这是一个物理障碍，即威维尔-汤姆森海脊，它造成了渔业的最大分割。海岭的最小深度约为500米，它将温暖的大西洋深层沃茨与寒冷得多的挪威海水分开，赫布里底群岛以西和近海沿岸的深水渔业与法罗群岛-设得兰海峡的渔业大不相同（设得兰群岛以西）.赫布里底群岛以西的渔业可按所用捕鱼方法进一步分为底拖网、半远洋拖网和延绳钓。底拖网渔业从陆架斜坡断裂处延伸至约1 700米，目标鱼种随深度而变化。船队中最小的船只在上坡捕鱼，那里的一个重要目标鱼种是琵琶鱼或安康鱼（Lophius spp.）。在中坡，主要目标鱼种是蓝鳍金枪鱼（Molva dypterygia）和圆鼻长吻鳕（Coryphaenoides rupestris），副渔获物是黑鱼（Aphanopus carbo）和深水鲨鱼。在低坡，橙子棘鲷（Hoplostethus atlanticus）是重要的目标物种。主要的半远洋拖网渔业是对蓝鳕鱼（Micromesistitus poutassou）产卵群体的季节性渔业。另一种半远洋渔业是大银胡瓜鱼或阿根廷鱼（阿根廷细鳍鱼）的产卵群。主要以无须鳕（Merluccius merluccius）为目标的西班牙和英国渔船以及以长翎（Molva molva）、蓝翎和象牙（Biosme brosme）为目标的挪威船队在上斜坡延绳钓渔业中占主导地位。在设得兰群岛以西，上斜坡的渔业与赫布里底群岛斜坡的渔业有一些相似之处，琵琶鱼和蓝翎是重要的目标鱼种。在大西洋和挪威海沃茨之间的过渡区有一种完全不同的渔业。这里的主要目标物种是格陵兰大比目鱼（Reinhardtius glossoides）。在过渡区以下，生物量迅速减少，没有渔业，人们普遍认为，许多深水鱼种生长缓慢，初熟年龄大，繁殖力低，因此容易受到过度开发。这些鱼类的其他特点，如丢弃和逃逸的高死亡率，将增加问题。尽管如此，唯一的管理程序是欧洲联盟管辖范围内的一般限制努力措施。(C)2001爱思唯尔科学有限公司版权所有。
The deep sea is often thought of as a cold, dark and uniform environment with a low-fish biomass, much of which is highly adapted for life in a food-poor environment. While this might be true of the pelagic fish living in the water column, it is certainly not true of the demersal fish which live on or close to the bottom on the continental slopes around the British Isles (the Atlantic Frontier). These fish are currently being commercially exploited. There is growing evidence to support the view that success of the demersal fish assemblages depends on the pelagic or benthopelagic food sources that impinge both vertically and horizontally onto the slope.There are several quite separate and distinct deep-water fisheries on the Atlantic Frontier. It is a physical barrier, the Wyville-Thomson Ridge, which results in the most significant division of the fisheries. The Ridge, which has a minimum depth of about 500 m, separates the warmer deep Atlantic waters from the much colder Norwegian Sea water and as a result, the deep-water fisheries to the west of the Hebrides and around the offshore banks are quite different from those of the Faroe-Shetland Channel (West of Shetland).The fisheries to the West of the Hebrides can be further divided by the fishing method used into bottom trawl, semipelagic trawl and longline. The bottom-trawl fisheries extend from the shelf-slope break down to about 1700 m and the target species varies with depth. The smallest vessels in the fleet fish on the upper slope, where an important target species is the anglerfish or monkfish (Lophius spp.). On the mid-slope the main target species are blue ling (Molva dypterygia) and roundnose grenadier (Coryphaenoides rupestris), with bycatches of black scabbardfish (Aphanopus carbo) and deep-water sharks. On the lower slope orange roughy (Hoplostethus atlanticus) is an important target species. The major semipelagic trawl fishery is a seasonal fishery on spawning aggregations of blue whiting (Micromesistitus poutassou). The other semipelagic fishery is on spawning aggregations of the greater silver smelt or argentine (Argentina silus). Spanish and UK vessels that target mainly hake (Merluccius merluccius) and a Norwegian fleet that targets ling (Molva molva), blue ling and tusk (Biosme brosme) dominate the upper slope longline fishery. West of Shetland, the fishery on the upper slope has some similarities with that of the Hebridean slope, with anglerfish and blue ling being important target species. A quite different fishery occurs in the transition zone between the Atlantic and Norwegian Sea waters. Here the main target species is Greenland halibut (Reinhardtius hippoglossoides). Below the transition zone biomass decreases rapidly and there is no fishery.It is generally agreed that many deep-water species have slow growth, a high age at first maturity and a low fecundity, which makes them vulnerable to over-exploitation. Other features of these fishes such as high mortality of discards and escapees will add to the problems. Despite this the only management procedures in place are general limitation of effort measures within the area of jurisdiction of the European Union. (C) 2001 Elsevier Science Ltd. Ah rights reserved.