Impacts of shellfisheries and nutrient inputs on waterbird communities in the Wash, England
Impacts of shellfisheries and nutrient inputs on waterbird communities in the Wash, England
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DOI：
10.1111/j.1365-2664.2009.01760.x
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发表时间：
2010-02-01
影响因子：
5.7
通讯作者：
Clark, Nigel A.
中科院分区：
文献类型：
--
作者：
Atkinson, Philip W.;Maclean, Ilya M. D.;Clark, Nigel A.
1. 渔业过度开发威胁着许多依赖被开发资源的物种。全球范围内的滨鸟数量正在下降，在此我们描述不断变化的贝类管理和养分投入如何对国际重要湿地的水鸟群落产生巨大影响。2。鸟蛤和贻贝渔业与滨鸟发生冲突，因为它们会消灭猎物并增加非目标底栖无脊椎动物的死亡率。有证据表明，在巨大的疏浚压力下，蠕虫等底栖无脊椎动物生长速度快、世代时间短，应该比双壳类等生长缓慢、世代时间长的物种占主导地位。 3．我们调查了 1981 年至 1982 年和 2002 年至 2003 年期间英格兰东部沃什河地区水鸟群落的变化。这一时期的特点是贻贝和鸟蛤面临巨大的捕捞压力，最终导致贻贝种群的崩溃。4。在研究期间，水鸟群经历了逐渐的变化，从饮食中双壳类或“其他”猎物（例如甲壳类动物、鱼类）比例较高的物种为主，到蠕虫比例较高的水鸟群。这种逐渐的变化伴随着重大转变，相当于三个冬季，蛎鹬 Haemotopus ostralegus 死亡率是正常冬季水平的 5-13 倍。5。蛎鹬、滨鹬和麻鸭的下降幅度最大。自 1996-1997 年发生的上一次重大蛎鹬死亡事件以来，该组合并未恢复到 1992.6 贻贝种群严重崩溃之前观察到的情况。水鸟组合的变化与贻贝和鸟蛤种群水平显着相关，在较小程度上与营养水平相关。尽管相关，但本研究的证据表明，渔业导致了水鸟群落的转变，该群落以饮食中蠕虫比例较高的物种为主。7.合成和应用。机械贝类捕捞直接与拥有国际重要水鸟种群的地点的自然保护利益相冲突。华盛顿河中贻贝床的拆除导致水鸟群落发生重大变化，转向以蠕虫为食。设定年度配额，为以贝类为食的鸟类提供足够的食物，对于维持该湿地和其他国际重要的贝类开采湿地的良好状态至关重要。
1. Overexploited fisheries threaten many species that depend on the exploited resource. Shorebird populations are in decline globally and here we describe how changing shellfishery management and nutrient inputs have had dramatic influence on waterbird communities on an internationally important wetland.2. Cockle Cerastoderma edule and mussel Mytilus edulis fisheries conflict with shorebirds by removing prey and increasing mortality amongst non-target benthic invertebrates. Under intense dredging pressure, evidence suggests that benthic invertebrates such as worms, with rapid growth and short-generation times, should predominate over species such as bivalves, with slower growth and longer generation times.3. We investigated the change in the waterbird assemblage in the Wash, eastern England, between 1981-1982 and 2002-2003. This period was characterized by heavy fishing pressure on mussels and cockles, ultimately leading to a crash in the mussel stocks.4. During the study period, the waterbird assemblage underwent a gradual change from one dominated by those species with a high proportion of bivalves or 'other' prey (e.g. crustaceans, fish) in their diet to those with a higher proportion of worms. This gradual change was punctuated by major shifts, corresponding to three winters when oystercatcher Haemotopus ostralegus mortality was 5-13 times normal winter levels.5. Oystercatcher, knot Calidris canutus and shelduck Tadorna tadorna showed the highest levels of decline. Since the last major oystercatcher mortality event in 1996-1997, the assemblage has not shifted back to that observed prior to the major crash in the mussel stock in 1992.6. Changes in the waterbird assemblage were significantly related to mussel and cockle stock levels and, to a lesser extent, nutrient levels. Although correlative, evidence from this study indicates that fisheries caused shifts towards a waterbird community dominated by species with a high proportion of worms in their diet.7.Synthesis and applications. Mechanical shellfisheries directly conflict with the nature conservation interest of sites holding internationally important waterbird populations. Removal of the mussel beds in the Wash led to major shifts in the waterbird assemblage, with a shift towards worm-feeders. Setting annual quotas that provide sufficient food for shellfish-eating birds is essential to maintain the favourable status of this and other internationally important wetlands where shellfish are exploited.