文章基本信息

标题：Indirect effects of fish cage aquaculture on shallow Posidonia oceanica seagrass patches in coastal Greek waters
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作者：Konstantine J. Rountos ; Bradley J. Peterson ; Ioannis Karakassis 等
期刊名称：Aquaculture Environment Interactions
印刷版ISSN：1869-215X
电子版ISSN：1869-7534
出版年度：2009
卷号：2
期号：2
页码：105-115
出版社：Inter-Research
摘要：Over the last 3 decades fish cage aquaculture has increased exponentially in the eastern Mediterranean Sea and has induced various levels of environmental change in coastal waters. The most apparent negative changes involve the degradation of the native seagrass Posidonia oceanica (L.) Delile. Our study examined the effects of fish cage aquaculture on seagrass health, sea urchin density and herbivore feeding pressure in shallow seagrass patches in the coastal waters of 2 Greek islands (Evia and Crete) between February and May of 2008. Evia and Crete represent a wide range of fish farming intensities, from small-scale (75 t yr⁻¹) to large-scale (1000 t yr⁻¹) fish production, respectively. On both islands, the seagrass variables, shoot productivity, standing crop and leaf morphometrics (length and width) were significantly lower (p < 0.0001) in impacted seagrass patches adjacent to fish farms compared with control patches. In addition, significantly higher sea urchin densities and herbivore feeding pressure (percentage of shoots with herbivore grazing scars) were found in impacted patches on both islands. Higher leaf tissue nitrogen and epiphyte loads were also found in impacted patches, but these increases could not be attributed to fish farming alone. Our results show that negative effects on seagrass patches can occur as a result of fish farming at both small-scale and large-scale intensities and that increased sea urchin densities and feeding pressures are important indirect effects of coastal aquaculture on these islands.
关键词：Aquaculture ; Seagrass ; Posidonia oceanica ; Paracentrotus lividus ; Nitrogen ; Herbivory ; Indirect effects