Species point records from 1993 MNCR Shetland Braer oil spill survey

Littoral and Sublittoral field surveys were carried out between 25 February and 2 March 1993 around the vicinity of the Braer oil tanker grounding. The aim was to provide a rapid assesment of the oil's impact on the marine benthos of the area with a view to suggesting where future work should be carried out. Nine sublittoral and 14 littoral sites were surveyed using standard MNCR techniques, with additional attention being paid to recording noticeable effects from oil pollution, absence of species which would be expected in particular habitats, fish numbers, and collection of sediment biota for possible hydrocarbon analysis by SOAFD. The effects of the oil spill on the littoral biota appeared very limited in geographical extent, with minimal noticeable difference to expected rocky shore community structure beyond 4 Km of the wreck site. The littoral zone of Garths Ness itself was the most heavily impacted as would be expected, with a high mortality of patellid limpets and littorinids. To the east, in Bay of Quendale, obvious effects were more limited, though there appeared still to be a reduction in the numbers of Patella vulgata and littorinids. Littoral algae and lichens appear unnaffected, with no visible signs of damage such as bleaching. Littoral sediments close to the wreck site occur only in the Bay of Quendale, where extreme sediment mobility results in a very impoverished Crustacean-Polychaete community (Howson 1988). Samples collected from these sediments indicated an absence of any biota. Sublittoral surveys on rock and sediment indicated variation in the extent of damage. Rocky sublittoral areas surveyed within 4 Km of the wreck showed no obvious signs of damage. There was a noticeable absence of fish species but whether this is attributable to the oil spill is not clear. Other elements of the biota appeared to be unnafected, with numerous urchins grazing coralline algae encrusted bedrock, and a sparse kelp zone showing no signs of bleaching. In the same vicinity however, sublittoral sediments showed gross effects, with major mortality of bivalves such as Ensis sp. and Spisula solida, and no other biota observed. This gross effect on sediment biota was still apparent in West Voe, some 20 Km north of the wreck, but was not noted in sites further north towards the head of Clift sound.

于1993年2月25日至3月2日，在布拉尔油轮搁浅附近的区域进行了沿岸及浅海地带的调查。目的在于对油污对该区域海洋底栖生物的影响进行快速评估，以期提出未来工作应着力之处。通过标准MNCR技术对9个浅海地带和14个沿岸地带进行了调查，特别关注了记录油污染的明显影响、特定栖息地中预期物种的缺失、鱼类数量的减少以及收集沉积生物体以供SOAFD进行可能的烃类分析。油 spill对沿岸生物的影响在地理范围上似乎非常有限，超出沉船地点4公里以外的岩石海岸群落结构变化微乎其微。正如预期，加斯尼斯内斯沿岸地带遭受了最严重的影响，帘蛤类和滨螺类死亡率极高。向东，在昆德尔湾，明显的效应更为有限，尽管帕泰拉属和滨螺类的数量仍有所减少。沿岸藻类和地衣似乎未受影响，未见任何损害迹象，如褪色。靠近沉船地点的沿岸沉积物仅在昆德尔湾出现，极端的沉积物流动性导致甲壳类和环节动物群落极度贫瘠（Howson 1988）。从这些沉积物中收集的样本表明，没有任何生物存在。对岩石和沉积物的浅海地带调查表明损害程度存在差异。在沉船地点4公里范围内的岩石浅海地带调查未发现明显的损害迹象。鱼类种类的明显缺失引人注目，但尚不清楚这是否归因于油 spill。其他生物群要素似乎未受影响，大量海胆在珊瑚藻覆盖的基岩上摄食，稀疏的海藻带未见褪色迹象。然而，在相同区域，浅海地带的沉积物显示了显著的效应，如双壳类如Ensis sp.和Spisula solida的大规模死亡，且未见其他生物。这种对沉积物生物群的严重影响在沉船以北约20公里的韦斯特沃仍很明显，但在克利夫湾北部的更北地点则未观察到。