Fischer Andrew M, Ryan John P, Levesque Christian, Welschmeyer Nicholas
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA; National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Australian Maritime College, Launceston, TAS 7250, Australia.
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA.
Mar Environ Res. 2014 Aug;99:106-16. doi: 10.1016/j.marenvres.2014.04.006. Epub 2014 May 1.
The transformation of estuaries by human activities continues to alter the biogeochemical balance of the coastal ocean. The disruption of this balance can negatively impact the provision of goods and services, including fisheries, commerce and transportation, recreation and esthetic enjoyment. Here we examine a link, between the Elkhorn Slough and the coastal ocean in Monterey Bay, California (USA) using a novel application of fatty acid and pigment analysis. Fatty acid analysis of filtered water samples showed biologically distinct water types between the Elkhorn Slough plume and the receiving waters of the coastal ocean. A remarkable feature of the biological content of the plume entering the coastal ocean was the abundance of bacteria-specific fatty acids, which correlated well with concentrations of colored dissolved organic matter (CDOM). Pigment analysis showed that plume waters contained higher concentrations of diatoms and cryptophytes, while the coastal ocean waters showed higher relative concentrations of dinoflagellates. Bacteria and cryptophytes can provide a source of labile, energy-rich organic matter that may be locally important as a source of food for pelagic and benthic communities. Surface and depth surveys of the plume show that the biogeochemical constituents of the slough waters are injected into the coastal waters and become entrained in the northward flowing, nearshore current of Monterey Bay. Transport of these materials to the northern portion of the bay can fuel a bloom incubator, which exists in this region. This study shows that fatty acid markers can reveal the biogeochemical interactions between estuaries and the coastal ocean and highlights how man-made changes have the potential to influence coastal ecological change.
人类活动对河口的改造持续改变着沿海海洋的生物地球化学平衡。这种平衡的破坏会对包括渔业、商业与运输、娱乐及审美享受在内的商品和服务供应产生负面影响。在此，我们运用脂肪酸和色素分析的新方法，研究了美国加利福尼亚州蒙特雷湾的埃尔克霍恩湿地与沿海海洋之间的联系。对过滤水样的脂肪酸分析显示，埃尔克霍恩湿地羽流与沿海海洋的接纳水域之间存在生物特征不同的水体类型。进入沿海海洋的羽流生物成分的一个显著特征是细菌特异性脂肪酸含量丰富，这与有色溶解有机物（CDOM）的浓度密切相关。色素分析表明，羽流水体中硅藻和隐藻的浓度较高，而沿海海洋水体中鞭毛藻的相对浓度较高。细菌和隐藻可以提供不稳定的、富含能量的有机物质来源，这作为浮游生物和底栖生物群落的食物来源可能在局部具有重要意义。对羽流的表层和深度调查表明，湿地水体的生物地球化学成分被注入沿海水域，并被卷入蒙特雷湾向北流动的近岸海流中。这些物质向海湾北部的输送可以为该区域存在的水华孵化器提供养分。这项研究表明，脂肪酸标记物可以揭示河口与沿海海洋之间的生物地球化学相互作用，并突出了人为变化如何有可能影响沿海生态变化。
