Herrera-Silveira Jorge A, Morales-Ojeda Sara M
CINVESTAV-IPN, Unidad Merida, Km 6 Ant. Carr. a Progreso, Merida Yucatan, Mexico.
Mar Pollut Bull. 2009;59(1-3):72-86. doi: 10.1016/j.marpolbul.2008.11.017. Epub 2009 Jan 20.
The coastal environment of the Yucatan Peninsula (SE, Mexico) includes a wide variety of ecosystems ranging from mangroves to coral reefs, resulting in a heterogeneous landscape. Specifically, the marine system is characterized by environmental differences which respond to regional and local forcing functions such as marine currents and groundwater discharges (GD). Such functional characteristics were used here to define four subregions across the Yucatan coast and diagnose the health status of this coastal marine ecosystem. To achieve this goal, we conducted an analysis and integration of water quality variables, an eutrophic assessment, evaluated changes in submerged aquatic vegetation (SAV), and analyzed the community structure and distribution of harmful phytoplankton. The first step was to determine the reference values for each subregion based on data previously collected from 2002 to 2006 along the coast of Yucatan, 200m offshore. The trophic index (TRIX) and Canadian index for aquatic life (CCMEWQI) were used to diagnose each subregion and then the ASSETS approach was conducted for Dzilam and Progreso, sampling localities on each end of the health status continuum (those with the best and worst conditions). Overall, results indicated that the marine coastal ecosystem of Yucatan is in good condition; however, differences were observed between subregions that can be attributed to local forcing functions and human impacts. Specifically, the central region (zone HZII, Progreso-Telchac) showed symptoms of initial eutrophication due to nutrient inputs from human activities. The eastern region (zone HZ III, Dzilam-Las Bocas) showed a meso-eutrophic condition linked to natural groundwater discharges, while the other two subregions western (zone HZI Celestun-Palmar) and caribbean (zone HZ IV Ria Lagartos-El Cuyo) exhibited symptoms of oligo-mesotrophic condition. These findings may be considered baseline information for coastal ecosystem monitoring programs in Yucatan, and the approach used could be replicated for other coastal areas.
尤卡坦半岛(墨西哥东南部)的沿海环境包含从红树林到珊瑚礁等多种多样的生态系统,形成了一个异质景观。具体而言,海洋系统的特点是存在环境差异,这些差异对诸如海流和地下水排放(GD)等区域和局部强迫作用做出响应。这里利用这些功能特征定义了尤卡坦海岸的四个子区域,并诊断了这个沿海海洋生态系统的健康状况。为实现这一目标,我们对水质变量进行了分析和整合,进行了富营养化评估,评估了沉水水生植被(SAV)的变化,并分析了有害浮游植物的群落结构和分布。第一步是根据2002年至2006年期间在尤卡坦海岸离岸200米处先前收集的数据,确定每个子区域的参考值。利用营养指数(TRIX)和加拿大水生生物指数(CCMEWQI)对每个子区域进行诊断,然后对健康状况连续体两端的采样地点(条件最佳和最差的地点)迪拉姆和普罗格雷索采用资产方法。总体而言,结果表明尤卡坦的海洋沿海生态系统状况良好;然而,各子区域之间存在差异,这可归因于局部强迫作用和人类影响。具体而言,中部地区(HZII区,普罗格雷索 - 特尔查克)由于人类活动的营养输入而出现了初期富营养化症状。东部地区(HZ III区,迪拉姆 - 拉斯博卡斯)呈现出与天然地下水排放相关的中富营养状态,而其他两个子区域西部(HZI区,塞莱斯通 - 帕尔马)和加勒比地区(HZ IV区,里亚拉加托斯 - 埃尔库约)表现出贫中营养状态的症状。这些发现可被视为尤卡坦沿海生态系统监测项目的基线信息,并且所采用的方法可在其他沿海地区复制。