RECOVER MAP 3.2.3.5 & 3.2.4.5 Epifaunal Communities of Mainland Nearshore South Biscayne Bay

Biscayne Bay’s benthic community is a primary source of its productivity and diversity. The benthic faunal community, consisting of small forage fish, juvenile game fish, and invertebrates such as pink shrimp, is particularly well developed in the shallow nearshore zone adjacent to the mainland and may be dependent, either directly or indirectly, upon freshwater inflow to the bay. Many small forage fish are found more abundantly in the shallow nearshore waters than in the deeper waters of the bay. The commercially important pink shrimp and blue crab also are found in western nearshore Biscayne Bay. Caridean shrimps form another important component of the epifauna. The epifaunal community is a direct food source for gray snapper, spotted seatrout, and great barracuda. It is an important link in the food web that leads to higher trophic level species such as crocodiles. This community will be the first to change when the Biscayne Bay Coastal Wetlands projects are started. A dynamic characterization of this community and how its components vary along the shoreline is needed to provide baseline information for evaluating CERP.
In a first view of our sample data from the community perspective, we addressed determining (1) whether sites nearest to each had more similar species compositions and (2) whether species with similar salinity requirements would have similar geographic distributions. The data were investigated with cluster analyses and multidimensional scaling to gain these perspectives.

比斯坎湾（Biscayne Bay）的底栖生物群落（benthic community）是其生产力与生物多样性的核心来源。由小型饵料鱼、幼体游钓鱼类以及粉红虾等无脊椎动物组成的底栖动物群落，在紧邻大陆的浅近岸带发育尤为繁盛，且可能直接或间接依赖于注入海湾的淡水输入。相较于海湾深水区，多数小型饵料鱼在浅近岸水域的种群丰度更高。具有商业开发价值的粉红虾与蓝蟹同样分布于比斯坎湾西部近岸海域。真虾类（Caridean shrimps）是底上生物群落（epifauna）的另一重要组成部分。底上生物群落是灰笛鲷、斑点海鳟与大梭鱼的直接食物来源，同时也是通往鳄鱼等更高营养级物种的食物网关键环节。当比斯坎湾滨海湿地工程启动后，该群落将最先发生改变。为给评估CERP提供基准数据，我们需要对该群落开展动态特征解析，并阐明其各组成组分沿岸线的变化规律。
从群落生态学视角初步审视我们的采样数据时，我们聚焦于明确两个核心问题：（1）空间距离彼此最近的采样点位，其物种组成是否更为相似；（2）具有相似盐度需求的物种，其地理分布是否具有一致性。我们通过聚类分析与多维尺度分析对数据集进行了探究，以达成上述研究目标。