Data from: Abiotic proxies for predictive mapping of near-shore benthic assemblages: implications for marine spatial planning

Marine spatial planning (MSP) should assist managers in guiding human activities towards sustainable practices and in minimizing user-conflicts in our oceans. A necessary first step is to quantify spatial patterns of marine assemblages in order to understand the ecosystem’s structure, function, and services. However, the large spatial scale, high economic value, and density of human activities in near-shore habitats often makes quantifying this component of marine ecosystems especially daunting. To address this challenge, we developed an assessment method that employs abiotic proxies to rapidly characterize marine assemblages in near-shore benthic environments with relatively high resolution. We evaluated this assessment method along 300 km of the State of Maine’s coastal shelf (< 100m depth)—a zone where high densities of buoyed lobster traps typically preclude extensive surveys by towed sampling gear (i.e., otter trawls). During the summer months of 2010-2013, we implemented a stratified-random survey using a small remotely operated vehicle that allowed us to work around lobster buoys and to quantify all benthic megafauna to species. Stratifying by substrate, depth, and coastal water masses, we found that abiotic variables explained a significant portion of variance (37- 59%) in benthic species composition, diversity, biomass and economic value. Generally, the density, diversity, and biomass of assemblages significantly increased with the substrate complexity (i.e., from sand-mud to ledge). The diversity, biomass and economic value of assemblages also decreased significantly with increasing depth. Lastly demersal fish densities, sessile invertebrate densities, species diversity, and assemblage biomass increased from east to west, while the abundance of mobile invertebrates and economic value decreased, corresponding mainly to the contrasting water-mass characteristics of the Maine Coastal Current system (i.e., summertime current direction, speed, and temperature). Integrating modeled predictions with existing GIS layers for abiotic conditions allowed us to scale up important assemblage attributes to define key foundational ecological principles of MSP and to find priority regions where some bottom-disturbing activities would have minimal impact to benthic assemblages. We conclude that abiotic proxies can be strong forcing functions for the assembly of marine communities and therefore useful tools for spatial extrapolations of marine assemblages in congested (heavily used) near-shore habitats.海洋空间规划（Marine Spatial Planning, MSP）旨在助力管理者引导人类活动转向可持续模式，并最大限度减少海洋中的用户冲突。量化海洋生物群落的空间格局，进而理解生态系统的结构、功能与服务，是开展相关工作的必要前提。然而，近岸生境中广阔的空间尺度、极高的经济价值与人类活动密度，使得量化海洋生态系统的这一组成部分尤为困难。为应对这一挑战，我们开发了一种评估方法，通过非生物替代指标（abiotic proxies）实现近岸底栖环境中海洋生物群落的快速、高分辨率刻画。 我们在缅因州（State of Maine）300公里长的近岸大陆架（水深<100米）区域对该评估方法进行了验证——该区域内高密度的带浮标龙虾笼通常会阻碍拖曳采样设备（即底拖网，otter trawls）开展大规模调查。2010-2013年夏季期间，我们借助小型遥控无人潜水器（remotely operated vehicle）开展了分层随机调查，该设备可绕行龙虾浮标，并能对所有底栖大型动物进行物种级别的量化。 基于底质、水深与近岸水团进行分层后，我们发现非生物变量能够解释底栖物种组成、多样性、生物量及经济价值中37%~59%的显著变异。总体而言，生物群落的密度、多样性与生物量随底质复杂度提升（即从沙泥质到岩礁）显著增加。生物群落的多样性、生物量与经济价值也随水深增加而显著下降。最后，底栖鱼类密度、固着无脊椎动物密度、物种多样性及群落生物量自东向西逐渐升高，而移动无脊椎动物丰度与经济价值则呈下降趋势，这主要与缅因沿岸流系统（Maine Coastal Current system）的水团特征差异相关（即夏季海流方向、流速与温度）。 将模型预测结果与现有非生物条件的GIS图层相结合，我们能够将关键群落属性外推至更大尺度，以此明确海洋空间规划（MSP）的核心基础生态原则，并识别出那些底栖干扰活动对底栖生物群落影响最小的优先区域。我们的研究表明，非生物替代指标可作为海洋群落组装的重要驱动因子，因此在人类活动密集的近岸生境中，该指标可作为海洋生物群落空间外推的有效工具。