McClainetal(2011)

Data for bivalves from the Northeast Pacific and Northwest Atlantic were collected through an extensive search of the primary literature and online databases resulting in complete information for 1,578 species from 75 families. Substantial information came from Desbruyeres et al. (2006), Malacolog v. 4.1.1 (Rosenberg 2009), and Coal et al. (2000). The data collected include: taxonomic information from the subclass to species; synonymies; maximum and minimum water depth in meters; maximum and minimum latitude; maximum reported shell length, width, and height in millimeters; habitat type; and ocean basin. Habitat type was broken into fine grain, coarse grain, sediment generalist, hard substrate, hydrothermal vent, methane seep, seamount, wood fall, whale fall, reducing generalist (a generalist on vents, seeps, wood falls, or whale falls) and other, which were primarily made up of commensal bivalves. | Data for gastropods of the Northwest Atlantic were derived from Malacolog v. 4.1.1 (Rosenberg 2009) resulting in data for 3,350 species from 112 families. The data collected included: taxonomic information from the subclass to species; maximum and minimum water depth in meters; maximum and minimum latitude; and maximum reported shell length. | Approximate biovolume for each species was calculated as length*height2 of the shell. In the absence of both length and height measurements, missing measurements were calculated from length:height ratios based on raw measurements from ImageJ v. 1.42 taken from the best available picture for each species from the literature or online collections. | The chemical energy available to the mollusks was estimated as particulate organic carbon (POC) flux (g of C m-2 year-1) based on the Lutz et al. (2007) model. The model utilizes empirically derived sediment trap POC flux estimates compared to remotely sensed estimates of net primary production (NPP) and sea surface temperature (SST). For each species, we quantified the mean, median, and standard deviation of carbon flux over their known latitudinal and depth ranges. Data from each species were manipulated using ArcGIS Workstation 10. We created a GIS coverage for each species’ north-south range extent. This was overlaid upon bathymetry data (GEBCO 08, 30 arc-second grid, September 2010 release, www.gebco.org) to limit each species’ distribution to their recorded depth range. To obtain the carbon flux values, each species’ range was overlaid upon the Lutz et al. (2007) model, with values exported to a text file. Values from each species were compiled into a single data file. | In some cases, because of the coarseness of the depth and carbon flux GIS grids and the small biogeographic ranges of some of the bivalves here, we slightly extended species ranges in order to obtain carbon flux data. This ensured that matching cells in the GIS grids would be found for each species. The smallest latitudinal extent for any species with small ranges was set at 1 degree. Species recorded from a single depth, or very narrow depths were also expanded. All species found at depths less than 10 m were adjusted to a minimum depth range of 10 m. Species at depths up to 20 m were adjusted so that their minimum depth range was 10 m, with an equal amount added to the minimum and maximum depth. Depth ranges from 20-49 m were adjusted to have a 20 m minimum depth range, 50-199 m to 40 m, 200-999 to 100 m, and >1000 m to 200 m. The grade of the continental shelf is low and thus depth ranges changes were limited to shorter intervals to prevent making biogeographic ranges substantially larger.

本数据集涉及东北太平洋与西北大西洋的双壳类（bivalves）数据，通过全面检索核心学术文献与在线数据库完成采集，最终获取75科共计1578个物种的完整信息。核心数据来源包括Desbruyeres等（2006）、Malacolog v.4.1.1（Rosenberg 2009）以及Coal等（2000）。所采集的数据涵盖：从亚纲到物种级的分类学信息、同物异名、以米为单位的最大与最小水深、最大与最小纬度、以毫米为单位的已报道最大壳长、壳宽与壳高、栖息地类型以及洋盆。栖息地类型细分为细颗粒沉积物、粗颗粒沉积物、沉积物广适种、硬质基质、热液喷口、甲烷冷泉、海山、木落物、鲸落、还原环境广适种（即可在热液喷口、甲烷冷泉、木落物或鲸落环境中生存的广适类群）及其他类群，后者主要包含共生双壳类。
西北大西洋的腹足类（gastropods）数据则源自Malacolog v.4.1.1（Rosenberg 2009），最终获取112科共计3350个物种的数据。所采集的数据涵盖：从亚纲到物种级的分类学信息、以米为单位的最大与最小水深、最大与最小纬度，以及已报道的最大壳长。
每个物种的近似生物体积通过公式「壳长×壳高²」计算得到。当同时缺乏壳长与壳高的实测数据时，缺失值将基于ImageJ v.1.42对文献或在线馆藏中各物种最优图片的原始测量结果推导得到的长-高比进行估算。
软体动物可利用的化学能以颗粒有机碳（particulate organic carbon, POC）通量（单位：g C m⁻² year⁻¹）进行估算，该估算基于Lutz等（2007）提出的模型。该模型将经验推导的沉积物捕获器POC通量估算值，与遥感获取的净初级生产力（net primary production, NPP）及海表温度（sea surface temperature, SST）估算值相结合。针对每个物种，我们量化了其已知纬度与深度范围内的碳通量均值、中位数与标准差。所有物种数据均通过ArcGIS Workstation 10进行处理：首先为每个物种的南北分布范围创建GIS覆盖图层，将其与水深地形数据（GEBCO 08，30弧秒网格，2010年9月发布，www.gebco.org）叠加，以将每个物种的分布限制在其记录的水深范围内；随后将每个物种的分布范围叠加至Lutz等（2007）的模型图层，导出碳通量数值至文本文件，并将所有物种的数值整合至单个数据文件中。
在部分案例中，由于水深与碳通量GIS网格的分辨率较低，且部分双壳类的生物地理分布范围较小，我们小幅扩展了物种分布范围以获取碳通量数据，确保每个物种均可在GIS网格中匹配到对应单元格。对于分布范围极小的物种，其最小纬度跨度被设定为1°。仅记录单一水深或极窄水深范围的物种，其水深范围也进行了扩展：所有水深小于10 m的物种，其最小水深范围被调整为10 m；水深不超过20 m的物种，其最小水深被调整为10 m，并对最小与最大水深同时增加等量数值；水深范围为20~49 m的物种，其水深跨度被调整为20 m；50~199 m调整为40 m跨度；200~999 m调整为100 m跨度；大于1000 m则调整为200 m跨度。由于大陆架坡度较低，因此水深范围的调整均采用较短的间隔，以避免大幅扩大物种的生物地理分布范围。