The Structure and Distribution of Benthic Communities on a Shallow Seamount (Cobb Seamount, Northeast Pacific Ocean)

Abstract

Partially owing to their isolation and remote distribution, research on seamounts is still in its infancy, with few comprehensive datasets and empirical evidence supporting or refuting prevailing ecological paradigms. As anthropogenic activity in the high seas increases, so does the need for better understanding of seamount ecosystems and factors that influence the distribution of sensitive benthic communities. This study used quantitative community analyses to detail the structure, diversity, and distribution of benthic mega-epifauna communities on Cobb Seamount, a shallow seamount in the Northeast Pacific Ocean. Underwater vehicles were used to visually survey the benthos and seafloor in ~1600 images (~5 m2 in size) between 34 and 1154 m depth. The analyses of 74 taxa from 11 phyla resulted in the identification of nine communities. Each community was typified by taxa considered to provide biological structure and/or be a primary producer. The majority of the community-defining taxa were either cold-water corals, sponges, or algae. Communities were generally distributed as bands encircling the seamount, and depth was consistently shown to be the strongest environmental proxy of the community-structuring processes. The remaining variability in community structure was partially explained by substrate type, rugosity, and slope. The study used environmental metrics, derived from ship-based multibeam bathymetry, to model the distribution of communities on the seamount. This model was successfully applied to map the distribution of communities on a 220 km2 region of Cobb Seamount. The results of the study support the paradigms that seamounts are diversity 'hotspots', that the majority of seamount communities are at risk to disturbance from bottom fishing, and that seamounts are refugia for biota, while refuting the idea that seamounts have high endemism.

Benthic habitat modelling and mapping as a conservation tool for marine protected areas: A seamount in the western Mediterranean

“…Fournier, Barbet‐Massin, Rome, & Courchamp, ; Stirling, Scott, & Wright, ). Depth and slope have been cited among the main environmental predictors associated with the zonation of benthic communities on seamounts (De la Torriente et al, ; Du Preez, Curtis, & Clarke, ; McClain & Lundsten, ; Serrano et al, ). Distributed as depth‐regulated bands, these assemblages or habitat structure patterns are likely to be a combination of suitable ecological conditions and local recruitment processes (De la Torriente et al, ).…”

Comparing eDNA metabarcoding and species collection for documenting Arctic metazoan biodiversity

“…The sum of the detections for each genus (i.e., presence/absence) has been combined for all primer sets variable seabed characteristics, which play an important role in distribution of megafauna as they impact several factors, including larval settlement, anchorages, and shelter (Kedra, Renaud, Andrade, Goszczko, & Ambrose, 2013;Preez, Curtis, & Clarke, 2016). The broader range of biodiversity dissimilarities observed among benthic communities may be explained by highly F I G U R E 7 Relative abundance of organisms obtained with eDNA and species collection within Churchill, Deception Bay, and Iqaluit ports by life history type.…”

“…Species collection for benthos includes benthic trawls, Van Veen grabs, and cores; plankton includes vertical and oblique pelagic plankton net tows. The sum of the detections for each genus (i.e., presence/absence) has been combined for all primer sets variable seabed characteristics, which play an important role in distribution of megafauna as they impact several factors, including larval settlement, anchorages, and shelter (Kedra, Renaud, Andrade, Goszczko, & Ambrose, 2013;Preez, Curtis, & Clarke, 2016). In contrast, zooplankton experience less variation in their habitat, due to the greater homogeneity of the water column relative to benthic substrates (Angel, 1993;Gray, 1997).…”

Unified Geomorphological Analysis Workflows with Benthic Terrain Modeler

“…Similar to Friedman et al [42], ACR evaluates surface ruggedness using a ratio of contoured area (surface area) to the area of a plane of best fit (POBF), where the POBF is a function of the boundary data. By using a POBF rather than a horizontal plane to determine planar area, rugosity is decoupled from slope at the scale of the surface, and is being adopted as an improved measure of surface roughness [44]. DuPreez [44] provides two three dimensional methods of deriving ACR that are independent of data dimensionality and scale; both are supported by BTM.…”

“…By using a POBF rather than a horizontal plane to determine planar area, rugosity is decoupled from slope at the scale of the surface, and is being adopted as an improved measure of surface roughness [44]. DuPreez [44] provides two three dimensional methods of deriving ACR that are independent of data dimensionality and scale; both are supported by BTM.…”