Frequency of sublethal injury in a deepwater ophiuroid, Ophiacantha bidentata, an important component of western Atlantic Lophelia reef communities

The occurrence and relative abundance of tissue (arm) regeneration in the ophiuroid, Ophiacantha bidentata (Retzius), was examined in individuals collected primarily among colonies of the deep-water coral Lophelia pertusa off the southeastern United States. Seven deep-water coral sites (384–756 m), located between Cape Lookout, NC, and Cape Canaveral, FL, were sampled in June 2004 using a manned submersible. The presence of regenerative tissue was evaluated by visual inspection of each individual ophiuroid, and the proportion of regenerating arms per individual was examined relative to size of individual, geographic location, and depth of collection. Ophiacantha bidentata, the dominant brittle star collected, commonly displayed signs of sublethal injury with over 60% of individuals displaying some evidence of regeneration. These levels of regeneration rival those reported for shallow-water ophiuroids. Larger individuals (\u3e6.5 mm disc size) had a higher incidence of regeneration than smaller individuals. Size of individual and percent of regeneration were negatively correlated with depth. Although O. bidentata was significantly less abundant in southern versus northern sites, ophiuroid abundance did not appear to be influenced by amount or density of coral substratum. Presence of dense aggregations of O. bidentata indicates that they are an important component of the invertebrate assemblage associated with deep-water coral habitat especially in the northern part of the study area. Assuming that observed frequencies of injury and subsequent regeneration represent predation events then dense ophiuroid aggregations in deepwater coral habitats represent an important renewable trophic resource within these communities

Annotated checklist of decapod crustaceans of Atlantic coastal and continental shelf waters of the United States

Volume: 116Start Page: 96End Page: 15

Symphurus prolatinaris, a new species of shallow-water tonguefish (Pleuronectiformes: Cynoglossidae) from the eastern Pacific

Volume: 104Start Page: 448End Page: 45

DEEPEND: Deep-Pelagic Nekton Dynamics of the Gulf of Mexico

The Deepwater Horizon Oil Spill (DWHOS) was primarily a deep-pelagic event. Variable amounts of discharged hydrocarbons reached the ocean surface and/or seafloor, whereas 100% occurred within the water column. Understanding this pelagic habitat is important because about half of all fish species that occur in the Gulf of Mexico (GoM) spend all or part of their lives in the open ocean. Most mesopelagic (200-1000 m depth) species of fishes vertically migrate each night to feed in epipelagic (0-200 m) depths and return to deep water during the day. This behavior affects rapid cycling of natural and anthropogenic material in the water column. Deep-pelagic fishes are prey for gamefishes, seabirds, and marine mammals. Given the steady growth of oil exploration and operations, the likelihood of future spills emphasizes the need to document acute and chronic effects on pelagic fauna. The DEEPEND (Deep-Pelagic Nekton Dynamics) Consortium will conduct a 3-year sampling and analysis program that builds on two intensive NOAA-supported surveys during 2010-11. DEEPEND will focus on short-term and long-term timescales to appraise the dynamic nature of communities using a suite of integrated approaches. These investigations include: 1) a direct assessment of GoM deep-pelagic community structure including the physical and biological drivers of this structure; 2) a time-series analysis/comparison of biophysical data from the years 2010- 2011 and 2015-2017; 3) a time-series examination of differences in genetic diversity among key species; and 4) a biogeochemical analysis of the effect of DWHOS on pelagic biota

Exploration of the Canyon-Incised Continental Margin of the Northeastern United States Reveals Dynamic Habitats and Diverse Communities

<div><p>The continental margin off the northeastern United States (NEUS) contains numerous, topographically complex features that increase habitat heterogeneity across the region. However, the majority of these rugged features have never been surveyed, particularly using direct observations. During summer 2013, 31 Remotely-Operated Vehicle (ROV) dives were conducted from 494 to 3271 m depth across a variety of seafloor features to document communities and to infer geological processes that produced such features. The ROV surveyed six broad-scale habitat features, consisting of shelf-breaching canyons, slope-sourced canyons, inter-canyon areas, open-slope/landslide-scar areas, hydrocarbon seeps, and Mytilus Seamount. Four previously unknown chemosynthetic communities dominated by <i>Bathymodiolus</i> mussels were documented. Seafloor methane hydrate was observed at two seep sites. Multivariate analyses indicated that depth and broad-scale habitat significantly influenced megafaunal coral (58 taxa), demersal fish (69 taxa), and decapod crustacean (34 taxa) assemblages. Species richness of fishes and crustaceans significantly declined with depth, while there was no relationship between coral richness and depth. Turnover in assemblage structure occurred on the middle to lower slope at the approximate boundaries of water masses found previously in the region. Coral species richness was also an important variable explaining variation in fish and crustacean assemblages. Coral diversity may serve as an indicator of habitat suitability and variation in available niche diversity for these taxonomic groups. Our surveys added 24 putative coral species and three fishes to the known regional fauna, including the black coral <i>Telopathes magna</i>, the octocoral <i>Metallogorgia melanotrichos</i> and the fishes <i>Gaidropsarus argentatus</i>, <i>Guttigadus latifrons</i>, and <i>Lepidion guentheri</i>. Marine litter was observed on 81% of the dives, with at least 12 coral colonies entangled in debris. While initial exploration revealed the NEUS region to be both geologically dynamic and biologically diverse, further research into the abiotic conditions and the biotic interactions that influence species abundance and distribution is needed.</p></div

Understanding deep-pelagic ecosystem dynamics: A new research initiative in the Gulf of Mexico (DEEPEND).

The Deepwater Horizon oil spill has demonstrated a worst-case scenario oil disaster at great depths, while also highlighting the paucity of baseline data for deep-ocean ecosystems in general. Without such data, and information on the drivers of natural variability in these systems, impacts from these activities are difficult or impossible to assess. Here we introduce a new research initiative, DEEPEND (Deep-Pelagic Nekton Dynamics of the Gulf of Mexico), whose mission will be to characterize the oceanic ecosystems of the Gulf of Mexico to infer baseline biophysical conditions in the water column. This information will establish a time-series with which natural and anthropogenic changes can be detected. The DEEPEND Consortium will conduct a 3-year (2015–2017) sampling and analysis program that will focus on short-term (sub-generational) and long-term (evolutionary) timescales to appraise the dynamic nature of communities using a suite of integrated approaches. These investigations include: (1) a direct assessment (taxonomic and genetic) of GoM deep-pelagic community structure, from microbes to nekton, with simultaneous investigation of the physical and biological drivers of this structure; (2) examination of the patterns of deep-scattering layer distributions in response to time (day vs. night) and oceanographic conditions; (3) a timeseries analysis/modeling of biophysical data from 2010–2017; (4) a time-series examination of differences in genetic diversity among key species; (5) biogeochemical assays of the effect of DWHOS on shallow- and deep-pelagic biota (otolith microchemistry and whole-body PAH analyses); and (6) traditional and isotope-based trophic analyses to examine the primary vectors in a food web context

Total number of morphospecies observed across six broad-scale habitat features for three taxonomic groups.

<p>^a Straight-line distance travelled over ground was approximated using the measuring tool in ArcMap.</p><p>Depth range and total distance travelled per area are included. Dive numbers are included.</p

Abundance estimates of dominant species in the region.

<p>(A) <i>Paragorgia</i> spp. (B) <i>Primnoa</i>? <i>resedaeformis</i>. (C) <i>Synaphobranchus</i> spp. (D) <i>Neocyttus helgae</i>. (E) <i>Chaceon quinquedens</i>. Circle size corresponds to number observed 10 m^-2 as shown in key inset at lower left of each graph. Black symbols denote dives in which no species were observed. OS/L = Open Slope/Landslide Scar, IS = Inter-canyon Slope, CS = Cold Seep, SC = Slope Canyon, SBC = Shelf-breaching Canyon, SMT = Seamount.</p

Species richness by depth.

<p>(A) corals. (B) fishes. (C) crustaceans. Best-fit linear trend lines are included.</p