Bathyal demersal fishes of the Charlie-Gibbs Fracture Zone region (49°–54°N) of the Mid-Atlantic Ridge : III. Results from remotely operated vehicle (ROV) video transects

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Links between deep-sea respiration and community dynamics

It has been challenging to establish the mechanisms that link ecosystem functioning to environmental and resource variation, as well as community structure, composition and compensatory dynamics. A compelling hypothesis of compensatory dynamics, known as 'zero-sum' dynamics, is framed in terms of energy resource and demand units, where there is an inverse link between the number of individuals in a community and the mean individual metabolic rate. However, body-size energy distributions that are non-uniform suggest a niche advantage at a particular size class, which suggests a limit to which metabolism can explain community structuring. Since 1989, the composition and structure of abyssal seafloor communities in the northeast Pacific and northeast Atlantic have varied inter-annually with links to climate and resource variation. Here, for the first time, class and mass-specific individual respiration rates were examined along with resource supply and time series of density and biomass data of the dominant abyssal megafauna, echinoderms. Both sites had inverse relationships between density and mean individual metabolic rate. We found fourfold variation in echinoderm respiration over inter-annual timescales at both sites, which were linked to shifts in species composition and structure. In the north-eastern Pacific, the respiration of mobile surface deposit feeding echinoderms was positively linked to climate-driven particulate organic carbon fluxes with a temporal lag of about one year, respiring about 1-6% of the annual particulate organic carbon flux

New and Poorly Known Species of Peniagone (Holothuroidea, Elpidiidae) from the Northwest Pacific Ocean with Discussion on Phylogeny of the Genus

The northwest Pacific fauna of Peniagone includes at least seven species. In the present study we considered the following six species: Peniagone dubia and P. mus are re-described, P. minuta and P. saveljevae are described as new to science, additional information is provided on P. vitrea and P. cf. purpurea. Peniagone japonica was not included in the analysis. A potentially new species Peniagone sp. “miniatura” was distinguished based on morphological and molecular data but not formally described due to insufficient material. In the northwest Pacific, the species of Peniagone are distributed from 2400 to 8200 m. The bathymetric range of most of the species is narrow except for P. mus being also one of the deepest representatives of the genus. Only one species, P. vitrea, is known outside the northwest Pacific region. Partial sequences of COI and 16S rDNA were obtained for provisionally ten species of the genus (four of them from the northwest Pacific) and two other species of Elpidiidae which were used as an outgroup in phylogenetic analyses. The phylogenetic analyses results suggest that the northwest Pacific species of Peniagone are not closely related.publishedVersio

Holothuroidea of the Charlie Gibbs Fracture Zone area, northern Mid-Atlantic Ridge

Holothurians are among the most species-rich taxa in the megabenthos on the northern Mid-Atlantic Ridge at depths of 2200–3700 m. Extensive new collections of 32 holothurian species were made in 2007–2010 in the Charlie Gibbs Fracture Zone area as part of the ECOMAR project. New material includes samples taken using a trawl and the ROV Isis. Samples and in situ observations from the ROV were of particular value because the morphological details of a number of holothurian species could be clarified. Many of these species are gelatinous and fragile and were damaged in trawls. Three species of elasipodid holothurians are described as new to science. An annotated check-list of all species of deep-sea holothurians collected in the Charlie Gibbs Fracture Zone area is provided. The checklist includes synonyms, distribution data and morphological descriptions as well as photographs taken in situ and in vivo. Ecological remarks are given for some species

Swimming deep-sea holothurians (Echinodermata: Holothuroidea) on the northern Mid-Atlantic Ridge

The ability to swim was recorded in 17 of 32 species of deep-sea holothurians during the RRS James CookECOMAR cruise in 2010 to the Mid-Atlantic Ridge. Holothurians were observed, photographed, and video recorded using the ROV Isis at four sites around the Charlie-Gibbs Fracture Zone at approximate depths of 2,200–2,800 m. For eleven species swimming is reported for the first time. A number of swimming species were observed on rocks, cliffs and steep slopes with taluses. These habitats are unusual for deep-sea holothurians, which are traditionally common on flat areas with soft sediment rich in detritus. Three species were found exclusively on cliffs. Swimming may provide an advantage in cliff habitats that are inaccessible to most epibenthic deposit-feeders

Impact of a web-supported programme of Constraint Induced Therapy following stroke (LifeCIT)

Background: upper extremity (UE) movement is often compromised following a stroke. Constraint Induced Therapy (CIT) is an evidence-based intensive intervention (1) which involves people with stoke practicing activites with their affected hand whilst wearing a mitt on their other hand, but it relies on intensive therapy. A study trialling CIT in a community setting without a therapist present found key barriers to be lack of motivation to wear the mitt and comply with the exercise programme (2). A web supported CIT system (LifeCIT) for UE stroke rehabilitation was developed to address this barrier. Objective: to evaluate the impact of using LifeCIT for UE stroke rehabilitation compared to usual care in subacute/chronic stroke patients at home.Methods: subacute/chronic stroke patients were randomized into a three week intervention consisting of LifeCIT or control groups. UE impairment and function were assessed with the Motor activity log (MAL), Fugl-Meyer (FMA-UE) and Wolf Motor Function Test (WMFT) pre and post intervention and at a six month follow-up. Results: sixteen patients completed the trial. Between group differences, favouring the LifeCIT group in MAL (AOU and QOU) and WMFT (FAS) were identified post intervention (ANCOVA) and controlled for baseline clinical scores, Orpington score and Sub-acute/chronic. Mean improvement in the LifeCIT group MALfrom baseline to post treatment (1.02 AOU and QOU) and at six months (0.6 AOU and QOU) was above the minimally clinically important difference (MCID) for the MAL (MCID = 0.5) Improvement in the LifeCIT group WMFT (FAS) met MCID from baseline to post intervention (0.35) and at six months (0.3) FAS MCID=0.2 - 0.4. Interview data confirmed positive acceptance of LifeCIT. Conclusion: use of LifeCIT in the community improved UE function in subacute/chronic stroke patients following a three week intervention and at a six month follow-up, suggesting a larger scale study should be run. References(1) Wolf SL, Winstein CJ, Miller JP, Taub E, Uswatte G, Morris D et al. Effect of constraint-induced movement therapy on upper extremity function 3 to 9 months after stroke: the EXCITE randomized clinical trial. Journal of the American Medical Association 2006; 296(17):2095-2104.(2) Burns A, Burridge J.H., Pickering R.M. Does the use of a constraint mitten to encourage use of the hemiplegic upper limb improve arm function in adults with subacute stroke? Clin Rehabil 2007; 21:895-904.Supported by the National Institute for Health Research (NIHR) Research for Patient Benefit (RFPB) <br/

New and Poorly Known Species of Peniagone (Holothuroidea, Elpidiidae) from the Northwest Pacific Ocean with Discussion on Phylogeny of the Genus

The northwest Pacific fauna of Peniagone includes at least seven species. In the present study we considered the following six species: Peniagone dubia and P. mus are re-described, P. minuta and P. saveljevae are described as new to science, additional information is provided on P. vitrea and P. cf. purpurea. Peniagone japonica was not included in the analysis. A potentially new species Peniagone sp. “miniatura” was distinguished based on morphological and molecular data but not formally described due to insufficient material. In the northwest Pacific, the species of Peniagone are distributed from 2400 to 8200 m. The bathymetric range of most of the species is narrow except for P. mus being also one of the deepest representatives of the genus. Only one species, P. vitrea, is known outside the northwest Pacific region. Partial sequences of COI and 16S rDNA were obtained for provisionally ten species of the genus (four of them from the northwest Pacific) and two other species of Elpidiidae which were used as an outgroup in phylogenetic analyses. The phylogenetic analyses results suggest that the northwest Pacific species of Peniagone are not closely related

Bathyal benthic megafauna from the Mid‐Atlantic Ridge in the region of the Charlie-Gibbs fracture zone based on remotely operated vehicle observations

Mid-ocean ridges are important geological features that cover around 33% of the global ocean floor, increase environmental heterogeneity on a regional scale and influence benthic community ecology. Benthic communities at the Mid-Atlantic Ridge (MAR) were studied at four contrasting sites, located east and west of the ridge, which were further separated into northern (54°N) and southern (48°N) sites by the Charlie-Gibbs Fracture Zone (CGFZ) and the Sub-Polar Front (SPF). The MAR in the CCFZ region area had flat areas surrounded by gentle slopes between rocky cliffs. A total of 32 remotely operated vehicle video transects (32,000 m2 of seafloor) were surveyed on the flat areas and sedimented slopes (10°). In total, 154 distinct taxonomic units were identified (from 9 phyla) across all sites. The sediments of the flat and sloping sites were generally similar, but differences were seen in the community composition and faunal abundance (~ 4 times higher in the flat sites, except at the northwestern site). Significant differences in abundance were observed between sites (highest in the northern sites). The two northern sites had distinct community compositions, while the two southern sites were similar. This suggests that the MAR acts as a stronger barrier between communities north of the CGFZ than it does to the south. There was high heterogeneity between transects and it was not possible to identify general drivers for the benthic megafauna at the MAR. Our results emphasize the limited knowledge of this vast system with its unique benthic megafauna

Bathyal benthic megafauna from the Mid‐Atlantic Ridge in the region of the Charlie-Gibbs fracture zone based on remotely operated vehicle observations

Mid-ocean ridges are important geological features that cover around 33% of the global ocean floor, increase environmental heterogeneity on a regional scale and influence benthic community ecology. Benthic communities at the Mid-Atlantic Ridge (MAR) were studied at four contrasting sites, located east and west of the ridge, which were further separated into northern (54°N) and southern (48°N) sites by the Charlie-Gibbs Fracture Zone (CGFZ) and the Sub-Polar Front (SPF). The MAR in the CCFZ region area had flat areas surrounded by gentle slopes between rocky cliffs. A total of 32 remotely operated vehicle video transects (32,000 m2 of seafloor) were surveyed on the flat areas and sedimented slopes (10°). In total, 154 distinct taxonomic units were identified (from 9 phyla) across all sites. The sediments of the flat and sloping sites were generally similar, but differences were seen in the community composition and faunal abundance (~ 4 times higher in the flat sites, except at the northwestern site). Significant differences in abundance were observed between sites (highest in the northern sites). The two northern sites had distinct community compositions, while the two southern sites were similar. This suggests that the MAR acts as a stronger barrier between communities north of the CGFZ than it does to the south. There was high heterogeneity between transects and it was not possible to identify general drivers for the benthic megafauna at the MAR. Our results emphasize the limited knowledge of this vast system with its unique benthic megafauna.</p

Trawled megafaunal invertebrate assemblages from bathyal depth of the Mid-Atlantic Ridge (48°–54°N)

We investigated the effects of contrasting surface primary production on the benthic invertebrate megafauna at four sites on the Mid-Atlantic Ridge. The sites, designated NW, NE, SW and SE, were located to the west and east of the Ridge axis and to the north and south of the Charlie–Gibbs Fracture Zone. Benthic megafauna were sampled in 2007 and 2009 with a semi-balloon otter trawl, at a target depth of 2,500 m. The total biomass and density of major taxonomic groups did not differ significantly between sites, despite those to the north being characterised by greater surface productivity than those to the south. However, the density and biomass of individual taxonomic groups, as well as diversity and body size, all showed significant differences between sites. Diversity was highest at the SE, and lowest at the NE site. Most species were larger to the north. Community composition was significantly different between all sites, with the greatest number of unique species found at the SE, and noticeably fewer unique species at the northern sites. There was no clear correlation between the surface productivity and community structure, suggesting complex ecological controls on the communities. It is speculated that, in addition to the energy supply, drivers such as strong currents and sediment characteristics, play an important role in shaping the communities at the different sites. To what extent the ridge acts as a dispersal barrier for benthic invertebrate fauna remains unclear. However, high numbers of species unique to the southern site suggest a limited dispersal between the northern and southern areas