Vertical Distribution of Deep-Pelagic (0-3000 M) Fishes Over the Charlie-Gibbs Fracture Zone Region of the Northern Mid-Atlantic Ridge

Only a tiny fraction of the world’s largest volume of living space, the ocean’s midwater biome, has ever been sampled. As part of the International Census of Marine Life field project, MAR-ECO, a discrete-depth trawling survey was conducted in 2009 aboard the NOAA ship Henry B. Bigelow to examine pelagic assemblage structure and distribution over the Charlie-Gibbs Fracture Zone of the northern Mid-Atlantic Ridge. The bottom topography in this region ranges from 4500 m in the channel to 700-800 m on top of adjacent seamounts. Sampling was conducted at 11 stations from 0-3000 m using a Norwegian “Krill” trawl with five codends that opened and closed by a pre-programmed timer. Seventy-five species of fishes were collected, with a maximum species diversity and biomass being observed between 700-1900 m. Other key features observed were a strong diel migrating component and frequent captures of putative bathypelagic fishes, shrimps, and cephalopods in the epipelagic zone (0-200 m). The results of MAR-ECO sampling show patterns unlike those previously reported for open ocean ecosystems

Deep-Sea Fishes of the Mid-Atlantic Ridge: Results of the 2009 Henry Bigelow Expedition

As part of an ongoing study of the northern Mid-Atlantic Ridge biodiversity and ecology (CoML field project MAR-ECO), a detailed survey of the pelagic and demersal fishes in the region of the Charlie-Gibbs Fracture Zone (~ 600 n.m. south of Greenland) was conducted. A total of 17181 pelagic fishes (92 spp., 35 families) were sampled from 0-3000+ m, with the Myctophidae the most species-rich. The bristlemouth Cyclothone microdon was by far the dominant species in numbers (82% of total), while the sawtooth eel Serrivomer beani dominated biomass (27%). A total of 441 deep-demersal fishes (28 spp., 13 families) were sampled from 1872-3527 m, with the Macrouridae and Alepocephalidae comprising half of species numbers. The abyssal halosaur Halosauropsis macrochir was most abundant, while the abyssal grenadier Coryphaenoides armatus contributed the most biomass. Remarkable among the pelagic fish data were routine shallow catches of bathypelagic fishes (see A.B. Cook et al., this volume), and among the demersal fishes were the large size of the individuals, above or near the maximum known for many species. The high species number relative to sample number portends the enhanced deep-sea biodiversity about abrupt topographic features, while the lack of asymptote of species number versus sampling effort underscores our incomplete inventory of this biodiversity

Additional Records of Deep-Sea Fishes from Off Greater New England

Recent review of deep-sea fishes captured deeper than 200m off greater New England, from the Scotian Shelf at 44°N to the southern New England Shelf at about 38°N, documented 591 species. Subsequent trawling activity and reviews of deep-sea taxa occurring in the area have revealed that an additional 40 species in habit the deep sea off New England. Thirty-two of these new records were captured in the course of 44 bottom trawls and 94 mid-water trawls over or in the proximity of Bear Seamount (39°55\u27N, 67°30\u27W). Five of the 40 species have been described as new to science, at least in part from material taken in the study area. In addition to describing such information as specimen size and position, depth, and date of capture, errors made in the previous study of deep-sea fishes in the area are identified and corrected

Deep-Pelagic (0-3000 m) Fish Assemblage Structure over the Mid-Atlantic Ridge Relative to the North Atlantic Subpolar Front

Only a tiny fraction of the world\u27s largest volume of living space, the ocean\u27s mid-water region, has ever been sampled. It is one of the least understood areas on earth, so as part of the International Census of Marine Life field project, MAR-ECO, a discrete-depth trawling survey was conducted in 2009 aboard the NOAA ship Henry Bigelow to examine pelagic assemblage structure and distribution over the Charlie-Gibbs Fracture Zone (CGFZ) of the northern Mid-Atlantic Ridge. The survey consisted of 11 stations divided into two transects, one northwest and one southeast of the CGFZ, which roughly coincides with the Subpolar Front. Sampling was conducted from 0-3000 m using a Norwegian Krill trawl with five codends that opened and closed by a preprogrammed timer. Seventy-five species of fish (29 families, 14 orders) were collected. Maximum species diversity was observed between 700-1900 m. Other key features observed were a strong diel migrating component and frequent captures of putative bathypelagic fishes in the epipelagic zone (0-200 m). Fish assemblage structure and distribution will be discussed as a function of physical oceanographic features. The results of this expedition have increased our knowledge about oceanic community structure in association with mid-ocean ridge systems and mesoscale circulation patterns

The Emergence and Evolution of the Multidimensional Organization

The article discusses multidimensional organizations and the evolution of complex organizations. The six characteristics of multidimensional organizations, disadvantages of the successful organizational structure that is categorized as a multidivisional, multi-unit or M-form, research by the Foundation for Management Studies which suggests that synergies across business divisions can be exploited by the M-form, a team approach to creating economic value, examples of multidimensional firms such as PricewaterhouseCoopers, and a comparison of various organization types including the matrix form are mentioned

Role of Mesoscale Eddies in Cross-Frontal Transport of Heat and Biogeochemical Tracers in the Southern Ocean

This study examines the role of processes transporting tracers across the Polar Front (PF) in the depth interval between the surface and major topographic sills, which this study refers to as the “PF core.” A preindustrial control simulation of an eddying climate model coupled to a biogeochemical model [GFDL Climate Model, version 2.6 (CM2.6)– simplified version of the Biogeochemistry with Light Iron Nutrients and Gas (miniBLING) 0.1° ocean model] is used to investigate the transport of heat, carbon, oxygen, and phosphate across the PF core, with a particular focus on the role of mesoscale eddies. The authors find that the total transport across the PF core results from a ubiquitous Ekman transport that drives the upwelled tracers to the north and a localized opposing eddy transport that induces tracer leakages to the south at major topographic obstacles. In the Ekman layer, the southward eddy transport only partially compensates the northward Ekman transport, while below the Ekman layer, the southward eddy transport dominates the total transport but remains much smaller in magnitude than the near-surface northward transport. Most of the southward branch of the total transport is achieved below the PF core, mainly through geostrophic currents. This study finds that the eddy-diffusive transport reinforces the southward eddy-advective transport for carbon and heat, and opposes it for oxygen and phosphate. Eddy-advective transport is likely to be the leading-order component of eddy-induced transport for all four tracers. However, eddy-diffusive transport may provide a significant contribution to the southward eddy heat transport due to strong along-isopycnal temperature gradients