The First In Situ Encounter of Gigantura chuni (Giganturidae: Giganturoidei: Aulopiformes: Cyclosquamata: Teleostei), with a Preliminary Investigation of Pair-Bonding

The Gulf of Mexico Scientific and Environmental ROV Partnership using Existing iNdustrial Technology (Gulf SERPENT) Project utilizes industrial work-class ROVs based at oceanic oil and gas facilities for scientific research and exploration. During Gulf SERPENT operations, an ROV documented the first in situ observations of Gigantura chuni at a depth of approximately 900 m in the northern Gulf of Mexico. The fish were identified to genus by the length of the caudal fin ventral lobe relative to standard length, reflectance from crystalline guanine, and relative mouth size to the head length. The width-length ratios suggest G. chuni as the species (approximately 1:5 for adult G. chuni vs. 1:10 for adult G. indica). The videos provided the second known in situ observation of giganturids and the first of G. chuni. The first video clearly shows two individuals in close proximity, with both oriented vertically in the water column; a second video clip shows a single individual at a slightly shallower depth, and also oriented vertically in the water column. An odds ratio comparison for collections of G. chuni and G. indica from the DEEPEND program to fitted theoretical distributions was used to preliminarily analyze the probability of encountering various numbers of individuals in a single-sample effort. Groups of two individuals, and in particular even number groupings, were encountered during the DEEPEND program sampling more often than would be expected based on theoretical distributions for both G. chuni and G. indica suggesting pair-bonding may be a likely reproductive strategy complementing synchronous hermaphroditism in giganturids

Determining dominant scatterers of sound in mixed zooplankton populations

Author Posting. © Acoustical Society of America, 2007. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 122 (2007): 3304-3326, doi:10.1121/1.2793613.High-frequency acoustic scattering techniques have been used to investigate dominant scatterers in mixed zooplankton populations. Volume backscattering was measured in the Gulf of Maine at 43, 120, 200, and 420 kHz. Zooplankton composition and size were determined using net and video sampling techniques, and water properties were determined using conductivity, temperature, and depth sensors. Dominant scatterers have been identified using recently developed scattering models for zooplankton and microstructure. Microstructure generally did not contribute to the scattering. At certain locations, gas-bearing zooplankton, that account for a small fraction of the total abundance and biomass, dominated the scattering at all frequencies. At these locations, acoustically inferred size agreed well with size determined from the net samples. Significant differences between the acoustic, net, and video estimates of abundance for these zooplankton are most likely due to limitations of the net and video techniques. No other type of biological scatterer ever dominated the scattering at all frequencies. Copepods, fluid-like zooplankton that account for most of the abundance and biomass, dominated at select locations only at the highest frequencies. At these locations, acoustically inferred abundance agreed well with net and video estimates. A general approach for the difficult problem of interpreting high-frequency acoustic scattering in mixed zooplankton populations is described.This research was supported in part by the U.S. GLOBEC program, NOAA (Grant nos. NA17RJ1223 and NA67RJ0148), the James S. Cole and Cecily C. Selby Endowed Funds, the Penzance Endowed Fund for Support of Assistant Scientists, and the Adams Chair at the Woods Hole Oceanographic Institution. A selected number of focused experiments were also funded by the ONR (Grant No. N00014-98-1-0362)

Microplastics in mainstem Mississippi River fishes

Microplastics are ubiquitous in Earth’s ecosystems and many efforts have begun to understand their distributions. Large rivers, like the Mississippi River, provide a unique system in which to look at large-scale patterns of microplastic distribution. In this study, we sampled four species of widely-distributed fishes from five sites along the mainstem Mississippi River, from Minnesota to Louisiana, United States. Microplastics were found in all fish species and at all sites; however, microplastics increased in occurrence in the Lower Mississippi River. Fragments were the most common morphologies and polypropylene was the most common polymer detected. We also examined the hypothesis that microplastic loads in fishes increased downstream, but found support for this hypothesis only when examining Largemouth Bass; Flathead Catfish, Shortnose Gar, and Bluegill were all found to have similar microplastic loads along the mainstem Mississippi River. It is clear that microplastics are heterogeneously distributed throughout ecosystems, and further understanding of microplastic distributional patterns and varying species burdens are needed to fully understand threats that microplastics present

Sleep and Fatigue Symptoms in Children and Adolescents With CKD: A Cross-sectional Analysis From the Chronic Kidney Disease in Children (CKiD) Study

Although symptoms of sleepiness and fatigue are common among adults with Chronic Kidney Disease (CKD), little is known about the prevalence of these symptoms in children with CKD

RAPID : research on automated plankton identification

Author Posting. © Oceanography Society, 2007. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 20, 2 (2007): 172-187.When Victor Hensen deployed the first true plankton1 net in 1887, he and his colleagues were attempting to answer three fundamental questions: What planktonic organisms are present in the ocean? How many of each type are present? How does the plankton’s composition change over time? Although answering these questions has remained a central goal of oceanographers, the sophisticated tools available to enumerate planktonic organisms today offer capabilities that Hensen probably could never have imagined.This material is based upon work supported by the National Science Foundation under Grants OCE-0325018, OCE-0324937, OCE-0325167 and OCE-9423471, and the European Union under grants Q5CR-2002-71699, MAS3-ct98-0188, and MAS2-ct92-0015