Macrobenthos of Simmons Bayou and an Adjoining Residential Canal

Species composition, abundance and seasonal variations of benthic macroinvertebrates in Simmons Bayou, Mississippi, and an adjoining dead-end canal were investigated from July 1976 through June 1977. Cluster analysis of the data summed over five stations indicated four major time periods: July, August-November, December-February, and March-June. Polychaetes and oligochaetes were most abundant in the winter and spring, amphipods in the summer, and chironomids in the spring. Temporal changes in abundance of polychaetes, oligochaetes, and chironomids appeared to reflect seasonal reproductive cycles. The peak in amphipod density corresponded with dense growths of Ruppia maritima. Within the dead-end canal, poor water quality and reduced infaunal densities appeared to be limitcd to the deeper water behind the sill

Spatial and Temporal Patterns in the Macrobenthos of St. Louis Bay, Mississippi

Benthic community structure in St. Louis Bay was studied for 23 months. Cluster analyses distinguished two habitats: open water areas and areas near the marshy shores of rivers and bayous. Two groups of “euryhaline opportunistic” species were dominant at the open water stations. Temporal patterns of the “euryhaline opportunists,” which appeared to be controlled by a combination of reproductive pulses and seasonally intense predation, showed that the greatest abundance of macroinfauna occurred during the cooler months with reduced recruitment during the second year. The river-bayou stations were characterized by two groups of “estuarine endemic” species. One of these groups was most abundant in the warmer months and the other in the cooler months. Changes in abundance of the “estuarine endemics” appeared to reflect seasonal cycles

Macrobenthos of Simmons Bayou and an Adjoining Residential Canal

Species composition, abundance and seasonal variations of benthic macroinvertebrates in Simmons Bayou, Mississippi, and an adjoining dead-end canal were investigated from July 1976 through June 1977. Cluster analysis of the data summed over five stations indicated four major time periods: July, August-November, December-February, and March-June. Polychaetes and oligochaetes were most abundant in the winter and spring, amphipods in the summer, and chironomids in the spring. Temporal changes in abundance of polychaetes, oligochaetes, and chironomids appeared to reflect seasonal reproductive cycles. The peak in amphipod density corresponded with dense growths of Ruppia maritima. Within the dead-end canal, poor water quality and reduced infaunal densities appeared to be limitcd to the deeper water behind the sill

Estimates of Harvest Potential and Distribution of the Deep Sea Red Crab, Chaceon quinquedens, in the North Central Gulf of Mexico

Harvest potential, relative abundance, and geographic and bathymetric distribution are discussed for the red crab, Chaceon quinquedens, in the northcentral Gulf of Mexico. Harvest potential is expressed as the number of trapable crabs present on fishing grounds defined as depths ranging from 677 m to 1043 m between 87.5o and 88.5oW longitude. Using various estimates of the effective fishing area (EFA) of a trap, the number of trapable red crabs on the fishing grounds ranged from 3.7 x 106 to 10.7 x 106. Estimatesofcrabnumberssuggest there is a potential for commercial harvest in the northcentral Gulf of Mexico, east of the Mississippi River. However, fishery development must take into consideration the preponderance of females on the defined fishing grounds (MF ratio = 1:2.1) and the high incidence of ovigerous females (~20%) during much of the year. Females generally dominated at all depth strata, but the proportion of males to females increased with depth. Reduced numbers of red crabs were collected off the western Louisiana coast and a shift in depth distribution was found. Minimum upper depth limit for red crabs west of the Mississippi River was 860 m as compared to 677 m east of the River. The known range of C. fenneri is extended to 92o12 W longitude

Estimates of Harvest Potential and Distribution of the Deep Sea Red Crab, Chaceon quinquedens, in the North Central Gulf of Mexico

Harvest potential, relative abundance, and geographic and bathymetric distribution are discussed for the red crab, Chaceon quinquedens, in the northcentral Gulf of Mexico. Harvest potential is expressed as the number of trapable crabs present on fishing grounds defined as depths ranging from 677 m to 1043 m between 87.5o and 88.5oW longitude. Using various estimates of the effective fishing area (EFA) of a trap, the number of trapable red crabs on the fishing grounds ranged from 3.7 x 106 to 10.7 x 106. Estimatesofcrabnumberssuggest there is a potential for commercial harvest in the northcentral Gulf of Mexico, east of the Mississippi River. However, fishery development must take into consideration the preponderance of females on the defined fishing grounds (MF ratio = 1:2.1) and the high incidence of ovigerous females (~20%) during much of the year. Females generally dominated at all depth strata, but the proportion of males to females increased with depth. Reduced numbers of red crabs were collected off the western Louisiana coast and a shift in depth distribution was found. Minimum upper depth limit for red crabs west of the Mississippi River was 860 m as compared to 677 m east of the River. The known range of C. fenneri is extended to 92o12 W longitude

Hydrocarbon seepage in the deep seabed links subsurface and seafloor biospheres

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chakraborty, A., Ruff, S. E., Dong, X., Ellefson, E. D., Li, C., Brooks, J. M., McBee, J., Bernard, B. B., & Hubert, C. R. J. Hydrocarbon seepage in the deep seabed links subsurface and seafloor biospheres. Proceedings of the National Academy of Sciences of the United States of America, 117(20), (2020): 11029-11037, doi: 10.1073/pnas.2002289117.Marine cold seeps transmit fluids between the subseafloor and seafloor biospheres through upward migration of hydrocarbons that originate in deep sediment layers. It remains unclear how geofluids influence the composition of the seabed microbiome and if they transport deep subsurface life up to the surface. Here we analyzed 172 marine surficial sediments from the deep-water Eastern Gulf of Mexico to assess whether hydrocarbon fluid migration is a mechanism for upward microbial dispersal. While 132 of these sediments contained migrated liquid hydrocarbons, evidence of continuous advective transport of thermogenic alkane gases was observed in 11 sediments. Gas seeps harbored distinct microbial communities featuring bacteria and archaea that are well-known inhabitants of deep biosphere sediments. Specifically, 25 distinct sequence variants within the uncultivated bacterial phyla Atribacteria and Aminicenantes and the archaeal order Thermoprofundales occurred in significantly greater relative sequence abundance along with well-known seep-colonizing members of the bacterial genus Sulfurovum, in the gas-positive sediments. Metabolic predictions guided by metagenome-assembled genomes suggested these organisms are anaerobic heterotrophs capable of nonrespiratory breakdown of organic matter, likely enabling them to inhabit energy-limited deep subseafloor ecosystems. These results point to petroleum geofluids as a vector for the advection-assisted upward dispersal of deep biosphere microbes from subsurface to surface environments, shaping the microbiome of cold seep sediments and providing a general mechanism for the maintenance of microbial diversity in the deep sea.We wish to thank Jody Sandel as well as the crew of R/V GeoExplorer for collection of piston cores, onboard core processing, sample preservation, and shipment. Cynthia Kwan and Oliver Horanszky are thanked for assistance with amplicon library preparation. We also wish to thank Jayne Rattray, Daniel Gittins, and Marc Strous for valuable discussions and suggestions, and Rhonda Clark for research support. Collaborations with Andy Mort from the Geological Survey of Canada, and Richard Hatton from Geoscience Wales are also gratefully acknowledged. This work was financially supported by a Mitacs Elevate Postdoctoral Fellowship awarded to A.C.; an Alberta Innovates-Technology Futures/Eyes High Postdoctoral Fellowship to S.E.R.; and a Natural Sciences and Engineering Research Council Strategic Project Grant, a Genome Canada Genomics Applications Partnership Program grant, a Canada Foundation for Innovation grant (CFI-JELF 33752) for instrumentation, and Campus Alberta Innovates Program Chair funding to C.R.J.H

Robert James Baker (1942-2018), Obituary

First paragraph: On 30 March 2018, the science of mammalogy and the American Society of Mammalogists lost one of the most influential figures of the last half-century. Robert James Baker died quietly at his home in Lubbock, Texas (Fig. 1). He was born on 8 April 1942 to James Simeon Baker and Laura Cooper in Warren, Arkansas. His father was killed during World War II and his mother remarried, resulting in his growing up with six half-siblings. According to Robert’s autobiography in Going afield (330—number refers to specific publication in “Bibliography”), he spent a good deal of his youth with his grandparents on a 100-acre farm in the West Gulf Coastal Plain of southeastern Arkansas. He identified his maternal grandmother, “Grandma Rosie,” as his best friend and his greatest influence during these years. His marriage to Jean Joyner on 19 August 1961 ended in divorce in 1975, but the marriage resulted in a daughter, April Baker-Padilla, and two grandchildren, Jason Baker and Faith Padilla. Robert was married to his wife of 39 years, Laura Kyle (M.D.), on 28 May 1978 in Lubbock. Their son, Robert Kyle Baker, preceded his father in death, which was a tragedy from which neither Robert nor Laura ever completely recovered

Relationships among repetitive behaviors, sensory features, and executive functions in high functioning autism

This study examined the relationship between repetitive behaviors and sensory processing issues in school-aged children with high functioning autism (HFA). Children with HFA (N = 61) were compared to healthy, typical controls (N = 64) to determine the relationship between these behavioral classes and to examine whether executive dysfunction explained any relationship between the variables. Particular types of repetitive behavior (i.e., stereotypy and compulsions) were related to sensory features in autism; however, executive deficits were only correlated with repetitive behavior. This finding suggests that executive dysfunction is not the shared neurocognitive mechanism that accounts for the relationship between restricted, repetitive behaviors and aberrant sensory features in HFA. Group status, younger chronological age, presence of sensory processing issues, and difficulties with behavior regulation predicted the presence of repetitive behaviors in the HFA group