Ontogenetic patterns and temperature-dependent growth rates in early life stages of Pacific cod (Gadus macrocephalus)

Pacific cod (Gadus macrocephalus) is an important component of fisheries and food webs in the North Pacific Ocean and Bering Sea. However, vital rates of early life stages of this species have yet to be described in detail. We determined the thermal sensitivity of growth rates of embryos, preflexion and postflexion larvae, and postsettlement juveniles. Growth rates (length and mass) at each ontogenetic stage were measured in three replicate tanks at four to five temperatures. Nonlinear regression was used to obtain parameters for independent stage-specific growth functions and a unified size- and temperature-dependent growth function. Specific growth rates increased with temperature at all stages and generally decreased with increases in body size. However, these analyses revealed a departure from a strict size-based allometry in growth patterns, as reduced growth rates were observed among preflexion larvae: the reduction in specific growth rate between embryos and free-swimming larvae was greater than expected based on body size differences. Growth reductions in the preflexion larvae appear to be associated with increased metabolic rates and the transition from endogenous to exogenous feeding. In future studies, experiments should be integrated across life transitions to more clearly define intrinsic ontogenetic and size-dependent growth patterns because these are critical for evaluations of spatial and temporal variation in habitat quality.

Charles Henry Gilbert (1859-1928), Naturalist-in-Charge, and Chauncey Thomas, Jr. (1850-1919), Commanding: Conflict Aboard the U. S. Fish Commission Steamer Albatross in 1902

Charles Henry Gilbert (1859-1928) was a pioneering ichthyologist who made major contributions to the study of fishes of the American West. As chairman of the Department ofZoology at Leland Stanford Junior University in Palo Alto, Calif., during 1891-1925, Gilbert was extremely devoted to his work and showed little patience with those ofa different mindset. While serving as Naturalist-in-Charge of the U.S. Fish Commission Steamer Albatross during her exploratory expedition to the Hawaiian Islands in 1902, Gilbert engaged in an acrimonious feud with the ship's captain, Chauncey Thomas, Jr. (1850-1919), U.S.N., over what Gilbert perceived to be an inadequate effort by the captain. This essay focuses on the conflict between two strong figures, each operatingf rom different world views, and each vying for authority. Despite the difficulties these two men faced, the voyage of the Albatross in 1902 must be considered a success, as reflected by the extensive biological samples collected, the many new species of animals discovered, and the resulting publication of important scientific papers.

Survey and impact assessment of derelict fish traps in St. Thomas and St. John, U.S. Virgin Islands

Since 2001, NOAA National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Monitoring and Assessment’s (CCMA) Biogeography Branch (BB) has been working with federal and territorial partners to characterize, monitor, and assess the status of the marine environment across the U.S. Virgin Islands (USVI). At the request of the St. Thomas Fisherman’s Association (STFA) and NOAA Marine Debris Program, CCMA BB developed new partnerships and novel technologies to scientifically assess the threat from derelict fish traps (DFTs). Traps are the predominant gear used for finfish and lobster harvesting in St. Thomas and St. John. Natural phenomena (ground swells, hurricanes) and increasing competition for space by numerous user groups have generated concern about increasing trap loss and the possible ecological, as well as economic, ramifications. Prior to this study, there was a general lack of knowledge regarding derelict fish traps in the Caribbean. No spatially explicit information existed regarding fishing effort, abundance and distribution of derelict traps, the rate at which active traps become derelict, or areas that are prone to dereliction. Furthermore, there was only limited information regarding the impacts of derelict traps on natural resources including ghost fishing. This research identified two groups of fishing communities in the region: commercial fishing that is most active in deeper waters (30 m and greater) and an unknown number of unlicensed subsistence and or commercial fishers that fish closer to shore in shallower waters (30 m and less). In the commercial fishery there are an estimated 6,500 active traps (fish and lobster combined). Of those traps, nearly 8% (514) were reported lost during the 2008-2010 period. Causes of loss/dereliction include: movement of the traps or loss of trap markers due to entanglement of lines by passing vessels; theft; severe weather events (storms, large ground swells); intentional disposal by fishermen; traps becoming caught on various bottom structures (natural substrates, wrecks, etc.); and human error.

An assessment of chemical contaminants detected in passive water samplers deployed in the St. Thomas East End Reserves (STEER)

This report is the second in a series from a project to assess land-based sources of pollution (LBSP) and effects in the St. Thomas East End Reserves (STEER) in St. Thomas, USVI, and is the result of a collaborative effort between NOAA’s National Centers for Coastal Ocean Science, the USVI Department of Planning and Natural Resources, the University of the Virgin Islands, and The Nature Conservancy. Passive water samplers (POCIS) were deployed in the STEER in February 2012. Developed by the US Geological Survey (USGS) as a tool to detect the presence of water soluble contaminants in the environment, POCIS samplers were deployed in the STEER at five locations. In addition to the February 2012 deployment, the results from an earlier POCIS deployment in May 2010 in Turpentine Gut, a perennial freshwater stream which drains to the STEER, are also reported. A total of 26 stormwater contaminants were detected at least once during the February 2012 deployment in the STEER. Detections were high enough to estimate ambient water concentrations for nine contaminants using USGS sampling rate values. From the May 2010 deployment in Turpentine Gut, 31 stormwater contaminants were detected, and ambient water concentrations could be estimated for 17 compounds. Ambient water concentrations were estimated for a number of contaminants including the detergent/surfactant metabolite 4-tert-octylphenol, phthalate ester plasticizers DEHP and DEP, bromoform, personal care products including menthol, indole, n,n-diethyltoluamide (DEET), along with the animal/plant sterol cholesterol, and the plant sterol beta-sitosterol. Only DEHP appeared to have exceeded a water quality guideline for the protection of aquatic organisms.

An assessment of chemical contaminants, toxicity and benthic infauna in sediments from the St. Thomas East End Reserves (STEER)

This report contains a chemical and biological characterization of sediments from the St. Thomas East End Reserves (STEER) in St. Thomas, U.S. Virgin Islands (USVI). The STEER Management Plan (published in 2011) identified chemical contaminants and habitat loss as high or very high threats and called for a characterization of chemical contaminants as well as an assessment of their effects on natural resources. The baseline information contained in this report on chemical contaminants, toxicity and benthic infaunal community composition can be used to assess current conditions, as well as the efficacy of future restoration activities. In this phase of the project, 185 chemical contaminants, including a number of organic (e.g., hydrocarbons and pesticides) and inorganic (e.g., metals) compounds, were analyzed from 24 sites in the STEER. Sediments were also analyzed using a series of toxicity bioassays, including amphipod mortality, sea urchin fertilization impairment, and the cytochrome P450 Human Reporter Gene System (HRGS), along with a characterization of the benthic infaunal community. Higher levels of chemical contaminants were found in Mangrove Lagoon and Benner Bay in the western portion of the study area than in the eastern area. The concentrations of polychlorinated biphenyls (PCBs), DDT (dichlorodiphenyltrichloroethane), chlordane, zinc, copper, lead and mercury were above a NOAA sediment quality guideline at one or more sites, indicating impacts may be present in more sensitive species or life stages in the benthic environment. Copper at one site in Benner Bay, however, was above a NOAA guideline indicating that effects on benthic organisms were likely. The antifoulant boat hull ingredient tributyltin, or TBT, was found at the third highest concentration in the history of NOAA’s National Status and Trends (NS&T) Program, which monitors the Nation’s coastal and estuarine waters for chemical contaminants and bioeffects. Unfortunately, there do not appear to be any established sediment quality guidelines for TBT. Results of the bioassays indicated significant sediment toxicity in Mangrove Lagoon and Benner Bay using multiple tests. The benthic infaunal communities in Mangrove Lagoon and Benner Bay appeared severely diminished.

Benthic habitats of Fish Bay, Coral Bay and the St. Thomas East End Reserve

NOAA’s National Centers for Coastal Ocean Science Biogeography Branch has mapped and characterized large portions of the coral reef ecosystems inside the U.S. coastal and territorial waters, including the U.S. Caribbean. The complementary protocols used in these efforts have enabled scientists and managers to quantitatively and qualitatively compare marine ecosystems in tropical U.S. waters. The Biogeography Branch used similar protocols to generate new benthic habitat maps for Fish Bay, Coral Bay and the St. Thomas East End Reserve (STEER). While this mapping effort marks the third time that some of these shallow-water habitats (≤40 m) have been mapped, it is the first time that nearly 100% of the seafloor has been characterized in each of these areas. It is also the first time that high resolution imagery describing seafloor depth has been collected in each of these areas. Consequently, these datasets provide new information describing the distribution of coral reef ecosystems and serve as a spatial baseline for monitoring change in the Fish Bay, Coral Bay and the STEER. Benthic habitat maps were developed for approximately 64.3 square kilometers of seafloor in and around Fish Bay, Coral Bay and the STEER. Twenty seven percent (17.5 square kilometers) of these habitat maps describe the seafloor inside the boundaries of the STEER, the Virgin Islands National Park and the Virgin Islands Coral Reef National Monument. The remaining 73% (46.8 square kilometers) describe the seafloor outside of these MPA boundaries. These habitat maps were developed using a combination of semi-automated and manual classification methods. Habitats were interpreted from aerial photographs and LiDAR (Light Detection and Ranging) imagery. In total, 155 distinct combinations of habitat classes describing the geology and biology of the seafloor were identified from the source imagery.