Stephen Jewett - Academia.edu (original) (raw)

Papers by Stephen Jewett

In April 2006, Alaska's Office of History and Archaeology collaborated with the University of... more In April 2006, Alaska's Office of History and Archaeology collaborated with the University of Alaska Fairbanks, the University of Rhode Island, the U.S. Minerals Management Service, and the National Oceanic and Atmospheric Administration (NOAA) National Marine Sanctuary Program to collect information on five historic shipwrecks in Southeast Alaska. Under a grant from the NOAA Office of Ocean Exploration, the project team documented the shipwrecks through dives, interviews, the use of a DIDSON sonar unit, and recordation of biota. Sediment samples adjacent to wrecks are being analyzed to detect changes in soil chemistry due to wreck degradation. These data sets will allow researchers to track changes to the sites as a result of vandalism and natural decay processes. Public education components of the project included public talks, radio and newspaper interviews, and the development of websites.

Journal of Marine Science: Research & Development, Jun 27, 2015

L arge climatological, environmental and oceanographic shifts are having great effects in the Arc... more L arge climatological, environmental and oceanographic shifts are having great effects in the Arctic including shallow waters of the northeastern Chukchi Sea, Alaska. The number of ice-free days is increasing, the extents of summer ice cover declining and biological communities are responding. While pelagic-benthic coupling is a major determinant for production, there are significant deviations from expected macrobenthic characteristics driven by other mechanisms including topographic control over water circulation and are potential sources of long-term change. Water from the Bering Sea flows northward through Bering Strait into the Chukchi Sea advecting organic carbon northward and contributing to the ecological characteristics of the Arctic Ocean. Water exits the shelf in part via Barrow Canyon. Increased biomass near the head of the canyon reflects increased transport of carbon as food for suspension feeders as compared to higher proportions of deposit-feeding organisms offshore. Benthic-feeding marine mammals relying on crustaceans utilize nearshore resources while mammals relying on other resources feed offshore. Changes in the flow of water through the area may be sources for future change as interactions between circulation, seafloor and coastline topography and biological processes appear to be drive spatial variations in benthic resources and are related to increased production in benthic hotspots. Biography Arny L Blanchard is a Benthic Ecologist and Biostatistician with the Institute of Marine Science, University of Alaska Fairbanks and is involved in marine studies throughout Alaska's waters from Prince William Sound to the Beaufort Sea. His research is focused on the spatial and temporal changes of marine communities and assessment of human disturbance in the environment. He currently manages the Port Valdez Environmental Studies Program and the benthic component of the Chukchi Sea Environmental Studies Program in northeastern Chukchi Sea and contributes to the Alaska Monitoring and Assessment Program.

American Geophysical Union eBooks, Feb 1, 2016

Integrated Environmental Assessment and Management, 2008

The operations connected with oil exploration, production, and transportation in the northeast Gu... more The operations connected with oil exploration, production, and transportation in the northeast Gulf of Alaska will present a wide spectrum of potential dangers to the marine environment. The report is an inventory of dominant invertebrates, their abundance and distribution patterns in the area of the Gulf of Alaska.

Biological Conservation, Nov 1, 2016

Sea ice dominates marine ecosystems in the Arctic, and recent reductions in sea ice may alter foo... more Sea ice dominates marine ecosystems in the Arctic, and recent reductions in sea ice may alter food webs throughout the region. Sea ice loss may also stress Pacific walruses (Odobenus rosmarus divergens), which feed on benthic macroinvertebrates in the Bering and Chukchi seas. However, no studies have examined the effects of sea ice on foraging Pacific walrus space use patterns. We tested a series of hypotheses that examined walrus foraging resource selection as a function of proximity to resting substrates and prey biomass. We quantified walrus prey biomass with 17 benthic invertebrate families, which included bivalves, polychaetes, amphipods, tunicates, and sipunculids. We included covariates for distance to sea ice and distance to land, and systematically developed a series of candidate models to examine interactions among benthic prey biomass and resting substrates. We ranked candidate models with Bayesian Information Criterion and made inferences on walrus resource selection based on the top-ranked model. Based on the top model, biomass of the bivalve family Tellinidae, distance to ice, distance to land, and the interaction of distances to ice and land all positively influenced walrus foraging resource selection. Standardized model coefficients indicated that distance to ice explained the most variation in walrus foraging resource selection followed by Tellinidae biomass. Distance to land and the interaction of distances to ice and land accounted for similar levels of variation. Tellinidae biomass likely represented an index of overall bivalve biomass, indicating walruses focused foraging in areas with elevated levels of bivalve and tellinid biomass. Our results also emphasize the importance of sea ice to walruses. Projected sea ice loss will increase the duration of the open water season in the Chukchi Sea, altering the spatial distribution of resting sites relative to current foraging areas and possibly affecting the spatial structure of benthic communities.

Journal of Sea Research, Feb 1, 2013

Abstract The flatfish yellowfin sole (Limanda aspera), northern rock sole (Lepidopsetta polyxystr... more Abstract The flatfish yellowfin sole (Limanda aspera), northern rock sole (Lepidopsetta polyxystra), and Alaska plaice (Pleuronectes quadrituberculatus) in the southeastern Bering Sea prey mainly on infauna. Spatial correspondence between their stomach contents and infauna assemblages across habitat types was examined to identify indices of prey availability for flatfish habitat characterization and quality assessment. Benthic samples and flatfish stomachs were collected in 2009 near the Alaska Peninsula in the southeastern Bering Sea. Polychaetes and bivalves were the most dominant infauna groups, each comprising 35–60% by weight in each infauna sample. These two were also the only prey groups that frequently averaged > 50% of stomach content by weight. Bivalves dominated the infauna biomass on the relatively sandy inner shelf (0–50 m depth). The muddier middle shelf (50–100 m) had the highest infauna biomass, which was dominated by polychaetes. Diet compositions of the flatfish varied spatially in correspondence with the infauna assemblage. Polychaetes were prevalent in all flatfish diets on the middle shelf, even yellowfin sole whose typical primary prey are amphipods and bivalves. Polychaete-rich habitats are potentially prime for flatfish as polychaetes are readily utilized where available and generally have high nutritional value. Flatfish did not select for specific polychaete taxa, so an index of habitat quality could be based on the biomass of aggregate polychaetes or on dominant polychaete families of the region. Under normal environmental conditions, the three flatfish have slightly-offset spatial distributions, enabling each to utilize different infauna assemblages across the shelf. However, during cold phases in the Bering Sea ecosystem, as when this study was conducted, a cold pool of

Deep-sea Research Part Ii-topical Studies in Oceanography, Oct 1, 2017

The shallow continental shelf waters of the Bering and Chukchi seas are the northernmost foraging... more The shallow continental shelf waters of the Bering and Chukchi seas are the northernmost foraging grounds of North Pacific gray whales (Eschrichtius robustus). Benthic amphipods are considered the primary prey of gray whales in these waters, although no comprehensive quantitative analysis has been performed to support this assumption. Gray whale relative abundance, distribution, and behavior in the

Zenodo (CERN European Organization for Nuclear Research), Dec 31, 2011

A new species of goniasterid sea star, Hippasteria aleutica sp. nov. is described from the Aleuti... more A new species of goniasterid sea star, Hippasteria aleutica sp. nov. is described from the Aleutian Islands, and compared to H. phrygiana (Parelius, 1768) from the North Atlantic-Arctic, as well as its congeners from the North Pacific. Distribution is discussed and a key to the described species of Hippasteria in Alaskan waters is presented.

Environmental Conservation, Mar 12, 2018

SUMMARYIn the Arctic, rapid climate change has kindled efforts to delineate and project the futur... more SUMMARYIn the Arctic, rapid climate change has kindled efforts to delineate and project the future of important habitats for marine birds and mammals. These animals are vital to subsistence economies and cultures, so including the needs of both animals and hunters in conservation planning is key to sustaining social-ecological systems. In the northeast Chukchi Sea, a nearshore corridor of open water is a major spring migration route for half a million eider ducks that are hunted along the landfast ice. Zoning areas for industrial activities or conservation should consider both eider habitat and hunter access to those habitats from the variable ice edge. Based on benthic sampling in 2010‒2012, a model of eider foraging energetics and satellite data on ice patterns in April and May 1997‒2011, we mapped the range of positions of the landfast ice edge relative to a given dispersion of habitat suitable for eider feeding. In some sectors, feeding areas were too limited or too far from landfast ice to provide regular hunting access. In other sectors, overlap of the ice edge with eider feeding habitat was quite variable, but often within a consistent geographic range. Areas accessible to hunters were a small fraction of total eider habitat, so areas adequate for conserving eiders would not necessarily include areas that meet the hunters’ needs. These results can inform spatial planning of industrial activities that yield cash income critical to subsistence hunting in less developed locations. Our study provides an approach for mapping ‘subsistence conservation areas’ throughout the Arctic and an example for such efforts elsewhere.

Fisheries Research, 2019

Snow crab (Chionoecetes opilio) were identified as a potential future target fishery species in f... more Snow crab (Chionoecetes opilio) were identified as a potential future target fishery species in federal waters of the Arctic Ocean off Alaska by the Arctic Fishery Management Plan (Arctic FMP) in 2009, but this plan currently prohibits commercial harvest until sufficient information is available to assess a sustainable commercial fishery. One drawback of the current Arctic FMP is that critical population and biomass estimates were based on limited data. Collaborative research efforts in the Chukchi and Beaufort seas over the past decade have yielded a much richer database on snow crab in the Arctic. Using these data, we generated new estimates of weight-at-size, maturity-at-size, fecundity, and biomass to recalculate sustainable yield of snow crab in the U.S. Arctic. Weightat-size was generally similar for male and female snow crab between the Chukchi and Beaufort seas, with males reaching overall larger sizes than females in both seas and largest male crabs occurring in the Beaufort Sea. Compared with snow crab in other geographic regions, 50% morphometric maturity was reached at a slightly smaller size in the Chukchi Sea; low sample sizes in the Beaufort Sea prevented maturity-at-size analysis. Fecundity-at-size in the Chukchi Sea was similar to known values estimated for snow crab in other regions. Estimated total reproductive output, using fecundity estimates obtained here, suggest that local reproduction may be sufficient to account for a large portion of observed small juvenile benthic snow crab abundances; further investigation is warranted to determine whether Chukchi and Beaufort populations are self-sustaining at this time. Although snow crab had high abundances in the Chukchi Sea, harvestable biomass of male snow crab only occurred in the Beaufort Sea because crab larger than the minimum marketable size (≥ 100 mm carapace width, based on Bering Sea metric) were absent in the Chukchi Sea over the study period. Our biomass estimates in the Chukchi Sea were substantially higher than previous estimates, owing at least in part to high abundances of small crab that were greatly under-sampled with the large-mesh gear such as was used in surveys referenced in the Arctic FMP. Estimates of biomass and sustainable yield for the Beaufort Sea were over twice as high as previous estimates in the Arctic FMP, but harvestable biomass was largely limited to the slope (> 200 m depth) and is unlikely to support commercial harvest. Our results expand overall understanding of arctic snow crab dynamics in light of potential future fisheries or other, non-fishing activities and inform the management of the Alaskan Arctic stock. 1. Introduction Snow crab Chionoecetes opilio are distributed across subarctic and Arctic waters, with lucrative commercial fisheries occurring in the North Atlantic (eastern Canada and Greenland), Bering Sea, and Sea of Japan. The eastern Bering Sea (EBS) fishery is one of the most valuable fisheries in the US, with an average harvest of 25,700 metric tons (56.6 million pounds) and an average ex-vessel value of $133 million dollars in 2017 (Alaska Department of Fish and Game, 2018; Fissel et al., 2018). Harvest is limited to only males at or above a marketable size (≥ 100 mm carapace width [CW]) in an attempt to protect the reproductive potential of mature females (Sainte-Marie and Gilbert, 1998; Zheng and Kruse, 2006; Turnock and Rugolo, 2012). In 1999, the EBS snow crab fishery was declared overfished after a period of declining snow crab biomass and abundance (Turnock and Rugolo, 2012). Additionally, a northward contraction of the center of snow crab

Coastal Research Library, 2016

In the Eastern Pacific (EP) the only region where rhodolith beds have been well studied in terms ... more In the Eastern Pacific (EP) the only region where rhodolith beds have been well studied in terms of taxonomy, ecology, distribution and conservation status is the Gulf of California. Outside this region the knowledge of rhodolith-forming species is attributed to the initial separate floristic surveys of Dawson and Lemoine, performed more than 50 years ago. After a detailed review of the published literature and information produced during our expeditions throughout the EP, a total of 36 rhodolith-forming species have been recorded from the Aleutian Islands in Alaska to Guarello Island in Chile. Despite the research efforts developed at present, more species remain to be discovered in the EP, particularly in the Tropical Pacific of Mexico and the Pacific coast of Baja California where we found undescribed species of Sporolithon and Lithothamnion. Therefore, we contend that further studies are needed in order to better catalogue the wide rhodolith-forming species diversity that is extremely relevant for the marine realm of the EP.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

The Condor, Nov 1, 2000

Methods for surveying Marbled Murrelets in forests. Pacific Seabird Group, Marbled Murrelet Techn... more Methods for surveying Marbled Murrelets in forests. Pacific Seabird Group, Marbled Murrelet Technical Committee, Tech. Paper No. 1. Oregon Cooperative Wildl. Res. Unit, Oregon State Univ., Corvallis, OR. RIC (RESOURCES INVENTORY COMMITTEE). 1997. Standardized inventory methodologies for components of British Columbia's biodiversity: Marbled Murrelets in marine and terrestrial habitats. Version 1.1.

Exxon …, 1999

... presented here was also incorporated into the trophic mass-balance model of Alaska's... more ... presented here was also incorporated into the trophic mass-balance model of Alaska's PWS Ecosystem (Okey and Pauley ... peak in abundance of Neocalanus plumchrus/flemingeri -Calanus marshallae/pacificus (hereafter referred to as Neocalanus/Calanus spp.; Cooney, 1993 ...