Retrospective and historical data analysis, nearshore ecology of marine systems; predator/prey dynamics; mammalian reproductive biology/ecology; marine food web dynamics and marine mammal foraging ecology; population biology.
Professional Experience
1995 - Present Research Wildlife Biologist, USGS, Alaska Science Center, Anchorage, Alaska
1995, 1996, 1998, 1999 Biologist, University of Minnesota, Antarctic Research Program, McMurdo, Antarctica
1992 - 1995 Graduate Research Assistant, University of California Santa Cruz, Santa Cruz, California
1992 - 1995 Statistical Assistant, NBS, Alaska Science Center, Anchorage, Alaska
1987 - 1992 Biological Technician, U.S. Fish & Wildlife Service, Anchorage, Alaska
1985 - 1987 Research Assistant, University of Minnesota, Northern Prairie Wildlife Research Center, Jamestown, North Dakota
1983 - 1985 Biological Technician, U.S. Fish & Wildlife Service, Kawishawi Field Station, Ely, Minnesota
Education and Certifications
Ph.D. 2009 University of California Santa Cruz, Santa Cruz, CA Ecology and Evolutionary Biology
M.S. 1995 University of California Santa Cruz, Santa Cruz, CA Marine Science
B.S. 1983 Luther College, Decorah, IA Biology
Affiliations and Memberships
The Wildlife Society
American Association for the Advancement of Science
Ecological Society of America
Science and Products
Nearshore Marine Ecosystem Research
Sea Otter Aerial Survey Data from Western Prince William Sound, Alaska, 2017
Sea Otter Aerial Survey Data from the outer Kenai Peninsula, Alaska, 2019
Sea Otter Survey Data, Carcass Recovery Data, and Blood Chemistry Data from Southwest Alaska
Morphometric and Reproductive Status Data for Sea Otters Collected or Captured in Alaska
Gulf Watch Alaska, Nearshore Component: Sea Otter Mortality Age Data from Katmai National Park and Preserve, Kenai Fjords National Park, and Prince William Sound, Alaska, 2006-2017
Gulf Watch Alaska Nearshore Component: Marine Water Quality, Water Temperature from Prince William Sound, Katmai National Park and Preserve, and Kenai Fjords National Park, 2014-2016
Abundance and distribution of sea otters (Enhydra lutris) in the southcentral Alaska stock, 2014, 2017, and 2019
Genetic variation in sea otters (Enhydra lutris) from the North Pacific with relevance to the threatened Southwest Alaska Distinct Population Segment
Sea otter population collapse in southwest Alaska: Assessing ecological covariates, consequences, and causal factors
Sea otter predator avoidance behavior
Ecosystem response persists after a prolonged marine heatwave
Changes in rocky intertidal community structure during a marine heatwave in the northern Gulf of Alaska
Future directions in sea otter research and management
Trends and carrying capacity of sea otters in Southeast Alaska
Factors affecting disaster preparedness, response, and recovery using the community capitals framework
Lactation and resource limitation affect stress responses, thyroid hormones, immune function, and antioxidant capacity of sea otters (Enhydra lutris)
Variation in abundance of Pacific Blue Mussel (Mytilus trossulus) in the Northern Gulf of Alaska, 2006–2015
Timelines and mechanisms of wildlife population recovery following the Exxon Valdez oil spill
Science and Products
- Science
Nearshore Marine Ecosystem Research
Nearshore ecosystems include many resources that are of high ecological, recreational, subsistence, and economic value. They also are subject to influences from a wide variety of natural and human-caused perturbations, which can originate in terrestrial or oceanic environments. Our research is designed to evaluate sources of variation in the nearshore and how they influence resources of high... - Data
Sea Otter Aerial Survey Data from Western Prince William Sound, Alaska, 2017
This dataset consists of three tables related to abundance and distribution of northern sea otters (Enhydra lutris kenyoni) in western Prince William Sound, Alaska, based on data collected during a series of population-wide aerial surveys in June 2017. The dataset consists of: (1) sea otter counts along strip transects, (2) sea otter counts in Intensive Search Unit (ISU) within the transects, andSea Otter Aerial Survey Data from the outer Kenai Peninsula, Alaska, 2019
This dataset consists of three tables related to abundance and distribution of northern sea otters (Enhydra lutris kenyoni) near the outer Kenai Peninsula, Alaska, based on data collected during a series of population-wide aerial surveys in June 2019. The dataset consists of: (1) sea otter counts along strip transects, (2) sea otter counts in Intensive Search Unit (ISU) within the transects, and (Sea Otter Survey Data, Carcass Recovery Data, and Blood Chemistry Data from Southwest Alaska
Three data sets are included here to aid in assessment of the sea otter population collapse in southwest Alaska. One data set consists of results of sea otter surveys conducted between 1959 and 2015 at Bering Island, Russia and a selection of western Aleutian Islands in Alaska. Sea otter counts are reduced to a comparable value of otters per linear kilometer. Another data set consists per-capita aMorphometric and Reproductive Status Data for Sea Otters Collected or Captured in Alaska
This dataset includes morphometric measurements and pregnancy / dependency status from sea otters captured or collected (experimental harvests or recovered after the Exxon Valdez Oil Spill) in Alaska, 1947-2019 by the U.S. Geological Survey (USGS) and the U.S. Fish and Wildlife Service (USFWS). Data collected include total body length, tail length, body mass, axillary girth, paw width, canine diamGulf Watch Alaska, Nearshore Component: Sea Otter Mortality Age Data from Katmai National Park and Preserve, Kenai Fjords National Park, and Prince William Sound, Alaska, 2006-2017
These data are part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. The dataset is a comma separated file exported from a Microsoft Excel spreadsheet. The data consist of information related to collection of sea otter carcasses. Collectors walked selected shorelines searching for signs of carcasses. Date, location, carcass condition, parts collected, anGulf Watch Alaska Nearshore Component: Marine Water Quality, Water Temperature from Prince William Sound, Katmai National Park and Preserve, and Kenai Fjords National Park, 2014-2016
This data is part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. The data consists of date, time, and temperature measurements from intertidal rocky sampling sites. The dataset is 5 comma separated files exported from a download from the HOBO temperature logger. Sites are in Alaska and include locations in Katmai National Park and Preserve, Kenai Fjor - Publications
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Abundance and distribution of sea otters (Enhydra lutris) in the southcentral Alaska stock, 2014, 2017, and 2019
The Southcentral Alaska (SCAK) sea otter (Enhydra lutris) stock is the northernmost stock of sea otters, a keystone predator known for structuring nearshore marine ecosystems. We conducted aerial surveys within the range of the SCAK sea otter stock to provide recent estimates of sea otter abundance and distribution. We defined three survey regions: (1) Eastern Cook Inlet (2017), (2) Outer Kenai PeGenetic variation in sea otters (Enhydra lutris) from the North Pacific with relevance to the threatened Southwest Alaska Distinct Population Segment
For the sea otter (Enhydra lutris), genetic population structure is an area of research that has not received significant attention, especially in Southwest Alaska where that distinct population segment has been listed as threatened since 2005 pursuant to the U.S. Endangered Species Act. In this study, 501 samples from 14 locations from Prince William Sound, Alaska to the Commander Islands in RussSea otter population collapse in southwest Alaska: Assessing ecological covariates, consequences, and causal factors
Sea otter (Enhydra lutris) populations in southwest Alaska declined substantially between about 1990 and the most recent set of surveys in 2015. Here we report changes in the distribution and abundance of sea otters, and covarying patterns in reproduction, mortality, body size and condition, diet and foraging behavior, food availability, health profiles, and exposure to environmental contaminantsSea otter predator avoidance behavior
Predators directly affect their prey as a source of mortality, and prey respond by employing antipredator strategies. Sea otters are a keystone predator within the nearshore community, but higher trophic level avian, terrestrial, and pelagic predators (e.g., bald eagles, brown bears, wolves, white sharks, and killer whales) prey on them. Three antipredator strategies used by sea otters are vigilanEcosystem response persists after a prolonged marine heatwave
Some of the longest and most comprehensive marine ecosystem monitoring programs were established in the Gulf of Alaska following the environmental disaster of the Exxon Valdez oil spill over 30 years ago. These monitoring programs have been successful in assessing recovery from oil spill impacts, and their continuation decades later has now provided an unparalleled assessment of ecosystem responseChanges in rocky intertidal community structure during a marine heatwave in the northern Gulf of Alaska
Marine heatwaves are global phenomena that can have major impacts on the structure and function of coastal ecosystems. By mid-2014, the Pacific Marine Heatwave (PMH) was evident in intertidal waters of the northern Gulf of Alaska and persisted for multiple years. While offshore marine ecosystems are known to respond to these warmer waters, the response of rocky intertidal ecosystems to this warminFuture directions in sea otter research and management
The conservation and management of sea otters has benefited from a dedicated research effort over the past 60 years enabling this species to recover from a few thousand in the early 20th century to about 150,000 today. Continued research to allow full, pre-exploitation recovery and restoration of nearshore ecosystems should focus on at least seven key challenges: 1) Defining sea otter populationsTrends and carrying capacity of sea otters in Southeast Alaska
Sea otter populations in Southeast Alaska (SEAK) have increased dramatically from fewer than 500 translocated animals in the late 1960s. The recovery of sea otters to ecosystems from which they had been absent has affected coastal food webs, including commercially important fisheries, and thus information on expected growth and equilibrium abundances can help inform resource management. We compileFactors affecting disaster preparedness, response, and recovery using the community capitals framework
Disaster research often focuses on how and why communities are affected by a discrete extreme event. We used the community capitals framework to understand how community characteristics influence their preparedness, response to, and recovery from successive or multiple disasters using the 1964 Good Friday Earthquake and the 1989 Exxon Valdez Oil Spill as case studies. This study assesses communityLactation and resource limitation affect stress responses, thyroid hormones, immune function, and antioxidant capacity of sea otters (Enhydra lutris)
Lactation is the most energetically demanding stage of reproduction in female mammals. Increased energetic allocation toward current reproduction may result in fitness costs, although the mechanisms underlying these trade‐offs are not well understood. Trade‐offs during lactation may include reduced energetic allocation to cellular maintenance, immune response, and survival and may be influenced byVariation in abundance of Pacific Blue Mussel (Mytilus trossulus) in the Northern Gulf of Alaska, 2006–2015
Mussels are conspicuous and ecologically important components of nearshore marine communities around the globe. Pacific blue mussels (Mytilus trossulus) are common residents of intertidal habitats in protected waters of the North Pacific, serving as a conduit of primary production to a wide range of nearshore consumers including predatory invertebrates, sea ducks, shorebirds, sea otters, humans, aTimelines and mechanisms of wildlife population recovery following the Exxon Valdez oil spill
Research and monitoring activities over the 28 years since the T/V Exxon Valdez ran aground and spilled oil into Prince William Sound, Alaska have led to an improved understanding of how wildlife populations were damaged, as well as the mechanisms and timelines of recovery. A key finding was that for some species, such as harlequin ducks and sea otters, chronic oil spill effects persisted for at l