Joe is a USGS biologist that is broadly interested in the ecology of coastal marine communities, particularly the influences of vertebrate predators on community structure.
Most of his field research has focused on sea otter populations around the Northeastern Pacific Ocean. His past and current study sites focus mostly on Central and Southern California (including the Channel Islands), but also include many other locations around the Northeast Pacific like the Aleutian Islands, Southeast and Southcentral Alaska, and Washington. These studies are designed to better understand the suite of direct and indirect interactions between sea otters and other species in the nearshore environment. Joe and his colleagues use this model system to elucidate the influence of high-trophic-level consumers on the organization of the communities in which they live. Their research questions aim to investigate various aspects of sea otter behavioral ecology including: foraging trends, activity budgets, movement patterns, survival, and reproduction. The information gathered from their research helps to obtain a better understanding of sea otter biology, which, through species interactions with biotic and abiotic factors in their environment, advances our knowledge base for entire nearshore marine ecosystems.
In addition to sea otter population studies, Joe's fieldwork also includes intertidal and subtidal surveys of nearshore communities, as well as dive work to capture and tag sea otters and collect data or samples that help us better understand the link between otters, kelp forests, estuaries, and people. Joe and his USGS colleagues are also the lead agency conducting the annual sea otter census in California, which monitors population change and distribution over time. Joe also serves on the USGS National Dive Safety Board as the Southwest Region Dive Safety Officer.
Education and Certifications
EDUCATION
MS, Marine Affairs & Policy/Marine Biology & Fisheries, University of Miami Rosenstiel School of Marine & Atmospheric Science (FL), 2007
BS, Marine Biology, University of Miami
Science and Products
Southern (California) sea otter population status and trends at San Nicolas Island, 2020–2023
Kelp-forest dynamics controlled by substrate complexity
Characterizing the oral and distal gut microbiota of the threatened southern sea otter (Enhydra lutris nereis) to enhance conservation practice
Kelp forest monitoring at Naval Base Ventura County, San Nicolas Island, California—Fall 2019, sixth annual repor
An integrated population model for southern sea otters
Habitat features predict carrying capacity of a recovering marine carnivore
Exposure to domoic acid is an ecological driver of cardiac disease in southern sea otters
Behavioral responses across a mosaic of ecosystem states restructure a sea otter–urchin trophic cascade
Examining the potential conflict between sea otter recovery and Dungeness crab fisheries in California
Southern (California) sea otter population status and trends at San Nicolas Island, 2017–2020
Kelp forest monitoring at Naval Base Ventura County, San Nicolas Island, California: Fall 2018 and Spring 2019, fifth annual report
Robust age estimation of southern sea otters from multiple morphometrics
California Sea Otter Stranding Network
California Sea Otter Surveys and Research
Population Biology and Behavior of Sea Otters
Pacific Nearshore Project
Santa Cruz Field Station
Annual California Sea Otter Census-2018 Spring Census Summary
Data for Southern Sea Otter Range Expansion and Habitat Use in the Santa Barbara Channel
Science and Products
- Publications
Filter Total Items: 23
Southern (California) sea otter population status and trends at San Nicolas Island, 2020–2023
The population of southern sea otters (Enhydra lutris nereis) at San Nicolas Island, California, has been monitored annually since the translocation of 140 southern sea otters to the island was completed in 1990. Monitoring efforts have varied in frequency and type across years. In 2017, the U.S. Navy and the U.S. Fish and Wildlife Service initiated a southern sea otter monitoring and research plaAuthorsJulie L. Yee, Joseph A. Tomoleoni, Michael C. Kenner, Jessica A. Fujii, Gena B. Bentall, Michelle M. Staedler, Brian B. HatfieldKelp-forest dynamics controlled by substrate complexity
The factors that determine why ecosystems exhibit abrupt shifts in state are of paramount importance for management, conservation, and restoration efforts. Kelp forests are emblematic of such abruptly shifting ecosystems, transitioning from kelp-dominated to urchin-dominated states around the world with increasing frequency, yet the underlying processes and mechanisms that control their dynamics rAuthorsZachary Randell, Michael C. Kenner, Joseph A. Tomoleoni, Julie L. Yee, Mark NovakCharacterizing the oral and distal gut microbiota of the threatened southern sea otter (Enhydra lutris nereis) to enhance conservation practice
The southern sea otter (Enhydra lutris nereis) is a threatened sub-species in coastal ecosystems. To understand better the role of diet, monitor health, and enhance management of this and other marine mammal species, we characterized the oral (gingival) and distal gut (rectal and fecal) microbiota of 158 wild southern sea otters living off the coast of central California, USA, and 12 captive sea oAuthorsNatasha K Dudek, Alexandra D Switzer, Elizabeth K Costello, Michael J. Murray, Joseph A. Tomoleoni, Michelle M. Staedler, M. Tim Tinker, David A RelmanKelp forest monitoring at Naval Base Ventura County, San Nicolas Island, California—Fall 2019, sixth annual repor
The U.S. Geological Survey conducts ecological monitoring of rocky subtidal communities at four permanent sites around San Nicolas Island. The sites—Nav Fac 100, West End, Dutch Harbor, and Daytona 100—were based on ones that had been monitored since 1980 by the U.S. Geological Survey and, in cooperation with the U.S. Navy, were combined or expanded in 2014 for better comparability with monitoringAuthorsMichael C. Kenner, Joseph A. TomoleoniAn integrated population model for southern sea otters
Southern sea otters (Enhydra lutris nereis) have recovered slowly from their near extinction a century ago, and their continued recovery has been challenged by multiple natural and anthropogenic factors. Development of an integrated population model (IPM) for southern sea otters has been identified as a management priority, to help in evaluating the relative impacts of known threats and guide bestAuthorsM. Tim Tinker, Lilian P. Carswell, Joseph A. Tomoleoni, Brian B. Hatfield, Michael D. Harris, Melissa A. Miller, Megan E. Moriarty, Christine K. Johnson, Colleen Young, Laird A. Henkel, Michelle M. Staedler, A. Keith Miles, Julie L. YeeHabitat features predict carrying capacity of a recovering marine carnivore
The recovery of large carnivore species from over‐exploitation can have socioecological effects; thus, reliable estimates of potential abundance and distribution represent a valuable tool for developing management objectives and recovery criteria. For sea otters (Enhydra lutris), as with many apex predators, equilibrium abundance is not constant across space but rather varies as a function of locaAuthorsM. Tim Tinker, Julie L. Yee, Kristin L. Laidre, Brian B. Hatfield, Michael D. Harris, Joseph A. Tomoleoni, Tom W. Bell, Emily Saarman, Lilian P. Carswell, A. Keith MilesExposure to domoic acid is an ecological driver of cardiac disease in southern sea otters
Harmful algal blooms produce toxins that bioaccumulate in the food web and adversely affect humans, animals, and entire marine ecosystems. Blooms of the diatom Pseudo-nitzschia can produce domoic acid (DA), a toxin that most commonly causes neurological disease in endothermic animals, with cardiovascular effects that were first recognized in southern sea otters. Over the last 20 years, DA toxicosiAuthorsMegan E. Moriarty, M. Tim Tinker, Melissa Miller, Joseph A. Tomoleoni, Michelle M. Staedler, Jessica A. Fujii, Francesca I. Batac, Erin M. Dodd, Raphael M. Kudela, Vanessa Zubkousky-White, Christine K. JohnsonBehavioral responses across a mosaic of ecosystem states restructure a sea otter–urchin trophic cascade
Consumer and predator foraging behavior can impart profound trait-mediated constraints on community regulation that scale up to influence the structure and stability of ecosystems. Here, we demonstrate how the behavioral response of an apex predator to changes in prey behavior and condition can dramatically alter the role and relative contribution of top-down forcing, depending on the spatial orgaAuthorsJoshua G Smith, Joseph A. Tomoleoni, Michelle M. Staedler, Sophia Lyon, Jessica Fujii, M. Tim TinkerExamining the potential conflict between sea otter recovery and Dungeness crab fisheries in California
Human exploitation of marine mammals led to precipitous declines in many wild populations within the last three centuries. Legal protections enacted throughout the 20th century have enabled the recovery of many of these species and some recoveries have resulted in conflict with humans for shared resources. With legal protections and reintroduction programs, the southern sea otter (Enhydra lutris nAuthorsAndre M. Boustany, David Hernandez, Emily A Miller, Fujii. Jessica, Teri E. Nicholson, Joseph A. Tomoleoni, Kyle S. Van HoutanSouthern (California) sea otter population status and trends at San Nicolas Island, 2017–2020
The southern sea otter (Enhydra lutris nereis) population at San Nicolas Island, California, has been monitored annually since the translocation of 140 sea otters to the island was completed in 1990. Monitoring efforts have varied in frequency and type across years. In 2017, the U.S. Navy and the U.S. Fish and Wildlife Service initiated a sea otter monitoring and research plan to determine the effAuthorsJulie L. Yee, Joseph A. Tomoleoni, Michael C. Kenner, Jessica Fujii, Gena B. Bentall, M. Tim Tinker, Brian B. HatfieldKelp forest monitoring at Naval Base Ventura County, San Nicolas Island, California: Fall 2018 and Spring 2019, fifth annual report
IntroductionKelp forests and rocky reefs are among the most recognized marine ecosystems and provide the primary habitat for several species of fishes, invertebrates, and algal assemblages (Stephens and others, 2006). In addition, kelp forests have been shown to be important carbon dioxide sinks (Wilmers and others, 2012) and are an important source of nearshore marine primary production (DugginsAuthorsMichael C. Kenner, Joseph A. TomoleoniRobust age estimation of southern sea otters from multiple morphometrics
Reliable age estimation is an essential tool to assess the status of wildlife populations and inform successful management. Aging methods, however, are often limited by too few data, skewed demographic representation, and by single or uncertain morphometric relationships. In this study, we synthesize age estimates in southern sea otters Enhydra lutris nereis from 761 individuals across 34 years ofAuthorsTeri E. Nicholson, Karl A. Mayer, Michelle M. Staedler, Tyler O Gagne, Michael J. Murray, Marissa A Young, Joseph A. Tomoleoni, M. Tim Tinker, Kyle S. Van Houtan - Science
California Sea Otter Stranding Network
The California Sea Otter Stranding Network is part of the USGS effort to monitor southern sea otters (Enhydra lutris nereis) and provide data to the U.S. Fish and Wildlife Service. WERC's sea otter team works with multiple institutions and partners to report, recover, and examine stranded sea otters. In addition, instructions on how to report a stranded sea otter are included in this webpage.California Sea Otter Surveys and Research
WERC collaborates with other research scientists to conduct annual population surveys of the southern sea otter -- a federally listed threatened species. In coordination with the California Department of Fish and Game and other institutions, ongoing surveys and research continues to inform the southern sea otter recovery plan for the U.S. Fish and Wildlife Service, and contributes to our...Population Biology and Behavior of Sea Otters
WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems.Pacific Nearshore Project
Sea otters are crucial indicators of the health of our nearshore waters and coastal resources, from kelp forests to fisheries. What clues does the sea otter's decline hold for our knowledge of ecosystem and global change? WERC's sea otter team and U.S. and Canadian researchers have teamed together to investigate. Relevance to USGS Missions: This research project has direct relevance for the...Santa Cruz Field Station
Scientists at the Santa Cruz Field Station study sea otters and seabirds in their environment. The USGS Western Ecological Research Center has two research missions based in the Santa Cruz region: - Data
Annual California Sea Otter Census-2018 Spring Census Summary
The spring 2018 mainland sea otter count began on April 26, and was completed by May 24, 2018. Overall viewing conditions this year were good and rounded off to the same conditions experienced during the 2017 spring census (View Score 2.4, where 0=poor, 1=fair, 2=good, 3=very good, and 4=excellent). The surface canopies of kelp (Macrocystis sp.) were considered by most participants to be above norData for Southern Sea Otter Range Expansion and Habitat Use in the Santa Barbara Channel
The current study was designed to provide critical information for resource managers (specifically the Bureau of Ocean Energy Management, henceforth BOEM, and the U.S. Fish and Wildlife Service, henceforth USFWS) about the spatial ecology, population status, and potential population threats to sea otters in Santa Barbara Channel, with particular reference to exposure to manmade structures and sour - Multimedia
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