Shawn Larson

Shawn Larson
Seattle Aquarium · Conservation Programs and Partnerships

PhD University of Washington
Sea otter biology and ecology, benthic ecosystem monitoring in the Salish Sea and Hawaii, and shark conservation.

About

102
Publications
26,499
Reads
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1,446
Citations
Citations since 2016
58 Research Items
651 Citations
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
Additional affiliations
January 1995 - present
Seattle Aquarium
Position
  • Curator of Conservation Research

Publications

Publications (102)
Article
Full-text available
Human use of marinescapes is rapidly increasing, especially in populated nearshore regions where recreational vessel traffic can be dense. Marine animals can have a physiological response to such elevated human activity that can impact individual health and population dynamics. To understand the physiological impacts of vessel traffic on baleen wha...
Article
Full-text available
Hawai′i coral reefs are essential ecosystems providing resources in the form of food and recreation as well as stabilizing nearshore biodiversity. The Seattle Aquarium has exhibited Hawai′i reef fishes and corals since the mid-1980s to educate guests about these critical ecosystems. In 2009, and in collaboration with Hawai′i’s Division of Aquatic R...
Article
Southern sea otter (Enhydra lutris nereis) population recovery is influenced by a variety of factors, including predation, biotoxin exposure, infectious disease, oil spills, habitat degradation, and resource limitation. This population has also experienced a significant genetic bottleneck, resulting in low genetic diversity. We investigated how two...
Preprint
Full-text available
Elevated noise from human activities in nature can impact animal behavior and physiology, with subsequent impacts on individual health and population dynamics. Baleen whale communication, navigation, habitat use, and ability to recognize and locate prey and predators may be impaired by anthropogenic activities that increase ocean noise within the w...
Article
Baleen whale physiology remains poorly understood, including knowledge gaps concerning relationships between body condition and hormone metabolite concentrations associated with stress and energy allocation (i.e., glucocorticoid and thyroid hormones). To better understand these relationships, we collected 73 fecal samples from 36 different mature g...
Article
Full-text available
Anthropogenic debris including microparticles (MP; <5mm) are ubiquitous in marine environments. The Salish Sea experiences seasonal fluctuations in precipitation, river discharge, sewage overflow events, and tourism– all variables previously thought to have an impact on MP transport and concentrations. Our goals are two‐fold: 1) Describe long‐term...
Article
Full-text available
Sea otters, Enhydra lutris, were once abundant along the nearshore areas of the North Pacific. The international maritime fur trade that ended in 1911 left 13 small remnant populations with low genetic diversity. Subsequent translocations into previously occupied habitat resulted in several reintroduced populations along the coast of North America....
Article
Southern Resident Killer Whale (SRKW, Orcinus orca) may be found year round in the Salish Sea. These orcas comprise three matrilineal pods (J, K, and L) and were listed as Endangered under the Canadian Species at Risk Act in 2003 and under the United States Endangered Species Act in 2005 because of prey scarcity, vessel noise and disturbance, small...
Chapter
Sharks are iconic and ecologically important predators found in every ocean. Because of their ecological role as predators, some considered apex predators, and concern over the stability of their populations due to direct and indirect overfishing, there has been an increasing amount of work focussed on shark conservation, and other elasmobranchs su...
Article
Full-text available
Baleen whale fecal samples have high potential for endocrine monitoring, which can be used as a non-invasive tool to identify the physiological response to disturbance events and describe population health and vital rates. In this study, we used commercial enzyme-linked immunosorbent assays to validate and quantify fecal steroid (progestins, androg...
Book
This is the second book in a series about the sharks of Mexico their biology, ecology and conservation. These are books in Elsevier's Advances in Marine Biology Series vol 83 (part A) and 85 (part B). Topics covered are: Shark movement patterns in the Mexican Pacific: A conservation and management perspective; Fisheries interactions and the challen...
Article
Spatial analyses of marine mammal stranding data can be used to identify stranding patterns and improve surveillance and monitoring. Using ArcGIS and SaTScan, we analyzed 12 years (2002–2014) of dead beachcast marine mammals from San Juan County, Washington, to better understand patterns of carcass deposition. We plotted the locations for 631 dead...
Chapter
Mexico is a country that makes heavy use of the shark populations that inhabit the southern portion of the Northeast Pacific Ocean (NEP). Shark meat has become an essential food source in this country, while shark fins are used to supply traditional Asian markets. In addition to consumptive utilization, charismatic shark species support an ecotouri...
Article
Full-text available
Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is...
Presentation
These are the Abstracts of the 2019 annual meeting of SNVB, WA TWS, and NW PARC. I have two abstracts in this compilation: Olson et al., Density Management and Riparian Buffer Study update, pp 154-155; Weil and Olson, NW PARC update, pp 162-163.
Article
Full-text available
The Bluntnose Sixgill Shark, Hexanchus griseus, is a large predatory shark, has a worldwide distribution and is listed as near-threatened by the International Union of Conservation of Nature (IUCN). The Seattle Aquarium collected observations of free-swimming Sixgill Sharks in Elliott Bay, Washington, under the aquarium’s pier in 20 m of water from...
Article
Habitat characteristics are primary determinants of nearshore marine communities. However, biological drivers like predation can also be important for community composition. Sea otters (Enhydra lutris ssp.) are a salient example of a keystone species exerting top‐down control on ecosystem community structure. The translocation and subsequent popula...
Article
Full-text available
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...
Chapter
Sharks exhibit a broad range of body forms, occupy diverse ecological niches, and are found in every ocean on earth. They have roles as both predator and prey and have an evolutionary history far longer than that of human beings. As long as humans have interacted with the ocean they have interacted with sharks and, as a result, sharks have featured...
Article
Full-text available
Southern resident killer whales (SRKWs) Orcinus orca may be present year round in the Salish Sea, i.e. the inland waterways of Washington State (USA) and southern British Columbia (Canada). SRKWs were listed as endangered in 2005 under the US Endangered Species Act. The Whale Museum (Washington, USA) has been collecting opportunistic sightings repo...
Article
Full-text available
Pathogens entering the marine environment as pollutants exhibit a spatial signature driven by their transport mechanisms. The sea otter (Enhydra lutris), a marine animal which lives much of its life within sight of land, presents a unique opportunity to understand land–sea pathogen transmission. Using a dataset on Toxoplasma gondii prevalence acros...
Poster
Glucocorticoid hormones in blood are frequently measured as indicators of vertebrate stress response. Sea otters (Enhydra lutris), common in zoos and aquariums, have been documented to secrete both cortisol and corticosterone from adrenal glands. Animals under human care allow for longitudinal study, and non-invasive collection of samples are a pri...
Presentation
The Puget Sound has been inundated with toxic contaminants for decades. As a highly urbanized body of water, contaminants are easily brought into the ecosystem through a variety of methods including runoff, air transport, industrial and residential use. The Seattle Aquarium is located centrally within downtown Seattle, and utilizes sand filtered Pu...
Chapter
Full-text available
The Seattle Aquarium is centrally located on Elliott Bay in Puget Sound, built on a pier along the central waterfront in Seattle, WA, USA. The Seattle Aquarium Water Quality Laboratory regularly measures water quality metrics on incoming saltwater pumped directly from Elliott Bay for use in the animal exhibits. This study provides a descriptive tem...
Article
Full-text available
Conservation genetic techniques and considerations of the evolutionary potential of a species are increasingly being applied to species conservation. For example, effective population size (Ne) estimates are useful for determining the conservation status of species, yet accurate estimates of current Ne remain difficult to obtain. The effective popu...
Article
Full-text available
The Soundwatch Boater Education Program is a vessel monitoring and public education outreach program. Soundwatch has been run by The Whale Museum (TWM) during the whale watch season (May through September) in the Haro Strait Region of the Central Salish Sea since 1993. Data collection has been in a consistent manner since 1998 and is presented here...
Data
Soundwatch Vessel Count/Whale Survey data sheet. (JPG)
Data
Soundwatch Vessel Contact data sheet. (JPG)
Data
Maximum vessel counts from 1998–2015. (XLSX)
Data
Soundwatch observed incident numbers 1998–2015. (XLSX)
Presentation
Full-text available
An improved understanding of baleen whale body condition and hormone variability is needed to identify and assess physiological responses to anthropogenic impacts. This paucity of data is especially apparent during the foraging season. We undertook a study on the seasonally-resident population of gray whales that forage in the coastal habitat off O...
Chapter
Sharks are iconic, sometimes apex, predators found in every ocean. Because of their ecological role as predators and concern over the stability of their populations, there has been an increasing amount of work focused on shark conservation around the world in recent decades. The populations of sharks that reside in the Northeast Pacific (NEP) Ocean...
Chapter
Full-text available
Conservation genetics is an applied science that utilizes molecular tools to help solve problems in species conservation and management. It is an interdisciplinary specialty in which scientists apply the study of genetics in conjunction with traditional ecological fieldwork and other techniques to explore molecular variation, population boundaries,...
Chapter
Sharks are iconic, sometimes apex, predators found in every ocean and, as a result, they have featured prominently in the mythology, history, and fisheries of diverse human cultures around the world. Because of their regional significance to fisheries and ecological role as predators, and as a result of concern over long-term stability of their pop...
Chapter
Full-text available
Welfare effects of human interactions on river and sea otters take many forms: trapping, fishing, water borne debris, toxic elements and captivity. Animal welfare issues associated with otter trapping, especially using leghold traps, are reviewed. Different trap models are described. Box traps or padded traps are used for the live capture of otters...
Chapter
In 2015 there were a minimum of 1621 otters of eight species (Asian small-clawed otter Aonyx cinereus, Sea otter Enhydra lutris, Spotted-necked otter Hydrictis maculicollis, N.A. river otter Lontra canadensis, Marine otter Lontra felina, Neotropical otter Lontra longicaudis, Eurasian otter Lutra lutra, Smooth-coated otter Lutrogale perspicillata, a...
Chapter
Zoos and Aquariums in North America have evolved over the past few decades from institutions that exhibit animals primarily for public enjoyment to conservation organizations whose mission is to inspire and contribute significantly to wildlife conservation. The Association of Zoo and Aquariums, AZA, accredits public institutions in North America th...
Article
Full-text available
This is the first in-situ study of feeding behaviors exhibited by bluntnose sixgill sharks. Bait was placed beneath the Seattle Aquarium pier situated on the waterfront in Elliott Bay, Puget Sound, Washington at 20m of water depth. Cameras and lights were placed around the bait box to record sixgill shark presence and behavior while feeding. Analys...
Data
Sixgill manipulating a sea star. A male sixgill shark (with a visual tag) manipulating a sunflower sea star while trying to eat the bait the sea star was holding. Video taken by SCUBA diver. (MP4)
Data
Two sixgill sharks feeding at the bait station. This video shows the research site with the cage for diver protection to the right with the bait station typically center; stationary cameras for video analysis can be seen multiple times. This video includes two sixgills feeding at the bait station, both with visual tags. A biopsy is performed on the...
Data
Representative strike 2. A feeding event with a 3.3m female (with a visual tag) approaching from the right. This female does not exhibit a preparatory bite but does show a prey capture bite, rolling of the eyes, manipulation bites, and shearing manipulation via twisting and tearing. Upper jaw protrusion is seen during manipulation. Footage from the...
Data
Data set. Minimal data set associated with this article. (XLSX)
Data
Representative strike 1. A feeding event with a 2.9m male sixgill approaching the bait station from the right. The shark starts the strike in an horizontal plane, parallel with the sea floor and goes into a head-down, tail-up position during manipulation, almost upside down at one point. View of the shark is obstructed by mid-water bait multiple ti...
Data
Representative strike 3. A 3m female approaches the bait station from below and starts a strike on mid-water bait once it swims over the bait box. The strike includes a preparatory bite, capture bite, eye rolling, upper jaw protrusion and manipulation/transport bites. The sixgill then ingests the bait and swings around and strikes the benthic bait....
Article
Full-text available
Nearshore vertebrate predators such as marine mammals and otters are apex predators, and as such, act both as drivers of the ecosystems in which they live and as sentinels of environmental health. As apex predators, these wild animals at the top of the food chain often bioaccumalate persistent organic pollutants (termed POPs) widespread throughout...
Conference Paper
The Southern Sea Otter (Enhydra lutris nereis) was nearly extirpated during the late 19th century as a result of the fur trade. Following protection by the US federal government, southern sea otter populations have rebounded from a small remnant population near Big Sur California. Tremendous effort has gone into monitoring the health and population...
Article
The story of sea otters over the past 275 years chronicles their decline to near extinction and the roads to recovery that cross various conflicts, and in the end provides lessons that will aid the conservation of other threatened species and compromised ecosystems. Sea otters inspire strong human emotions ranging from adoration to disdain. They ar...
Article
Conservation genetics is the science focused on the understanding of hereditary processes and mitigating factors that endanger populations at risk of extinction. It is an interdisciplinary specialty in which geneticists explore genetic variation, with the goal of enabling resource managers to better conserve biodiversity. Sea otters offer a unique...
Article
Full-text available
The broadnose sevengill shark, Notorynchus cepedianus, a common coastal species in the eastern North Pacific, was sampled during routine capture and tagging operations conducted from 2005-2012. One hundred and thirty three biopsy samples were taken during these research operations in Willapa Bay, Washington and in San Francisco Bay, California. Gen...
Article
Full-text available
A total of 77 giant Pacific octopus, Enteroctopus dofleini, tissue samples were collected from the Oregon Coast (OR), Neah Bay Washington (NB), Puget Sound Washington (PS) and the southeast coast of Vancouver Island, British Columbia, Canada (BC) for genetic analyses. A suite of eight variable microsatellite markers developed from giant Pacific oct...
Book
Sea Otter Conservation brings together the extensive knowledge from well-respected leaders in the field, offering insight into more than 100 years of conservation and research that have resulted in recovery from near extinction. This publication assesses the issues influencing prospects for continued conservation and recovery of sea otter populatio...
Article
Sea otters are good indicators of ocean health. In addition, they are a keystone species, offering a stabilizing effect on ecosystem, controlling sea urchin populations that would otherwise inflict damage to kelp forest ecosystems. The kelp forest ecosystem is crucial for marine organisms and contains coastal erosion. With the concerns about the im...
Article
Full-text available
The bluntnose sixgill shark, Hexanchus griseus, is a widely distributed but poorly understood large, apex predator. Anecdotal reports of diver-shark encounters in the late 1990's and early 2000's in the Pacific Northwest stimulated interest in the normally deep-dwelling shark and its presence in the shallow waters of Puget Sound. Analysis of underw...
Data
Full-text available
Novel leafy seadragon (Phycodurus eques) microsatellite loci were developed via standard cloning techniques and tested for use in population genetics studies. Six out of a total of twelve microsatellites tested were usable for population analysis. Seadragon samples from Western Australia (N = 6), Southern Australia (N = 11), and a captive group (N...
Article
Full-text available
The sea otter (Enhydra lutris) is a popular exhibit animal in many zoos and aquariums worldwide. Captive sea otters from these populations are owned by the United States Fish and Wildlife Service (USFWS). The USFWS has requested that these sea otters be prevented from breeding in order to save captive space for wild rescued animals. Sea otters are...
Data
Sea otter (Enhydra lutris) populations experienced widespread reduction and extirpation due to the fur trade of the 18th and 19th centuries. We examined genetic variation within four microsatellite markers and the mitochondrial DNA (mtDNA) d-loop in one prefur trade population and compared it to five modern populations to determine potential losses...
Article
Full-text available
The sea otter (Enhydra lutris) is a popular exhibit animal in many zoos and aquariums worldwide. Captive sea otters from these populations are owned by the United States Fish and Wildlife Service (USFWS). The USFWS has requested that these sea otters be prevented from breeding in order to save captive space for wild rescued animals. Sea otters are...
Article
Full-text available
All existing sea otter, Enhydra lutris, populations have suffered at least one historic population bottleneck stemming from the fur trade extirpations of the eighteenth and nineteenth centuries. We examined genetic variation, gene flow, and population structure at five microsatellite loci in samples from five pre-fur trade populations throughout th...
Article
Full-text available
The bluntnose sixgill shark (Hexanchus griseus) is a widely distributed species found in tropical and temperate waters of every ocean, yet we know relatively little about their basic biology including their life history and population structure. From 2003–2007, we collected over 300 biopsy samples from sixgills during research operations in Puget S...
Chapter
Full-text available
of longstanding speculation by fi shermen, biologists, and California Fish and Game repre-sentatives. Sea otters are a keystone predator in kelp forests along the central California coast, and they are voracious consumers of shellfi sh. Since their return from the brink of extinction early in the 20th century, their impact on shell-fi sh population...
Article
Full-text available
The captive husbandry of giant Pacific octopuses Enteroctopus dofleini is well understood, but their endocrine signatures are not well documented. The major vertebrate reproductive hormones--estrogen, progesterone, and testosterone--and the stress-related hormone corticosterone are relatively well known for many vertebrate species. However, few stu...
Article
Full-text available
Novel sixgill shark (Hexanchus griseus) microsatellite loci were developed and tested on five shark species. A suite of microsatellite loci previously developed for lemon sharks (Negaprion brevirostris) was also tested. Data on 15 microsatellites are presented including primer sequences, number of alleles (a), observed (H(O) ) and expected heterozy...