Search results | Digital Commons of Moss Landing Marine Laboratories

Title: Internesting movements and behavior of hawksbill turtles (Ertemochelys imbricata) around Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands
Author: Starbird, Hillis-Starr, Harvey, Eckert

Title: Prey and plastic ingestion of Pacific Northern Fulmars (Fulmarus glacialis rogersii) from Monterey Bay, California
Description: Marine plastic pollution affects seabirds, including Pacific Northern Fulmars (Fulmarus glacialis rodgersii), that feed at the surface and mistake plastic for prey or incidentally ingest it. Direct and indirect health issues can result, including satiety and possibly leading to inefficient foraging. Our objective was to examine fulmar body condition, identify cephalopod diet to species, enumerate and weigh ingested plastic, and determine if prey number and size were correlated with ingested plastics in beach-cast fulmars wintering in Monterey Bay California (2003, n= 178: 2007, n= 185). Fulmars consumed mostly Gonatus pyros, G. onyx, and G. californiensis of similar size for both years. We found a significant negative correlation between pectoral muscle index and average size of cephalopod beaks per stomach; a significant increase in plastic categories between 2003 and 2007; and no significant correlation between number and mass of plastic compared with number and size of prey for either year. © 2014 Elsevier Ltd.
Author: Donnelly-Greenan, Harvey, Nevins, Hester, Walker

Title: Survival probabilities and movements of harbor seals in central California
Description: Article in Press, Harbor seal numbers and population trajectories differ by location in central California. Within San Francisco Bay (SFB) counts have been relatively stable since the 1972 Marine Mammal Protection Act, but in coastal areas like Tomales Bay (TB), counts increased before stabilizing in the 1990s. Emigration, poor survival, and environmental effects have been hypothesized as contributors to differences between trajectories; however, basic demographic data were not available to evaluate these hypotheses. We monitored 32 radio-tagged adult females (SFB n = 17, TB n = 15) for 20 mo (2011-2013), and estimated survival, resight, and movement probabilities using mark-resight analyses and multistate mark-resight models. Annual survival probability for both sites was 0.90 (95% CI = 0.18-0.99). Six seals were observed moving between locations resulting in an estimated probability of 0.042 (95% CI = 0.023-0.076) per month equal movement between sites. Resight probability was less in SFB relative to TB, likely due to differential haul-out access, area surveyed, visibility, and resight effort. Because of wide confidence intervals and low precision of these first estimates of adult female harbor seal survival in California, this demographic must be further examined to dismiss its contribution to differing population trajectories. Using aerial survey data, we estimated 950 harbor seals in SFB (95% CI = 715-1,184) confirming numbers are still stable.
Author: Manugian, Greig, Lee, Becker, Allen, Lowry, Harvey

Title: An integrated approach for assessing translocation as an effective conservation tool for Hawaiian monk seals
Description: For threatened and endangered species, translocations have been widely used to mitigate multiple sources of mortality that threaten population recovery. Although numerous Hawaiian monk seals Neomonachus schauinslandi have been translocated for a variety of purposes, few monk seal translocations have addressed the problem of prey limitation. To assess the efficacy of using translocations to mitigate reduced prey availability, 12 weanling monk seals were translocated with pre-release health screening and post-release monitoring. Specifically, the health, foraging behavior, habitat use, and survival of translocated seals were compared with those of 17 monk seals resident to the release site. There was little evidence of infectious diseases in translocated and resident seals, although Chlamydophila abortus antibodies and enteric bacteria were detected in many individuals. Translocated and resident weanling seals also demonstrated similar diving, movements, and habitat use, whereas resident adult seals had greater variability in foraging patterns. First-year survival for translocated weanlings (50%, n = 12) and non-translocated weanlings at the donor (31%, n = 36) and recipient sites (69%, n = 16) was related to weaning body size, with larger individuals having greater survivorship. These results supported 3 main conclusions that have important consequences for future translocation and population recovery efforts: (1) there was minimal risk of exposing seals to novel infectious diseases as a result of translocation; (2) individuals translocated with limited foraging experience rapidly adapted to their post-release environment; and (3) translocation for the purpose of mitigating prey limitation is a viable and important conservation tool for Hawaiian monk seals. © Outside the USA the US Government 2017., Article
Author: Norris, Littnan, Gulland, Baker, Harvey

Title: Testing tag attachments to increase the attachment duration of archival tags on baleen whales
Description: As biologging technology has advanced to study whale behavior, various tag attachment methods have been developed. Suction cup attachments were developed for short-term (<24 h) studies using high-resolution archival tags, and implantable or dart attachments were developed for long-term (months) studies using coarse-resolution satellite tags. The purpose of this study was to test various tag attachment configurations to increase the deployment duration of archival tags while minimizing potential physical impacts to the whale.
Author: Szesciorka, Calambokidis, Harvey

Title: Acoustic evidence that harbor porpoises (Phocoena phocoena) avoid bottlenose dolphins (Tursiops truncatus)
Author: Jacobsen, Forney, Harvey

Title: Dynamics of vibrio with virulence genes detected in Pacific harbor seals (Phoca vitulina richardii) off California: Implications for marine mammal health
Description: Given their coastal site fidelity and opportunistic foraging behavior, harbor seals (Phoca vitulina) may serve as sentinels for coastal ecosystem health. Seals using urbanized coastal habitat can acquire enteric bacteria, including Vibrio that may affect their health. To understand Vibrio dynamics in seals, demographic and environmental factors were tested for predicting potentially virulent Vibrio in free-ranging and stranded Pacific harbor seals (Phoca vitulina richardii) off California. Vibrio prevalence did not vary with season and was greater in free-ranging seals (29 %, n = 319) compared with stranded seals (17 %, n = 189). Of the factors tested, location, turbidity, and/or salinity best predicted Vibrio prevalence in free-ranging seals. The relationship of environmental factors with Vibrio prevalence differed by location and may be related to oceanographic or terrestrial contributions to water quality. Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio cholerae were observed in seals, with V. cholerae found almost exclusively in stranded pups and yearlings. Additionally, virulence genes (trh and tdh) were detected in V. parahaemolyticus isolates. Vibrio cholerae isolates lacked targeted virulence genes, but were hemolytic. Three out of four stranded pups with V. parahaemolyticus (trh+ and/or tdh+) died in rehabilitation, but the role of Vibrio in causing mortality is unclear, and Vibrio expression of virulence genes should be investigated. Considering that humans share the environment and food resources with seals, potentially virulent Vibrio observed in seals also may be of concern to human health. © 2013 Springer Science+Business Media New York., Marine Mammals, Birds & Turtles Harbor Seals, CODEN: MCBEB
Author: Hughes, Greig, Miller, Byrne, Gulland, Harvey
Date: 2013-01-01T00:00:00Z

Title: An application of underwater imaging for marine vertebrate ecology,
Description: Moss Landing Marine Laboratories (MLML) and the National Marine Fisheries Service have conducted leatherback (Dermochelys coriacea) sea turtle research for the last eight years. Leatherbacks come to the central California coast to forage on concentrations of jellyfish that accumulate in the nutrient rich waters over the coastal shelf. The research includes tracking leatherbacks across the Pacific Ocean with satellite transmitters, suction-cup attachment of time-depth-recorders (TDR) tags, and collection of morphological data. The TDRs are used to record the dive profiles of the leatherbacks foraging for jellyfish near shore. The TDR data provide graphical representation of the dive profile, showing decent and ascent rates, along with variations or deviations in the ascent pattern. This paper describes an application of a modest, but unique underwater imagining system designed and constructed at MLML to answer some of the questions inspired by the dive profiles. MLML's Turtle Cam synchronizes dive profiles with video images, providing researchers with a tool that is giving new insights to leatherback foraging ecology. ©2010 IEEE., Marine Mammals, Birds & Turtles, Art. No.: 5664044, ,
Author: Watson, Benson, Harvey
Date: 2010-01-01T00:00:00Z

Title: Variability in reactions of Pacific harbor seals, Phoca vitulina richardsi, to disturbance
Description: Disturbances to harbor seals, Phoca vitulina richardsi, during 1991 and 1992 pupping seasons were observed at Puffin Island, Clements Reef, and Skipjack Island in Washington state. Harassment (≥ one seal entering the water) of seals ashore was common (≥71% of survey days) and primarily caused by powerboat operators approaching to observe seals. Recovery (number of seals on a haul-out site returned to preharassment levels) following a harassment was less at Puffin Island (19%) than at Clements Reef (54%) and Skipjack Island (45%). Additionally, seals were more vigilant (P<0.003) at Puffin Island than at the other two locations. These results indicated that seals at Puffin Island were less tolerant of disturbance than seals at other sites. This could possibly be attributed to a greater (P<0.05) percentage of pups ashore (17%) than at Clements Reef (3%) and Skipjack Island (3%). Because of this, we expected that powerboats would disturb seals from greater distances at Puffin Island. To test this, we used a theodolite to determine distance between seals and an approaching vessel at Puffin Island and Clements Reef. There was, however, no significant (P>0.05) difference in distances at which disturbances occurred. The most notable difference in distance of disturbance was between initial and subsequent harassments during a haul-out period. Those seals remaining or returning to shore after a harassment were more tolerant of powerboats, allowing significantly (P<0.05) closer approaches than those initially harassed. Seals detected (head raised and oriented toward the potential disturbance) a powerboat at a mean distance of 264 m, and harassments occurred when boats approached, on average, to within 144 m. Results of this study exemplify the variability in reaction to disturbance and the necessity for considering these differences for minimizing disturbance., Cited By (since 1996):29, CODEN: FSYBA, Marine Mammals, Birds & Turtles Harbor Seals
Author: Suryan, Harvey
Date: 1999-01-01T00:00:00Z

Title: Trace element concentrations in the Pacific harbor seal (Phoca vitulina richardii) in central and northern California
Description: To determine concentrations of trace elements (THg, MeHg, Se, and Pb) in tissues of the Pacific harbor seal (Phoca vitulina richardii), live (n = 186) and dead seals (n = 53) were sampled throughout central and northern California from March 2003 to January 2005. There were significant differences in THg concentrations in blood and hair based on age (p < 0.001). Adult male harbor seals had greater THg concentrations in their hair than adult female harbor seals (p < 0.003). THg concentrations in liver increased linearly with age and δ15N (p < 0.001); whereas, MeHg concentrations in liver increased exponentially until approximately 5 years of age with an asymptote at 1.3 μg/g wet weight. MeHg expressed as a percentage of THg (%MeHg) was best described by a decay function (r2 = 0.796, p < 0.001), decreasing to a minimum at 4 years of age. Hepatic Se increased with age and was in equimolar ratios with THg in adults; whereas, molar ratio of Se:THg in pups deviated from a 1:1 ratio. Significant differences among study locations in THg concentrations in blood and hair were not detected. Assessing the possible effect of sampling location on Hg concentrations, however, was confounded and limited by lack of equal sample sizes for basic age and sex cohorts, a common dilemma in pinniped research. © 2006 Elsevier B.V. All rights reserved., Cited By (since 1996):26, Marine Mammals, Birds & Turtles Harbor Seals, CODEN: STEVA
Author: Brookens, Harvey, O'Hara
Date: 2007-01-01T00:00:00Z