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Keenan M, Misarti N, Horstmann L, Crawford SG, O'Hara T, Rea LD, Avery JP. Total mercury concentrations in Steller sea lion bone: Variability among locations and elements. MARINE POLLUTION BULLETIN 2024; 203:116471. [PMID: 38754323 DOI: 10.1016/j.marpolbul.2024.116471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/03/2024] [Accepted: 05/04/2024] [Indexed: 05/18/2024]
Abstract
Mercury is a global contaminant that bioaccumulates in a tissue-specific manner in long-lived predators such as Steller sea lions (SSL). Bone is a well-preserved material amenable for studying millennial scale trends; however, little is known about the distribution and variability of total mercury concentrations ([THg]) within individual bones and among bone elements in SSL. We assessed SSL bone [THg] variability with respect to physiologic age, bone type, longitudinally within a bone, and among bone elements. Pup bones (mean ± SD; 31.4 ± 13.58 ppb) had greater [THg] than adults (7.9 ± 1.91 ppb). There were greater and more variable [THg] within individual long bones near epiphyses compared to mid-diaphysis. Pup spongy bone in ribs (62.7 ± 44.79 ppb) had greater [THg] than long bones (23.5 ± 8.83 ppb) and phalanges (19.6 ± 10.78 ppb). These differences are likely due to variability in bone composition, growth, and turnover rate. This study informs standardized sampling procedures for [THg] in bone to improve interpretations of mercury variability over time and space.
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Affiliation(s)
- Mary Keenan
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska, 1764 Tanana Loop, PO Box 75 5910, Fairbanks, AK 99775, USA; College of Fisheries and Ocean Sciences, University of Alaska, 2150 Koyukuk Drive, PO Box 757220, Fairbanks, AK 99775, USA.
| | - Nicole Misarti
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska, 1764 Tanana Loop, PO Box 75 5910, Fairbanks, AK 99775, USA
| | - Lara Horstmann
- College of Fisheries and Ocean Sciences, University of Alaska, 2150 Koyukuk Drive, PO Box 757220, Fairbanks, AK 99775, USA
| | - Stephanie G Crawford
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska, 1764 Tanana Loop, PO Box 75 5910, Fairbanks, AK 99775, USA
| | - Todd O'Hara
- Veterinary Integrative Biosciences, School of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 402 Raymond Stotzer Pkwy, College Station, TX 77843, USA
| | - Lorrie D Rea
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska, 1764 Tanana Loop, PO Box 75 5910, Fairbanks, AK 99775, USA
| | - Julie P Avery
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska, 1764 Tanana Loop, PO Box 75 5910, Fairbanks, AK 99775, USA
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McClintock BT, Lander ME. A multistate Langevin diffusion for inferring behavior-specific habitat selection and utilization distributions. Ecology 2024; 105:e4186. [PMID: 37794831 DOI: 10.1002/ecy.4186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 06/29/2023] [Accepted: 09/07/2023] [Indexed: 10/06/2023]
Abstract
The identification of important habitat and the behavior(s) associated with it is critical to conservation and place-based management decisions. Behavior also links life-history requirements and habitat use, which are key to understanding why animals use certain habitats. Animal population studies often use tracking data to quantify space use and habitat selection, but they typically either ignore movement behavior (e.g., foraging, migrating, nesting) or adopt a two-stage approach that can induce bias and fail to propagate uncertainty. We develop a habitat-driven Langevin diffusion for animals that exhibit distinct movement behavior states, thereby providing a novel single-stage statistical method for inferring behavior-specific habitat selection and utilization distributions in continuous time. Practitioners can customize, fit, assess, and simulate our integrated model using the provided R package. Simulation experiments demonstrated that the model worked well under a range of sampling scenarios as long as observations were of sufficient temporal resolution. Our simulations also demonstrated the importance of accounting for different behaviors and the misleading inferences that can result when these are ignored. We provide case studies using plains zebra (Equus quagga) and Steller sea lion (Eumetopias jubatus) telemetry data. In the zebra example, our model identified distinct "encamped" and "exploratory" states, where the encamped state was characterized by strong selection for grassland and avoidance of other vegetation types, which may represent selection for foraging resources. In the sea lion example, our model identified distinct movement behavior modes typically associated with this marine central-place forager and, unlike previous analyses, found foraging-type movements to be associated with steeper offshore slopes characteristic of the continental shelf, submarine canyons, and seamounts that are believed to enhance prey concentrations. This is the first single-stage approach for inferring behavior-specific habitat selection and utilization distributions from tracking data that can be readily implemented with user-friendly software. As certain behaviors are often more relevant to specific conservation or management objectives, practitioners can use our model to help inform the identification and prioritization of important habitats. Moreover, by linking individual-level movement behaviors to population-level spatial processes, the multistate Langevin diffusion can advance inferences at the intersection of population, movement, and landscape ecology.
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Affiliation(s)
- Brett T McClintock
- Marine Mammal Laboratory, Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, Washington, USA
| | - Michelle E Lander
- Marine Mammal Laboratory, Alaska Fisheries Science Center, NOAA, National Marine Fisheries Service, Seattle, Washington, USA
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Warlick AJ, Johnson DS, Gelatt TS, Converse SJ. Environmental drivers of demography and potential factors limiting the recovery of an endangered marine top predator. Ecosphere 2022. [DOI: 10.1002/ecs2.4325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Amanda J. Warlick
- School of Aquatic and Fishery Sciences University of Washington Seattle Washington USA
| | - Devin S. Johnson
- Pacific Islands Fisheries Science Center National Marine Fisheries Service Honolulu Hawaii USA
| | - Tom S. Gelatt
- Marine Mammal Laboratory Alaska Fisheries Science Center, National Marine Fisheries Service Seattle Washington USA
| | - Sarah J. Converse
- U.S. Geological Survey, Washington Cooperative Fish and Wildlife Research Unit, School of Environmental and Forest Sciences & School of Aquatic and Fishery Sciences University of Washington Seattle Washington USA
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Keogh MJ, Charapata P, Fadely BS, Zeppelin T, Rea L, Waite JN, Burkanov V, Marshall C, Jones A, Sprowls C, Wooller MJ. Whiskers as a novel tissue for tracking reproductive and stress-related hormones in North Pacific otariid pinnipeds. CONSERVATION PHYSIOLOGY 2021; 9:coaa134. [PMID: 33489238 PMCID: PMC7808128 DOI: 10.1093/conphys/coaa134] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/07/2020] [Accepted: 12/15/2020] [Indexed: 05/30/2023]
Abstract
Keratinized tissues, including whiskers, are ideal for acquiring a record of physiological parameters. Most tissues provide a snapshot of physiological status; however, whiskers may support longitudinal sampling for reproductive and stress-related hormones, if hormones are incorporated as whiskers grow and concentrations change with physiological state. Whiskers from female Steller sea lions (Eumetopias jubatus) and northern fur seals (Callorhinus ursinus) were serially sectioned and pulverized and steroid hormones were extracted. Standard methods were used to validate enzyme immunoassay kits for cortisol, progesterone, 17β-estradiol and testosterone. All hormones were measurable in whisker segments from both species with progesterone concentrations showing cyclical patterns, which appear to signify previous pregnancies or luteal phases. Yearly progesterone concentrations were greater in years a pup was produced compared with years when no pup was observed. Free-ranging female Steller sea lions had reproductive rates between 0 and 1.0 (0.53 ± 0.33, n = 12) using a yearly progesterone concentration of 30 pg/mg or greater to classify a reproductive year as producing a pup and below 30 pg/mg as non-reproductive. Cortisol concentrations were greater near the root and rapidly declined, lacking any obvious patterns, throughout the rest of the whisker. Progesterone and testosterone concentrations were able to help determine sex of unknown individuals. Immunohistochemistry revealed that steroid hormones most likely do not leach out of whiskers based on the deposition patterns of progesterone and cortisol being present throughout the whisker length. Overall, measuring steroid hormones in whiskers can reveal individual reproductive histories over multiple years in sea lions and fur seals. Cyclical patterns of δ15N were useful for identifying periods of up to ~10 years of growth within whiskers, and measuring both stable isotopes and hormones may be useful for differentiating periods of active gestation from diapause and potentially track multi-year reproductive histories of female otariids.
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Affiliation(s)
- Mandy J Keogh
- Division of Wildlife Conservation, Alaska Department of Fish and Game, P.O. Box 110024 Douglas, AK 99811-0024, USA
| | - Patrick Charapata
- Division of Wildlife Conservation, Alaska Department of Fish and Game, 1300 College Road, Fairbanks, AK 99701, USA
- Biology Department, Baylor University, One Bear Place #97388, Waco, TX 76798, USA
| | - Brian S Fadely
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - Tonya Zeppelin
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - Lorrie Rea
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Jason N Waite
- Division of Wildlife Conservation, Alaska Department of Fish and Game, P.O. Box 110024 Douglas, AK 99811-0024, USA
| | - Vladimir Burkanov
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115, USA
- Kamchatka Branch of the Pacific Geographical Institute Far East Branch, Russian Academy of Sciences, Petropavlovsk-Kamchatsky 683000, Russia
| | - Chris Marshall
- Department of Marine Biology, Texas A&M University, Galveston Campus, Galveston, TX 77553, USA
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Aubree Jones
- Department of Marine Biology, Texas A&M University, Galveston Campus, Galveston, TX 77553, USA
| | - Caitlin Sprowls
- Department of Marine Biology, Texas A&M University, Galveston Campus, Galveston, TX 77553, USA
| | - Matthew J Wooller
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
- Alaska Stable Isotope Facility, Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
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Hastings KK, Johnson DS, Pendleton GW, Fadely BS, Gelatt TS. Investigating life-history traits of Steller sea lions with multistate hidden Markov mark-recapture models: Age at weaning and body size effects. Ecol Evol 2021; 11:714-734. [PMID: 33520160 PMCID: PMC7820167 DOI: 10.1002/ece3.6878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/03/2020] [Accepted: 09/10/2020] [Indexed: 11/07/2022] Open
Abstract
The duration of offspring care is critical to female fitness and population resilience by allowing flexibility in life-history strategies in a variable environment. Yet, for many mammals capable of extended periods of maternal care, estimates of the duration of offspring dependency are not available and the relative importance of flexibility of this trait on fitness and population viability has rarely been examined. We used data from 4,447 Steller sea lions Eumetopias jubatus from the Gulf of Alaska and multistate hidden Markov mark-recapture models to estimate age-specific weaning probabilities. Maternal care beyond age 1 was common: Weaning was later for animals from Southeast Alaska (SEAK) and Prince William Sound (PWS, weaning probabilities: 0.536-0.648/0.784-0.873 by age 1/2) compared with animals born to the west (0.714-0.855/0.798-0.938). SEAK/PWS animals were also smaller than those born farther west, suggesting a possible link. Females weaned slightly earlier (+0.080 at age 1 and 2) compared with males in SEAK only. Poor survival for weaned versus unweaned yearlings occurred in southern SEAK (female survival probabilities: 0.609 vs. 0.792) and the central Gulf (0.667 vs. 0.901), suggesting poor conditions for juveniles in these areas. First-year survival increased with neonatal body mass (NBM) linearly in the Gulf and nonlinearly in SEAK. The probability of weaning at age 1 increased linearly with NBM for SEAK animals only. Rookeries where juveniles weaned at earlier ages had lower adult female survival, but age at weaning was unrelated to population trends. Our results suggest the time to weaning may be optimized for different habitats based on long-term average conditions (e.g., prey dynamics), that may also shape body size, with limited short-term plasticity. An apparent trade-off of adult survival in favor of juvenile survival and large offspring size in the endangered Gulf of Alaska population requires further study.
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Affiliation(s)
- Kelly K. Hastings
- Division of Wildlife ConservationAlaska Department of Fish and GameJuneauAlaskaUSA
| | - Devin S. Johnson
- NOAA FisheriesAlaska Fisheries Science CenterSeattleWashingtonUSA
| | - Grey W. Pendleton
- Division of Wildlife ConservationAlaska Department of Fish and GameJuneauAlaskaUSA
| | - Brian S. Fadely
- NOAA FisheriesAlaska Fisheries Science CenterSeattleWashingtonUSA
| | - Thomas S. Gelatt
- NOAA FisheriesAlaska Fisheries Science CenterSeattleWashingtonUSA
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Rea LD, Castellini JM, Avery JP, Fadely BS, Burkanov VN, Rehberg MJ, O'Hara TM. Regional variations and drivers of mercury and selenium concentrations in Steller sea lions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 744:140787. [PMID: 32717470 DOI: 10.1016/j.scitotenv.2020.140787] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/01/2020] [Accepted: 07/04/2020] [Indexed: 06/11/2023]
Abstract
Mercury (Hg) can be neurotoxic to mammals and impact reproduction, whereas selenium (Se) is an important antioxidant known to ameliorate some adverse effects of Hg. Total Hg concentrations ([THg]) were measured in lanugo (pelage grown in utero) of 812 Steller sea lion (Eumetopias jubatus) pups across Alaska and Russia to assess fetal exposure during late gestation. The molar ratio of total Se to THg (TSe:THg) was determined in whole blood collected from 291 pups. Stable isotope ratios of carbon and nitrogen were measured in sections of vibrissae (whiskers, n = 498) and in lanugo (n = 480) of pups grown during late gestation to track diet variations among adult females that can drive Hg and Se exposure during this critical fetal development period. Lanugo [THg] ranged from 1.4 to 73.7 μg/g dry weight with the lowest median [THg] in Southeast Alaska. Pups from the Western Aleutian Islands had higher median lanugo [THg] than pups from other metapopulations in Alaska. Over 25% of pups in the Western Aleutian Islands had [THg] above published risk thresholds (20 μg/g) for other mammals. Whole blood molar TSe:THg was significantly lower in the Western Aleutian Islands and in some parts of the Central Aleutian Islands with higher molar ratios found in the Eastern Aleutian Islands and Central Gulf of Alaska. This suggests a limitation on potential protective functions of Se in the western regions with the highest relative [THg]. The Central Aleutian Island pups with [THg] over 20 μg/g had higher δ15N ratios than pups with lower [THg] suggesting dams consuming higher trophic level prey is a key driver for Hg exposure. However, regional differences likely reflect variability in diet of the dam during gestation and in Hg food web dynamics between oceanic regimes east and west of key passes in the Aleutian Islands.
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Affiliation(s)
- L D Rea
- Institute of Northern Engineering, Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, USA; Alaska Department of Fish and Game, Division of Wildlife Conservation, Anchorage, AK 99518, USA.
| | - J M Castellini
- Department of Veterinary Medicine, College of Natural Sciences and Mathematics, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - J P Avery
- Institute of Northern Engineering, Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - B S Fadely
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98115, USA.
| | - V N Burkanov
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98115, USA; Kamchatka Branch of the Pacific Geographical Institute, Far East Branch of Russian Academy of Sciences, 6 Partizanskaya Street, Petropavlovsk-Kamchatsky 683000, Russia.
| | - M J Rehberg
- Alaska Department of Fish and Game, Division of Wildlife Conservation, Anchorage, AK 99518, USA.
| | - T M O'Hara
- Department of Veterinary Medicine, College of Natural Sciences and Mathematics, University of Alaska Fairbanks, Fairbanks, AK 99775, USA; Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
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