Article
Environmental Sciences
Jamie N. Womble, Perry J. Williams, Robert W. McNabb, Anupma Prakash, Rudiger Gens, Benjamin S. Sedinger, Cheyenne R. Acevedo
Summary: The study quantified seasonal and annual changes in ice habitat for harbor seals in Johns Hopkins Inlet, Glacier Bay National Park in southeastern Alaska. It found that there is consistently more ice in the fjord during the pupping season in June than during the molting season in August, likely driven by seasonal variation in physical processes influencing calving dynamics of tidewater glaciers.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Marine & Freshwater Biology
Chelsea E. Anderson, Karisa Tang, Courtney Pace, David A. S. Rosen, Martin Haulena
Summary: Between 2012 and 2022, the Vancouver Aquarium Marine Mammal Rescue Centre successfully sedated harbor seal pups using an injectable protocol of butorphanol and midazolam. The sedation duration ranged from 14 to 52 minutes, and the maximum sedation was achieved within an average of 8.5 minutes. This protocol proved to be effective for physical examinations, minimally invasive diagnostic procedures, and as a premedication for general anesthesia in stabilized young harbor seals.
MARINE MAMMAL SCIENCE
(2023)
Article
Zoology
Shawna A. Karpovich, John P. Skinner, Carlene N. Miller, Lori K. Polasek, Grey W. Pendleton
Summary: Accurate estimation of whisker growth and shedding timing is crucial for interpreting biochemical information. This study examined harbor seal whisker growth and shedding and found an asymptotic growth pattern as well as significant variation in shedding dates among individuals and follicle positions.
CANADIAN JOURNAL OF ZOOLOGY
(2022)
Article
Marine & Freshwater Biology
Samantha Sangster, Martin Haulena, Chad Nordstrom, Joseph K. Gaydos
Summary: This study compared the movements and survival of rehabilitated harbor seal pups released in different years with wild seal pups, showing that rehabilitated pups traveled significantly farther daily and cumulatively. The differences in transmission duration, total cumulative distance, and average daily distance varied annually.
MARINE MAMMAL SCIENCE
(2021)
Article
Marine & Freshwater Biology
Samanta Seganfreddo, Jonas Teilmann, Floris M. van Beest, Anders Galatius
Summary: Surveys were conducted in Denmark to assess pup production of harbor seals during the assumed breeding season peak. The best-performing model for analyzing the effects of weather conditions and timing of surveys on pup counts included date and wind speed. Pup counts grew from the start of the observation period and were predicted to peak on June 22.
MARINE MAMMAL SCIENCE
(2023)
Article
Zoology
Cynthia L. Christman, Josh M. London, Paul B. Conn, Stacie K. Hardy, Gavin M. Brady, Shawn P. Dahle, Benjamin X. Hou, Heather L. Ziel
Summary: Aerial surveys of harbor seals in the Aleutian Islands of Alaska have traditionally relied on human visual detections. However, due to the small numbers and inconspicuousness of harbor seals in this region, accurate surveying is challenging. To improve detections, a study compared visual detections from color photographs with thermal detections from infrared images. The thermal method detected more seals early in the day, with greater cloud cover and more experienced observers. Incorporating thermal technology into the existing monitoring program for harbor seals in the Aleutian Islands could be beneficial, but differences need to be controlled for if new survey methods based on thermal detection are implemented.
Article
Physiology
William D. Paterson, Simon E. Moss, Ryan Milne, John I. Currie, Dominic J. McCafferty, Dave Thompson
Summary: The study found that harbor seals have higher metabolic rates when hauled out during molting, especially in the early stages of haul-out. Oxygen consumption peaks in the first 40 minutes post-haul-out and then decreases but remains relatively high. Factors such as air temperature, feed heat increment, and body size all influence the metabolic rate of harbor seals.
PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY
(2021)
Article
Multidisciplinary Sciences
Mila Varola, Laura Verga, Marlene Gunda Ursel Sroka, Stella Villanueva, Isabelle Charrier, Andrea Ravignani
Summary: The study showed that some seal pups reacted more to familiar vocalizations, with longer duration, when presented with playback of familiar or unfamiliar pup sounds. However, statistical analysis revealed no significant difference between the conditions. There was also no significant asymmetry in orientation towards familiar and unfamiliar sounds. Further research with a larger sample size is needed to confirm this hypothesis.
Article
Multidisciplinary Sciences
A. Pacheco-Sandoval, A. Lago-Leston, A. Abadia-Cardoso, E. Solana-Arellano, Y. Schramm
Summary: Dietary changes are the main factor causing variations in the composition of gut microbiota in harbor seals. Age and sex have significant effects on the microbiota, with adults and females having a greater microbial richness. The transition from a milk-based to a solid diet in pups is associated with changes in microbial pathways. Higher metabolic stress is observed in pups during the late breeding season when they are weaned and start intermittent fasting.
SCIENTIFIC REPORTS
(2022)
Article
Veterinary Sciences
Nanett Kvist Nikolaisen, Mikkel Lindegaard, Ulrike Lyhs, Mikael Lenz Strube, Mette Sif Hansen, Tina Struve, Mariann Chriel, Lars Bogo Jensen, Karl Pedersen
Summary: This study reports the first finding of S. phocae infection in farmed mink, with close relations between isolates from mink and seals. The infected animals showed symptoms such as pulmonary infections and septicemia, indicating S. phocae is associated with the pathology of the infection. Further research is required to determine if S. phocae is establishing as a commensal organism in farmed mink.
RESEARCH IN VETERINARY SCIENCE
(2021)
Article
Ecology
Willian T. A. F. Silva, Elio Bottagisio, Tero Harkonen, Anders Galatius, Morten Tange Olsen, Karin C. Harding
Summary: Conservation efforts have focused on depleted marine mammal populations, but many have recovered to historical levels; new management strategies and models are needed for ecological risk assessment; a study on harbor seal metapopulation in Swedish and Danish waters shows that the population is close to carrying capacity and faces various future stressors.
Article
Environmental Sciences
Eric Gismondi, Lucienne Daneels, France Damseaux, Kristina Lehnert, Ursula Siebert, Krishna Das
Summary: This preliminary study investigated the potential correlations between trace elements concentrations in red blood cells and oxidative stress biomarkers assessed in serum of male and female P. vitulina. The study found significant positive and negative correlations between biomarkers and trace element concentrations, suggesting that the studied biomarkers could be useful for the assessment of oxidative stress in harbour seals exposed to trace elements. Further research with larger sample sizes is needed to better understand their specific associations.
MARINE POLLUTION BULLETIN
(2021)
Article
Veterinary Sciences
Courtney N. Pace, Martin Haulena, Hannah E. Drumm, Lindsaye Akhurst, Stephen A. Raverty
Summary: A retrospective study was conducted to categorize and describe the causes of mortality in harbor seals along the British Columbia coast. The study found that infectious disease was the most common cause of death, with pups being the most affected age group and Phocid herpesvirus-1 infection being a significant factor.
JOURNAL OF WILDLIFE DISEASES
(2023)
Article
Marine & Freshwater Biology
Victoria M. Neises, Shawna A. Karpovich, Mandy J. Keogh, Stephen J. Trumble
Summary: Pregnancy and lactation are energetically expensive processes for female mammals and have significant impacts on species-specific reproductive strategies. The lactation strategy of harbor seals is believed to be intermediate between sea lions and true seals. This study characterized the fatty acid composition of blubber in pregnant and lactating harbor seals and compared it to other pinnipeds. The results showed that pregnant harbor seals prioritize the storage of polyunsaturated fatty acids (PUFAs) in their blubber, while lactating harbor seals exhibit similar fatty acid profiles to other true seals.
Article
Marine & Freshwater Biology
Justine Cole, David Fraser
Summary: A study examined veterinary records of 718 unweaned Pacific harbor seal pups to identify clinical factors associated with preweaning survival, finding that physical, serum chemical, and hematological variables were related to survival likelihood. A decision tree model based on serum concentrations of phosphorus, sodium, and calcium successfully stratified the pups into clinical subgroups according to their preweaning mortality risk, guiding care towards high-risk pups for better outcomes.
MARINE MAMMAL SCIENCE
(2021)