Frank, Tamara

Hirons, Amy

Stevenson, Rachael

English

NSU Works

Nova Southeastern UniversityNSUWorksMarine & Environmental Sciences FacultyProceedings, Presentations, Speeches, Lectures Department of Marine and Environmental Sciences10-2017A Comparison of the Rate of Oxygen StoreDevelopment in Phocid SealsqRachael StevensonNova Southeastern University, rs2078@nova.eduTamara FrankNova Southeastern University, tfrank1@nova.eduAmy HironsNova Southeastern University, hirons@nova.eduFollow this and additional works at: https://nsuworks.nova.edu/occ_facpresentationsPart of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences andMeteorology CommonsThis Poster is brought to you for free and open access by the Department of Marine and Environmental Sciences at NSUWorks. It has been accepted forinclusion in Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures by an authorized administrator of NSUWorks.For more information, please contact nsuworks@nova.edu.NSUWorks CitationStevenson, Rachael; Frank, Tamara; and Hirons, Amy, "A Comparison of the Rate of Oxygen Store Development in Phocid Sealsq"(2017). Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures. 531.https://nsuworks.nova.edu/occ_facpresentations/531A Comparison of the Rate of Oxygen Store Development in Phocid SealsRachael Stevenson*, Tamara Frank, Amy C. Hironsrs2078@nova.edu, tfrank1@nova.edu, hirons@nova.edu Halmos College of Natural Sciences and Oceanography, Nova Southeastern UniversityDania Beach, FL 33004 USAAbstractPhocids have large oxygen stores that result in prolonged diving capabilities. Pups do not have fully developed stores at birth for diving and foraging and require a terrestrial post-weaning fast to develop adequate oxygen. A review of previously published data of various oxygen components in three high latitude phocid species, gray, harbor, and northern elephant seals, was conducted. Analyses of variances (ANOVA) indicates weight had a significant (p<0.05) effect on blood oxygen stores in gray seals while age class did not. Age had a significant (p<0.01) effect on blood oxygen stores in harbor seals, while age and weight had a significant (p<0.05) effect on muscle oxygen stores in northern elephant seals. Multiple comparison Steel post-hoc test indicates juveniles and adults had significantly higher blood oxygen stores than nursing, and weaned/fasting pups (p<0.05). Age and weight significantly affects the rate of O2 store development in the blood and muscle and may correlate to nursing and weaning duration necessary for pups to develop adequate oxygen stores for aerobic diving.AcknowledgementsRaw hematologic data were contributed by Ailsa Hall, Sea Mammal Research Unit, University of St. Andrews; Amber Thomas and Kathryn Ono, Marine Animal Rehabilitation and Conservation Program; and Derek Somo and Dan Crocker, Sonoma State University. Philip Thorson, UCSC, Mike Castellini, UAF, and David Rosen, UBC, are also contributing to this research. C. Blanar assisted with statistical analyses.Future Work• Raw myoglobin data has only been acquired thus far for one species. In order to conduct more rigorous analysis of Mb contribution to oxygen stores, data from other phocid species are needed• Expand analysis to include harp, hooded, Weddell, and southern elephant seals• The addition of these species will allow for comparison among subpopulations and between hemispheres• Add otariid data to compare diving ontogeny differences between familiesKey Findings• Weight significantly affected Hb and Hct in gray seals• Age class significantly affected Hb and Hct in harbor seals• Age and weight had a significant effect on Mb in weaned northern elephant seals• Nursing and weaned pups had similar Hb and Hct values adults, although there were significant increases among age classes (Figures 5 & 6)• Based on this preliminary study, pups appear to store proportionately more oxygen in their blood than their muscles• Research on individual species indicates seals do not develop greater muscle oxygen stores until they begin diving and foraging• In northern elephant seals, there was a substantial difference in the amount of oxygen stored in Hb compared to Mb during the terrestrial fasting period, which lends support to the hypothesis that Hb is more developed than Mb (Figure 7)Northern Elephant Seal• Age had a significant (p<0.01) effect on weight but not on Hb or Hct in weaned pups (Figure 7)• Age and weight had a significant (p<0.05) effect on Mb throughout the weaning period (Figure 7)Results Results- cont.IntroductionPhocids have substantial blood and muscle oxygen stores which lead to great diving capabilities. Most pups do not have fully developed oxygen stores (O2) at birth, and cannot dive immediately. Instead, their ability to store oxygen increases during the period from nursing to post-weaning. A terrestrial post-weaning fast (PWF) is crucial for pups to rapidly develop mature O2 stores. As pups age and diving becomes a regular component of daily life, muscle oxygen tends to increase while blood oxygen concentrations maintain a steady level. The rate of oxygen development may be affected by age, body weight, or differences in nursing and weaned periods among species, which may affect thediving ontogeny of pups.Gray (Halichoerus grypus), harbor (Phoca vitulina), and northern elephant seals (Mirounga angustirostris) from discrete locations were analyzed for oxygen stores (Figures 1 & 2). Northern elephant seals have significantly greater diving capacity than gray and harbor seals, which would indicate that there are differences in oxygen stores (Figure 3). Age and weight (kg) were compared within each species to determine the effects on hemoglobin (Hb), hematocrit (Hct), and myoglobin (Mb).Figure 2. Location of gray, harbor, and northern elephant seals sampled for hematology. Data were provided by Hall 1998, Sea Mammal Research Unit; Thomas and Ono 2015, Marine Animal Rehabilitation and Conservation Program; and Somo et al. 2015, Año Nuevo State Reserve.Gray Seal• Born w/o blubber• Nurse ~ 18 days• PWF 10-28 daysHarbor Seal• Born w/ blubber• Nurse 21-28 days• PWF 15-17daysNorthern Elephant Seal• Born w/o blubber• Nurse ~ 28 days• PWF ~ 2.5 monthsFigure 3. Typical and maximum dive depths of the study species (Reeves et al. 2002; Shirihai 2006; Jefferson 2008).Figure 1. Study species of young A) gray, B) harbor, and C) northern elephant seals.BA C©Justin Minns ©Alaska SeaLife Center ©Mike BairdHarbor Seal• Age had a significant (p<0.05) effect on weight and on Hb between weaned and juvenile, and weaned and adult seals (p<0.05 and p<0.01, respectively) (Figure 6)• Weight had no effect on hematology parametersGray Seal• Age had a significant (p<0.01) effect on weight but had no effect on either Hb or Hct• Weight had a significant effect on both Hb and Hct (p<0.01 and p<0.05, respectively) (Figure 5)Figure 6. Hb compared with age and weight in harbor seals. Overall• There were species specific hematologic differences• Hb was highly correlated to Hct (p<0.05, r=0.89)• Combined, age and weight had no significant effect on Hb in gray and harbor seals, but there were individual effects (Figure 4)• Only post-weaning data for northern elephant sealsFigure 4. Hb differences within species’ age class.Figure 5. Effect of weight on Hb and Hct in gray seals. Figure 7. Hb and Mb changes post-weaning in northern elephant seals. Oxygen stores is the relationship between Hb and Mb.

A Comparison of the Rate of Oxygen Store Development in Phocid Sealsq

https://nsuworks.nova.edu/cgi/viewcontent.cgi?article=1536&amp;context=occ_facpresentations

A Comparison of the Rate of Oxygen Store Development in Phocid Sealsq

Abstract

Similar works

Full text

Available Versions

NSU Works