Hematology Values, Dive Characteristics and Food Habits of ... · Hemoglobin and Packed Cell Volume...
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Acknowledgments We would like to thank Bill Walker for critical help with identifying otoliths. Many thanks to Paul Conn who analyzed the blood parameter data and to Tony Orr for valuable contributions to this poster. Karna McKinney from the AFSC Graphics Unit designed the poster. A special thanks to the officers and crew of the NOAA ship McArthur II, from which we gained access to the Bering Sea marginal ice zone to collect ribbon and spotted seal samples. Hematology Values, Dive Characteristics and Food Habits of Ribbon and Spotted Seals in the Bering Sea Heather Ziel, Josh London, Michael Cameron, Peter Boveng National Marine Mammal Laboratory, Alaska Fisheries Science Center, NMFS, NOAA, Seattle, We examined dive characteriscs, hematology parameters, and fecal samples from ribbon and spoed seals to try to ascertain whether differences in diving behavior, blood parameters, and primary prey items consumed by each species were related. Hemoglobin and Packed Cell Volume We used linear mixed models to examine the influence of species, age, and sex on hemoglobin (Hb) concentraon and packed cell volume (PCV) and found strong evidence that Hb and PCV differ significantly by species. These parameters are indicators of blood oxygen storage, a key factor in the diving ability of marine mammals. Ribbon seals have higher Hb concentraons and PCVs than spoed seals. The model for Hb concentraon also indicated that sex and age had an effect on Hb levels and that there are interacve effects among all three predictors. However, lile discernible paern could be observed when examining regression coefficients or boxplots of the raw data for age class and sex. Diving Behavior We deployed satellite-linked dive recorder tags on 24 ribbon and 14 spoed seals. Ribbon seals generally make longer and deeper dives than spoed seals. Ribbon seal dives were distributed over a wider range of depths than spoed seal dives, and some dives exceeded 600 meters. The majority of ribbon seal dives were 8-16 minutes in duraon. The majority of spoed seal dives were less than 200 meters, and most dive duraons were less than 8 minutes. Diet Ribbon (n=49) and spoed (n=29) seal scats were collected from the pack-ice edge in spring 2007-2010. Walleye pollock and Pacific herring were the two most frequently occurring prey in both ribbon and spoed seals. However, walleye pollock were more important in ribbon seal diets and Pacific herring were more important to spoed seals. Spoed seals generally had higher %FO of shallow-water prey taxa, and ribbon seals had higher %FO of benthic prey taxa. Two benthic prey taxa were only found in ribbon seals. Conclusions Models indicated Hb and PCV were higher in ribbon seals than spoed seals, and dive data results revealed that ribbon seals dive to greater depths and for longer duraon than spoed seals. Thus, physiological data supports observed dive behavior of each species. Although food habits data are limited to one season, the important prey species of each seal also support the observaon that ribbon seals are diving deeper than spoed seals. No difference in PCV among age classes may be due to the fact that we collected samples from weaned pups (YOY) and did not collect any samples from dependent pups. Pups of both species are weaned in about a month, and they are likely developing Hb and PCV stores within that me period. We may have seen differences among age if we were able to sample dependent pups. As seals grow older, increasing oxygen storage may be occurring in the muscles rather than the blood, which could also explain our finding of no difference in PCV among age classes. Future work includes idenfying bones and other prey parts collected from scats, as well as using stable isotopes to get a beer understanding of foraging ecology during other seasons. 5 10 15 20 25 30 35 Hemoglobin conc (g/dl) Ribbon.ADULT.F Spotted.ADULT.F Ribbon.SUB.F Spotted.SUB.F Ribbon.YOY.F Spotted.YOY.F Ribbon.ADULT.M Spotted.ADULT.M Ribbon.SUB.M Spotted.SUB.M Ribbon.YOY.M Spotted.YOY.M 0.4 0.5 0.6 0.7 PCV (%) Ribbon Spotted 80 60 40 20 0 20 40 60 80 Northern smoothtongue Walleye pollock Eelpout Careproctus sp. Enteroctopus dofleini Pacific cod Arctic cod Flathead sole Daubed shanny Euphausiid spp. Cottid spp. Stichaeid spp. Pleuronectid spp. Bering flounder Stout eelblenny Capelin Pacific herring % FO Percent frequency of occurrence (%FO) of prey taxa identified from otoliths Spotted seal Ribbon seal Shallow Benthic Mean hours of use by ribbon seals Mar – May (2007 – 2011) - 500 simulations Mean hours of use by spotted seals Mar – May (2007 – 2011) - 500 simulations 500 hours Mean Number of Dives 600+ 501−600 401−500 301−400 251−300 201−250 151−200 101−150 71−100 51−70 31−50 11−30 4−10 600+ 501−600 401−500 301−400 251−300 201−250 151−200 101−150 71−100 51−70 31−50 11−30 4−10 600+ 501−600 401−500 301−400 251−300 201−250 151−200 101−150 71−100 51−70 31−50 11−30 4−10 Non−Ice Ice ADULT SUB YOY Ribbon seal Spotted seal Mean Number of Dives 50+ 40−50 30−40 20−30 16−20 12−16 10−12 8−10 6−8 4−6 3−4 2−3 1−2 0−1 50+ 40−50 30−40 20−30 16−20 12−16 10−12 8−10 6−8 4−6 3−4 2−3 1−2 0−1 50+ 40−50 30−40 20−30 16−20 12−16 10−12 8−10 6−8 4−6 3−4 2−3 1−2 0−1 Non−Ice Ice ADULT SUB YOY Ribbon seal Spotted seal Locations and movements of ribbon and spotted seals during the period when we collected blood and scat and deployed satellite tags. The recommendations and general content presented in this poster do not necessarily represent the views or official position of the Department of Commerce, the National Oceanic and Atmospheric Administration, or the National Marine Fisheries Service. 3 min 1 hr 24 hr 500 hr 3 min 1 hr 24 hr 500 hr Meters Minutes Dive Depth Dive Duration ribbon seals spotted seals
Transcript of Hematology Values, Dive Characteristics and Food Habits of ... · Hemoglobin and Packed Cell Volume...
AcknowledgmentsWe would like to thank Bill Walker for critical help with identifying otoliths. Many thanks to Paul Conn who analyzed the blood parameter data and to Tony Orr for valuable contributions to this poster. Karna McKinney from the AFSC Graphics Unit designed the poster. A special thanks to the o�cers and crew of the NOAA ship McArthur II, from which we gained access to the Bering Sea marginal ice zone to collect ribbon and spotted seal samples.
Hematology Values,Dive Characteristics and Food Habits of Ribbon and Spotted Seals in the Bering SeaHeather Ziel, Josh London, Michael Cameron, Peter BovengNational Marine Mammal Laboratory, Alaska Fisheries Science Center, NMFS, NOAA, Seattle,
We examined dive characteristics, hematology parameters, and fecal samples from ribbon and spotted seals to try to ascertain whether differences in diving behavior, blood parameters, and primary prey items consumed by each species were related.
Hemoglobin and Packed Cell VolumeWe used linear mixed models to examine the influence of species, age, and sex on hemoglobin (Hb) concentration and packed cell volume (PCV) and found strong evidence that Hb and PCV differ significantly by species. These parameters are indicators of blood oxygen storage, a key factor in the diving ability of marine mammals.
Ribbon seals have higher Hb concentrations and PCVs than spotted seals.
The model for Hb concentration also indicated that sex and age had an effect on Hb levels and that there are interactive effects among all three predictors. However, little discernible pattern could be observed when examining regression coefficients or boxplots of the raw data for age class and sex.
Diving BehaviorWe deployed satellite-linked dive recorder tags on 24 ribbon and 14 spotted seals.
Ribbon seals generally make longer and deeper dives than spotted seals.
Ribbon seal dives were distributed over a wider range of depths than spotted seal dives, and some dives exceeded 600 meters. The majority of ribbon seal dives were 8-16 minutes in duration.
The majority of spotted seal dives were less than 200 meters, and most dive durations were less than 8 minutes.
DietRibbon (n=49) and spotted (n=29) seal scats were collected from the pack-ice edge in spring 2007-2010.
Walleye pollock and Pacific herring were the two most frequently occurring prey in both ribbon and spotted seals. However, walleye pollock were more important in ribbon seal diets and Pacific herring were more important to spotted seals.
Spotted seals generally had higher %FO of shallow-water prey taxa, and ribbon seals had higher %FO of benthic prey taxa. Two benthic prey taxa were only found in ribbon seals.
ConclusionsModels indicated Hb and PCV were higher in ribbon seals than spotted seals, and dive data results revealed that ribbon seals dive to greater depths and for longer duration than spotted seals. Thus, physiological data supports observed dive behavior of each species. Although food habits data are limited to one season, the important prey species of each seal also support the observation that ribbon seals are diving deeper than spotted seals.
No difference in PCV among age classes may be due to the fact that we collected samples from weaned pups (YOY) and did not collect any samples from dependent pups. Pups of both species are weaned in about a month, and they are likely developing Hb and PCV stores within that time period. We may have seen differences among age if we were able to sample dependent pups.
As seals grow older, increasing oxygen storage may be occurring in the muscles rather than the blood, which could also explain our finding of no difference in PCV among age classes.
Future work includes identifying bones and other prey parts collected from scats, as well as using stable isotopes to get a better understanding of foraging ecology during other seasons.
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Hem
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ADU
LT.F
Spot
ted.
ADU
LT.F
Rib
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SUB.
F
Spot
ted.
SUB.
F
Rib
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YOY.
F
Spot
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YOY.
F
Rib
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ADU
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Spot
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Rib
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SUB.
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PCV
(%)
Rib
bon
Spot
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80 60 40 20 0 20 40 60 80
Northern smoothtongue
Walleye pollock
Eelpout
Careproctus sp.
Enteroctopus dofleini
Pacific cod
Arctic cod
Flathead sole
Daubed shanny
Euphausiid spp.
Cottid spp.
Stichaeid spp.
Pleuronectid spp.
Bering flounder
Stout eelblenny
Capelin
Pacific herring
% FO
Percent frequency of occurrence (%FO) of prey taxa identified from otoliths
Spotted seal Ribbon seal
Shallow
Benthic
Mean hours of use by ribbon sealsMar – May (2007 – 2011) - 500 simulations
Mean hours of use by spotted sealsMar – May (2007 – 2011) - 500 simulations
500 hours
Mean Number of Dives
600+501−600401−500301−400251−300201−250151−200101−15071−10051−7031−5011−304−10
600+501−600401−500301−400251−300201−250151−200101−15071−10051−7031−5011−304−10
600+501−600401−500301−400251−300201−250151−200101−15071−10051−7031−5011−304−10
Non−Ice Ice
ADU
LTSU
BYOY
Ribbon seal Spotted seal
Mean Number of Dives
50+40−5030−4020−3016−2012−1610−128−106−84−63−42−31−20−1
50+40−5030−4020−3016−2012−1610−128−106−84−63−42−31−20−1
50+40−5030−4020−3016−2012−1610−128−106−84−63−42−31−20−1
Non−Ice Ice
ADU
LTSU
BYOY
Ribbon seal Spotted seal
Locations and movements of ribbon and spotted seals during the period when we collected blood and scat and deployed satellite tags.
The recommendations and general content presented in this poster do not necessarily represent the views or o�cial position of the Department of Commerce, the National Oceanic and Atmospheric Administration, or the National Marine Fisheries Service.
3 min
1 hr24 hr
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3 min
1 hr24 hr
500 hr
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Dive Depth Dive Duration
ribbon seals spotted seals
