Population structure of North Pacific humpback whales on their feeding grounds revealed by stable carbon and nitrogen isotope ratios

Witteveen, Briana H.; Worthy, Graham A. J.; Wynne, Kate M.; Roth, James D.

doi:10.3354/meps07900

Cited by 47 publications

(69 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Potential sources of contaminants to Steller sea lions (Eumetopias jubatus) throughout the Gulf of Alaska and Aleutian Islands have been examined [56], but no specific point sources are known that could account for the higher levels observed. Stable nitrogen isotope analyses [57] do not provide support for the hypothesis that humpback whales in the Shumagin Islands feed at higher trophic levels compared with whales from adjoining areas, thereby experiencing greater bioaccumulation of POPs. Mean trophic level for western Gulf of Alaska samples was similar to that of eastern Aleutian Islands and Bering Sea; highest trophic level values in the North Pacific were found for animals sampled in the northern Gulf of Alaska and along the west coasts of the United States and Canada [57].…”

Section: Ecological and Biological Factors Affecting Contaminant Loadsmentioning

confidence: 62%

“…Stable nitrogen isotope analyses [57] do not provide support for the hypothesis that humpback whales in the Shumagin Islands feed at higher trophic levels compared with whales from adjoining areas, thereby experiencing greater bioaccumulation of POPs. Mean trophic level for western Gulf of Alaska samples was similar to that of eastern Aleutian Islands and Bering Sea; highest trophic level values in the North Pacific were found for animals sampled in the northern Gulf of Alaska and along the west coasts of the United States and Canada [57]. Therefore, regional differences in prey do not appear to explain the higher levels observed in western Gulf of Alaska animals.…”

Section: Ecological and Biological Factors Affecting Contaminant Loadsmentioning

confidence: 62%

See 1 more Smart Citation

Geographic variation of persistent organic pollutant levels in humpback whale (Megaptera novaeangliae) feeding areas of the North Pacific and North Atlantic

Elfes

VanBlaricom

Boyd

et al. 2010

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Abstract-Seasonal feeding behavior and high fidelity to feeding areas allow humpback whales (Megaptera novaeangliae) to be used as biological indicators of regional contamination. Biopsy blubber samples from male individuals (n ¼ 67) were collected through SPLASH, a multinational research project, in eight North Pacific feeding grounds. Additional male samples (n ¼ 20) were collected from one North Atlantic feeding ground. Persistent organic pollutants were measured in the samples and used to assess contaminant distribution in the study areas. North Atlantic (Gulf of Maine) whales were more contaminated than North Pacific whales, showing the highest levels of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and chlordanes. The highest dichlorodiphenyltrichloroethane (DDT) levels were detected in whales feeding off southern California, USA. High-latitude regions were characterized by elevated levels of hexachlorocyclohexanes (HCHs) but generally nondetectable concentrations of PBDEs. Age was shown to have a positive relationship with SPCBs, SDDTs, Schlordanes, and total percent lipid. Contaminant levels in humpback whales were comparable to other mysticetes and lower than those found in odontocete cetaceans and pinnipeds. Although these concentrations likely do not represent a significant conservation threat, levels in the Gulf of Maine and southern California may warrant further study. Environ. Toxicol. Chem. 2010;29:824-834. # 2009 SETAC

show abstract

Section: Ecological and Biological Factors Affecting Contaminant Loadsmentioning

confidence: 62%

Section: Ecological and Biological Factors Affecting Contaminant Loadsmentioning

confidence: 62%

Geographic variation of persistent organic pollutant levels in humpback whale (Megaptera novaeangliae) feeding areas of the North Pacific and North Atlantic

Elfes

VanBlaricom

Boyd

et al. 2010

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

show abstract

“…As the cellular component and whole blood of seabirds have a low lipid content (i.e., C:N < 3.5), lipid extraction from these samples was unnecessary (Post et al, 2007). A 0.400-0.600 mg subsample was removed from each dried and homogenized sample, sealed in a 5 × 9 mm tin capsule and placed in a plastic tray with labeled divides (Witteveen et al, 2009;Haro et al, 2016). Carbon and nitrogen isotopic ratios were quantified using a continuous flow mass spectrometer coupled with an elemental analyzer (University of Windsor, Ontario).…”

Section: Stable Isotope Analysismentioning

confidence: 99%

“…Lipid extraction was conducted using petroleum ether in a Soxhlet for 8 h (Dobush et al, 1985). Samples were then oven dried for 48 h at 60 • C (Witteveen et al, 2009). As the cellular component and whole blood of seabirds have a low lipid content (i.e., C:N < 3.5), lipid extraction from these samples was unnecessary (Post et al, 2007).…”

Section: Stable Isotope Analysismentioning

confidence: 99%

Dietary Niche Shifts of Multiple Marine Predators under Varying Prey Availability on the Northeast Newfoundland Coast

et al. 2017

View full text Add to dashboard Cite

Understanding species interactions among top marine predators and interactions with their prey can provide important insight into community-level responses to changing prey availability and the role of apex predators as indicators of ecosystem change. On the northeast Newfoundland coast, marine predators rely on capelin (Mallotus villosus), a dominant forage fish, as a food source. Capelin migrate into coastal regions to spawn during July, essentially transforming the food supply from low during early summer (i.e., pre-spawning) to high later in the summer (i.e., spawning). During July-August, 2016, we used stable isotopic ratios of nitrogen (δ 15 N) and carbon (δ 13 C) to investigate shifts in dietary niche metrics at the predator group-level (trophic position, dietary niche breadth) and community-level (niche overlap, trophic diversity) for multiple marine predators under varying capelin availability. Predator groups included non-breeding shearwaters (great shearwater Ardenna gravis, sooty shearwater A. grisea), humpback whales (Megaptera novaeangliae), and gull chicks (herring gull Larus argentatus, great black-backed gull Larus marinus). We also tested the sensitivity of community-level dietary metrics to a variety of published trophic discrimination factors. Tissue samples from shearwaters (blood cellular component), gull chicks (whole blood), and whales (skin), representing average diets over 2-3 weeks, were collected during three periods (early, mid, late) corresponding to increasing capelin availability. Isotopic niche breadth (Standard Ellipse Area, SEA b ) narrowed and trophic position shifted toward higher δ 15 N for all predator groups as capelin availability increased, suggesting a higher reliance on capelin. Trophic diversity (distance to centroid) decreased with increased capelin availability, while pairwise niche overlap between predator groups was highly variable and sensitive to trophic discrimination factors. Findings suggest that although capelin is the dominant forage fish during the summer, predators rely on capelin as prey to varying degrees. Combining species-and community-level metrics of dietary niche and trophic diversity may provide a more complete picture of predator responses to prey availability and, thus, may be important monitoring tools to indicate changes in the food supply of marine predators.

show abstract

“…Over the past decade, stable isotope (SI) ratios ( 13 C/ 12 C and 15 N/ 14 N reported as d 13 C and d 15 N, respectively) have been widely used to study trophic ecology of marine mammals, allowing the assessment of their trophic position in the food web and their foraging habitat (Newsome et al, 2010). The combined use of SI and POPs may also be used to trace feeding habits and thus to provide further insights into population structure and movement pattern of migratory species (Witteveen et al, 2009). Research efforts should further investigate the feeding strategies and ecology of Southern Hemisphere humpback whales, in order to boost the scarce information about the connection between populations, their dependency on local prey stocks as well as their exposure to contaminants.…”

Section: Introductionmentioning

confidence: 99%

Linking pollutant exposure of humpback whales breeding in the Indian Ocean to their feeding habits and feeding areas off Antarctica

Das

Malarvannan

Dirtu

et al. 2017

Environmental Pollution

View full text Add to dashboard Cite

a b s t r a c tHumpback whales, Megaptera novaeangliae, breeding off la Reunion Island (Indian Ocean) undergo largescale seasonal migrations between summer feeding grounds near Antarctica and their reproductive winter grounds in the Indian Ocean. The main scope of the current study was to investigate chemical exposure of humpback whales breeding in the Indian Ocean by providing the first published data on this breeding stock concerning persistent organic pollutants (POPs), namely polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), DDT and its metabolites (DDTs), chlordane compounds (CHLs), polybrominated diphenyl ethers (PBDEs), and methoxylated PBDEs (MeOPBDEs). Analyses of stable isotopes d 13 C and d 15 N in skin resulted in further insight in their feeding ecology, which was in agreement with a diet focused mainly on low trophic level prey species, such as krill from Antarctica. POPs were measured in all humpback whales in the order of HCB > DDTs > CHLs > HCHs > PCBs > PBDEs > MeO-BDEs. HCB (median: 24 ng g À1 lw) and DDTs (median: 7.7 ng g À1 lw) were the predominant compounds in all whale biopsies. Among DDT compounds, p,p 0 -DDE was the major organohalogenated pollutant, reflecting its long-term accumulation in humpback whales. Significantly lower concentrations of HCB and DDTs were found in females than in males (p < 0.001). Other compounds were similar between the two genders (p > 0.05). Differences in the HCB and DDTs suggested gender-specific transfer of some compounds to the offspring. POP concentrations were lower than previously reported results for humpback whales sampled near the Antarctic Peninsula, suggesting potential influence of their nutritional status and may indicate different exposures of the whales according to their feeding zones. Further investigations are required to assess exposure of southern humpback whales throughout their feeding zones.

show abstract

Population structure of North Pacific humpback whales on their feeding grounds revealed by stable carbon and nitrogen isotope ratios

Cited by 47 publications

References 51 publications

Geographic variation of persistent organic pollutant levels in humpback whale (Megaptera novaeangliae) feeding areas of the North Pacific and North Atlantic

Geographic variation of persistent organic pollutant levels in humpback whale (Megaptera novaeangliae) feeding areas of the North Pacific and North Atlantic

Dietary Niche Shifts of Multiple Marine Predators under Varying Prey Availability on the Northeast Newfoundland Coast

Linking pollutant exposure of humpback whales breeding in the Indian Ocean to their feeding habits and feeding areas off Antarctica

Contact Info

Product

Resources

About