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

Abstract

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

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

“…Lower POP concentrations were recently described in humpback whales from the Southern Hemisphere (Bengtson Nash et al, 2013;Dorneles et al, 2015;Waugh et al, 2012) compared to humpback whales from the Northern Hemisphere (Elfes et al, 2010;Gauthier et al, 1997;Metcalfe et al, 2004;Ryan et al, 2013), probably due to the greater historical usage of POPs and the higher trophic position of humpbacks whales in the Northern Hemisphere (Ryan et al, 2014). Low d 13 C and d 15 N values combined with low POP concentrations measured in the present study confirm a diet mainly focused on krill for humpback whales breeding off La Reunion.…”

Levels of persistent organic pollutants in eastern North Atlantic humpback whales

“…Intrinsic markers are increasingly being used to this end, including molecular genetic (Palsbøll et al 1997), stable isotope (Ryan et al 2013a), trace elemental (Born et al 2003) and fatty acid analyses (Herman et al 2005). A recent study capitalised on spatially explicit patterns in blubber POP concentrations to elucidate population structuring among humpback whales Mega ptera novaeangliae throughout the North Pacific Ocean (Elfes et al 2010). Geographic patterns in POP tissue concentrations have also been used to investigate fine-scale population structure in inter alia bottlenose dolphins Tursiops truncatus, narwhals Monodon monoceros and bowhead whales Balaena mysticetus (Hoekstra et al 2002, Hansen et al 2004, Borrell et al 2006.…”

“…Contaminant burdens in humpback whales are therefore primarily reflective of each individual's summer feeding ground. As such, contaminant concentrations such as those of POPs can potentially be used to infer population structure in humpback whales (Elfes et al 2010).…”

“…To our knowledge, these are the first POP concentrations to be reported for cetaceans from Cape Verde waters or indeed the tropical eastern North Atlantic. Our results are compared directly with those from a similar study in the western North Atlantic (Gulf of Maine; Elfes et al 2010), to evaluate the hypothesis that humpback whales sampled in Cape Verde and Ireland belong to a different population than those in the Gulf of Maine. We also present data for the first time on sex ratios of humpback whales from Ireland and Cape Verde, to shed light on the migratory ecology of this species, which remains poorly studied in these areas.…”

Blue whale earplug reveals lifetime contaminant exposure and hormone profiles

“…Besides whaling activities, well-known anthropogenic activities including fishery entanglement, chemical use/emission, environmental noise, ship strikes, and climate change are impacting whales, with evidence found through morphological or epidemiological analysis as well as chemical profiles from tissue, fecal, and exhalation samples (3)(4)(5)(6). However, we are currently unable to monitor and therefore assess the lifetime impacts of such anthropogenic pollution/activities on whales.…”