Organochlorines and Marine Mammal Reproduction

1989 ◽  
Vol 46 (2) ◽  
pp. 360-368 ◽  
Author(s):  
R. F. Addison

Reproductive failures in four populations of marine mammals (Californian sea lions (Zalophus californianus), Bothnian Bay ringed seals (Pusa hispida), Dutch Waddensee harbour seals (Phoca vitulina), and most recently, Gulf of St. Lawrence beluga whales (Delphinapterus leucas)) have been attributed to the effects of contamination by organochlorine (OC) residues. In this article, I review the evidence for these effects. I conclude that since (a) crucial biological information in the light of which OC residue data can be interpreted is often missing, (b) the nature of the supposed reproductive effect is variable, and (c) the OC residues to which these effects are attributed vary qualitatively and quantitatively, correlations between observed residue concentrations and apparent reproductive changes do not provide any firm evidence for a cause – effect relationship. In a single experimental study, a diet with a higher OC content than that used as a control impaired reproduction in harbour seals; however, dietary components other than OC content also differed. Although there appears to be no firm correlative evidence sinking residue concentrations in marine mammals with reproductive effects, there is enough concern about possible links to justify more experimental studies, with the aim of identifying the possible biochemical mechanisms involved.

2021 ◽  
Author(s):  
Karyn Booy ◽  
Xavier Mouy ◽  
Steven H. Ferguson ◽  
Marianne Marcoux

The Cumberland Sound (Nunavut, Canada) beluga whale (Delphinapterus leucas) population has been designated as threatened and updated biological information about summer distribution is required for a sound recovery plan. Variation in aerial survey counts are speculated to occur due to movement of belugas in and out of the fiord, and there is still uncertainty related to their distribution within key summer habitat. To address these knowledge gaps, non-invasive passive acoustic monitoring (PAM) systems were deployed in August of 2010 and 2011. An automated detector was used to determine presence/absence and quantify calls by recorder site. Results were verified by partial manual analysis of 20% of the files. The detector had a minimum accuracy of 85% for presence/absence and 42% for call quantification. Belugas were detected primarily at the uppermost site of Clearwater Fiord, with detections subsiding with increasing proximity to the fiord entrance. Diel variation in call patterns were quantified at two separate sites in different years, but no correlation was observed between tidal cycles and number of detections. This study indicates that Cumberland Sound beluga may prefer sites at the head of Clearwater Fiord. Further research is required to identify which environmental variables contribute to this observed summer distribution.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0254380
Author(s):  
Bertrand Charry ◽  
Emily Tissier ◽  
John Iacozza ◽  
Marianne Marcoux ◽  
Cortney A. Watt

Emergence of new technologies in remote sensing give scientists a new way to detect and monitor wildlife populations. In this study we assess the ability to detect and classify two emblematic Arctic cetaceans, the narwhal (Monodon monoceros) and beluga whale (Delphinapterus leucas), using very high-resolution (VHR) satellite imagery. We analyzed 12 VHR images acquired in August 2017 and 2019, collected by the WorldView-3 satellite, which has a maximum resolution of 0.31 m per pixel. The images covered Clearwater Fiord (138.8 km2), an area on eastern Baffin Island, Canada where belugas spend a large part of the summer, and Tremblay Sound (127.0 km2), a narrow water body located on the north shore of Baffin Island that is used by narwhals during the open water season. A total of 292 beluga whales and 109 narwhals were detected in the images. This study contributes to our understanding of Arctic cetacean distribution and highlights the capabilities of using satellite imagery to detect marine mammals.


1989 ◽  
Vol 46 (11) ◽  
pp. 1914-1921 ◽  
Author(s):  
John D. Buck ◽  
L. Louise Shepard ◽  
Patricia M. Bubucis ◽  
Stephen Spotte ◽  
Kate McClave ◽  
...  

For proper husbandry, it is important to sample the environment from which marine mammals for captivity are taken and to monitor the animals frequently over an extended period. Samples for microbiological analysis were collected from 20 beluga whales during capture in the Churchill River. Seven animals were retained in three U.S. aquaria with anal and blowhole cultures taken over a 945-d period. Bacteria isolated from whales at capture included many soil and water forms found also in environmental samples. Pasteurella multocida was isolated from three whales at capture and infrequently several times in captivity from two of these which were studied the most intensively. From this latter group maintained at Mystic (CT) Marinelife Aquarium, the most frequently recovered bacteria from both animals were members of the Achromobacter-Acinetobacter-Alcaligenes-CDC IV E-Moraxella-Pasteurella-Pseudomonas group, Escherichia coli, Pseudomonas putrefaciens, Staphylococcus epidermidis, Streptococcus faecalis, and Vibrio fluvialis. Only one of these whales yielded cultures of Klebsiella pneumoniae, Plesiomonas shigelloides, and coagulase positive Staphylococcus aureus. Species of Acinetobacter, Aeromonas, Pseudomonas, and Vibrio were most common in whales maintained at the other aquaria although, as noted for animals at Mystic, several species were isolated from some samples and were absent in others.


ARCTIC ◽  
2017 ◽  
Vol 70 (3) ◽  
pp. 273 ◽  
Author(s):  
Lloyd F. Lowry ◽  
Michael C.S. Kingsley ◽  
Donna D.W. Hauser ◽  
Janet Clarke ◽  
Robert Suydam

The eastern Chukchi Sea (ECS) stock of beluga whales is one of three stocks in western Alaska that are co-managed by the National Marine Fisheries Service and the Alaska Beluga Whale Committee. Abundance of this stock was estimated as 3710 in 1991 from incomplete data. Analysis of data from satellite-linked time-depth recorders (SDRs) attached to belugas in summer concentration areas of the ECS and Beaufort Sea (BS) stocks provided an overview of beluga distribution and movements and allowed the identification of an area (140˚ W to 157˚ W in the BS) and a time period (19 July – 20 August) in which the distributions of the two stocks do not overlap. Aerial survey data were collected by the Aerial Surveys of Arctic Marine Mammals (ASAMM) project in that region and time period in 2012. We used those data in a line transect analysis that estimated there were 5547 (CV = 0.22) surface-visible belugas in the study area. Data from SDRs were used to develop correction factors to account for animals that were missed because they were either outside of the study area or diving too deep to be seen, resulting in a total abundance estimate of 20 752 (CV = 0.70). The average annual Alaska Native subsistence harvest from the ECS stock (57) is about 0.3% of the population estimate. Without data collected by the ASAMM project and from satellite-linked tags, this analysis would not have been possible. Additional surveys and tagging of ECS belugas are warranted.


2013 ◽  
Vol 127 (1) ◽  
pp. 31
Author(s):  
Keith G. Chaulk ◽  
Daniel Michelin ◽  
Melva Williams ◽  
Tony Wolfrey

Experienced observers from the community of Rigolet, Newfoundland and Labrador, recorded marine mammal observations at Rigolet on the coast of Labrador from July to September 2012. During this study, a total of nine species of marine mammals were documented. A daily average of 2.6 (range 1–5) marine mammal species were observed, with Harp Seals (Pagophilus groenlandicus) and Common Minke Whales (Balaenoptera acutorostrata) being the most common. The area is thought to be regionally important for Ringed Seal (Pusa hispida) whelping; however, Ringed Seals were not observed in large numbers. Beluga Whales (Delphinapterus leucas) were also reported anecdotally, but were less common than the other species, with the possible exception of the Harbour Porpoise (Phocoena phocoena). Labrador is experiencing significant industrial growth related to hydroelectric development and offshore oil and gas exploration. These data should aid environmental assessment and environmental effects monitoring and assist researchers in understanding regional marine mammal ecology, including species diversity, seasonal occurrence, and relative abundance.


ARCTIC ◽  
2017 ◽  
Vol 70 (1) ◽  
Author(s):  
Héloïse Frouin-Mouy ◽  
Katie Kowarski ◽  
Bruce Martin ◽  
Koen Bröker

The expansion of hydrocarbon exploration in northwest Greenland has made it increasingly important to understand the occurrence of marine mammals in the region. We describe the seasonal occurrence of marine mammals and the spatial distribution of their calls in Baffin Bay and Melville Bay. Four Autonomous Multichannel Acoustic Recorders (AMARs) were deployed during summer 2012 (late July to early October), five recorders during September 2013, and two recorders from late September 2013 to early September 2014. The call presence of several species was analyzed using automatic call detection and manual verification analysis methods. A novel approach to discern narwhal (Monodon monoceros) clicks from beluga (Delphinapterus leucas) clicks was implemented during the verification process. Narwhal calls were detected in spring and fall, showing a south-to-north migration pattern in spring and a north-to-south migration pattern in fall. Few beluga whales were detected during fall 2013 and spring 2014. Bearded seal (Erignathus barbatus) calls were detected mainly during spring (mating period). A small number of bowhead whale calls (Balaena mysticetus) were detected during fall 2013 and spring and summer 2014. For the first time at this latitude in Baffin Bay, long-finned pilot whales (Globicephala melas) and sperm whales (Physeter macrocephalus) were detected during summer and fall. Our results suggest that the presence of marine mammals in Baffin Bay and Melville Bay is governed mainly by the annual cycle of sea ice formation and decay.


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