The Acoustic Drone projectThe emergence of Unmanned Aerial Vehicle (UAVs) provide new perspectives and data collection capabilities for marine mammal research. Although UAVs have been frequently exploited for visual observations of whales, most approaches for monitoring and recording sounds from individual whales are still performed using overside hydrophones from a boat or using acoustic tags attached to the animals. Laguna San Ignacio (LSI), Mexico, is one of the breeding and calving grounds of the Eastern North Pacific gray whale population. LSI area's restricted geography, combined with the short dive times of the whales, provided an excellent field laboratory to test a dual drone approach. We used two UAVs: one to obtain acoustic measurements close to the whales and another one to obtain overhead visual observations. This study provided an initial demonstration of a combined two-UAV system for measuring the underwater source levels and behavioural context of vocal and non-vocal marine mammal signals.
Collaboration with Scripps Institution of Oceanography, Laguna San Ignacio Ecosystem Science Program and Universidad Autonoma de Baja California Sur.
National Geographic (Field Notes) |
Hooded seals of Eastern CanadaThe hooded seal is a migratory species inhabiting the North Atlantic. They whelp and breed during mid- to late March on pack ice near Jan Mayen Island, in the Davis Strait, off the northeastern Newfoundland coast, and in the Gulf of St. Lawrence. After breeding, hooded seals return to the pack ice off eastern Greenland to moult during June and July, and then they disperse broadly for summer and fall before returning to their respective breeding areas. Passive acoustic monitoring conducted over spatial scales consistent with known and potential habitat of the hooded seal could add insight into seasonal and spatial occurrence patterns of this species. To better characterize its acoustic repertoire (notably underwater calls), airborne and underwater acoustic signals of hooded seals were recorded during their breeding season on the pack ice in the Gulf of St. Lawrence from 12 to 17 March 2018.
Collaboration with Fisheries and Oceans Canada.
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Ribbon seals in the Bering, Chukchi, and Beaufort SeasThe ribbon seal is one of the world’s least studied pinnipeds. It is primarily a sub-Arctic species, that whelps, mates and molts on the seasonal pack ice in the Bering Sea and the Sea of Okhotsk from mid-March to mid-July. Knowledge of their distribution outside the winter breeding season is currently limited. We aggregated data from four different research groups and locations from 53 sites that span a large part of the range of ribbon seals to monitor the acoustic occurrence of this species over a one-year period (August 2012 to July 2013) in the Bering, Chukchi, and Beaufort Seas. In this study, we evaluated the temporal and spatial distribution of ribbon seal and note possible changes in its distribution that might be influenced by the effects of Arctic sea ice decline. We examined the ribbon seal underwater acoustic repertoire and examined the monthly patterns in proportional use of each call type to infer the function of their calls in the Bering, Chukchi, and Beaufort Seas.
Collaboration with NOAA, University of Washington, and Greeneridge Sciences.
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Bearded seals in Chukchi SeaConsiderable advances in knowledge concerning the reproductive strategies of aquatic-mating pinnipeds have been made over recent years. However, clear gaps still exist. By using autonomous long-term acoustic recordings, we have been able to investigate the acoustic behavior and seasonal occurrence of marine mammals in areas, and in periods, where ship-based or on ice studies were not previously possible. This study investigates the spatio-temporal distribution of bearded seals between July 2007 and October 2010 in Chukchi Sea using calls produced by males. Bearded seals were identified by their trills, ascents and moans. A comparison of the temporal occurrence of the various call types may lead to insights into the significance of each call type, as well as the ecology of bearded seals. Monthly patterns in proportional use of each call type and call duration were examined for the first time using 3 years of overwinter data at 5-8 sites throughout the northeastern Chukchi Sea.
Collaboration with the Chukchi Sea Environmental Science Project, sponsored by Statoil, ConocoPhillips, and Shell.
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Gray whales of Sakhalin Island (Russia)The western subpopulation of North Pacific gray whale has been listed as Critically Endangered in the Russian Red Book (Category I) and by the World Conservation Union (IUCN). Gray whales are primarily bottom feeders and consequently are restricted to shallow continental shelf waters for feeding. The western gray whale summers in the Okhotsk Sea, mainly on the shallow (5-15 m) shelf of northeastern Sakhalin island, particularly off the southern portion of Piltun Lagoon. This water area is characterized by a 20-m isobath located at the distance of 5-10 km offshore, mainly used by mother-calf pairs as well as youth Gray whales (first year). Offshore gas and oil development in the Okhotsk Sea within 20 km of the Piltun feeding area is of concern, and substantial monitoring effort has been dedicated to identifying possible effects on the population. Activities related to oil and gas exploration, including geophysical seismic surveying, pipelaying and drilling operations, increased vessel traffic, and oil spills, all pose potential threats to western gray whales.
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Marine mammals of British Columbia (Canada)Passive acoustic monitoring at several locations in British Columbia provides insight into the (acoustic) occurrence of several marine mammal species (notably the critically endangered Southern Resident Killer Whales) and highlight areas of potential significance to species that overlap with anthropogenic activities.
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Beluga whales of Canadian ArcticFrom an environmental toxicology perspective, methylmercury (MeHg) is the most important of the different chemical forms of Hg. The toxic effects of MeHg in wildlife have been reported and scientifically studied for over 50 years, during which time much has been learned about its food chain transfer, metabolism, and toxicity. Because MeHg biomagnifies through food webs, it is generally agreed that top predatory animals, particularly those linked to aquatic food chains, are at greatest risk for increased dietary MeHg exposure and potential Hg-related health effects. Exposure to Hg impairs specific immune defences of many species including marine mammals. In the Arctic, species at greater risk include top predators such as toothed whales. As part of the beluga sampling program at Hendrickson Island, a health assessment of contaminant effects on known toxicological endpoints was conducted.
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Harbor, grey, and harp seals of Eastern CanadaThe St. Lawrence Marine Ecosystem (SLME), which includes the St. Lawrence Estuary and the Gulf of St. Lawrence, is inhabited by four species of seals. There are several colonies of harbor seals inhabiting the SLME. Grey seals summer in the St. Lawrence Estuary but overwinter in the Gulf of St. Lawrence or on the Atlantic coast of Canada. Harp and hooded seals winter in the SLME but summer in Arctic waters. The objectives of this research were to determine levels and distribution profiles of several contaminants in several tissues (blood, blubber, and milk), to evaluate the transfer of contaminants from mother to pup during lactation, and to investigate the effects of contaminants on their immune system.
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