PCB and PBDE levels in southern and northern resident killer whales: update on contaminant levels and related health effects

Salish Sea’s killer whale populations are among the most contaminated marine mammals in the world and face risks related to the effects of polychlorinated biphenyls (PCBs) and related contaminants such as polybrominated diphenylethers (PBDEs). While PCBs have long been banned, they continue to present toxic risks to marine mammals, along with a number of other, emerging persistent, bioaccumulative and toxic (PBT) contaminants. Since PBTs have been identified as a threat to the recovery of resident killer whale populations under the auspices of the US Endangered Species Act and the Canadian Species at Risk Act (SARA), documenting the presence, trends and health effects of emerging PBT contaminants represents an important line of research. In the summer of 2016 and 2017, we collected blubber biopsies from 10 southern resident and nine northern resident killer whales. PCB and PBDE analyses were conducted using high resolution gas chromatography/high resolution mass spectrometry. Given the likelihood of significant temporal changes in the concentrations of these contaminants, this study will provide updated contaminant concentration data and strengthen our ability to prioritize contaminants of concern in resident killer whales. In addition, stable isotope and fatty acid analyses will provide important information on diet and nutritional status. Together with analyses of the expression of essential genes involved in immune response, hormone regulation and lipid metabolism, this study provides new essential information on the health status of resident killer whales as it relates to contaminant exposure and will help inform the development and application of recovery action plans

New insights into seasonal foraging ranges and migrations of minke whales from the Salish Sea and coastal British Columbia.

In the Salish Sea and coastal waters of British Columbia, minke whales are known to establish small home ranges during the feeding season. Beyond the feeding season little is known of their movements or distribution. To determine movement patterns of minke whales in these waters we used photo-identification data that were collected opportunistically from 2005-2012. These data were from four non-overlapping areas between 48ºN and 53ºN. Despite year-round search effort, minke whales were only encountered between April and October. Most of the 44 unique minke whales identified in 405 encounters displayed fidelity to areas both within and among feeding seasons. Five of these individuals also made relatively large-scale intra-annual movements between areas on six occasions. They were documented to move up to at least 424km in a northerly direction early in the season and up to at least 398km in a southerly direction late in the season. We believe that the seasonal patterns of these movements provide new insight into the foraging ranges and migrations of individuals. Ecological markers provide further evidence that the minke whales we photographed undertake annual long distance migrations. Scars believed to be from cookiecutter shark bites were observed on 43 individuals and the majority of minke whales documented with good quality images each year had acquired new scars since the previous feeding season. Furthermore, the commensal barnacle Xenobalanus globicipitis was observed on three individuals. Since these sharks and barnacles are from warm waters, it can be inferred that they interacted with the minke whales at lower latitudes. These findings may have important implications for our understanding of minke whale populations in the Salish Sea and the management of this species in the North Pacific

A long postreproductive life span is a shared trait among genetically distinct killer whale populations.

The extended female postreproductive life span found in humans and some toothed whales remains an evolutionary puzzle. Theory predicts demographic patterns resulting in increased female relatedness with age (kinship dynamics) can select for a prolonged postreproductive life span due to the combined costs of intergenerational reproductive conflict and benefits of late-life helping. Here, we test this prediction using >40 years of longitudinal demographic data from the sympatric yet genetically distinct killer whale ecotypes: resident and Bigg's killer whales. The female relatedness with age is predicted to increase in both ecotypes, but with a less steep increase in Bigg's due to their different social structure. Here, we show that there is a significant postreproductive life span in both ecotypes with >30% of adult female years being lived as postreproductive, supporting the general prediction that an increase in local relatedness with age predisposes the evolution of a postreproductive life span. Differences in the magnitude of kinship dynamics however did not influence the timing or duration of the postreproductive life span with females in both ecotypes terminating reproduction before their mid-40s followed by an expected postreproductive period of about 20 years. Our results highlight the important role of kinship dynamics in the evolution of a long postreproductive life span in long-lived mammals, while further implying that the timing of menopause may be a robust trait that is persistent despite substantial variation in demographic patterns among populations

A deep learning approach to photo–identification demonstrates high performance on two dozen cetacean species

We thank the countless individuals who collected and/or processed the nearly 85,000 images used in this study and those who assisted, particularly those who sorted these images from the millions that did not end up in the catalogues. Additionally, we thank the other Kaggle competitors who helped develop the ideas, models and data used here, particularly those who released their datasets to the public. The graduate assistantship for Philip T. Patton was funded by the NOAA Fisheries QUEST Fellowship. This paper represents HIMB and SOEST contribution numbers 1932 and 11679, respectively. The technical support and advanced computing resources from University of Hawaii Information Technology Services—Cyberinfrastructure, funded in part by the National Science Foundation CC* awards # 2201428 and # 2232862 are gratefully acknowledged. Every photo–identification image was collected under permits according to relevant national guidelines, regulation and legislation.Peer reviewedPublisher PD

Fin Whales in the Salish Sea

Historically, fin whales (Balaenoptera physalus) were relatively common off the west coast of North America but very few records of their occurrence in the Salish Sea exist. Due to the potential for misidentification of fin whales with other species of baleen whales, we use photographs to confirm sightings of this species in these waters. A total of 11 sightings of 8 fin whales from 1999 to 2012 are reported. These records are the first of live fin whales in Georgia, Juan De Fuca and Johnstone Straits and are also the only confirmed sightings of live fin whales in the Salish Sea since 1930. Additionally, 11 dead fin whales all with evidence of having been struck by ships are also reported from the Salish Sea between 1986 and 2013. We suggest that because this recovering endangered species has a propensity for being struck by ships, that any fin whales in these busy inside waters may be at greater risk to ship strikes than in less confined waters further offshore

Sighting rates and prey of Minke Whales (Balaenoptera acutorostrata) and other cetaceans off Cormorant Island, British Columbia

From June to August 2012, we conducted over 500 h of visual surveys from Cormorant Island, British Columbia, to determine behaviour and habitat use patterns of nearby cetaceans. Seven species were documented, but Minke Whales (Balaenoptera acutorostrata) were by far the most common and were observed lunge feeding at the surface on 15 occasions. In addition, this species was documented surface lunge feeding on Pacific Herring (Clupea pallasi) and Pacific Sand Lance (Ammodytes personatus) on 32 occasions during vessel-based cetacean surveys around Cormorant Island between 2010 and 2014. Although Minke Whales are relatively uncommon in British Columbia, these results indicate that they can regularly be found in specific feeding areas during the summer

Anthropogenic threats to humpback whales in the Salish Sea: insights from northeastern Vancouver Island

As humpback whale (Megaptera novaeangliae) populations recover from commercial whaling throughout the North Pacific Ocean, these whales are returning to areas where they were rarely encountered or absent for the past four decades. These areas include the coastal waters of northeastern Vancouver Island (NVI) and more recently, the Salish Sea. The return of humpback whales to coastal waters leads to increased overlap between humpback whales and human activities, including vessel traffic and fisheries. We use data from NVI, an area where humpback whale numbers have been increasing over the past ten years, as an example of the effects of this overlap. Data were collected through dedicated research effort, as well as opportunistically from whale watch vessels. Between 2003 and 2013, we documented a total of 176 humpback whales off NVI. The annual number of individual humpback whales sighted off NVI increased from seven individuals in 2003 to a maximum of 71 individuals in 2011. A minimum of eight vessel strikes and five entanglements in fishing gear were witnessed off NVI since 2006. Fishing gear involved in these entanglements included prawn, crab, and seine gear. A further nine entanglement events can be inferred based on scarring and injuries on whales’ bodies. Due to the intense levels of human activity in the Salish Sea, these anthropogenic threats are likely to negatively impact both the endangered humpback whales and the humans using these coastal waters. They may also have implications for the management of humpback whales and fisheries in the Salish Sea

Killer whales of the Crozet Archipelago and adjacent waters: photo-identification catalogue, population status and distribution in 2020

International audienceThree forms of killer whales (Orcinus orca) occur around the subantarctic islands of the southern Indian Ocean (42-53°S; 34-74°E). The form encountered in both inshore and offshore waters, described as generalist in its feeding preferences (seals, whales, penguins and fish as prey) and known to depredate toothfish from longliners has been opportunistically photo-identified around the Crozet archipelago since the 1960s. Together with photo-identification data collected in the Prince Edward/Marion EEZ, Kerguelen EEZ and international waters, this report provides up to date information on the abundance and distribution of the Crozet killer whales. In total, 124,313 photographs taken during 2,109 encounters since 1964 were analysed, allowing for 299 individuals to be identified. Most encounters with available data were from the Crozet EEZ (1,432 from longliners, 602 from Île de la Possession) and occurred after 2003 when photo-identification was implemented in the fishery observer program. Among the 188 individuals recorded in the Crozet EEZ since 2003, 22 (12%) were also photographed in the Kerguelen EEZ, 13 (7%) in the Prince Edward/Marion EEZ and 13 (7%) in adjacent international waters. The frequently encountered subset of the Crozet killer whale population was composed of 23 social units (maternal groups), 19 of which included individuals alive in 2020. These social units ranged in size from 1 to 11 individuals with a mean (± SD) of 4 ± 3 per unit. As of June 2020 when the latest photographs included in the study were taken, abundance of this subset was 89-94 individuals. However, detailed analysis of data collected between 2005 and 2020 shows that the number of confirmed deaths (n = 51) exceeds the number of recorded births (n = 46), resulting in a 5% decrease of the population size over this period. These deaths were distributed across the population with the majority occurring in the most common sex and age classes - adult females and juveniles. Factors contributing to mortalities are unclear, but may include lethal interactions with illegal fisheries. When paired with the fact that the Crozet killer whales already underwent a severe mortality episode in the 1990s, these findings raise strong concerns about the future of the population and stress the necessity of conservation actions while maintaining an intensive monitoring effort

Killer whales of the Crozet Archipelago and adjacent waters: photo-identification catalogue, population status and distribution in 2020

International audienceThree forms of killer whales (Orcinus orca) occur around the subantarctic islands of the southern Indian Ocean (42-53°S; 34-74°E). The form encountered in both inshore and offshore waters, described as generalist in its feeding preferences (seals, whales, penguins and fish as prey) and known to depredate toothfish from longliners has been opportunistically photo-identified around the Crozet archipelago since the 1960s. Together with photo-identification data collected in the Prince Edward/Marion EEZ, Kerguelen EEZ and international waters, this report provides up to date information on the abundance and distribution of the Crozet killer whales. In total, 124,313 photographs taken during 2,109 encounters since 1964 were analysed, allowing for 299 individuals to be identified. Most encounters with available data were from the Crozet EEZ (1,432 from longliners, 602 from Île de la Possession) and occurred after 2003 when photo-identification was implemented in the fishery observer program. Among the 188 individuals recorded in the Crozet EEZ since 2003, 22 (12%) were also photographed in the Kerguelen EEZ, 13 (7%) in the Prince Edward/Marion EEZ and 13 (7%) in adjacent international waters. The frequently encountered subset of the Crozet killer whale population was composed of 23 social units (maternal groups), 19 of which included individuals alive in 2020. These social units ranged in size from 1 to 11 individuals with a mean (± SD) of 4 ± 3 per unit. As of June 2020 when the latest photographs included in the study were taken, abundance of this subset was 89-94 individuals. However, detailed analysis of data collected between 2005 and 2020 shows that the number of confirmed deaths (n = 51) exceeds the number of recorded births (n = 46), resulting in a 5% decrease of the population size over this period. These deaths were distributed across the population with the majority occurring in the most common sex and age classes - adult females and juveniles. Factors contributing to mortalities are unclear, but may include lethal interactions with illegal fisheries. When paired with the fact that the Crozet killer whales already underwent a severe mortality episode in the 1990s, these findings raise strong concerns about the future of the population and stress the necessity of conservation actions while maintaining an intensive monitoring effort

Movements and dive behaviour of a toothfish-depredating killer and sperm whale

Depredation of demersal longlines by killer and sperm whales is a widespread behaviour that impacts fisheries and whale populations. To better understand how depredating whales behave in response to fishing activity, we deployed satellite-linked location and dive-profile tags on a sperm and killer whale that were depredating Patagonian toothfish from commercial longlines off South Georgia. The sperm and killer whale followed one fishing vessel for >180 km and >300 km and repeatedly depredated when longlines were being retrieved over periods of 6 and 7 d, respectively. Their behaviours were also sometimes correlated with the depths and locations of deployed gear. They both dove significantly deeper and faster when depredating compared with when foraging naturally. The killer whale dove >750 m on five occasions while depredating (maximum: 1087 m), but these deep dives were always followed by long periods (3.9-4.6 h) of shallow (<100 m) diving. We hypothesize that energetically and physiologically costly dive behaviour while depredating is driven by intra- and inter-specific competition due to the limited availability of this abundant resource