Redefining North Atlantic right whale habitat‐use patterns under climate change

Abstract

Changes in the physical oceanography of the Northwest Atlantic stemming from both natural and anthropogenic climate change impact the foraging ecology and distribution of endangered North Atlantic right whales. In this study, right whale sightings from 1990 to 2018 were analyzed to examine decadal patterns in monthly habitat use in 12 high-use areas. Depth-integrated abundances of late-stage Calanus finmarchicus and Calanus hyperboreus were also analyzed for decadal variations in the right whale foraging habitats. There were significant differences in the occurrence, seasonal timing, and persistence of foraging habitats across these three decades. In the decades of the 1990s and the 2010s, prey was less abundant than in the 2000s, corresponding to reduced use of the Southeast US calving grounds in the winter, increased use of Cape Cod Bay in winter and spring, and reduced use of Roseway Basin in the fall. In the 2010s, right whale sightings increased in Southern New England and the Gulf of St. Lawrence in the spring and summer, respectively. Summertime declines in the 2010s in late-stage copepod abundances in the Gulf of Maine and surrounding regions, as well as in the Gulf of St. Lawrence, indicate that recent increased use of the Gulf of St. Lawrence is driven by a decline in prey in traditional foraging habitats rather than by an increase in prey in the new foraging habitat. This analysis of decadal-scale differences in right whale sightings and prey abundance is critical for redefining right whale distribution patterns for the most recent (post-2010) decade.

Estimating the effects of stressors on the health, survival and reproduction of a critically endangered, long‐lived species

“…Nonetheless, our results highlight the need for an ecosystem‐based approach to contextualise management efforts within the current environmental regime (Meyer‐Gutbrod et al 2015). Climate‐driven ocean warming and changes in circulation in the northwest Atlantic (Seidov et al 2021) have had cascading consequences on right whale copepod prey (Record et al 2019), which resulted in changes in the foraging ecology, movements and habitat use of the population (Meyer‐Gutbrod et al 2021, 2022). Quantifying and tackling this pervasive stressor will require robust, spatially explicit data on right whale prey and broader ecosystem dynamics, and widespread policies to address climate change and its effects on prey availability (Tulloch et al 2019).…”

“…In order to do this effectively, quantifying the relative consequences of different stressors on demographic rates is an important first step towards the robust prioritisation of management solutions. For example, right whales are protected by extensive policies to reduce the risk of vessel strikes (Laist et al 2014, van der Hoop et al 2015) and fishing gear entanglement (Knowlton et al 2012), but these management actions are often inadequate (Pace et al 2021) and further lose efficacy when the population undergoes rapid demographic or distributional shifts (Davies et al 2019, Meyer‐Gutbrod et al 2022). Modelling exercises that investigate the mechanisms underlying these shifts will be useful for updating protective policies across the population's range and complementing them with dynamic management systems (Koubrak et al 2021).…”

“…Right whales typically forage in waters off New England and the Canadian Maritimes in the spring, summer and fall (Kenney et al 1995, Baumgartner et al 2003, Mayo et al 2018, Davies et al 2019). Recent climate‐driven shifts in right whale prey distribution are linked to increased use of southern New England (Quintana‐Rizzo et al 2021) and the Gulf of St. Lawrence (Crowe et al 2021), and a shift out of previously used habitats such as the Great South Channel and the Bay of Fundy (Meyer‐Gutbrod et al 2022). Their wintertime distribution is less understood, but a subset of the population migrates to calving grounds off the coast of the southeast US (Keller et al 2012).…”

Cascading, interactive, and indirect effects of climate change on aquatic communities, habitats, and ecosystems

“…One contribution identified how species‐specific differences reflected differences in coral reef capacity to recover and accrete carbon after a bleaching event (Lange et al 2023). Another showed the significance of pod identity in explaining behavioral differences among subgroups of right whales (Meyer‐Gutbrod et al 2023). Even different life cycle stages of the same species responded uniquely to environmental drivers.…”

The distribution of North Atlantic right whales in Canadian waters from 2015-2017 revealed by passive acoustic monitoring

“…NARW occurrence and movement from the Gulf of Maine northward are strongly influenced by the abundance and distribution of their preferred prey (Pendleton et al, 2009;Pershing et al, 2009;Record et al, 2019), lipid-rich copepods of the genus Calanus (Kann and Wishner, 1995;Baumgartner et al, 2003). The reduced NARW occurrence observed in Great South Channel and Roseway Basin in the 1990s (Kenney, 2001;Patrician and Kenney, 2010a;Davies et al, 2015;Davies et al, 2019;Meyer-Gutbrod et al, 2022) and in the Gulf of Maine, Bay of Fundy, and Roseway Basin, in the 2010s (Davis et al, 2017;Grieve et al, 2017;Johnson et al, 2017;Meyer-Gutbrod and Greene, 2017;Hayes et al, 2018;Record et al, 2019;Meyer-Gutbrod et al, 2021;Meyer-Gutbrod et al, 2022) has been linked to decadal-scale reductions in the availability of NARW temperate prey, Calanus finmarchicus, in and around these habitats. Since 2010, NARW occurrence decreased precipitously in their critical habitats in the Gulf of Maine and on the Scotian Shelf, and increased in the Gulf of St. Lawrence (GSL; Khan et al, 2014;Pettis and Hamilton, 2015;Pettis and Hamilton, 2016;Davies et al, 2019;Record et al, 2019;Simard et al, 2019).…”