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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. [ABSTRACT FROM AUTHOR]

Much is known about how climate change impacts ecosystem richness and turnover, but we have less understanding of its influence on ecosystem structures. Here, we use ecological metrics (beta diversity, compositional disorder and network skewness) to quantify the community structural responses of temperature‐sensitive chironomids (Diptera: Chironomidae) during the Late Glacial (14 700–11 700 cal a bp) and Holocene (11 700 cal a bp to present). Analyses demonstrate high turnover (beta diversity) of chironomid composition across both epochs; however, structural metrics stayed relatively intact. Compositional disorder and skewness show greatest structural change in the Younger Dryas, following the rapid, high‐magnitude climate change at the Bølling–Allerød to Younger Dryas transition. There were fewer climate‐related structural changes across the early to mid–late Holocene, where climate change was more gradual and lower in magnitude. The reduced impact on structural metrics could be due to greater functional resilience provided by the wider chironomid community, or to the replacement of same functional‐type taxa in the network structure. These results provide insight into how future rapid climate change may alter chironomid communities and could suggest that while turnover may remain high under a rapidly warming climate, community structural dynamics retain some resilience. [ABSTRACT FROM AUTHOR]

North Atlantic right whale monitoring in Roseway Basin, Canada, is primarily based on short‐term (<14 d) visual surveys conducted during August–September. Variability in survey effort has been the biggest limiting factor to studying changes in the population's occurrence and habitat use. Such efforts could be enhanced considerably using passive acoustic monitoring (PAM). We sought to determine if variation in whale presence, relative abundance, demography, and/or behavior (estimated through visual surveys) could be explained by variation in three right whale call types in this habitat. A generalized linear model was fit to 23 d of concurrent PAM and visual monitoring during four summers within the Roseway Basin Right Whale Critical Habitat boundaries. The model revealed significant positive relationships between relative abundance, call counts and presence of surface‐active group behavior. PAM can refine daily right whale presence estimates. While visual observations (n = 23 d) implied a 40% decline in right whale presence during 2014–2015 relative to 2004–2005, PAM data (n = 211 d) showed right whales were present between 71%–85% of survey days throughout all years analyzed. We demonstrate that PAM is a useful tool to extend periods of right whale monitoring, especially in areas where visual monitoring efforts may be limited. [ABSTRACT FROM AUTHOR]

Current conservation templates prioritize biogeographic regions with high intensity ecosystem values, such as exceptional species richness or threat. Intensity‐based targets are an important consideration in global efforts, but they do not capture all available opportunities to conserve ecosystem values, including those that accrue in low intensity over large areas. We assess six globally‐significant ecosystem values—intact wilderness, freshwater availability, productive marine environments, breeding habitat for migratory wildlife, soil carbon storage, and latitudinal potential for range shift in the face of climate change—to highlight opportunities for high‐impact broadly‐distributed contributions to global conservation. Nations can serve as a cohesive block of policy that can profoundly influence conservation outcomes. Contributions to global ecosystem values that exceed what is predicted by a nation's area alone, can give rise to countries with the capacity to act as 'conservation superpowers', such as Canada and Russia. For these conservation superpowers, a relatively small number of national policies can have environmental repercussions for the rest of the world. [ABSTRACT FROM AUTHOR]

ABSTRACT Lake sediments spanning the Last Glacial-Interglacial Transition (LGIT: ca. 14.7 to 8 ka BP) from Muir Park Reservoir (MPR) in west-central Scotland were analysed for chironomids. The site lies just outside the southern limit of a former glacier that advanced into the Loch Lomond Basin during the Loch Lomond (Younger Dryas) Stadial. Chironomid-inferred mean July temperatures were derived using a modern Norwegian calibration dataset. Three tephra layers constrain the sequence chronologically. Inferred temperatures decline from a high value early in the Interstadial, punctuated by two cold oscillations, probably equivalent to GI-1d and GI-1b in the Greenland ice-core record, and a warm oscillation (equivalent to GI-1a) immediately before the severe cooling at the start of the Loch Lomond Stadial (GS-1), when summer temperatures fell by about 5 °C below the Interstadial average. Summer temperatures fell by about 3 °C below the Interstadial average during GI-1d, which is less severe than inferred from other chironomid records from eastern Scotland, and may reflect the influence of an oceanic-continental gradient. Cooling during GI-1b was particularly strong at MPR when minimum temperatures were about the same as those reached during GI-1d, unlike other sites investigated where GI-1d is usually between 1 and 2 °C cooler than GI-1b. [ABSTRACT FROM AUTHOR]