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Ocean warming linked to anthropogenic climate change is impacting the ecology of marine species around the world. In 2010, the Gulf of Maine and Scotian Shelf regions of the Northwest Atlantic underwent an unprecedented regime shift. Forced by climate-driven changes in the Gulf Stream, warm slope waters entered the region and created a less favorable foraging environment for the endangered North Atlantic right whale population. By mid-decade, right whales had shifted their late spring/summer foraging grounds from the Gulf of Maine and the western Scotian Shelf to the Gulf of St. Lawrence. The population also began exhibiting unusually high mortality in 2017. Here, we report that climate-driven changes in ocean circulation have altered the foraging environment and habitat use of right whales, reducing the population’s calving rate and exposing it to greater mortality risks from ship strikes and fishing gear entanglement. The case of the North Atlantic right whale provides a cautionary tale for the management of protected species in a changing ocean.

North Atlantic right whales Eubalaena glacialis (hereafter right whales) have recently shifted their distribution away from some protected feeding habitats, which suggests large-scale changes in food supply have occurred. Quantifying the nature and extent of the apparent shift is key to exploring this hypothesis and planning or revising conservation strategies. This paper characterizes decadal right whale occurrence in the Bay of Fundy summer feeding habitat using data derived from 7522 h of survey effort collected over 30 yr (1987 to 2016) that yielded 11483 right whale sightings. Eight occurrence descriptors were derived to quantify temporal variation in right whale presence, encounter rates and time of arrival in the Bay. Time of arrival was modeled using linear and power function models fit to annual discovery curves. Principal component analysis showed 2 modes that explained 58 and 14% of the variation in occurrence, respectively. The first mode captured a significant decline in summertime right whale occurrence beginning in 2010. The second mode captured a decadal-scale cycle in seasonal timing of occurrence, which highlighted a sharp change from early to late occupancy at the turn of the millennium. Annual occurrence during the 2010-2016 period was anomalously low in both the Grand Manan Basin critical habitat and the Bay of Fundy Traffic Separation Scheme (shipping lanes), whereas encounters in the region NW of the critical habitat containing Owen Basin and The Wolves islands may be increasing due to a distributional shift within the Bay. We discuss the consequences of these changes for both population dynamics and future conservation of the species.

“If we don't take robust, science-based, coherent measures to protect these highly endangered North Atlantic right whales, we're really playing Russian roulette with the entire future of the Canadian fish and seafood industry,” Fisheries and Oceans Minister Dominic LeBlanc, CBC New Brunswick, 16 June 2018. Governments are required to demonstrate that they manage natural resources in an environmentally and economically sustainable manner. Evidence of an environmental conservation problem is often not considered sufficient by government to warrant a change in the way human activities are managed until the problem becomes a societal crisis (e.g., large effects on economics, operations or infrastructure). Governments are then challenged to nimbly implement effective reactionary measures that both solve the problem and protect livelihoods. The mass mortality of North Atlantic right whales (Eubalaena glacialis) that occurred over a 3 month period in Canadian waters in 2017 due at least in part to fishing gear entanglements and ship strike is an example of a situation wherein evidence of a growing conflict between whales and humans was not acted upon until it became an emergency. The disaster galvanized a number of recent federal environmental initiatives into a powerful government force that was able to collaborate with many non-government groups in promptly responding to the problem. This led to commendable implementation and enforcement of crisis management measures. However, implementation came after many mortalities had already occurred because management plans were developed extemporaneously. Further, the need for crisis management negatively impacted local communities and industries. The eventual implementation of federal regulations led to zero attributable right whale deaths and a profitable fishery in the area of highest whale densities the following year. This shows that government leaders can act effectively on issues of environmental conservation, but that these actions can be drastic (i.e., requiring significant and rapid change to human activities) if there is a historic lack of action to address chronic conservation problems. Being proactive requires acting in proportion to evidence, using plans that are adaptive, precautionary and based on science. Canada must now look to sustainable, preventative measures to reduce right whale mortality risk.

Variation in water mass transport is a key driver of variability in zooplankton ecology. Data distribution (e.g., sparseness) is often an important factor limiting robust delineation of zooplankton-water mass associations. Mobile autonomous profiling gliders can help address the sparseness issue because gliders can sample across water mass domains spanning tens to hundreds of kilometers at high frequency during a single deployment. The goal of our study was to research the use of gliders as a tool to increase the spatiotemporal scale and robustness of zooplankton-water mass datasets. An autonomous ocean glider was deployed in Roseway Basin, Scotian Shelf, Canada for 2 months along a set of transects that crossed two water masses, a cold-fresh coastal water mass, and a warm-salty continental slope water mass. Zooplankton backscatter was measured with a single frequency Imagenex 300 kHz hydroacoustic echosounder mounted to the underside of the glider at an angle of 26°, such that it was directed vertically downward on the glider downcast. During the deployment, an unusual basin flushing event occurred, where the slope water mass that is typically present in the deep water of Scotian Shelf basins was almost completely replaced by coastal water at all depths. This unique event offered an opportunity to study how extreme changes in water mass affected zooplankton distribution. The impact of basin flushing on both diel- and non-diel-vertically migrating zooplankton communities within the basin was investigated using General Linear Models. The analysis demonstrated some key relationships exist among zooplankton acoustic scattering layers, water mass properties, and basin bathymetry. Zooplankton backscatter was higher in the slope water mass, and declined substantially during the basin flushing event, suggesting that coastal water is not zooplankton habitat for either community. Spatial gradients in the extent of flushing provided local refuge for zooplankton within one margin of the Basin. These patterns would be challenging to measure using conventional shipboard surveys. Our study provides guidance on the use of gliders to supplement shipboard research on biophysical coupling in the plankton, which is of value as the use of gliders for this purpose is proliferating.

From butterflies to elephants, the rapidly developing science of movement ecology is providing increasingly detailed spatio-temporal data on a wide array of mobile animals. Thus, this discipline also holds great promise for improving the conservation of wildlife. To measure progress towards this promise, we investigated the degree to which movement ecology research is connected to conservation goals as well as the proportion of studies that were incorporated into federal and international status assessments for mobile species at risk. We examined 13,349 “movement ecology” papers published between 1990 and 2014 and found that explicit connections to conservation and management were made in 35% (n = 4, 672) of these papers, with the number of connections increasing over time. We then measured the uptake of movement ecology research into species status assessment and recovery plans (n = 72 documents) produced by three different governance agencies for 12 endangered mobile species. We found that on average 60 % of available movement ecology research was used in the status assessment process, demonstrating that when movement ecology research is available, it is generally being utilized in conservation planning. However, for 25% of these species, there was little movement research available to be used, highlighting that knowledge gaps remain for some at-risk species despite the general growth of movement ecology research. We outline opportunities for movement ecology to promote more effective conservation of taxa that move.

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.

Rising global temperatures are causing a poleward shift in species distribution. Range shift velocities are higher in the marine environment, with observed rates of 30–130 km per decade. Both protected and exploited species will be at risk if marine species management policies are not structured to anticipate these range shifts. The 2017 mass mortality event of the North Atlantic right whale showcases the detrimental impact of unanticipated climate-mediated behavior in a species protected by geographically and seasonally fixed policies. Based on the results of a demographic capture-​recapture model, right whales may face extinction in fewer than 30 years unless protective policies are expanded to cover their shifting distribution. Increased support of long-term monitoring programs paired with environmental modeling research is critical to developing more proactive conservation management strategies and preventing further ecological crises.

Oceanographic surveys were conducted in Roseway Basin, western Scotian Shelf, during late-summer from 2007 through 2009 to measure the magnitude of interannual variation in the spatial distribution of diapausing copepods Calanus finmarchicus and C. hyperboreus and associated water mass characteristics. Calanus spp. abundance, energy density and hydrography were measured at depths > 50 m along transects using a Towed Underwater Biological Sampling System equipped with an Optical Plankton Counter (OPC) and a conductivity-temperature-depth (CTD) sensor, as well as at fixed stations using a Biological Net and Environmental Sampling System equipped with nets, OPC and CTD. Water mass density and in some cases salinity explained variation in the deep copepod layer across both time and space, whereas temperature did not. Water mass density, copepod energy density and thickness of the copepod layer were statistically lower during 2008 than 2007 or 2009. The copepod layer was absent from the western Basin margin during 2008 where low density continental water resided that year, whereas during 2007 and 2009 higher density continental slope water and copepods were each present along the western margin. Our results suggest that water mass density is an important characteristic defining the spatial and interannual ecology of the deep copepod layer in Roseway Basin. The 26 σ t isopycnal may be a lower density limit to diapausing Calanus spp. habitat on continental shelves with shallow bathymetry, that helps the animals maintain neutral buoyancy during diapause.

The Roseway and Grand Manan basins on the Canadian Atlantic coast are neighboring late-summer critical feeding habitats for endangered North Atlantic right whales. Although in late summer these habitats regularly contain thick aggregations of right whale food – the copepod Calanus spp. – right whales periodically abandon one or both habitats in the same year. The causes of abandonments, their relationship to food supply, and the locations of whales during abandonment periods are unclear. The goals of this study were to explain variation in right whale abundance indices from a habitat perspective, and to determine whether or not oceanographic variation in the habitats influences occupancy. Four indices of whale abundance and habitat occupancy, including sightings per unit effort (SPUE), photographic sightings of known individuals, population size and habitat transition probabilities, were analyzed in relation to unique datasets of Calanus concentration and water mass characteristics in each basin over the period 1987 through 2009. Calanus concentration, water mass sources and various hydrographic properties each varied coherently between basins. Calanus concentration showed an increasing trend over time in each habitat, although a short-lived reduction in Calanus may have caused right whales to abandon Roseway Basin during the mid-1990s. Food supply explained variation in right whale sightings and population size in Roseway Basin, but not in Grand Manan Basin, suggesting that the Grand Manan Basin has important habitat characteristics in addition to food supply. Changes in the distribution of whale abundance indices during years when oceanographic conditions were associated with reduced food supply in the Scotia-Fundy region suggest that other suitable feeding habitats may not have existed during such years and resulted in negative effects on whale health and reproduction.

North Atlantic right whales Eubalaena glacialis foraging on deep (>100 m) popula- tions of diapausing Calanus spp. in the Roseway Basin right whale Critical Habitat (south of Nova Scotia, Canada) are most often located along the southern margin of the basin. We investigated the physical and biological oceanographic characteristics that make this margin a lucrative feed- ing ground. Bottom-moored acoustic Doppler current profilers equipped with conductivity, tem- perature, and depth sensors were deployed cross-isobath on the southeastern slope of the basin to simultaneously measure variation in Calanus spp. concentration, current velocity, and water mass characteristics in time and space. Variation in upslope tidal advection of deep-basin water with densities >1026 kg m �3 and containing highly concentrated copepod aggregations was the most important process influencing cross-isobath variation in copepod concentrations on the slope. The aggregations were maintained in the slope region through time despite extensive along-isobath advection, implying the existence of copepod re-supply mechanisms to the southern margin. Pro- posed mechanisms include immigration from surface populations, horizontal advection, and gyre- like re-circulation within the basin. A simple empirically-driven particle tracking model illustrated tidally-forced particle convergence between the 100 and 140 m isobaths on the southeastern slope, followed by upward and along-isobath advection. Cross-isobath 'compression' of copepods coupled with the maintenance of their vertical position through neutral buoyancy is proposed as a mechanism resulting in accumulation on the slope, making the area uniquely beneficial to right whales feeding at depth along the slope margin.

Calanus finmarchicus stage-C5 and C. hyperboreus stage-C4 diapausing in Scotian Shelfbasins are high-quality food sources because they are abundant and high inenergy content. When combined, these two variables are informative for quantify-ing energy density, carrying capacity and energy transfer in marine ecosystems.However, measuring energy content directly can be difficult and expensive. Here,we present energy (caloric) content estimates for two co-located diapausingcopepod species; C. finmarchicus C5 and C. hyperboreus C4 collected during late-summer when their energy content is at or near the annual maximum. We thendevelop several practical energy content calibrations, each designed to estimateenergy content using simple measures of Calanus spp. body size or weight. Weight-specific energy content (energy quality, kJ g

Increasing atmospheric carbon dioxide levels are causing ocean acidification, compromising the ability of some marine organisms to build and maintain support structures. An analysis of mussels from a submarine volcano setting with natural low-pH conditions shows low shell thicknesses and growth rates, but survival over up to four decades. Increasing atmospheric carbon dioxide levels are causing ocean acidification1,2, compromising the ability of some marine organisms to build and maintain support structures3 as the equilibrium state of inorganic carbon moves away from calcium carbonate4. Few marine organisms tolerate conditions where ocean pH falls significantly below today’s value of about 8.1 and aragonite and calcite saturation values below 1 (refs 5, 6). Here we report dense clusters of the vent mussel Bathymodiolus brevior in natural conditions of pH values between 5.36 and 7.29 on northwest Eifuku volcano, Mariana arc, where liquid carbon dioxide and hydrogen sulphide emerge in a hydrothermal setting. We find that both shell thickness and daily growth increments in shells from northwest Eifuku are only about half those recorded from mussels living in water with pH>7.8. Low pH may therefore also be implicated in metabolic impairment7. We identify four-decade-old mussels, but suggest that the mussels can survive for so long only if their protective shell covering remains intact: crabs that could expose the underlying calcium carbonate to dissolution are absent from this setting. The mussels’ ability to precipitate shells in such low-pH conditions is remarkable. Nevertheless, the vulnerability of molluscs to predators is likely to increase in a future ocean with low pH.

The aim of our study was to assess the ability of brain-derived neurotrophic factor (BDNF) to rescue motor and sensory neurons from programmed cell death. It is clearly demonstrated that the administration of a single injection of a putative neurotrophic factor to mouse embryos in utero on embryonic day (E) 14.5 is sufficient to significantly reduce the death of motor neurons when assessed on E18.5. However, the trophic requirements of somatic neurons have not been unequivocally determined in a mammalian species in vivo. Indeed, the unexpectedly high numbers of surviving neurons observed in neurotrophin and tyrosine kinase receptor knockout mice are probably the consequence of functional redundancy between the neurotrophins and their receptors. We studied spinal cord and facial motor nucleus neurons and proprioceptive neurons in the dorsal root ganglion and mesencephalic nucleus. The action of BDNF was assessed in wild-type fetuses to gain insight into its ability to rescue neurons from naturally occurring programmed cell death. In addition, we used Myf5−/−:MyoD−/− embryos, which completely lack skeletal musculature, to assess the ability of BDNF to rescue neurons from excessively occurring programmed cell death. We found that BDNF differentially rescued neurons from naturally vs. excessively occurring cell death and that its ability to do so varied among neuronal subpopulations. Developmental Dynamics 235:2175–2184, 2006. © 2006 Wiley-Liss, Inc.

This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological–physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.