We have recently published two papers on trends in cetacean abundance in an offshore MPA from a 35-year study.  Some good news!

Both papers are open access.


Whitehead, H., and L.J. Feyrer. 2026. Thirty-five years of cetaceans in a canyon: patterns, shifts, and surprises in the Gully marine protected area.  Marine Ecology Progress Series 776: meps15045  https://www.int-res.com/abstracts/meps/v776/meps15045

Abstract
The Gully, a large submarine canyon on the edge of the Scotian Shelf, was made a marine protected area (MPA) in 2004. Together with 2 neighbouring smaller canyons, it has a particularly high density and diversity of cetaceans. We compiled sightings made from vessels during summer months between 1988 and 2023 to describe temporal and spatial trends of occurrence for 9 commonly sighted cetacean species in the Gully MPA and nearby waters. We looked for correlations between species as well as potential drivers of trends. Sighting rates increased for Sowerby’s beaked whales Mesoplodon biden and long-finned pilot whales Globicephala melas; decreased for humpback whales Megaptera novaeangliae, Atlantic white-sided dolphins Leucopleurus acutus, and striped dolphins Stenella coeruleoalba; while northern bottlenose Hyperoodon ampullatus and fin whales Balaenoptera physalus showed U-shaped trajectories. White-sided dolphins were more abundant in June, when water temperatures are cooler, whereas most of the other species showed a preference for the warmer months. Blue whales Balaenoptera musculus were most abundant with sea temperatures of ~18°C. The northern bottlenose whale is exceptional in that a large portion of the population is in the Gully at any time, there was no seasonal variation in sighting rates, and the inter-annual U-shaped trend can be linked with some confidence to reduced anthropogenic impact following the introduction of the MPA. For the other species, drivers are more speculative but include changes in relative resource abundance due to oceanographic and ecological processes, climate change, and variation in anthropogenic impacts.



Feyrer, L., S.F. Walmsley, M.A. Stewart, M.A. MacNeil and H. Whitehead. 2025. Reversing decline: The impact of spatial conservation on endangered northern bottlenose whales. Journal of Applied Ecology  62: 2464-2474 Journal article

Abstract
  1. Despite the end of commercial whaling in 1972, the northern bottlenose whale (Hyperoodon ampullatus) remains endangered in Canada and faces multiple human threats. The effectiveness of marine protected areas (MPAs) in safeguarding highly mobile species like these whales is still unclear. We examined 35 years (1988–2023) of population trends in the Gully submarine canyon, off Canada's east coast and assessed spatial changes in human activities within protected and unprotected habitat on the Scotian Shelf.
  2. We analysed population size and habitat use using sighting rates and photo-identification mark-recapture data. We also evaluated whether spatial protections implemented through the designation of the Gully MPA in 2004 were associated with changes in the spatial distribution of threats, including ship strikes, entanglement, pollution and military sonar.
  3. We found the northern bottlenose whale population declined from 1988 until the mid-2000s. However, from 2004 to 2010, coinciding with the establishment of spatial protections, this trend reversed, with the population growing near its maximum biological potential (~4% per year).
  4. Our analysis indicates that the intensity of two serious threats—commercial fishing and vessel traffic—has decreased within the highly protected Zone 1 area of the Gully MPA, where approximately 42% of the population can be found at any time. However, these activities now occur relatively more often in important habitat areas outside the MPA, indicating a spatial shift in fishing effort that raises concerns about potential displacement effects.
  5. Synthesis and applications. Spatial protection of the Gully MPA in 2004 coincided with a shift in human activities and the first signs of population recovery for northern bottlenose whales. While this suggests that well-designed MPAs can contribute to conservation outcomes even for highly mobile species, long-term success likely depends on continued monitoring and effective threat reduction both within the MPA and across other important habitats. Coordinated management across fisheries, shipping, offshore energy and defence sectors is essential. The Gully stands out as a rare conservation success in the open ocean, but its gains are not guaranteed.



Hal Whitehead, Dalhousie University (hwhitehe@dal.ca)
Laura Feyrer, University of Manitoba (laura.joan@gmail.com)