Stomach contents from 30 long-finned pilot whales Globicephala melascaptured incidentally in the Distant Water Fleet (DWF) mackerel fishery off the northeastern United States were examined. Several methods of assessing prey importance were used in order to construct a true representation of the pilot whale diet. Separate analyses of trace (free, durable body parts from well-digested prey) and non-trace (relat~vely lntact prey) food materials were conducted to address biases caused by differential rates of dlgest~on and passage. Squids dom~nated the diet and lonq-f~nned squid Lollgo pealei was the most ~mportant prey, but we noted large yearly fluctuat~ons in prey importance. Metnc multidimensional scal~ng analyses of trace and non-trace stomach contents of individual whales suggest that many a n~m a l s \\?ere caught while feeding oppol-tunlst~cally near fishing operations, resulting in a bias of non-trace [intact) stomach contents. The divers~ty of prey in this study was greater than previous reports of the food hablts of western North Atlantic long-finned pilot whales.

Anthropogenic noise is increasing throughout the world's oceans. One major contributor is industrial seismic surveys -a process typically undertaken to locate and estimate the quantity of oil and gas deposits beneath the seafloor -which, in recent years, has increased in magnitude and scope in some regions. Regulators permit this activity despite widespread uncertainties regarding the potential ecological impacts of seismic surveys and gaps in baseline information on some key species of conservation concern. Research to date suggests that impacts vary, from displacement to direct mortality, but these effects remain poorly understood for most species. Here, we summarize potential effects of seismic surveys, describe key knowledge gaps, and recommend broad-scale research priorities for 3 impacted taxonomic groups: fish, marine mammals, and sea turtles. We also suggest further technological advances, improved mitigation measures, and better policy and management structures to minimize the ecological impacts of seismic surveys in light of scientific uncertainty.

Predators adapt their foraging behavior to exploit a variety of prey in a range of environments. Short-finned pilot whales are wide-ranging predators in tropical and sub-tropical oceans, but most previous studies of their foraging ecology have been conducted near oceanic islands. We deployed sound- and movement-recording tags on 43 short-finned pilot whales off Cape Hatteras, North Carolina, USA, to measure their foraging behavior in a continental shelf-break ecosystem and investigate how variation in the environment shapes their behavior. Overall, the foraging behavior of pilot whales off Cape Hatteras was similar to that of their counterparts from island-associated habitats. Off Cape Hatteras, pilot whales made foraging dives as deep as 1077 m (mean: 445 m), lasting up to 23 min (mean: 12.8 min), with sprints (pursuit at speeds over 3 m s-1 and up to 6.9 m s-1) in more than half of foraging dives. However, tagged whales off Cape Hatteras produced higher buzz rates (11.3 buzzes dive-1), foraged more extensively in daytime hours, and engaged in more frequent benthic foraging than island-associated ecotypes. By parsing the echoic scene generated by the animal’s own echolocation clicks, we show that pilot whales off Cape Hatteras frequently exploit bathymetric features for foraging, with benthic dives resulting in higher prey capture attempts than pelagic dives. The ability of these predators to strategically adapt foraging strategies to local habitat features likely contributes to their ecological success and may allow them to adjust to shifts in prey distributions in a rapidly changing Anthropocene ocean.

The Union of the Comoros is host to internationally-significant populations of sea turtles, dugongs and cetaceans, all of which are potentially threatened by incidental catch in artisanal fishing gears. This work presented here was part of a larger initiative, known as Project GloBAL (Global Bycatch Assessment of Long-lived species), to evaluate artisanal fishing effort and bycatch of sea turtles and marine mammals in data-deficient areas. Questionnaire surveys were conducted with 409 out of the estimated 8,500 artisanal fishers in the Comoros, on the islands of Grande Comore (25/44 landing sites) and Mohéli (5/13 landing sites). Sea turtles (mainly Chelonia mydas) were reportedly captured in large numbers, although it was not always clear if captures were accidental or deliberate. Lower rates of turtle capture were reported from Mohéli, possibly as a result of awareness-raising activities associated with Mohéli Marine Park. Gillnets presented the most serious bycatch-related threat to dugongs (Dugong dugons) and current mitigation efforts such as closed areas to limit gillnet use are essential for the continued presence of this species in the Comoros. Cetaceans were rarely captured and mortality was reportedly low; with spinner dolphin (Stenella longirostris) the most common of several species recorded as bycatch.