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A state-space model, using the Jolly-Seber assumption about population entry, was used to characterize the changing abundance of North Atlantic right whales (Eubalaena glacialis) between 1990 and 2015. Estimates from this modeling approach were only slightly higher than published values, except for the most recent years (capture rates substantially declined). North Atlantic right whale abundance increased about 2.8%/annually from the median estimate of 270 individuals in 1990 to 483 in 2010, followed by a decline to 458 in 2015. There is evidence of diverging abundance trends between sexes, a result of reduced survival of females.

Photographic data on body and skin condition, blowhole cyamids and rake marks were used to evaluate the health of North Atlantic right whales (Eubalaena glacialis) from 1980-2008. A hierarchical Bayesian model was applied to the data to estimate demographic groups, underlying health status conditions and the population to characterize health patterns and temporal trends. Visual health scores (0-100 scale) (N=48,560) were used to estimate the health of 622 identified right whales on a monthly basis. Most whales’ health scores fluctuated between 70 and 90. Whales in poor condition had health scores >60. Health varied by sex, age-class and reproductive state. The largest annual variability was observed in active reproducing females. Calving females had significantly higher health scores than non-calving females. Population health declined and coincided with a decrease in calving from 1998-2000. Over three generations the health in all demographic groups declined.

The fecal glucocorticoid metabolites (fGC) concentrations from right whales (Eubalaena glacialis) chronically entangled in fishing gears or live stranded were compared to right whales quickly killed by vessels and healthy right whales. The study aimed to characterize fGC responses to acute vs. chronic stress. fGCs in entangled whales and stranded whales were significantly higher than in whales killed by vessels and healthy whales. Serum cortisol and corticosterone in a live stranded whale were much higher than values reported in other cetaceans.

The kinematics of a tagged entangled North Atlantic right whale, before, during and after disentanglement were examined. Three sets of gear attached to a load-cell tensiometer at multiple speeds were used to calculate additional drag forces and energetic demand. Tag analyses revealed significant increases in dive depths and duration; ascent, descent and fluke stroke rates; and decreases in rot mean square fluke amplitude were significantly greater than in the non-entangled case. Increases in total power input over the non-entangled condition ranged from 1.6% to 120.9% for all gear configurations tested. Locomotory power requirements increased 60-164.6%. These results suggest significant alteration to swimming patterns and the magnitude of energy depletion in a chronically entangled whale.

This study evaluated drag characteristics of entangled North Atlantic right whales, contextualized gear drag measurements for individual whales and quantified the benefits of partial disentanglement. A load cell was used to measure drag forces on 15 sets of fishing gear removed from entangled right whales, a towed satellite telemetry buoy and 200 m of polypropylene line as it was shored to 25 m, as they were towed behind a vessel at -0.77, 1.3 and 2.1 m/s and 0, 3 and 6 m depth. Information suggests that on average entanglements increase drag and propulsive power by 1.47 fold. Reducing trailing line length by 75% can reduce parasitic gear drag by 85%.

Standardized external injury assessments were used to investigate the relative importance of direct anthropogenic and natural threats to northwest Atlantic leatherback turtles (Dermochelys coriacea). The information was used to assess whether the susceptibility to these threats varies between low latitude nesting and high latitude foraging region, by size and sex. Leatherback turtles foraging off the coast of Nova Scotia and at nesting sites in Trinidad were sampled. Combined, 62% showed characteristic marking associated with one injury. No significant differences in injury rate or type between regions, sexes or sizes were found. The proportion of turtles showing injuries suspected to be of anthropogenic origin (34%) was significantly higher than those thought to be associated with predatory behavior (16%). Entanglement with rope was thought to occur in 19% of the injuries and 17% from hooks. This population of leatherback turtles faces potentially common widespread threats from predation and fishing gear across its range.

Incidental catch of the loggerhead sea turtle (Caretta caretta) in the Mediterranean basin is the main threat to its conservation. In this basin, fisheries are multi-species, multi-gears and multi-national, making demersal fishing activities profitable, while preserving sea turtles is a challange. In this study, scientists developed bycatch reducer devices and alternative fishing gears to mitigate the impact of demersal fishing gears on seaturtles. This included (i) testing hard and flexible Turtle Excluder Devices in bottom trawling nets and (ii) using ultraviolet LEDs as visual deterrents to illuminate set nets to avoid entanglement. The results of this study suggest the different devices did not affect the commercial catch, while bycatch reduction was instead evident. These reuslts advocate for a global effort to introduce bycatch reduction devices in different areas and fisheries of the Mediterranean. 

Fishing-related seabird mortalities are considered the most pervasive threat to seabird conservation status. Specifically, warp wire interactions (warp strike) and net captures of trawl vessels in Australia’s Commonwealth-managed Southern and Eastern Scalefish and Shark fisheries has been identified as a growing concern. This paper describes an industry-led study that developed and tested the effectiveness of 2 experimental mitigation devices for trawl vessels: a "baffler" and a "water sprayer". These were tested against a control which was previously the only prescribed device, called a "pinkie". Seabird interactions were observed during 69 tests comparing the "sprayer" against the control, and 55 tests comparing the "baffler" against the control. Both experimental mitigation devices showed significant reductions in heavy interaction rates (interactions per test) compared with the "pinkie" (83.7 and 58.9%). Based on the findings from this study, the Australian Fisheries Management Authority now allows vessels to meet seabird bycatch mitigation requirements through use of either new device.

1,700 lbf prototypes were developed and tested both in a lab and at sea to determine their fishing practicality. Use of these ropes have been documented as a strategy for reducing the incidence and severity of large whale entanglements in lobster pot buoy lines. Additionally, modeling work was carried out to assess the tensions placed on ropes when hauling gear in normal fishing operations and to evaluate what forces a whale might put on gear during an entanglement. Both lab and field testing showed the feasibility of using these ropes within near and mid-shore lobster gear off Massachusetts.

In the Mediterranean Sea, trawl nets have high levels of bycatch of protected species, including the loggerhead turtle (Caretta caretta), with high rates of mortality. A new flexible Turtle Excluder Device (TED) was tested for the first time on a commercial scale in the Mediterranean Sea to assess its effectiveness in reducing bycatch. The results did not show any significant (α = 0.05) loss in terms of commercial catch weight, but resulted in a significant reduction of debris in the codend of the nets in comparison to traditional nets. During the study, no turtles were captured in either the traditional or TED net. While modification of fishing gears require significant investment, the flexible TED is technically feasible in the Mediterranean and may assist in the conservation of loggerhead sea turtles.