Henry
Allison G.
Henry
Allison G.
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PresentationDon’t assume it’s ghost gear : accurate gear characterization is critical for entanglement mitigation [poster](Woods Hole Oceanographic Institution, 2017-10-25) Henry, Allison G. ; Barco, Susan G. ; Cole, Tim ; Johnson, Amanda ; Knowlton, Amy R. ; Landry, Scott ; Mattila, David K. ; Moore, Michael J. ; Robbins, Jooke ; van der Hoop, Julie ; Asmutis-Silvia, ReginaEntanglement is a significant conservation and welfare issue which is limiting the recovery of a number of marine species, including marine mammals. It is therefore important to reliably identify the causes of these events, including the nature of the entangling gear in order to reduce or prevent them in the future. A recently published review of marine debris assessed 76 publications and attributed a total of 1805 cases of cetacean entanglements in “ghost gear”, of which 78% (n=1413) were extracted from 13 peer reviewed publications. We examined the 13 publications cited in the review and found that the specific gear type or status of gear involved in the reported events was rarely mentioned beyond the fact that it was fishing related. This is likely due to the fact that determinations of debris as the entangling material are very difficult. In fact, in reviewing 10 years of large whale entanglement records for the U.S., the authors of another study reported that Hawaii was the only region in which any entangling gear was positively identified as ghost gear. The assumption that entangling gear is marine debris unless otherwise stated is dangerous because it could impact efforts to modify or restrict risk-prone fishing in key marine mammal habitats. Entanglement in actively fished gear poses a very real threat, and claims that only lost or abandoned fishing gear is responsible for entanglements can undermine conservation efforts.
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ArticleAssessing North Atlantic Right whale health: a review of threats, and development of tools critical for conservation of the species(Inter Research, 2021-02-25) Moore, Michael J. ; Rowles, Teresa K. ; Fauquier, Deborah A. ; Baker, Jason T. ; Biedron, Ingrid S. ; Durban, John W. ; Hamilton, Philip K. ; Henry, Allison G. ; Knowlton, Amy R. ; McLellan, William A. ; Miller, Carolyn A. ; Pace, Richard M., III ; Pettis, Heather M. ; Raverty, Stephen A. ; Rolland, Rosalind M. ; Schick, Robert S. ; Sharp, Sarah M. ; Smith, Cynthia R. ; Thomas, Len ; van der Hoop, Julie M. ; Ziccard, Michael H.Whaling decimated North Atlantic right whales (Eubalaena glacialis - NARW) since the 11th century and southern right whales (E. australis - SRW) since the 19th century. Today, NARWs are critically endangered and decreasing, whereas SRWs are recovering. We review NARW health assessment literature, NARW Consortium databases, and efforts and limitations to monitor individual and species health, survival, and fecundity. Photographs are used to track individual movement and external signs of health such as evidence of vessel and entanglement trauma. Post mortem examinations establish cause of death and determine organ pathology. Photogrammetry is used to assess growth rates and body condition. Samples of blow, skin, blubber, baleen and feces quantify hormones that provide information on stress, reproduction, and nutrition, identify microbiome changes, and assess evidence of infection. We also discuss models of the population consequences of multiple stressors, including the connection between human activities (e.g., entanglement) and health. Lethal and sublethal vessel and entanglement trauma have been identified as major threats to the species. There is a clear and immediate need for expanding trauma reduction measures. Beyond these major concerns, further study is needed to evaluate the impact of other stressors, such as pathogens, microbiome changes, and algal and industrial toxins, on NARW reproductive success and health. Current and new health assessment tools should be developed and used to monitor the effectiveness of management measures, and will help determine whether they are sufficient for a substantive species recovery.
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ArticleAssessment of management to mitigate anthropogenic effects on large whales(John Wiley & Sons, 2012-10-01) van der Hoop, Julie ; Moore, Michael J. ; Barco, Susan G. ; Cole, Timothy V. N. ; Daoust, Pierre-Yves ; Henry, Allison G. ; McAlpine, Donald F. ; McLellan, William A. ; Wimmer, Tonya ; Solow, Andrew R.United States and Canadian governments have responded to legal requirements to reduce human-induced whale mortality via vessel strikes and entanglement in fishing gear by implementing a suite of regulatory actions. We analyzed the spatial and temporal patterns of mortality of large whales in the Northwest Atlantic (23.5°N to 48.0°N), 1970 through 2009, in the context of management changes. We used a multinomial logistic model fitted by maximum likelihood to detect trends in cause-specific mortalities with time. We compared the number of human-caused mortalities with U.S. federally established levels of potential biological removal (i.e., species-specific sustainable human-caused mortality). From 1970 through 2009, 1762 mortalities (all known) and serious injuries (likely fatal) involved 8 species of large whales. We determined cause of death for 43% of all mortalities; of those, 67% (502) resulted from human interactions. Entanglement in fishing gear was the primary cause of death across all species (n= 323), followed by natural causes (n= 248) and vessel strikes (n= 171). Established sustainable levels of mortality were consistently exceeded in 2 species by up to 650%. Probabilities of entanglement and vessel-strike mortality increased significantly from 1990 through 2009. There was no significant change in the local intensity of all or vessel-strike mortalities before and after 2003, the year after which numerous mitigation efforts were enacted. So far, regulatory efforts have not reduced the lethal effects of human activities to large whales on a population-range basis, although we do not exclude the possibility of success of targeted measures for specific local habitats that were not within the resolution of our analyses. It is unclear how shortfalls in management design or compliance relate to our findings. Analyses such as the one we conducted are crucial in critically evaluating wildlife-management decisions. The results of these analyses can provide managers with direction for modifying regulated measures and can be applied globally to mortality-driven conservation issues.
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ArticleErratum to “Vessel strikes to large whales before and after the 2008 Ship Strike Rule”(John WIley & Sons, 2016-06-15) van der Hoop, Julie ; Vanderlaan, Angelia S. M. ; Cole, Timothy V. N. ; Henry, Allison G. ; Hall, Lanni ; Mase-Guthrie, Blair ; Wimmer, Tonya ; Moore, Michael J.
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PreprintRebuttal to published article “A review of ghost gear entanglement amongst marine mammals, reptiles and elasmobranchs” by M. Stelfox, J. Hudgins, and M. Sweet( 2016-11) Asmutis-Silvia, Regina ; Barco, Susan G. ; Cole, Tim ; Henry, Allison G. ; Johnson, Amanda ; Knowlton, Amy R. ; Landry, Scott ; Mattila, David K. ; Moore, Michael J. ; Robbins, Jooke ; van der Hoop, JulieWe reviewed the findings of the recently published article by Stelfox et al. (2016): “A review of ghost gear entanglement amongst marine mammals, reptiles and elasmobranchs” published in this journal (Volume 111, pp 6–17) and found that they are both flawed and misleading as they do not accurately reflect the prevalence of “ghost gear” cases reported in the literature. While we commend the authors for recognizing the importance of attempting to quantify the threat and for recommending more comprehensive databases, the methods, results and conclusions of this review have not advanced the understanding of the issue. As authors of the papers on whale entanglements in the North Atlantic that were reviewed by Stelfox et al. (2016) and others who are knowledgeable about the topic, we provide specific comments regarding misrepresentations of both the source of entanglement (e.g., actively fished gear versus “ghost gear”) and the number of reported entanglements for whale species included in the North Atlantic.
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ArticleVessel strikes to large whales before and after the 2008 Ship Strike Rule(John WIley & Sons, 2014-05-01) van der Hoop, Julie ; Vanderlaan, Angelia S. M. ; Cole, Timothy V. N. ; Henry, Allison G. ; Hall, Lanni ; Mase-Guthrie, Blair ; Wimmer, Tonya ; Moore, Michael J.To determine effectiveness of Seasonal Management Areas (SMAs), introduced in 2008 on the U.S. East Coast to reduce lethal vessel strikes to North Atlantic right whales, we analyzed observed large whale mortality events from 1990–2012 in the geographic region of the “Ship Strike Rule” to identify changes in frequency, spatial distribution, and spatiotemporal interaction since implementation. Though not directly coincident with SMA implementation, right whale vessel-strike mortalities significantly declined from 2.0 (2000–2006) to 0.33 per year (2007–2012). Large whale vessel-strike mortalities have decreased inside active SMAs, and increased outside inactive SMAs. We detected no significant spatiotemporal interaction in the 4-year pre- or post-Rule periods, although a longer time series is needed to detect these changes. As designed, SMAs encompass only 36% of historical right whale vessel-strike mortalities, and 32% are outside managed space but within managed timeframes. We suggest increasing spatial coverage to improve the Rule's effectiveness.