Corkeron
Peter
Corkeron
Peter
No Thumbnail Available
Search Results
Now showing
1 - 13 of 13
-
ArticleEntanglement is a costly life-history stage in large whales(John Wiley & Sons, 2016-12-11) van der Hoop, Julie ; Corkeron, Peter ; Moore, Michael J.Individuals store energy to balance deficits in natural cycles; however, unnatural events can also lead to unbalanced energy budgets. Entanglement in fishing gear is one example of an unnatural but relatively common circumstance that imposes energetic demands of a similar order of magnitude and duration of life-history events such as migration and pregnancy in large whales. We present two complementary bioenergetic approaches to estimate the energy associated with entanglement in North Atlantic right whales, and compare these estimates to the natural energetic life history of individual whales. Differences in measured blubber thicknesses and estimated blubber volumes between normal and entangled, emaciated whales indicate between 7.4 × 1010 J and 1.2 × 1011 J of energy are consumed during the course to death of a lethal entanglement. Increased thrust power requirements to overcome drag forces suggest that when entangled, whales require 3.95 × 109 to 4.08 × 1010 J more energy to swim. Individuals who died from their entanglements performed significantly more work (energy expenditure × time) than those that survived; entanglement duration is therefore critical in determining whales’ survival. Significant sublethal energetic impacts also occur, especially in reproductive females. Drag from fishing gear contributes up to 8% of the 4-year female reproductive energy budget, delaying time of energetic equilibrium (to restore energy lost by a particular entanglement) for reproduction by months to years. In certain populations, chronic entanglement in fishing gear can be viewed as a costly unnatural life-history stage, rather than a rare or short-term incident.
-
ArticleLong-term passive acoustic recordings track the changing distribution of North Atlantic right whales (Eubalaena glacialis) from 2004 to 2014(Nature Publishing Group, 2017-10-18) Davis, Genevieve E. ; Baumgartner, Mark F. ; Bonnell, Julianne M. ; Bell, Joel ; Berchok, Catherine L. ; Bort Thornton, Jacqueline ; Brault, Solange ; Buchanan, Gary ; Charif, Russell A. ; Cholewiak, Danielle ; Clark, Christopher W. ; Corkeron, Peter ; Delarue, Julien ; Dudzinski, Kathleen ; Hatch, Leila ; Hildebrand, John ; Hodge, Lynne ; Klinck, Holger ; Kraus, Scott D. ; Martin, Bruce ; Mellinger, David K. ; Moors-Murphy, Hilary ; Nieukirk, Sharon ; Nowacek, Douglas P. ; Parks, Susan E. ; Read, Andrew J. ; Rice, Aaron N. ; Risch, Denise ; Širović, Ana ; Soldevilla, Melissa ; Stafford, Kathleen M. ; Stanistreet, Joy ; Summers, Erin ; Todd, Sean ; Warde, Ann M. ; Van Parijs, Sofie M.Given new distribution patterns of the endangered North Atlantic right whale (NARW; Eubalaena glacialis) population in recent years, an improved understanding of spatio-temporal movements are imperative for the conservation of this species. While so far visual data have provided most information on NARW movements, passive acoustic monitoring (PAM) was used in this study in order to better capture year-round NARW presence. This project used PAM data from 2004 to 2014 collected by 19 organizations throughout the western North Atlantic Ocean. Overall, data from 324 recorders (35,600 days) were processed and analyzed using a classification and detection system. Results highlight almost year-round habitat use of the western North Atlantic Ocean, with a decrease in detections in waters off Cape Hatteras, North Carolina in summer and fall. Data collected post 2010 showed an increased NARW presence in the mid-Atlantic region and a simultaneous decrease in the northern Gulf of Maine. In addition, NARWs were widely distributed across most regions throughout winter months. This study demonstrates that a large-scale analysis of PAM data provides significant value to understanding and tracking shifts in large whale movements over long time scales.
-
ArticlePopulation comparison of right whale body condition reveals poor state of the North Atlantic right whale(Inter Research, 2020-04-23) Christiansen, Fredrik ; Dawson, Stephen M. ; Durban, John W. ; Fearnbach, Holly ; Miller, Carolyn A. ; Bejder, Lars ; Uhart, Marcela ; Sironi, Mariano ; Corkeron, Peter ; Rayment, William ; Leunissen, Eva ; Haria, Eashani ; Ward, Rhianne ; Warick, Hunter A. ; Kerr, Iain ; Lynn, Morgan S. ; Pettis, Heather M. ; Moore, Michael J.The North Atlantic right whale Eubalaena glacialis (NARW), currently numbering <410 individuals, is on a trajectory to extinction. Although direct mortality from ship strikes and fishing gear entanglements remain the major threats to the population, reproductive failure, resulting from poor body condition and sublethal chronic entanglement stress, is believed to play a crucial role in the population decline. Using photogrammetry from unmanned aerial vehicles, we conducted the largest population assessment of right whale body condition to date, to determine if the condition of NARWs was poorer than 3 seemingly healthy (i.e. growing) populations of southern right whales E. australis (SRWs) in Argentina, Australia and New Zealand. We found that NARW juveniles, adults and lactating females all had lower body condition scores compared to the SRW populations. While some of the difference could be the result of genetic isolation and adaptations to local environmental conditions, the magnitude suggests that NARWs are in poor condition, which could be suppressing their growth, survival, age of sexual maturation and calving rates. NARW calves were found to be in good condition. Their body length, however, was strongly determined by the body condition of their mothers, suggesting that the poor condition of lactating NARW females may cause a reduction in calf growth rates. This could potentially lead to a reduction in calf survival or an increase in female calving intervals. Hence, the poor body condition of individuals within the NARW population is of major concern for its future viability.
-
PresentationEntanglements of North Atlantic right whales increase as their distribution shifts in response to climate change: The need for a new management paradigm [poster](Woods Hole Oceanographic Institution, 2019-12-09) Pendleton, Daniel ; Pettis, Heather M. ; Hamilton, Philip K. ; Knowlton, Amy R. ; Landry, Scott ; Moore, Michael J. ; McLellan, William A. ; Corkeron, Peter ; Kraus, Scott D.Detection rate of severely injured or entangled NARWs began to increase around 2004 - 2007.
-
ArticleSlocum gliders provide accurate near real-time estimates of baleen whale presence from human-reviewed passive acoustic detection information(Frontiers Media, 2020-02-25) Baumgartner, Mark F. ; Bonnell, Julianne M. ; Corkeron, Peter ; Van Parijs, Sofie M. ; Hotchkin, Cara ; Hodges, Benjamin A. ; Bort Thornton, Jacqueline ; Mensi, Bryan L. ; Bruner, Scott M.Mitigating the effects of human activities on marine mammals often depends on monitoring animal occurrence over long time scales, large spatial scales, and in real time. Passive acoustics, particularly from autonomous vehicles, is a promising approach to meeting this need. We have previously developed the capability to record, detect, classify, and transmit to shore information about the tonal sounds of baleen whales in near real time from long-endurance ocean gliders. We have recently developed a protocol by which a human analyst reviews this information to determine the presence of marine mammals, and the results of this review are automatically posted to a publicly accessible website, sent directly to interested parties via email or text, and made available to stakeholders via a number of public and private digital applications. We evaluated the performance of this system during two 3.75-month Slocum glider deployments in the southwestern Gulf of Maine during the spring seasons of 2015 and 2016. Near real-time detections of humpback, fin, sei, and North Atlantic right whales were compared to detections of these species from simultaneously recorded audio. Data from another 2016 glider deployment in the same area were also used to compare results between three different analysts to determine repeatability of results both among and within analysts. False detection (occurrence) rates on daily time scales were 0% for all species. Daily missed detection rates ranged from 17 to 24%. Agreement between two trained novice analysts and an experienced analyst was greater than 95% for fin, sei, and right whales, while agreement was 83–89% for humpback whales owing to the more subjective process for detecting this species. Our results indicate that the presence of baleen whales can be accurately determined using information about tonal sounds transmitted in near real-time from Slocum gliders. The system is being used operationally to monitor baleen whales in United States, Canadian, and Chilean waters, and has been particularly useful for monitoring the critically endangered North Atlantic right whale throughout the northwestern Atlantic Ocean.
-
ArticleNear real-time detection of low-frequency baleen whale calls from an autonomous surface vehicle: implementation, evaluation, and remaining challenges(Acoustical Society of America, 2021-05-04) Baumgartner, Mark F. ; Ball, Keenan R. ; Partan, James W. ; Pelletier, Léo‐Paul ; Bonnell, Julianne M. ; Hotchkin, Cara ; Corkeron, Peter ; Van Parijs, Sofie M.Mitigation of threats posed to marine mammals by human activities can be greatly improved with a better understanding of animal occurrence in real time. Recent advancements have enabled low-power passive acoustic systems to be integrated into long-endurance autonomous platforms for persistent near real-time monitoring of marine mammals via the sounds they produce. Here, the integration of a passive acoustic instrument capable of real-time detection and classification of low-frequency (LF) tonal sounds with a Liquid Robotics wave glider is reported. The goal of the integration was to enable monitoring of LF calls produced by baleen whales over periods of several months. Mechanical noises produced by the platform were significantly reduced by lubricating moving parts with polytetrafluoroethylene, incorporating rubber and springs to decelerate moving parts and shock mounting hydrophones. Flow noise was reduced with the development of a 21-element hydrophone array. Surface noise produced by breaking waves was not mitigated despite experimentation with baffles. Compared to a well-characterized moored passive acoustic monitoring buoy, the system greatly underestimated the occurrence of sei, fin, and North Atlantic right whales during a 37-d deployment, and therefore is not suitable in its current configuration for use in scientific or management applications for these species at this time.
-
ArticleMulti-event modeling of true reproductive states of individual female right whales provides new insights into their decline(Frontiers Media, 2022-10-06) Reed, Joshua ; New, Leslie ; Corkeron, Peter ; Harcourt, RobertAbundance and population trends of Critically Endangered North Atlantic right whales (Eubalaena glacialis, NARW) have been estimated using mark-recapture analyses where an individual’s state is based upon set delineations of age, using historical estimates of age at first reproduction. Here we assigned individual females to states based upon their reproductive experience, rather than age. We developed a Bayesian mark-recapture-recovery model to investigate how survival, recapture, site-fidelity and dead-recovery probabilities vary for female NARW in different states, using data collected from 1977-2018. States were assigned as calves for individuals in their first year; pre-breeder for individuals greater than one year of age who had yet to produce a calf, or breeder if an individual had reproduced. A decline in abundance of female NARW was seen starting in 2014, with 185 females declining yearly to 142 by 2018. The largest decline was seen in breeding females, with 72 estimated to be alive at the beginning of 2018, while female pre-breeder abundance plateaued at around 70 between 2011- 2018. Females born from 2000 onwards had an average 4% (95% CI:0.03-0.06) chance of transitioning from pre-breeder to breeder, compared to 8% (95%CI:0.06-0.1) for females born prior. This reduction in transition rate from non-breeder to breeder for the current cohort resulted in breeding females declining to 51% of the female population by 2018. We show that a collapse in fecundity of breeding females, and the failure of pre-breeders to start breeding, is an important factor in understanding the current decline in abundance of the NARW.
-
ArticleInvestigating the thermal physiology of critically endangered North Atlantic right whales Eubalaena glacialis via aerial infrared thermography(Inter Research, 2022-07-21) Lonati, Gina ; Zitterbart, Daniel ; Miller, Carolyn A. ; Corkeron, Peter ; Murphy, Christin T. ; Moore, Michael J.The Critically Endangered status of North Atlantic right whales Eubalaena glacialis (NARWs) warrants the development of new, less invasive technology to monitor the health of individuals. Combined with advancements in remotely piloted aircraft systems (RPAS, commonly ‘drones’), infrared thermography (IRT) is being increasingly used to detect and count marine mammals and study their physiology. We conducted RPAS-based IRT over NARWs in Cape Cod Bay, MA, USA, in 2017 and 2018. Observations demonstrated 3 particularly useful applications of RPAS-based IRT to study large whales: (1) exploring patterns of cranial heat loss and providing insight into the physiological mechanisms that produce these patterns; (2) tracking subsurface individuals in real-time (depending on the thermal stratification of the water column) using cold surface water anomalies resulting from fluke upstrokes; and (3) detecting natural changes in superficial blood circulation or diagnosing pathology based on heat anomalies on post-cranial body surfaces. These qualitative applications present a new, important opportunity to study, monitor, and conserve large whales, particularly rare and at-risk species such as NARWs. Despite the challenges of using this technology in aquatic environments, the applications of RPAS-based IRT for monitoring the health and behavior of endangered marine mammals, including the collection of quantitative data on thermal physiology, will continue to diversify.
-
ArticleExploring movement patterns and changing distributions of baleen whales in the western North Atlantic using a decade of passive acoustic data(Wiley, 2020-05-25) Davis, Genevieve E. ; Baumgartner, Mark F. ; Corkeron, Peter ; Bell, Joel ; Berchok, Catherine L. ; Bonnell, Julianne M. ; Bort Thornton, Jacqueline ; Brault, Solange ; Buchanan, Gary ; Cholewiak, Danielle ; Clark, Christopher W. ; Delarue, Julien ; Hatch, Leila ; Klinck, Holger ; Kraus, Scott D. ; Martin, Bruce ; Mellinger, David K. ; Moors-Murphy, Hilary ; Nieukirk, Sharon ; Nowacek, Douglas P. ; Parks, Susan E. ; Parry, Dawn ; Pegg, Nicole ; Read, Andrew J. ; Rice, Aaron N. ; Risch, Denise ; Scott, Alyssa ; Soldevilla, Melissa ; Stafford, Kathleen M. ; Stanistreet, Joy ; Summers, Erin ; Todd, Sean ; Van Parijs, Sofie M.Six baleen whale species are found in the temperate western North Atlantic Ocean, with limited information existing on the distribution and movement patterns for most. There is mounting evidence of distributional shifts in many species, including marine mammals, likely because of climate‐driven changes in ocean temperature and circulation. Previous acoustic studies examined the occurrence of minke (Balaenoptera acutorostrata ) and North Atlantic right whales (NARW; Eubalaena glacialis ). This study assesses the acoustic presence of humpback (Megaptera novaeangliae ), sei (B. borealis ), fin (B. physalus ), and blue whales (B. musculus ) over a decade, based on daily detections of their vocalizations. Data collected from 2004 to 2014 on 281 bottom‐mounted recorders, totaling 35,033 days, were processed using automated detection software and screened for each species' presence. A published study on NARW acoustics revealed significant changes in occurrence patterns between the periods of 2004–2010 and 2011–2014; therefore, these same time periods were examined here. All four species were present from the Southeast United States to Greenland; humpback whales were also present in the Caribbean. All species occurred throughout all regions in the winter, suggesting that baleen whales are widely distributed during these months. Each of the species showed significant changes in acoustic occurrence after 2010. Similar to NARWs, sei whales had higher acoustic occurrence in mid‐Atlantic regions after 2010. Fin, blue, and sei whales were more frequently detected in the northern latitudes of the study area after 2010. Despite this general northward shift, all four species were detected less on the Scotian Shelf area after 2010, matching documented shifts in prey availability in this region. A decade of acoustic observations have shown important distributional changes over the range of baleen whales, mirroring known climatic shifts and identifying new habitats that will require further protection from anthropogenic threats like fixed fishing gear, shipping, and noise pollution.
-
ArticlePersistent near real-time passive acoustic monitoring for baleen whales from a moored buoy: System description and evaluation(Wiley, 2019-06-24) Baumgartner, Mark F. ; Bonnell, Julianne M. ; Van Parijs, Sofie M. ; Corkeron, Peter ; Hotchkin, Cara ; Ball, Keenan R. ; Pelletier, Léo‐Paul ; Partan, James W. ; Peters, Donald B. ; Kemp, John N. ; Pietro, Jeff ; Newhall, Kris ; Stokes, Andrew ; Cole, Timothy V. N. ; Quintana, Ester ; Kraus, Scott D.1. Managing interactions between human activities and marine mammals often relies on an understanding of the real‐time distribution or occurrence of animals. Visual surveys typically cannot provide persistent monitoring because of expense and weather limitations, and while passive acoustic recorders can monitor continuously, the data they collect are often not accessible until the recorder is recovered. 2. We have developed a moored passive acoustic monitoring system that provides near real‐time occurrence estimates for humpback, sei, fin and North Atlantic right whales from a single site for a year, and makes those occurrence estimates available via a publicly accessible website, email and text messages, a smartphone/tablet app and the U.S. Coast Guard's maritime domain awareness software. We evaluated this system using a buoy deployed off the coast of Massachusetts during 2015–2016 and redeployed again during 2016–2017. Near real‐time estimates of whale occurrence were compared to simultaneously collected archived audio as well as whale sightings collected near the buoy by aerial surveys. 3. False detection rates for right, humpback and sei whales were 0% and nearly 0% for fin whales, whereas missed detection rates at daily time scales were modest (12%–42%). Missed detections were significantly associated with low calling rates for all species. We observed strong associations between right whale visual sightings and near real‐time acoustic detections over a monitoring range 30–40 km and temporal scales of 24–48 hr, suggesting that silent animals were not especially problematic for estimating occurrence of right whales in the study area. There was no association between acoustic detections and visual sightings of humpback whales. 4. The moored buoy has been used to reduce the risk of ship strikes for right whales in a U.S. Coast Guard gunnery range, and can be applied to other mitigation applications.
-
ArticleIn plane sight: a mark-recapture analysis of North Atlantic right whales in the Gulf of St. Lawrence(Inter Research, 2021-12-02) Crowe, Leah M. ; Brown, Moira W. ; Corkeron, Peter ; Hamilton, Philip K. ; Ramp, Christian ; Ratelle, Stephanie ; Vanderlaan, Angelia S. M. ; Cole, Tim V. N.North Atlantic right whales Eubalaena glacialis are most commonly observed along the eastern seaboard of North America; however, their distribution and occupancy patterns have become less predictable in the last decade. This study explored the individual right whales captured photographically from both dedicated and opportunistic sources from 2015 to 2019 in the Gulf of St. Lawrence (GSL), an area previously understudied for right whale presence. A total of 187 individuals, including reproductive females, were identified from all sources over this period. In years when more substantial survey effort occurred (2017-2019), similar numbers of individuals were sighted (mean = 133, SD = 1.5), and dedicated mark-recapture aerial surveys were highly effective at capturing almost all of the whales estimated in the region (2019: N = 137, 95% CI = 135-147). A high rate of inter-annual return was observed between all 5 study years, with 95% of the animals seen in 2019 sighted previously. Capture rates indicated potential residencies as long as 5 mo, and observed behaviors included feeding and socializing. Individuals were observed in the northern and southern GSL, regions divided by a major shipping corridor. Analyses suggest that individuals mostly moved less than 9.1 km d-1, although rates of up to 79.8 km d-1 were also calculated. The GSL is currently an important habitat for 40% of this Critically Endangered species, which underscores how crucial protection measures are in this area.
-
DatasetInvestigating thermal physiology in large whales via aerial infrared thermography(Woods Hole Oceanographic Institution, 2021-04-23) Lonati, Gina ; Zitterbart, Daniel ; Miller, Carolyn A. ; Corkeron, Peter ; Murphy, Christin T. ; Moore, Michael J.The critically endangered status of North Atlantic right whales (NARWs, Eubalaena glacialis) warrants the development of new, less invasive technology to monitor the health of individuals. Combined with advancements in remotely piloted aircraft systems (RPAS, commonly “drones”), infrared thermography (IRT) is being increasingly used to detect and count marine mammals and study their physiology. We conducted RPAS-based IRT over NARWs in Cape Cod Bay, Massachusetts, USA in 2017 and 2018. Observations demonstrated three particularly useful applications of RPAS-based IRT to study large whales: 1) exploring patterns of cranial heat loss and providing insight into the physiological mechanisms that produce these patterns; 2) tracking subsurface individuals in real-time (depending on the thermal stratification of the water column) using cold surface water anomalies resulting from fluke upstrokes; and 3) detecting natural changes in superficial blood circulation or diagnosing pathology based on hot anomalies on post-cranial body surfaces. These qualitative applications present a new, important opportunity to study and monitor large whales, particularly rare and at-risk species like NARWs. Despite the challenges of using this technology in aquatic environments, the applications of RPAS-based IRT for monitoring the health and behavior of endangered marine mammals, including the collection of quantitative data on thermal physiology, will continue to diversify.
-
ArticleUncertain bioenergetics of North Atlantic right whales(Inter-Research Science Publisher, 2023-12-21) Hutt, Jasmin C. ; Corkeron, Peter ; van der Hoop, Julie M. ; Moore, Michael J.Without substantive reduction in anthropogenic trauma, Critically Endangered North Atlantic right whales Eubalaena glacialis (NARWs) risk extinction. Decreasing population size is attributable to 2 main issues besides vessel collision: entanglement in fishing gear and changes in food availability due to ecosystem changes in the face of climate disruption. Both can affect NARW energetics, leading to reduced body condition, decreased reproductive success of individuals, and deterioration of overall population health. To measure the impact of these stressors and their interaction, energetic costs associated with entanglement and starvation were incorporated in a bioenergetics model, established for a generic female right whale. We compared models for a NARW living now, one from 2 decades ago, when the species’ abundance was increasing at approximately 2% yr-1, and a southern right whale (SRW) from a population increasing at approximately 6% yr-1. Parameter uncertainty associated with daily estimates of energy income, basal metabolic rate, and possible influences of baleen rack disruption from entanglement was so great that differences between the 3 generic right whale females were indistinguishable. Therefore, we included a stunted whale in the model. It was also indistinguishable from our first 3 model whales. Further, it made robust predictions of NARW energy budgets, let alone the impact of specific stressors of varying intensity, impossible. The capacity of bioenergetic modeling to inform conservation management of NARWs will be substantially enhanced by resolving these parameter uncertainties.