Amy R Knowlton

New England Aquarium · Research

Understanding the causes of mortality for a declining species is essential for developing effective conservation and management strategies, particularly when anthropogenic activities are the primary threat. Using a competing hazards framework allows for robust estimation of the cause-specific variation that may exist across multiple dimensions, suc...

The North Atlantic right whale (Eubalaena glacialis) is among the most endangered whale species in the world and has been in decline since 2010. Considerable effort is directed toward its recovery by striving to remove threats. In this report, we describe the development of a population viability analysis for right whales that is designed to assess...

Quantifying the cumulative effects of stressors on individuals and populations can inform the development of effective management and conservation strategies. We developed a Bayesian state–space model to assess the effects of multiple stressors on individual survival and reproduction. In the model, stressor effects on vital rates are mediated by ch...

The appropriate use and interpretation of passive acoustic data for monitoring the Critically Endangered North Atlantic right whale Eubalaena glacialis (hereafter right whale) rely on knowledge of their calling behavior and how it varies with respect to time, space, demographics, and observed behavior. To assess such relationships in a habitat of i...

North Atlantic right whales frequently become entangled in fishing gear, which can negatively affect their reproductive output and probability of survival. We estimated individual whale health from a hierarchical Bayesian model fit to photographic indices of health. We reviewed 696 whales sighted from 1980 to 2011 and assigned 1196 entanglement eve...

North Atlantic right whales (NARW) are critically endangered and have been declining in abundance since 2011. In the past decade, human-caused mortalities from vessel strikes and entanglements have been increasing, while birth rates in the population are at a 40 yr low. In addition to declining abundance, recent studies have shown that NARW length-...

Offshore wind energy development is growing quickly around the world. In southern New England, USA, one of the largest commercial offshore wind energy farms in the USA will be established in the waters off Massachusetts and Rhode Island, an area used by the Critically Endangered North Atlantic right whale Eubalaena glacialis. Prior to 2011, little...

Whales are now largely protected from direct harvest, leading to partial recoveries in many previously depleted species.¹ However, most populations remain far below their historical abundances and incidental human impacts, especially vessel strikes and entanglement in fishing gear, are increasingly recognized as key threats.² In addition, climate-d...

Whaling has 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 limitatio...

Abstract Evaluations of the conservation status of the endangered North Atlantic right whale as well as many other wildlife species often rely extensively on counts and cause‐of‐death determinations of carcasses found accidentally or during dedicated surveys. Even when survey effort dedicated to a population is extensive, many deaths may go unseen....

The 2017 North Atlantic right whale (NARW) unusual mortality event and an increase in humpback whale entanglements off the U.S. West Coast have driven significant interest in ropeless trap/pot fishing. Removing the vertical buoy lines used to mark traps on the sea floor and haul them up would dramatically reduce or eliminate entanglements, the lead...

Animal movement plays a fundamental role in the ecology of migratory species, and understanding migration patterns is required for effective management. To evaluate intrinsic and environmental factors associated with probabilities of endangered North Atlantic right whales Eubalaena glacialis migrating to a wintering ground off the southeastern Unit...

Abandoned, lost or discarded fishing gear (ALDFG) comprises a significant amount of global marine debris, with diverse impacts to marine environments, wildlife, and the fishing industry. Building evidence on ALDFG is critical to holistically understand the marine debris issue, and to inform the development of solutions that reduce amounts of ALDFG...

North Atlantic right whales (Eubalaena glacialis) are highly endangered and frequently exposed to a myriad of human activities and stressors in their industrialized habitat. Entanglements in fixed fishing gear represent a particularly pervasive and often drawn-out source of anthropogenic morbidity and mortality to the species. To better understand...

Large whales are frequently entangled in fishing gear and sometimes swim while carrying gear for days to years. Entangled whales are subject to additional drag forces requiring increased thrust power and energy expenditure over time. To classify entanglement cases and aid potential disentanglement efforts, it is useful to know how long an entangled...

Body condition has been correlated with survival and reproductive success in bothterrestrial and marine mammals, including North Atlantic right whales Eubalaena glacialis. Weused photographs of individually identified right whales to assess visual changes in body conditionin reproductive females, adult males, juveniles, and entangled whales. Images...

Right whales are vulnerable to many sources of anthropogenic disturbance including ship strikes, entanglement with fishing gear, and anthropogenic noise. The effect of these factors on individual health is unclear. A statistical model using photographic evidence of health was recently built to infer the true or hidden health of individual right wha...

The impacts of human activities on cryptic marine species can be difficult to assess. The North Atlantic right whale is an endangered species numbering just over 500 individuals. Entanglement in fishing gear is one documented source of injury and mortality, but population-level effects have been difficult to quantify. We used documented entanglemen...

Entanglement in fixed fishing gear is a conservation concern for whales worldwide, including in the United States where deaths of North Atlantic right and humpback whales have exceeded management limits for decades. We examined fishing gear removed from live and dead entangled whales along the US East Coast and the Canadian Maritimes from 1994-2010...

Marine mammals are faced with increasing challenges from environmental fluctuation, climate change, and disturbances from human activities. Anthropogenic mortalities have been well documented, but it is difficult to assess the sub-lethal effects of disturbance on the fitness of marine wildlife, and to distinguish these impacts from natural variatio...

North Atlantic right whales still number in the hundreds, not thousands. Vessel strike is one of the leading causes of preventable mortality. Vessel strike accounts for 18% of right whale mortalities in which the cause of death was determined, and 15% of the population carries visible scars from a vessel strike. NOAA is mandated to protect endanger...

ABSTRACT: To reduce right whale Eubalaena glacialis deaths caused by ship collisions along the US East Coast, a rule was implemented on 8 December 2008 requiring all vessels ≥65 feet (19.8 m) to travel 10 knots (18.5 km h−1) or less in 10 seasonal management areas (SMAs). To evaluate the effectiveness of this rule, we plotted the locations of all r...

Body condition is an indicator of health, and it plays a key role in many vital processes for mammalian species. While evidence of individual body condition can be obtained, these observations provide just brief glimpses into the health state of the animal. An analytical framework is needed for understanding how health of animals changes over space...

This appendix contains further details on the model and the construction of the Gibbs sampler. In addition, it details the priors for the ordinal health classes and for movement. (DOCX)

Entanglement in non-mobile fishing gear has been identified as one of the leading causes of mortality in North Atlantic right whales Eubalaena glacialis. To investigate this issue further, all available photographs of right whales taken from 1980 to 2009 were examined for evidence of entanglement with gear used in fisheries based on presence of rop...

The high variability in reproductive performance of North Atlantic right whales Eubalaena glacialis compared to southern right whales Eubalaena australis may reflect differences in lipid reserves. Amplitude-mode ultrasound was used to measure the thickness of right whale integument (epidermis and blubber, herein referred to as blubber thickness) in...

Vessel strikes are the leading cause of mortality for the endangered North Atlantic right whale Eubalaena glacialis. Prior to a December 2008 implementation of a mandatory, seasonally based vessel-speed rule (10 knots, 18.5 km h -1) along the eastern US seaboard, voluntary recommended speeds and routes were established. We used Automatic Identifica...

Although trends in reproduction, mortality, and entanglement events have been analyzed for the endangered North Atlantic right whale (Eubalaena glacialis) population, no method has been available to assess individual right whale health. Here, we describe a technique for assessing health based on evaluation of selected physical parameters from archi...

The North Atlantic right whale (Eubalaena glacialis) inhabits five areas along the east coast of North America at different times of the year. During 17 years of field observations, it has been found that only 59% of the newborn calves are brought to the Bay of Fundy nursery area. To examine whether this is because of population structuring, the mi...

Vessel-whale collision events represented the ultimate cause of death for 21 (52.5%) of the 40 North Atlantic right whales (Eubalaena glacialis) necropsied between 1970 and December 2006. Injuries seen in vessel-struck whales fall into two distinct categories: 1) sharp trauma, often resulting from contact with the propeller, and 2) blunt trauma, pr...

Parentage analyses of baleen whales are rare, and although mating systems have been hypothesized for some species, little data on realized male reproductive success are available and the patterns of male reproductive success have remained elusive for most species. Here we combine over 20 years of photo-identification data with high-resolution genet...

Marine mammal social interactions are poorly understood primarily because of the difficulty of observing these behaviors in the wild. Observations of copulations in North Atlantic right whale surface active groups (SAGs) have led to the hypothesis that the function of these groups is for conception. The occurrence and composition of SAGs sighted fr...

Unlike smaller marine mammals that lack the mass and power to break free from serious entanglements in fixed fishing gear, right whales can do so, but they are not always rope free. The remaining rope can gradually constrict one or more body parts and the resulting debilitation and ultimate death can take many months. Thus the practices that lead t...

The population levels of this protected species are dangerously low. Current estimates indicate that no more 350 individuals are alive today in the western North Atlantic, and only a few may be found in other parts of the North Atlantic. Recently acquired photographs are able to provide further evidence on population ranges and stock differentiatio...

Author Posting. © IEEE, 2006. This article is posted here by permission of IEEE for personal use, not for redistribution. The definitive version was published in Proceedings Oceans 2006, Boston, MA, USA, 3 pp, doi:10.1109/OCEANS.2006.306792. Unlike smaller marine mammals that lack the mass and power to break free from serious entanglements in fixed...

Right whales carry large populations of three 'whale lice' (Cyamus ovalis, Cyamus gracilis, Cyamus erraticus) that have no other hosts. We used sequence variation in the mitochondrial COI gene to ask (i) whether cyamid population structures might reveal associations among right whale individuals and subpopulations, (ii) whether the divergences of t...

The survival of North Atlantic right whales ( Eubalaena glacialis ) is seriously threatened by mortality caused by ships and entanglements in fishing gear. Demographic modeling indicates that the population is declining despite efforts to reduce anthropogenic mortalities, and in spite of recent increases in calving. The authors of this [Policy Foru...

Fifty-four right whale mortalities have been reported from between Florida, USA and the Canadian Maritimes from 1970 to 2002. Th irty of those animals were examined: 18 adults and juveniles, and 12 calves. Morphometric data are presented such that prediction of body weight is possible if the age, or one or more measurements are known. Calves grew a...

North Atlantic right whale reproduction was assessed for the period 1980 through 1998. At the end of this period, we estimated there were between 299 and 437 right whales alive, including 70 mature females. Using maximum and minimum population estimates for the entire period, mean values for gross annual reproductive rate were 0.36 and 0.49 respect...

Northern right whales in the western North Atlantic number about 300 animals and have shown little sign of recovery in recent decades. Mortality and serious injury due to human activities, particularly commercial fishing and shipping, are thought to be significant factors limiting their recovery. From 1970-1999, 45 right whale deaths were reliably...

A bstract Although collisions with motorized ships are a recognized source of whale mortality, little has been done to compile information on the frequency of their occurrence or contributing factors. We searched historical records and computerized stranding databases for evidence of ship strikes involving great whales ( i. e. , baleen whales and t...

The population of western North Atlantic right whales (Eubalaena glacialis) is distributed primarily between Florida, USA and NovaScotia, Canada, aggregating seasonally in five geographically distinct, high-use areas. To test the effectiveness of monitoring alldemographic classes (juvenile and adult males and females) of the population in these fiv...

Although there are a number of techniques for determining age in dead baleen whales, few exist for live, free-swimming animals. Photo-identification records of 374 cataloged individuals through 1996 were used to assess the age of first parturition, the age structure and the longevity of the North Atlantic fight whale Eubalaena glacialis. Nearly the...

Between 20 January and 14 February 1996, a 20 m auxiliary ketch investigated the coastal waters of Southern Morocco, a former wintering ground for right whales (Eubalaena glacialis). The aims were to: verify if right whales could still be found in the area; evaluate the environmental conditions of the region and assess its suitability as a right wh...

The reproductive biology of the western North Atlantic right whale population was assessed using photoidentification techniques. From 1980 to 1992, 145 calves were born to 65 identified cows. There was no detectable trend in the number of calves produced per year. Mean age at first parturition was 7.57 years. The reproductively active female pool w...

Opportunistic recordings were made on 12 days during the months of August and September in 1986–1989 between Browns and Baccari Banks on the Nova Scotian shelf. Sei whales, Balaenoptera borealis, were seen in the recording area on 16 of the 32 recording sessions. Subsequent signal analysis revealed that a distinctive sound type was recorded on all...

Aerial surveys over the coastal waters of the SE USA in February and March of 1984 and 1985 yielded sightings and photographs of 25 right whales, including 7 newborn calves and 1 juvenile; the region is thus a significant calving ground for these whales in the W North Atlantic. Right whale cows reproduce every 2-5 years (mean 3.12) and segregate th...

Human-induced traumas in North Atlantic right whales (Eubalaena glacialis) fall in to three categories (Campbell-Malone et al. In press; Moore et al. 2004): sharp propeller incisions, blunt vessel impacts and constrictive laceration by fishing gear. Accurate prognoses from field observations of live but impacted animals are essential for triage of...

Vessel speed restrictions have three potentially beneficial effects on the risk of right whale ship strikes: a better chance for the whale to avoid the ship, a better chance for the crew to spot and avoid the whale, and less energy imparted to the whale in the event of a collision. We have developed a model of the first of these effects, using data...