Randall R. Reeves's research while affiliated with Marine Mammal Commission and other places

Publications (169)

Article
Some populations of marine mammals (particularly odontocete cetaceans, and pinnipeds) have responded to the expansion of fisheries by modifying their behaviour to take advantage of the foraging opportunities provided by fishing. This has led to interactions that include forms of “depredation”, referring to the removal of, or damage to, marketable o...
Chapter
This chapter offers some personal thoughts and reflections on strategies taken to manage human activities and limit or lessen their impacts on whales, dolphins, and porpoises. OverkillOverkill in one form or another, whether by targeted hunting or by accidental mortality from entanglementEntanglementin fishing gearFishing gearor vessel strikesVesse...
Article
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Several populations of odontocete cetaceans, including at least 19 species, have modified their behavior and adapted to foraging in association with trawlers. We review information on odontocete interactions with different types of trawlers across 13 Food and Agriculture Organization fishing areas around the world. We also review knowledge gaps, th...
Poster
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Several populations of odontocete cetaceans, including at least 19 species, are known to forage and feed in association with trawlers. We reviewed information on odontocete interactions with different kinds of trawlers across 13 FAO fishing areas around the world. We also identified knowledge gaps, effects on odontocete ecology, distribution, behav...
Article
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This tool provides a way for managers and other stakeholders to explore bycatch scenarios, based on simple information about marine mammal life history and rough estimates of abundance and bycatch. The tool consists of an R package (R Core Team, 2021) and a Shiny application (Chang et al., 2021). The primary machinery in the package is an age-struc...
Article
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We consider the current evidence of climate change effects on marine mammals that occur in U.S. waters relative to past predictions. Compelling cases of such effects have been documented, though few studies have confirmed population-level impacts on abundance or vital rates. While many of the observed effects had been predicted, some unforeseen and...
Article
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Fisheries bycatch is the greatest current source of human-caused deaths of marine mammals worldwide, with severe impacts on the health and viability of many populations. Recent regulations enacted in the United States under the Fish and Fish Product Import Provisions of its Marine Mammal Protection Act require nations with fisheries exporting fish...
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Bycatch in marine fisheries is the leading source of human-caused mortality for marine mammals, has contributed to substantial declines of many marine mammal populations and species, and the extinction of at least one. Schemes for evaluating marine mammal bycatch largely rely on estimates of abundance and bycatch, which are needed for calculating b...
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Recent cetacean taxonomic changes and conservation action Taxonomic uncertainty continues to be an impediment to efficient conservation, even for large and charismatic animals such as whales and dolphins. This is exemplified by several discoveries in the last few months alone: a new species of great whale was described in the Gulf of Mexico (Rosel...
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Motivated by the need to estimate the abundance of marine mammal populations to inform conservation assessments, especially relating to fishery bycatch, this paper provides background on abundance estimation and reviews the various methods available for pinnipeds, cetaceans and sirenians. We first give an “entry-level” introduction to abundance est...
Article
Within just one human lifetime, the underlying motivation to conserve whales, dolphins and porpoises has shifted from being purely practical and anthropogenic to something much broader, reflecting a desire to protect populations as well as individual animals. In European waters, cetacean conservation currently tends to focus on direct and obvious t...
Article
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The effects of human-caused mortality, such as fisheries bycatch, of endangered, threatened and protected (ETP) species of marine mammals can be evaluated using population model-based stock assessments. The information available to conduct such assessments is often very limited. Available data might include fragmented time-series of abundance estim...
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Preventing declines in common species is key to sustaining the structure and function of marine ecosystems. Yet for many common marine mammals, including oceanic dolphins, statistical power to detect declines remains low due to patchy distribution and large variability in group sizes. In this study, population viability analyses (PVA) were used to...
Chapter
We provide a pan-Arctic synopsis of bowhead whale ecology for four stocks, namely, the Bering–Chukchi–Beaufort (BCB), Eastern Canada–West Greenland (ECWG), East Greenland–Svalbard–Barents Sea (EGSB), and Okhotsk Sea (OKH) stocks. Each stock occupies distinct subarctic and arctic ecosystems that are undergoing disparate rates of change in sea-ice co...
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Determining acceptable rates of human‐caused mortality in low‐data situations is a concern for many taxa worldwide. An established approach for determining acceptable levels of human‐caused mortality of marine mammals and other species of conservation concern is the Potential Biological Removal (PBR) framework, but PBR requires near‐unbiased estima...
Article
The potential biological removal (PBR) formula used to determine a reference point for human-caused mortality of marine mammals in the United States has been shown to be robust to several sources of uncertainty. This study investigates the consequences of the quality of monitoring on PBR performance. It also explores stochastic and demographic unce...
Article
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The potential biological removal (PBR) formula used to determine a reference point for human-caused mortality of marine mammals in the United States has been shown to be robust to several sources of uncertainty. This study investigates the consequences of the quality of monitoring on PBR performance. It also explores stochastic and demographic unce...
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The monodontids—narwhals, Monodon monoceros, and belugas, Delphinapterus leucas—are found in much of the Arctic and in some subarctic areas. They are hunted by indigenous subsistence users. In the past, some populations were substantially reduced by commercial hunting and culling; more recently, some populations have declined due to uncontrolled su...
Article
A Management Strategy Evaluation is used to estimate success at achieving conservation goals for marine mammals while also aiming to minimize impacts on commercial fisheries. It is intended to improve understanding of US import rules that require nations exporting fish and fish products to the US to adhere to marine mammal bycatch standards “compar...
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All species of large whales are susceptible to vessel strikes, but the true scale and geographical extent of such strikes is not known. This paper provides a qualitative assessment of the range-wide risks posed to gray whales Eschrichtius robustus by vessels, by comparing patterns of whale distribution with the density of vessel traffic seasonally...
Article
Ecological baselines—reference states of species' distributions and abundances—are key to the scientific arguments underpinning many conservation and management interventions, as well as to the public support to such interventions. Yet societal as well as scientific perceptions of these baselines are often based on ecosystems that have been deeply...
Article
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The conservation status of small cetaceans has significantly worsened since the 1980s, when the baiji was the only species of small cetacean listed as Endangered by IUCN. Now the baiji is almost certainly extinct and 13 other species, subspecies, or populations (hereafter units-to-conserve or units) of small cetaceans are listed as Critically Endan...
Article
Often perceived as environmentally benign, 'green' renewable energy technologies have ecological costs that are often overlooked, especially those occurring below the waterline. After briefly discussing the impacts of hydropower on freshwater and marine organisms, we focus this review on the impacts of marine renewable energy devices (MREDs) on und...
Chapter
Sociality—collective living—confers multiple advantages to oceanic dolphins, including enhanced foraging, predator avoidance, and alloparental care and may be particularly important in oceanic environments where prey is patchy and refuge nonexistent. This chapter covers broad aspects of the social lives of the delphinid community that inhabits the...
Chapter
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Some mammalian species that have not succumbed to pervasive human impacts and encroachments have managed to adapt to certain types of human activities. Several odontocetes have modified their behavior to persist, and in some cases even prosper, in human-altered riverine, coastal, and oceanic habitat. Examples include cooperation with fishers to cat...
Article
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Electrofishing is an accepted practice for legal fish sampling and surveying, but its use for subsistence food and market fishing has long been illegal in most countries. Illegal use affects freshwater fish populations in many parts of the world, and has been cited as a cause of mortality for endangered freshwater cetaceans in China (Yangtze dolphi...
Article
Evolutionary relationships among cetaceans within the family Delphinidae have been difficult to resolve due to the high number of species and their relatively rapid radiation. This is the case for the dolphin species currently placed in the genus Lagenorhynchus, and their relations to Cephalorhynchus and Lissodelphis species. Phylogenetic relations...
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Bowhead whales generally migrate into high Arctic waters in the summer months and move to lower latitudes in the wintertime. During the 1800s and early 1900s commercial whaling greatly reduced the numbers of bowhead whales in waters adjacent to the North Atlantic Ocean. In recent decades their numbers have been increasing. Thirteen sightings of a b...
Article
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Western gray whales Eschrichtius robustus (WGWs) are endangered, and their range overlaps areas where several important commercial fisheries operate in the Russian Far East (RFE). Throughout their range, gray whales commonly become entangled or entrapped in fishing gear. In the western North Pacific, they have been killed in set nets and seen entan...
Article
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Global warming is significantly altering arctic marine ecosystems. Specifically, the precipitous loss of sea ice is creating a dichotomy between ice-dependent polar bears and pinnipeds that are losing habitat and some cetaceans that are gaining habitat. While final outcomes are hard to predict for the many and varied marine mammal populations that...
Article
The scientific study of death across animal taxa—comparative thanatology—investigates how animals respond behaviourally, physiologically and psychologically to dead conspecifics, and the processes behind such responses. Several species of cetaceans have been long known to care for, attend to, be aroused by, or show interest in dead or dying individ...
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Small cetaceans (dolphins and porpoises) face serious anthropogenic threats in coastal habitats. These include bycatch in fisheries; exposure to noise, plastic and chemical pollution; disturbance from boaters; and climate change. Generating reliable abundance estimates is essential to assess sustainability of bycatch in fishing gear or any other fo...
Article
Obtaining the representative morphological data required for traditional taxonomy is difficult, and sometimes impossible, for cetaceans, especially large ones. As a result, three quarters of the 88 currently recognized extant species have no subspecies and 40 taxa likely have additional unnamed taxa. Conservation needs give urgency to improving tax...
Article
Taxonomy is an imprecise science that delimits the evolutionary continuum into discrete categories. For marine mammals, this science is complicated by the relative lack of morphological data for taxa that inhabit remote and often vast ranges. We provide guidelines to promote consistency in studies relying primarily on molecular genetic data to deli...
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R. Stone's In Depth News story “Dambuilding threatens Mekong fisheries” (2 December, p. [1084][1]) explains why the scores of dams planned for the Mekong River are likely to have major impacts on eight of the world's largest freshwater fishes, all of which are already at risk of extinction.
Article
On 1 January 2017, the U.S. National Oceanic and Atmospheric Administration (NOAA) will enact a new rule ( 1 ) requiring countries exporting seafood to the United States to demonstrate that their fisheries comply with the U.S. Marine Mammal Protection Act (MMPA). The United States is the world's largest seafood importer ( 2 ); the MMPA is among the...
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The North Atlantic right whale (NARW) (Eubalaena glacialis) is one of the world's most threatened whale species, having come close to extinction after nearly a millennium of exploitation, and currently persisting as a population of only ca. 500 individuals. Setting appropriate conservation targets for this species requires an understanding of its h...
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No global synthesis of the status of baleen whales has been published since the 2008 IUCN Red List assessments. Many populations remain at low numbers from historical commercial whaling, which had ceased for all but a few by 1989. Fishing gear entanglement and ship strikes are the most severe current threats. The acute and long-term effects of anth...
Article
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AimTo obtain a plausible hypothesis for the historical distribution of North Atlantic right whales (NARWs) (Eubalaena glacialis) in their summer feeding grounds. Previously widespread in the North Atlantic, after centuries of hunting, these whales survive as a small population off eastern North America. Because their exploitation began before forma...
Article
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There is a high risk that incidental mortality (bycatch) in gillnets will lead to extinction of the vaquita Phocoena sinus, a small porpoise endemic to Mexico's northern Gulf of California. A zoned Biosphere Reserve established in 1993 proved ineffective at slowing the population's decline, and in 2005, a Vaquita Refuge was declared. The Refuge Pro...
Article
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Since the 1970s the role of fishery bycatch as a factor reducing, or limiting the recovery of, marine mammal populations has been increasingly recognized. The proceedings of a 1990 International Whaling Commission symposium and workshop summarized fishery and bycatch data by region, fishery, and species, and estimated the significance of the 'impac...
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There is great interest in exploring and exploiting hydrocarbon resources in the Arctic, and one of the main methods of locating and assessing such resources is seismic survey. Marine seismic surveys involve the use of airguns that introduce high-energy noise to the Arctic’s largely pristine underwater acoustic environment. Narwhals may be particul...
Chapter
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This species is considered to be Endangered A4d due to an ongoing and projected decline of greater than 50% over 3 generations (approx. 39 years, Slooten et al. 2000) considering both the past and the future. It is also important to consider that although its extent of occurrence and area of occupancy likely exceed the thresholds for criteria B1, B...
Chapter
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The best available information indicates that the total population size is only in the low thousands, meaning that the number of mature individuals is likely to be fewer than 10,000 and therefore it is likely that the population size threshold for Vulnerable under criterion C is met. Subcriterion C1 requires an estimated continuing decline of at le...
Chapter
The species was previously listed as Vulnerable but is now considered Data Deficient due to the limited amount of current information available on threats, ecology, and population numbers and trends. In areas where botos have been studied, they appear widespread and relatively abundant. However, these areas represent only a small proportion of the...
Chapter
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Although some progress has been made towards increasing what is known about this species since the previous 1996 listing as Data Deficient, the information is still insufficient for evaluation against the criteria, particularly with regard to population size, trends, and threats. There is reason to suspect that the species overall, and at least the...
Article
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Despite lessons from terrestrial systems, conservation efforts in marine systems continue to focus on identifying priority sites for protection based on high species richness inferred from range maps. Range maps oversimplify spatial variability in animal distributions by assuming uniform distribution within range and de facto giving equal weight to...
Chapter
There is inadequate information to assess this species against the criteria and therefore it must remain listed as Data Deficient pending a credible estimate of population size and/or better information on population trend. Heaviside’s Dolphins have a limited range and are not particularly common anywhere. Several threats have been identified, incl...
Article
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Marine seismic surveys, which use loud, primarily low-frequency sound to penetrate the sea floor, are known to disturb and could harm marine life. The use of these surveys for conventional and alternative offshore energy development as well as research is expanding. Given their proliferation and potential for negative environmental impact, there is...
Data
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a b s t r a c t The Arctic is one of the fastest-changing parts of the planet. Global climate change is already having major impacts on Arctic ecosystems. Increasing temperatures and reductions in sea ice are particular conservation concerns for ice-associated species, including three endemic cetaceans that have evolved in or joined the Arctic symp...
Article
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Many severely depleted populations of baleen whales (Mysticeti) have exhibited clear signs of recovery whereas there are few examples in toothed whales (Odontoceti). We hypothesize that this difference is due, at least in part, to social and behavioural factors. Clearly, a part of the lack of resilience to exploitation is explained by odontocete li...
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We analyzed variation in nine non-metric and eight metric variables in the skulls of 132 narwhals (Monodon monoceros) from five localities in Greenland (Inglefield Bredning, Melville Bay, Uummannaq, Disko Bay, and Scoresby Sound) and one in the eastern Canadian Arctic (Eclipse Sound). Metric variables were used to compare the combined Disko Bay and...
Article
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River dolphins are among the world's most threatened mammals, and indeed the baiji (Lipotes vexillifer), a species endemic to China's Yangtze River, is likely extinct. Exploitation for products such as meat, oil, and skins has been a lesser feature in the population histories of river dolphins compared to most large mammals. Habitat factors are the...
Article
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American whalemen sailed out of ports on the east coast of the United States and in California from the 18(th) to early 20(th) centuries, searching for whales throughout the world's oceans. From an initial focus on sperm whales (Physeter macrocephalus) and right whales (Eubalaena spp.), the array of targeted whales expanded to include bowhead whale...
Article
The recent loss of Arctic sea ice provides humans unprecedented access to the region. Marine mammals rely on sound as a primary sensory modality, and the noise associated with increasing human activities offshore can interfere with vital life functions. Many coastal communities rely on marine mammals for food and cultural identity, and subsistence...
Chapter
At the global level the species does not qualify for a threatened status under any of the criteria although there is substantial uncertainty about numbers and trends for at least some large parts of the range, especially in the Russian Arctic. Given that uncertainty, and the fact that cessation of national and international, taxon-specific conserva...
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