Nicholas K Dulvy

Nicholas K Dulvy
Simon Fraser University · Department of Biological Sciences

Professor

About

389
Publications
209,080
Reads
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29,264
Citations
Introduction
A fundamental question in population ecology is what factors influence variation in the intrinsic rate of population increase and intrinsic sensitivity to extinction among species? My goal is to arrive on a remote island armed only with the tools of an 18th century naturalist (and a computer and the models I am developing) to undertake ecological risk assessments of the local fisheries.
Additional affiliations
January 2008 - present
Simon Fraser University
January 2008 - April 2016
Simon Fraser University
Position
  • Professor and Canada Research Chair in Marine Biodiversity and Conservation
September 2003 - December 2009
the Centre for Environment, Fisheries and Aquaculture Science

Publications

Publications (389)
Preprint
Life history theory argues that the maximum size of an organism and its corresponding growth rate have evolved to maximize lifetime reproductive output. The Gill Oxygen Limitation Theory suggests that in aquatic organisms, maximum size is instead constrained by the surface area of the gills, the primary site of gas exchange with the environment. A...
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A curated database of shark and ray biological data is increasingly necessary both to support fisheries management and conservation efforts, and to test the generality of hypotheses of vertebrate macroecology and macroevolution. Sharks and rays are one of the most charismatic, evolutionary distinct, and threatened lineages of vertebrates, comprisin...
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threatened with extinction, resulting in a sampled RLI of 0.914 for all species, 0.968 in marine and 0.862 in freshwater ecosystems. Our sample showed fishing as the principal threat for marine species, and pollution by agricultural and forestry effluents for freshwater fishes. The sampled list provides a robust representation for tracking trends i...
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Understanding how changing environmental conditions affect fish growth and reproduction is critical to predict the consequences of climate change, yet studies focused on the physiological effects of temperature upon life histories often ignore size-dependent foraging and risk of predation. We embedded a state-dependent energetic model in an ecosyst...
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Fisheries management is essential to guarantee sustainable capture of target species and avoid undesirable declines of incidentally captured species. A key challenge is halting and reversing declines of shark and ray species, and specifically assessing the degree to which management is sufficient to avoid declines in relatively data‐poor fisheries....
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Chondrichthyan fishes are among the most threatened vertebrates on the planet because many species have slow life histories that are outpaced by intense fishing. The Western Central Atlantic Ocean, which includes the Greater Caribbean, is a hotspot of chondrichthyan biodiversity and abundance, but has been characterized by extensive shark and ray f...
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While some sharks are subject to trade regulations, much of the international trade in fins (and likely meat too) is derived from requiem sharks (Carcharhinus spp). Here, we quantify catch, trade, and the shortfall in fisheries management (M-Risk) for 18 requiem shark species based on 230 assessments across 27 countries and four Regional Fisheries...
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Full-text available
Fisheries management is essential to guarantee sustainable capture of target species and avoid undesirable declines of incidentally captured species. A key challenge is halting and reversing declines of shark and ray species, and specifically assessing the degree to which management is sufficient to avoid declines in relatively data-poor fisheries....
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Full-text available
Global biodiversitytargets require us to identify species at risk of extinction and quantify status and trends of biodiversity. The Red List Index (RLI) tracks trends in the conservation status of entire species groups over time by monitoring changes in categories assigned to species. Here, we calculate this index for the world’s fishes in 2010, us...
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The southwest Indian Ocean (SWIO) is a hotspot of endemic and evolutionarily distinct sharks and rays. We summarise the extinction risk of the sharks and rays endemic to coastal, shelf, and slope waters of the SWIO and adjacent waters (Namibia to Kenya, including SWIO islands). Thirteen of 70 species (19%) are threatened: one is Critically Endanger...
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Over the past 4 decades there has been a growing concern for the conservation status of elasmobranchs (sharks and rays). In 2002, the first elasmobranch species were added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Less than 20 yr later, there were 39 species on Appendix II and 5 o...
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Small-scale shark fisheries support the livelihoods of a large number of coastal communities in developing countries. Shark meat comprises a cheap source of protein and is traded locally in many parts in developing countries, while the skins, oil, and fins are exported to the international market. This study addresses a gap in literature regarding...
Preprint
Chondrichthyan fishes are among the most threatened vertebrates on the planet because many species have slow life histories that are outpaced by intense fishing. The Western Central Atlantic Ocean, which includes the greater Caribbean, is a hotspot of chondrichthyan biodiversity and abundance, but is historically characterized by extensive shark an...
Preprint
Full-text available
Across vertebrates, live-bearing has evolved at least 150 times from the ancestral state of egg-laying into a diverse array of forms and degrees of prepartum maternal investment. A key question is how this diversity of reproductive modes arose and whether reproductive diversification underlies species diversification? To test these questions, we ev...
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The scale and drivers of marine biodiversity loss are being revealed by the International Union for Conservation of Nature (IUCN) Red List assessment process. We present the first global reassessment of 1,199 species in Class Chondrichthyes—sharks, rays, and chimeras. The first global assessment (in 2014) concluded that one-quarter (24%) of species...
Preprint
Full-text available
The southwest Indian Ocean (SWIO) is a hotspot of endemic and evolutionarily distinct sharks and rays. We summarise the extinction risk of the sharks and rays endemic to coastal, shelf, and slope waters of the SWIO and adjacent waters (Namibia to Kenya, including SWIO islands). Thirteen of 70 species (19%) are threatened: one is Critically Endanger...
Article
Full-text available
The scale and drivers of marine biodiversity loss are being revealed by the International Union for Conservation of Nature (IUCN) Red List assessment process. We present the first global reassessment of 1,199 species in Class Chondrichthyes—sharks, rays, and chimeras. The first global assessment (in 2014) concluded that one-quarter (24%) of species...
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Full-text available
Many species of sharks are threatened with extinction, and there has been a longstanding debate in scientific and environmental circles over the most effective and appropriate strategy to conserve and protect them. Should we allow for sustainable fisheries exploitation of species which can withstand fishing pressure, or ban all fisheries for sharks...
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The loss of biodiversity is increasingly well understood on land, but trajectories of extinction risk remain largely unknown in the ocean. We present regional Red List Indices (RLIs) to track the extinction risk of 119 Northeast Atlantic and 72 Mediterranean shark and ray species primarily threatened by overfishing. We combine two IUCN workshop ass...
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All life acquires energy through metabolic processes and that energy is subsequently allocated to life-sustaining functions such as survival, growth and reproduction. Thus, it has long been assumed that metabolic rate is related to the life history of an organism. Indeed, metabolic rate is commonly believed to set the pace of life by determining wh...
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Brain size varies dramatically, both within and across species, and this variation is often believed to be the result of trade-offs between the cognitive benefits of having a large brain for a given body size and the energetic cost of sustaining neural tissue. One potential consequence of having a large brain is that organisms must also meet the as...
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Metabolic rate underlies a wide range of phenomena from cellular dynamics to ecosystem structure and function. Models seeking to statistically explain variation in metabolic rate across vertebrates are largely based on body size and temperature. Unexpectedly, these models overlook variation in the size of gills and lungs that acquire the oxygen nee...
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Advances in experimental design and equipment have simplified the collection of maximum metabolic rate (MMR) data for a more diverse array of water-breathing animals. However, little attention has been given to the consequences of analytical choices in the estimation of MMR. Using different analytical methods can reduce the comparability of MMR est...
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Current shark conservation and management conflicts represent an underrecognized expression of long-standing debates over whether the goal of modern conservation should be sustainable exploitation of natural resources or maximum possible preservation of wilderness and wildlife. In the developing world, exploitation of fisheries resources can be ess...
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Sharks and rays are possibly the most threatened Class of marine fishes and their declines can be halted if protected areas are optimised to benefit these species. We identify spatial priorities for all 63 endemic sharks and rays in the marine biodiversity hotspot, the Western Indian Ocean (WIO). Collectively, while the WIO nations currently surpas...
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An important challenge in ecology is to understand variation in species' maximum intrinsic rate of population increase, r max , not least because r max underpins our understanding of the limits of fishing, recovery potential, and ultimately extinction risk. Across many vertebrates, terrestrial and aquatic, body mass and environmental temperature ac...
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Measuring scientific success has traditionally involved numbers and statistics. However, due to an increasingly uncertain world, more than ever we need to measure the effect that science has on real-world scenarios. We asked researchers to share their points of view on what scientific impact means to them and how impact matters beyond the numbers.
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Extinctions on land are often inferred from sparse sightings over time, but this technique is ill-suited for wide-ranging species. We develop a space-for-time approach to track the spatial contraction and drivers of decline of sawfishes. These iconic and endangered shark-like rays were once found in warm, coastal waters of 90 nations and are now pr...
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Overfishing is the primary cause of marine defaunation, yet declines in and increasing extinction risks of individual species are difficult to measure, particularly for the largest predators found in the high seas. Here we calculate two well-established indicators to track progress towards Aichi Biodiversity Targets and Sustainable Development Goal...
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Full-text available
Small-scale shark fisheries support a large number of coastal community livelihoods in developing countries. Shark meat comprises a cheap source of protein and is traded locally in many parts in developing countries, while the skins, oil, fins and gill rakers are exported to the international market. This study addresses a gap in literature regardi...
Preprint
Full-text available
Local Ecological Knowledge has the potential to improve fishery management by providing new data on the fishing efforts, behavior, and abundance trends of fish and other aquatic animals. Here, we relied on local knowledge of fishers to investigate ecological factors that affect elasmobranch fishers operations and the changes in stock status of shar...