Demian Chapman

Demian Chapman
Florida International University | FIU · Basic Sciences Departments

About

137
Publications
58,080
Reads
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5,076
Citations
Additional affiliations
January 2009 - May 2015
Stony Brook University
Position
  • Professor (Assistant)

Publications

Publications (137)
Article
Full-text available
Shark meat and fin soup are seafood commodities exported and consumed worldwide. Because sharks are large and slow-growing marine predators they tend to accumulate a large amount of mercury in the form of methylmercury. Due to this well-documented biomagnification, many nations have blanket advisories urging citizens, especially pregnant women and...
Article
Full-text available
One third of chondrichthyan species (sharks, rays, and chimeras) are threatened with extinction, mainly due to unsustainable fishing. Large accessible international markets for meat and luxury products like dried fins can help drive overfishing by encouraging targeted capture or retention of high-value export species. If this is common, then specie...
Article
Full-text available
Spatial comparisons of reef shark abundance inside and outside marine protected areas (MPAs) are common and generally report positive MPA effects, yet few studies have tracked abundance trends over long time periods. This is problematic because inside:outside comparisons at a single point in time cannot evaluate whether populations are declining. I...
Article
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Identifying the geographical scale at which natural populations structure themselves is essential for conservation. One way to gauge this structure is by estimating local effective population size (Ne) and the associated measure of effective number of breeders (Nb), as the smaller and more isolated natural populations are, the smaller Ne and Nb the...
Article
Resolving the identity, phylogeny, and distribution of cryptic species within species complexes is an essential precursor to management. The bonnethead shark, Sphyrna tiburo, is a small coastal shark distributed in the Western Atlantic from North Carolina (U.S.A) to southern Brazil. Genetic analyses based on mitochondrial markers revealed that bonn...
Article
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106,107 ✉ replying to A. V. Harry & J. M. Braccini Nature https://doi.org/10.1038/s41586-021-03463-w (2021) Our global analysis 1 estimated the overlap and fishing exposure risk (FEI) using the space use of satellite-tracked sharks and longline fishing effort monitored by the automatic identification system (AIS). In the accompanying Comment, Harry...
Article
This article is a response to Murua et al.'s Matters Arising article in Nature, "Shark mortality cannot be assessed by fishery overlap alone," which arose from arising from N. Queiroz et al. Nature https://doi.org/10.1038/s41586-019-1444-4 (2019).
Article
• Illegal wildlife trade is a major global threat to biodiversity. Environmental authorities around the world face many challenges enforcing and implementing laws intended to protect wild species. Wildlife forensic protocols can help to solve many of these implementation and enforcement issues. • Matamata turtles comprise two different species that...
Article
Shark populations have declined across the Caribbean region, with negative associations between shark abundance and human population density, open access to fishing, and proximity to large markets (‘market gravity’). This decline is frequently attributed to fishing mortality, which increases in areas closer to humans and outside marine reserves. Al...
Article
The status of elasmobranchs in Southeast Asia has been highlighted as a serious concern, yet there are limited data to assess stocks and develop appropriate management plans. Surveys of elasmobranchs at two fishery ports in Singapore were conducted between 2017 and 2020. These fishery ports receive fresh, whole imports of seafood from the region as...
Article
Developing-world shark fisheries are typically not assessed or actively managed for sustainability; one fundamental obstacle is the lack of species and size-composition catch data. We tested and implemented a new and potentially widely applicable approach for collecting these data: mandatory submission of low-value secondary fins (anal fins) from l...
Article
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Animal dietary information provides the foundation for understanding trophic relationships, which is essential for ecosystem management. Yet, in marine systems, high-resolution diet reconstruction tools are currently under-developed. This is particularly pertinent for large marine vertebrates, for which direct foraging behaviour is difficult or imp...
Article
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Proximity and size of the nearest market (‘market gravity’) have been shown to have strong negative effects on coral reef fish communities that can be mitigated by the establishment of closed areas. However, moray eels are functionally unique predators that are generally not subject to targeted fishing and should therefore not directly be affected...
Article
Full-text available
The silky shark is the second most common shark in Southeast Asia’s dried fin markets and is managed in the Atlantic Ocean by the International Commission for the Conservation of Atlantic Tuna (ICCAT) and by three Indo-Pacific regional fisheries management organizations (RMFOs). ICCAT reports ~ 7% of global silky landings but there is a moratorium...
Article
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The critically endangered smalltooth sawfish Pristis pectinata reproduces biennially in central west Florida, United States of America. Here we demonstrate that smalltooth sawfish are physiologically capable of reproducing annually in a captive environment. The smalltooth sawfish are held in an open system, with abiotic conditions that vary natural...
Article
Fins from highly mobile shark species entering large shark fin trade hubs can originate from various geographical locations and stocks. Tracing fins from internationally regulated species to their starting point in the supply chain can have important implications for the monitoring and enforcement of international laws intended to protect threatene...
Article
Full-text available
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Shark fin is one of Asia's most valued dried seafood products, with over 80 shark species traded in Hong Kong [HK]. We analyzed processed shark fins from mainland China and HK markets (n = 267) for mercury, methyl‑mercury, and arsenic, to inform consumers, policy makers and public health officials on the health risks of ingesting fins from nine of...
Article
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Species-specific monitoring through large shark fin market surveys has been a valuable data source to estimate global catches and international shark fin trade dynamics. Hong Kong and Guangzhou, mainland China, are the largest shark fin markets and consumption centers in the world. We used molecular identification protocols on randomly collected pr...
Article
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Decades of overexploitation have devastated shark populations, leaving considerable doubt as to their ecological status1,2. Yet much of what is known about sharks has been inferred from catch records in industrial fisheries, whereas far less information is available about sharks that live in coastal habitats³. Here we address this knowledge gap usi...
Article
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The integration of eDNA analysis into the population assessment and monitoring of sharks could greatly improve temporal and spatial data used for management purposes. This study aimed to compare eDNA detection against well-established seasonal changes in blacktip shark (Carcharhinus limbatus) abundance in Terra Ceia Bay (FL, USA). We used a species...
Article
An oceanic whitetip shark (Carcharhinus longimanus ) was observed off the coast of Kona, Hawaii, with scars having been caused by the tentacles of a large cephalopod. While the exact species could not be confirmed, candidate species include the giant squid (Architeuthis dux ), or species from the genera Thysanoteuthis and Megalocranchia . Telemetry...
Article
There is an urgent need for population‐specific trade information for overexploited sharks, as international trade regulations are becoming an important tool for their conservation [i.e., listings on the Convention on International Trade in Endangered Species (CITES)]. We tested a genetic stock identification (GSI) workflow to quantify the relative...
Article
Full-text available
Microsatellites are useful in studies of population genetics, sibship, and parentage. Here, we screened for microsatellites from multiple elasmobranch genomic libraries using an enrichment protocol followed by sequencing on an Illumina platform. We concurrently screened five and then nine genomes and describe the number of potential loci from each...
Article
No-take marine protected areas (MPAs) are a commonly applied tool to reduce human fishing impacts on marine and coastal ecosystems. However, conservation outcomes of MPAs for mobile and long-lived predators such as sharks are highly variable. Here, we use empirical animal tracking data from 459 individual sharks and baited remote underwater video s...
Article
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Our understanding of marine communities and their functions in an ecosystem relies on the ability to detect and monitor species distributions and abundances. Currently, the use of environmental DNA (eDNA) metabarcoding is increasingly being applied for the rapid assessment and monitoring of aquatic species. Most eDNA metabarcoding studies have eith...
Article
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Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of...
Article
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Emerging conservation efforts for the world’s large predators may, if successful, restore natural predator–prey interactions. Marine reserves, where large predators tend to be relatively common, offer an experimental manipulation to investigate interactions between large-bodied marine predators and their prey. We hypothesized that southern stingray...
Article
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In 2007, the critically endangered European eel (Anguilla anguilla) was listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Flora and Fauna, due to declines in abundance across its range and significant international demand. Illegal trade in live European eel and its products is still occurring to satisfy th...
Article
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The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is a multilateral environmental agreement to ensure that the international trade of threatened species is either prohibited (Appendix I listed species) or being conducted legally, sustainably, and transparently (Appendix II listed species). Twelve threatened...
Article
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• The night shark, Carcharhinus signatus, is a mesopelagic, semi‐oceanic shark species found only in the Atlantic Ocean. It is one of the most frequently caught sharks in pelagic longline fisheries and is classified as Vulnerable by the International Union for the Conservation of Nature (IUCN). Despite their prevalence in commercial fisheries, the...
Chapter
Here, we review how DNA forensics is being applied to meet elasmobranch conservation challenges on a global scale. We first outline the legal frameworks under which elasmobranchs are protected and the types of situations that then arise requiring law enforcement person- nel to turn to DNA forensics to prosecute illicit activity. We then review the...
Article
Full-text available
Trade‐driven overexploitation threatens many sharks. Twelve of the world's most vulnerable shark species have been listed on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) to regulate internationally traded products such as meat and dried fins. CITES records indicate that Hong Kong was the world's top le...
Article
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Bulk stable isotope analysis was used to assess the trophic level and foraging habitats of Caribbean reef sharks (Carcharhinus perezi) compared to three large sympatric predatory teleosts (the Nassau grouper Epinephelus striatus, black grouper Mycteroperca bonaci, and great barracuda Sphyraena barracuda) in an isolated Caribbean coral reef ecosyste...
Article
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Animal behavior should optimize the difference between the energy they gain from prey and the energy they spend searching for prey. This is all the more critical for predators occupying the pelagic environment, as prey is sparse and patchily distributed. We theoretically derive two canonical swimming strategies for pelagic predators, that maximize...
Article
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Sawfishes (Family Pristidae) constitute one of the most threatened families of marine fish, and substantial management efforts are required to stabilize and recover their populations worldwide. Philopatry is common in marine animals, including sharks and rays, and can be a key driver of population structure, which in turn determines the most approp...
Article
Full-text available
Sharks are charismatic predators that play a key role in most marine food webs. Their demonstrated vulnerability to exploitation has recently turned them into flagship species in ocean conservation. Yet, the assessment and monitoring of the distribution and abundance of such mobile species in marine environments remain challenging, often invasive a...
Article
Full-text available
Photographic identification was used to track the movements of the whitespotted eagle ray Aetobatus narinari around South Caicos, Turks and Caicos Islands. A total of 165 individuals were identified, aided by the computer program I3S Spot. The sex ratio across all study sites in 2015 was not significantly different from 1:1 (χ2 = 2·8, P > 0·05). 33...
Article
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The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species-specific basis. Species-specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the...
Article
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Protecting sharks from overexploitation has become global priority after widespread population declines have occurred. Tracking catches and trade on a species-specific basis has proven challenging, in part due to difficulties in identifying processed shark products such as fins, meat, and liver oil. This has hindered efforts to implement regulation...
Data
Compound character attributes (cCA) for CITES-listed shark species. (XLSX)
Data
Number of nucleotide differences between species of the Carcharhinus genus in samples from Guangzhou, China, at the Shark150 region (above diagonal) and Shark474 region (below diagonal). Highlighted cells and number in bold depict two or less nucleotide differences. (XLSX)
Data
Alignment of the Shark150 and Shark474 for common Carcharhinus spp. found in Asian shark fin markets. (TXT)
Data
Carcharhinus samples used to design Shark474F. (DOCX)
Article
Full-text available
Marine reserves, areas protected from ex ploitative anthropogenic processes, are being widely implemented to conserve biodiversity and initiate species recovery. Evidence supports the effectiveness of marine reserves in improving biological attributes such as biodiversity, density, biomass, and body-size for sedentary species or those with r-select...
Article
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The Caribbean reef shark (Carcharhinus perezi) is one of few extant reef sharks inhabiting the Atlantic Ocean. Its variability in movements across habitat types suggests the possibility of a complex genetic population structure. Here, we use mitochondrial and nuclear DNA to investigate the genetic connectivity of the Caribbean reef shark across con...
Article
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Non-intrusive and non-destructive acquisition of length measurements for marine megafauna is increasingly valuable given growing threats to many species’ long-term survival. Stereo-videography provides a means of obtaining length data with minimal impact on the organism and minimal observer bias. However, for many researchers there are still signif...
Article
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Mechanisms driving selection of body size and growth rate in wild marine vertebrates are poorly understood, thus limiting knowledge of their fitness costs at ecological, physiological and genetic scales. Here, we indirectly tested whether selection for size-related traits of juvenile sharks that inhabit a nursery hosting two dichotomous habitats, p...
Article
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Animal movements, in particular residency or return migrations (collectively defined as ‘philopatry’), can shape population structure and have implications for management. This review examines the evidence for philopatry in batoids, which are some of the least understood and most threatened vertebrates, and updates a prior review of the same in sha...
Article
Population structure and lineage diversification within a small, non-dispersive hammerhead shark species, the bonnethead shark Sphyrna tiburo, was assessed. Sphyrna tiburo is currently described as one continuously distributed species along the Atlantic continental margins of North, Central and South America, but recent genetic analysis of an insul...
Article
Full-text available
Understanding how endangered species use nursery habitats is vital for recovery planning. Research on the smalltooth sawfish (Pristis pectinata) has shown that areas of estuarine nurseries, called hotspots, are used consistently. The objectives of our study were 1) to determine whether 10 young-of-the-year smalltooth sawfish in an artificial, non-m...