• Home
  • Jeffrey C. Mangel
Jeffrey C. Mangel

Jeffrey C. Mangel
ProDelphinus

PhD

About

180
Publications
69,527
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,042
Citations
Additional affiliations
August 2012 - present
University of Exeter
Position
  • Darwin Research Fellow

Publications

Publications (180)
Article
The Northern Humboldt Current System (NHCS) is one of the most productive seas due to its coastal upwelling producing a high abundance of zooplankton that supports the large biomass of the Peruvian anchoveta (Engraulis ringens) and other species of ecological importance such as jumbo squid (Dosidicus gigas), squat lobster (Pleuroncodes monodon), an...
Article
Environmental DNA (eDNA) has become a powerful tool for assessing biodiversity in different environments and may be a complementary method compared to traditional methods to assess biodiversity. We tested eDNA as a complementary tool to assess marine biodiversity at Lobos de Afuera islands (ILA) in Peru. Nine water samples were collected from three...
Article
Peru has a large small-scale fishing fleet upon which many coastal communities depend for their food and livelihoods. Nonetheless, no thorough assessments have been conducted of solid waste production and management of small-scale fisheries (SSF) and associated communities. We aimed to assess gillnet SSF and household solid waste generation in San...
Article
La pesca con arpón es un método ancestral de alta selectividad, desplazado en los últimos años por aparejos mecanizados que han logrado maximizar las capturas. A pesar de ello, en algunas partes del mundo, se sigue empleando esta práctica para la captura de grandes pelágicos como los peces picudos. Los reportes de la pesquería con arpón son cada ve...
Article
Full-text available
Unsustainable fisheries practices carried out in large parts of the Amazon, Tocantins, and Orinoco basins have contributed to the decline in the populations of the Amazon River dolphins (Inia spp.), considered Endangered by the International Union for Conservation of Nature (IUCN). Amazon River dolphin byproducts are often obtained through unregula...
Article
Full-text available
Aim Understanding the spatial ecology of animal movements is a critical element in conserving long‐lived, highly mobile marine species. Analyzing networks developed from movements of six sea turtle species reveals marine connectivity and can help prioritize conservation efforts. Location Global. Methods We collated telemetry data from 1235 indivi...
Article
Illegal wildlife trade has been identified as a major source of worldwide commerce of seahorses. The Convention on International Trade in Endangered Species of Wild Fauna and Flora listed the genus Hippocampus in Appendix II since 2004, when several countries that commercialized these species also banned transactions through domestic legislation, P...
Article
Fishery interactions pose the most significant direct anthropogenic threat to marine mammals. In this study, we tested the effectiveness of acoustic alarms at reducing the bycatch of cetaceans by small-scale gillnet vessels operating from the northern Peru port of Mancora. We equipped nets with 10 kHz pingers for vessels targeting sharks, tuna, dol...
Article
Full-text available
In Peru, while several mass mortality events have been reported in the last two decades, there has been minimal systematic stranding monitoring. In this study, we report on repeated stranding monitoring that took place between October 2003 and October 2015, at Ite beach, Tacna (17° 54′ 47" S 70° 58′ 21" W). The objectives of the study were to asses...
Article
A total of 7,215 observation hours were completed for all surveys. A total of 82 Chatham albatrosses were sighted from Callao (12°S) to the oceanic border with Chile (19°S) and 12–290 km offshore (Fig. 2). Most of the sightings (71%, n = 58) occurred in autumn, followed by winter (21%, n =17) and spring (5%, n = 4). Very few birds (4%, n =3) were o...
Article
Full-text available
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...
Article
Avoiding unwanted catches and reducing discards is an important objective of fisheries management. Fishers can avoid unwanted catches to some extent by improving selectivity of their fishing operations. This can be achieved through technical measures and gear modifications but also by adjusting when and where fishing takes place. Having access to r...
Article
Full-text available
Uncertainties about the magnitude of bycatch in poorly assessed fisheries impede effective conservation management. In northern Peru, small-scale fisheries (SSF) bycatch negatively impacts marine megafauna populations and the livelihoods of fishers which is further elevated by the under-reporting of incidents. Within the last decade, accounts of en...
Article
Full-text available
The effectiveness of behavioural interventions in conservation often depends on local resource users' underlying social interactions. However, it remains unclear to what extent differences in related topics of information shared between resource users can alter network structure—holding implications for information flows and the spread of behaviour...
Presentation
Full-text available
Influencia de los predictores ecológicos sobre el tamaño del rango de hogar de Inia geoffrensis IV Congreso Colombiano de Mastozoología Del 22 - 26 de Noviembre de 2021
Presentation
Full-text available
Análisis espacial de Inia geoffrensis - Una estrategia para identificar áreas potenciales de riesgo de capturas dirigidas ID 175 IV Congreso Colombiano de Mastozoología Del 22-26 de Noviembre de 2021
Article
With the entry into force of the Fish and Fish Products Import Provisions of the United States Marine Mammal Protection Act (MMPA), countries that export such products to the U.S. market could face significant challenges. Provisions include that fish and fish products exported to the U.S. must come from fisheries with a regulatory program comparabl...
Technical Report
Full-text available
In July 2020, the Conservation Planning Specialist Group (CPSG) of the International Union for Conservation of Nature (IUCN) Species Survival Commission (SSC) was enlisted by the international non-profit sea turtle conservation organization, Upwell, to design and facilitate a two-step decision making process to inform conservation efforts for the C...
Article
Full-text available
Global commitments prioritize protection of wildlife and improvements to human wellbeing. Local disconnects in these commitments are rarely acknowledged—or their implications assessed—preventing the development of effective solutions. National and international efforts to protect marine mammals along South America's west coast have contributed to s...
Article
Full-text available
Studying the variables that describe the spatial ecology of threatened species allows us to identify and prioritize areas that are critical for species conservation. To estimate the home range and core area of the Endangered (EN) Amazon river dolphin Inia geoffrensis , 23 individuals (6♀, 17♂) were tagged during the rising water period...
Article
Full-text available
Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 s...
Article
Marine species may exhibit genetic structure accompanied by phenotypic differentiation related to adaptation despite their high mobility. Two shape-based morphotypes have been identified for the green turtle (Chelonia mydas) in the Pacific Ocean: the south-central/western or yellow turtle and north-central/ eastern or black turtle. The genetic diff...
Article
Marine species may exhibit genetic structure accompanied by phenotypic differentiation related to adaptation despite their high mobility. Two shape-based morphotypes have been identified for the green turtle (Chelonia mydas) in the Pacific Ocean: the south-central/western or yellow turtle and north-central/eastern or black turtle. The genetic diffe...
Article
Full-text available
Cosmopolitan marine pelagic species display variable patterns of population connectivity among the world’s major oceans. While this information is crucial for informing management, information is lacking for many ecologically important species, including apex predators. In this study we examine patterns of genetic structure in the broadnose sevengi...
Article
Peru is a major fishing country and has a high consumption of fish per capita of approximately 24.4 kg/person. The gastronomic boom of the Peruvian seafood business has been increasing steadily, mostly led by seafood restaurants called cevicherias for the prevalence of their main dish “ceviche”. We investigated the incidence of seafood fraud (i.e....
Article
Full-text available
Fishery pressure on nursery areas of smooth hammerhead in northern Peruvian coast have become a serious threat to sustainability of this resource. Even though, some management actions focused on conservation of the smooth hammerhead populations were proposed in recent years, their scientific foundations are often limited, and biomass of smooth hamm...
Article
Full-text available
Angel sharks are distributed worldwide in tropical to subtropical waters. Across the Eastern Pacific Ocean (EPO), two valid species are reported: The Pacific angelshark Squatina californica and the Chilean angelshark Squatina armata; however, there is still uncertainty about their geographic distribution, mainly along the northern Peru coast where...
Article
Full-text available
Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climat...
Article
The Peruvian sea represents one of the most productive ocean ecosystems and possesses one of the largest elasmobranch fisheries in the Pacific Ocean. Ecosystem based management of these fisheries will require information on the trophic ecology of elasmobranchs. This study aimed to understand the diet, trophic interactions and the role of nine comme...
Article
The marine otter (Lontra felina) has a patchy distribution associated with rocky coastlines along the Pacific coast of South America. In Peru marine otters are found from La Libertad (8°04′S) to Tacna (18°09′S), however, few studies have assessed its population and conservation status. To assess marine otters' current distribution along the Peru co...
Article
Patterns of genetic structure in highly mobile marine vertebrates may be accompanied by phenotypic variation. Most studies in marine turtles focused on population genetic structure have been performed at rookeries. We studied whether genetic and morphological variation of the endangered green turtle (Chelonia mydas) is consistent geographically, fo...
Article
Full-text available
The Eastern Pacific leatherback turtle population (Dermochelys coriacea) has declined precipitously in recent years. One of the major causes is bycatch from coastal and pelagic fisheries. Fisheries observations are often underutilized, despite strong potential for this data to affect policy. In this study, we created a spatiotemporal species distri...
Article
Full-text available
Between October 2018 and October 2019, seven megamouth sharks were reported as bycatch in the small-scale surface and midwater gillnet fisheries operating from the ports of Mancora and Salaverry in northern Peru. Here we present details of these specimens and bycatch events that represent the first documented records of this species in Peruvian wat...
Preprint
Full-text available
The effectiveness of biodiversity conservation interventions is often dependent on local resource users' underlying social interactions. However, it remains unclear how fine-scale differences in information shared between resource users can influence network structure and the success of behavior-change interventions. Using network null models that...
Preprint
Full-text available
The effectiveness of biodiversity conservation interventions is often dependent on local resource users' underlying social interactions. However, it remains unclear how fine-scale differences in information shared between resource users can influence network structure and the success of behaviour-change interventions. We investigate this knowledge...
Article
Full-text available
The use of small cetaceans as bait is a practice that has been reported worldwide, affecting the conservation status of vulnerable species. In Peru specifically, it has been documented since at least the late 1990s. Here we document the various contemporary uses of small cetaceans, including targeted capture for subsequent use as fishing bait. We des...
Article
Full-text available
In Ecuador, one of the main hazards for threatened marine species, such as sea turtles, is small-scale fisheries bycatch. At a global scale, currently, bycatch reduction technologies (BRTs) are being tested in many coastal nations to mitigate this issue. Despite some advances in Ecuadorian efforts for wildlife protection, BRTs to reduce bycatch hav...
Article
The freshwater tucuxi (Sotalia flluviatilis) and the Amazon River dolphin (Inia geoffrensis) are endemic to the Amazon-Orinoco river basin. Their conservation is hindered by human disturbance and uncertainty about total population size and distribution. In this study, we used rapid assessment questionnaires to identify threats to river dolphins Per...
Conference Paper
Full-text available
Industrial and small-scale coastal (i.e., ‘artisanal’) pelagic fisheries in the eastern Pacific Ocean (EPO) interact with one of the most vulnerable fishery bycatch species, the East Pacific (EP) stock of leatherback turtle (Dermochelys coriacea). As a result of the species’ longevity, slow growth, low reproductive output, and critically low popula...
Article
Full-text available
Whale-watching tourism is growing rapidly worldwide. Currently, it occurs in more than 119countries and is estimated to produce more than US$2.5 billion in annual revenue. In northern Peru,this industry is relatively new, and the economic impact generated from whale-watching remainsunknown. This study was designed to provide an assessment of the ec...
Article
Full-text available
Failure to improve the conservation status of endangered species is often related to inadequate allocation of conservation resources to highest priority issues. Eastern Pacific (EP) leatherbacks are perhaps the most endangered sea turtle population in the world, and continue on a path to regional extinction. To provide coherent, regional conservati...
Article
Full-text available
Filling ecological and social data gaps for small-scale fisheries is crucial for global conservation of shark species. In 2016, international protection of vulnerable smooth hammerhead sharks (Sphyrna zygaena) resulted in a seasonal fishing ban to protect juvenile sharks in Peru's small-scale fisheries. Richer data on the fisheries' social-ecologic...
Article
Full-text available
The mitigation hierarchy has been proposed as an overarching framework for managing fisheries and reducing marine megafauna bycatch, but requires empirical application to show its practical utility. Focusing on a small-scale fishing community in Peru as a case study system, we test how the mitigation hierarchy can support efforts to reduce captures...
Article
Full-text available
We compare judgments of green turtle (Chelonia mydas) captures elicited from local gillnet skippers and not‐for‐profit conservation organization employees operating in a small‐scale fishery in Peru, to capture rates calculated from a voluntary at‐sea observer program operating out of the same fishery. To reduce cognitive biases and more accurately...
Article
Full-text available
The East Pacific (EP) leatherback population is listed by the IUCN Red List of Threatened Species as Critically Endangered. Despite conservation efforts, mainly focused on nesting beaches, its population has declined by over 90% since the 1980s. A major current threat is fisheries bycatch, which has been primarily documented in small-scale gillnets...
Preprint
Full-text available
Globally, the populations of many marine mammals remain of critical concern after centuries of exploitation and hunting. However, some marine mammal populations (e.g. pinnipeds) have largely recovered from exploitation, and interactions between these species and fisheries - particularly small-scale fisheries - is once again of concern globally. The...
Article
Found in the coastal waters of all continents, gillnets are the largest component of small-scale fisheries for many countries. Numerous studies show that these fisheries often have high bycatch rates of threatened marine species such as sea turtles, small cetaceans and seabirds, resulting in possible population declines of these non-target groups....
Article
Full-text available
Limited data on the spatial, environmental, and human dimensions of small‐scale fisheries hinder conservation planning, so the incorporation of fishers' local ecological knowledge may be a valuable way to fill data gaps while legitimizing management decisions. In Peru, vulnerable and poorly assessed juvenile smooth hammerhead sharks (Sphyrna zygaen...
Article
Full-text available
The utilization and capabilities of biotelemetry are expanding enormously as technology and access rapidly improve. These large, correlated datasets pose statistical challenges requiring advanced statistical techniques to appropriately interpret and model animal movement. We used satellite telemetry data of critically endangered Eastern Pacific lea...
Article
The humpback smooth-hound shark (Mustelus whitneyi) is one of the most captured shark species in the south-east Pacific and is classified as vulnerable, yet its reproductive biology has been poorly studied. The aim of this study was to increase our knowledge of the reproductive biology of the humpback smooth-hound shark. In all, 41 pregnant females...
Article
Full-text available
ABSTRACT: Ocean sunfish (Mola spp.) have largely been considered as obligate gelativores, but recent research has suggested that they undergo an unusual life history shift. In this study, analyses of bulk and amino acid nitrogen (δ15N) and carbon (δ13C) stable isotope ratios were employed to provide detailed insight into ontogenetic variation in su...
Article
Reports were compiled of sunfish (family Molidae) by‐catch in Peruvian small‐scale fisheries and sunfish by‐catch rates were estimated using data from shore‐based and onboard monitoring programmes. A total of 114 sunfishes were reported in the longline and gillnet fisheries along the Peru coast from 2005 to 2017. Systematic monitoring effort of sma...
Article
Full-text available
This study provides baseline information on the feeding habits of five batoid species from the genera Mobula and Myliobatis sampled from the small-scale driftnet fishery in northern Peru. The diets of Mobula mobular, Mobula munkiana and Mobula thurstoni consisted mainly of euphausiids. Dietary niche breadth indicated a pelagic feeding behaviour of...
Article
Full-text available
The blue shark (Prionace glauca) is the most landed shark species in Peruvian shark fisheries, representing 42% of total landings. Despite its importance for fisheries, the ecological role of the blue shark in Peruvian waters remains poorly understood. Therefore, in this study, we aimed to assess the food habits of blue sharks off northern Peru thr...
Article
Full-text available
Relevant and distinctive vernacular species names are essential to assure efficient communication among scientists under field and laboratory conditions, but also among non-specialists including the public at large. We provide a rationale for recommended vernacular and alternative names for the lesser beaked whale Mesoplodon peruvianus Reyes, Mead...
Article
Full-text available
In the eastern Pacific Ocean, whale sharks (Rhincodon typus) have mostly been studied off the Galápagos Islands, Ecuador, and Baja California, Mexico. Recently, satellite telemetry data revealed connectivity between whale sharks off the Galápagos Islands and Peru. Historic and some recent observa- tions have reported rare occurrences of whale sh...
Article
The stomach contents of thresher sharks ( Alopias spp.; 162–385 cm total length) were collected from five landing points in northern Peru during 2015. A total of 128 thresher sharks were sampled, with 38 individuals identified as Alopias pelagicus and 90 aggregated to the genus level Alopias sp. to prevent any misidentification. The diet comprised...