Jérôme Bourjea

Jérôme Bourjea
Institut Français de Recherche pour l'Exploitation de la Mer | Ifremer · Department of Environment and Resources

PhD

About

99
Publications
30,627
Reads
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2,517
Citations
Additional affiliations
September 2002 - September 2015
Department of Agriculture, Fisheries and Food
Position
  • Researcher in La Réunion Délégation, Indian Ocean

Publications

Publications (99)
Article
Full-text available
Although published literature regarding the 5 species of marine turtle found along the continental African east coast has grown substantially over the last decades, a comprehensive synthesis of their status and ecology is lacking. Using a mixed methods approach, which com- bined an exhaustive literature review and expert elicitation, we assessed th...
Article
Although published literature regarding the 5 species of marine turtle found along the continental African east coast has grown substantially over the last decades, a comprehensive synthesis of their status and ecology is lacking. Using a mixed methods approach, which combined an exhaustive literature review and expert elicitation, we assessed the...
Article
Gilthead seabream were equipped with intraperitoneal biologging tags to investigate cardiac responses to hypoxia and warming, comparing when fish were either swimming freely in a tank with conspecifics or confined to individual respirometers. After tag implantation under anaesthesia, heart rate (fH) required 60 hours to recover to a stable value in...
Article
Full-text available
Advances in biologging technology have enabled 3D dead-reckoning reconstruction of marine animal movements at spatiotemporal scales of meters and seconds. Examining high-resolution 3D movements of sharks (Galeocerdo cuvier, N = 4; Rhincodon typus, N = 1), sea turtles (Chelonia mydas, N = 3), penguins (Aptenodytes patagonicus, N = 6), and marine mam...
Conference Paper
Full-text available
INFORMATION DOCUMENT related to THE WORK PROGRAMME 2020-2024 measure #6 “Compile information on the status of on-board observer programmes and the status of marine turtle bycatch recording within those observer programmes and share with the Advisory Committee”
Article
Full-text available
Despite the large number of species distribution modelling (SDM) applications driven by tracking data, individual information is most of the time neglected and traditional SDM approaches commonly focus on predicting the potential distribution at the species or population-level. By running classical SDMs (population approach) with mixed models inclu...
Preprint
Full-text available
Cardiac and behavioural responses to hypoxia and warming were investigated in free-swimming gilthead seabream Sparus aurata equipped with biologging tags in the peritoneal cavity. After suitable recovery in a holding tank, heart rate ( f H ) and the variance of tri-axial body acceleration (VAR m ) were logged during exposure to stepwise progressive...
Article
Full-text available
Bivalve predation by seabream has been observed worldwide and is a major concern for bivalve farmers. Farmed bivalve-seabream interactions must be better understood to ensure the sustainability of bivalve aquaculture. The objectives of this study were to characterize gilthead seabream Sparus aurata presence in a bivalve farm in Prevost Lagoon (Medi...
Article
Oxygen uptake, heart rate and contraction frequencies of slow oxidative (SO) and fast glycolytic (FG) muscle were measured simultaneously in gilthead seabream Sparus aurata submitted to stepwise increases in current speed in a swimming respirometer. Variation in oxygen uptake was closely related to variation in heart rate, over initial steps these...
Article
Full-text available
Albacore tuna (Thunnus alalunga) is an important target of tuna fisheries in the Atlantic and Indian Oceans. The commercial catch of albacore is the highest globally among all temperate tuna species, contributing around 6% in weight to global tuna catches over the last decade. The accurate assessment and management of this heavily exploited resourc...
Article
Albacore tuna (Thunnus alalunga) is a highly economically important species in the western Indian Ocean. However, knowledge of its ecological and nutritional characteristics, essential for proper management of the species, is lacking in the region. The trophodynamics of the Indian Ocean albacore was thus examined using known fatty acid trophic mark...
Article
The trophic ecology of albacore tuna in the western Indian Ocean and adjacent Atlantic waters based on stomach content analysis, using a reconstituted length and weight of prey approach, was studied. From a total of 686 non-empty stomachs, collected between 2001 and 2015 across three biogeographic provinces, we described the diet composition of alb...
Article
Full-text available
Understanding how ocean currents impact the distribution and connectivity of marine species, provides vital information for the effective conservation management of migratory marine animals. Here, we used a combination of molecular genetics and ocean drift simulations to investigate the spatial ecology of juvenile green turtle (Chelonia mydas) deve...
Article
Full-text available
Background: A strong behavioural plasticity is commonly evidenced in the movements of marine megafauna species, and it might be related to an adaptation to local conditions of the habitat. One way to investigate such behavioural plasticity is to satellite track a large number of individuals from contrasting foraging grounds, but despite recent adv...
Article
To investigate dispersal and connectivity between spawning and lagoon nursery habitats of the gilthead seabream, Sparus aurata, in the Gulf of Lions (northwestern Mediterranean Sea), we modeled the potential transport of the species' larvae between its supposed main spawning site in the region (the Planier Island) and two of its main local nursery...
Article
Full-text available
Environmental factors shape the spatial distribution and dynamics of populations. Understanding how these factors interact with movement behavior is critical for efficient conservation, in particular for migratory species. Adult female green sea turtles, Chelonia mydas, migrate between foraging and nesting sites that are generally separated by thou...
Article
We investigated links between swimming behavior and muscle bioenergetics in two emblematic Mediterranean fish species that have very different ecologies and activity levels. European sardines Sardina pilchardus are pelagic, they swim aerobically, school constantly and have high muscle fat content. Gilthead seabream Sparus aurata are bentho-pelagic,...
Article
Aim To examine the genetic structure and global phylogeography of the endangered green sea turtle, Chelonia mydas, in light of past climatic events and current conservation needs. Location Tropical and subtropical beaches around the world. Methods We analysed 386 base pairs of the mitochondrial (mt)DNA control region of 4,878 individual nesting g...
Book
Full-text available
SWOT Report XIV features an up-to-date, comprehensive map of sea turtle distribution in the Mediterranean, a picture of loggerhead movements in the Atlantic, and expert answers to the most frequently asked questions about sea turtles. Other articles explore the effects of red tides on turtles, best practices for transporting stranded turtles, and...
Article
Full-text available
Various protocols are currently used to study marine lipids, but there is a growing interest in working on dry samples that are easier to transport. However, reference protocols are still lacking for dry samples. In order to make recommendations on this use, lipid classes and fatty acids (FA) obtained from six analytical protocols using two differe...
Article
Full-text available
Albacore is one of the most important commercially harvested species in the world’s oceans. Despite a long history of scientific research, there is no global review or synthesis of knowledge about the species across all oceanic regions. We analysed 613 published studies that report on albacore and summarize the current state of knowledge on biology...
Article
Full-text available
In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology , biogeography, population ecology, threats and conservation strategies...
Article
Full-text available
The reproductive biology of albacore tuna, Thunnus alalunga, in the western Indian Ocean was examined through analysis of the sex ratio, spawning season, length-at-maturity (L50), spawning frequency and fecundity. From 2013 to 2015, a total of 923 female and 867 male albacore were sampled. A bias in sex ratio was found in favor of females with fork...
Data
Number of fish per oocyte developmental stage or ovarian phase by 3-cm interval fork length (LF) used for maturity analysis of female albacore tuna in the western Indian Ocean based on histology. In the first criterion, immature fish were viewed as containing the most advanced oocyte stage the primary growth (PG) stage, cortical alveolar (CA) and v...
Article
Full-text available
Swordfish Xiphias gladius is an oceanic-pelagic species. Its population structure in the Western Indian Ocean was studied from the shape of the sagittal otoliths of 391 individuals collected from 2009 to 2014. Normalised elliptical Fourier descriptors (EFDs) were extracted automatically using TNPC software. Principal components analysis (PCA) condu...
Book
Full-text available
The GERMON project had several aims i) to understand the populations’ structure between albacore tuna southwest of the Indian Ocean and southeast Atlantic, ii) to determine the origin of juveniles observed in South Africa iii) to improve the understanding of the biology field (Size/Size and Size/Weight; reproduction and feeding area; trophic linkag...
Conference Paper
This paper provides information on the length-length (fork-length, FL with pectoral length, PL and first dorsal length, LD1) and length-weight relationships of albacore tuna (Thunnus alalunga) in five regions of the Western Indian Ocean. Data were obtained for a total of 923 female and 867 male albacore, caught by different fishing gears, and sampl...
Article
Full-text available
Recent developments in sequencing technologies and bioinformatics analysis provide a greater amount of DNA sequencing reads at a low cost. Microsatellites are the markers of choice for a variety of population genetic studies, and high quality markers can be discovered in non-model organisms, such as tuna, with these recent developments. Here, we us...
Article
To refine our understanding of the spatial structure of the green turtle (Chelonia mydas) populations in the South West Indian Ocean (SWIO), we analysed patterns of mitochondrial DNA (396 base pairs control region fragment) variation among 171 samples collected at five distinct locations (Kenya, Northern Mozambique, and three locations in the Repub...
Article
Full-text available
Situated about 500 km off the Malagasy east coast, the island of Tromelin is a key nesting site for the endangered green turtle, Chelonia mydas, in the south Western Indian Ocean. Nesting turtles found in this isolated island have been closely monitored since the 1970s, but the most recent estimates of nesting parameters date from 1986. Using mark–...
Article
Full-text available
Nesting green turtles Chelonia mydas were studied at Moheli Island, Union of Comoros, southwestern Indian Ocean (SWIO). Five contiguous beaches near Itsamia village, in the southeastern part of the island, were monitored daily for nesting activity from January 1999 to June 2007 and irregularly between August 2009 and December 2014; nesting success...
Thesis
Full-text available
This thesis is a comprehensive work aiming to improve scientific knowledge on the green turtle (Chelonia mydas) in order to provide key scientific evidences needed for the implementation of coherent and effective management measures to protect at the Western Indian Ocean scale this threatened species. In a first step, this work aimed to established...
Data
Supplementary material Online Resource 2 Representation of individual’s track and behavioral mode, time-at-depth distribution, and dive depth distribution according to behavioral mode.
Article
Full-text available
The most comprehensive contribution to our understanding of albacore tuna, Thunnus alalunga, comes from studies in the Pacific and Atlantic Ocean. In the Indian Ocean, there is little information about this species in the literature. In the present paper, we propose a short review on albacore in the Indian Ocean with a particular attention on the b...
Article
Full-text available
This document presents a characterization of the Reunion Island pelagic longline fishery, with a first description of the albacore catches, catch-at-size, and the standardized catch per unit of effort (CPUE) series for the period 1992-2013. The spatial catch and effort analysis revealed the major areas of operation of the fishery, and the identific...
Article
Full-text available
While our understanding of the early oceanic developmental stage of sea turtles has improved markedly over recent decades, the spatial context for this life history stage remains unknown for Indian Ocean loggerhead turtle populations. To address this gap in our knowledge, 18 juvenile loggerheads were satellite tracked from Reunion Island (21.2°S, 5...
Article
The reef fauna connectivity of the West Indian Ocean (WIO) is one of the least studied globally. Here we use genetic analyses of the grouper Epinephelus merra (Bloch 1793) to determine patterns of connectivity and to identify barriers to dispersal in this WIO marine area. Phylogeographic and population-level analyses were conducted on cytochrome b...
Article
Full-text available
Because one of the most common problems in fisheries is the definition of management units, we propose in this paper a bibliometric review focusing on the differentiation of Albacore populations, Thunnus alalunga, among and within oceanic regions (Atlantic, Pacific and Indian Oceans, and Mediterranean Sea). This paper is the first step of a current...
Article
Full-text available
In long-distance migratory marine species foraging behaviour remains particularly difficult to study even though it has important consequences for individual life history. Indeed, studies assessing concurrent dive patterns and feeding behaviour remain rare. We investigated the daily and seasonal feeding rhythms of green turtles Chelonia mydas on a...
Article
Full-text available
Genetic population structure of swordfish Xiphias gladius was examined based on 2231 individual samples, collected mainly between 2009 and 2010, among three major sampling areas within the Indian Ocean (IO; twelve distinct sites), Atlantic (two sites) and Pacific (one site) Oceans using analysis of nineteen microsatellite loci (n = 2146) and mitoch...
Data
containing: Appendix F1: Geographic location of sampling areas and of the biogeographic provinces (Longhurst, 1998). Appendix F2: Swordfish sampling schedule. Appendix F3: Mismatch distribution for swordfish based on 1007 bp of the ND2 sequences. Appendix F4: Neighbor-joining trees showing the relationship between sample sets on the basis of pairwi...
Article
Full-text available
Changes in phenology, the timing of seasonal activities, are among the most frequently observed responses to environmental disturbances and in marine species are known to occur in response to climate changes that directly affects ocean temperature, biogeochemical composition and sea level. We examined nesting seasonality data from long-term studies...
Data
Interpolation method. We tested our interpolation method by comparing its predictive power with three additional methods: (1) sampling randomly in the range of the time series, (2) sampling randomly from the values neighbouring the missing data, (3) interpolating linearly between the values neighbouring the missing data. To assess the predictive po...
Article
Full-text available
Tunas are important commercial species that represent a share of about 8 percent of total fish exports. In 2010, the total catch of tuna in three oceans was about 6.6 million tons, 4.3 million tons for the most marketed species, a level roughly stable since 2002 (FAO 2012). Among these tuna species, there are in descending order of capture: skipjac...
Article
Full-text available
Examining the genetic structure of species allows an estimate of the level of evolutionary connectivity between localities; this information is important for marine biodiversity protection, in particular, for the delineation of marine protected areas. In this context, a total of 601 Lutjanus kasmira (Forsskal, 1775) were sampled in 16 localities of...
Article
Full-text available
The reef fish Myripristis berndti (Jordan & Everman 1903) is a pantropical species. A genetic analysis was conducted on 353 individuals from 10 localities distributed across the SW Indian Ocean (SWIO) in order to determine patterns of connectivity in the SWIO. Both the mtDNA sequences (711-bp cytochrome b sequences) and the microsatellites (8 newly...
Article
Full-text available
Laboratory and field experiments have provided evidence that sea turtles use geomagnetic cues to navigate in the open sea. For instance, green turtles (Chelonia mydas) displaced 100 km away from their nesting site were impaired in returning home when carrying a strong magnet glued on the head. However, the actual role of geomagnetic cues remains un...
Data
Categories in which RMUs for each species occurred (including critical data needs RMUs). Categories: HR-HT = High risk-High threats; HR-LT = High risk-Low threats; LR-LT = Low risk-Low threats; LR-HT = Low risk-High threats. (DOCX)
Data
Paired risk and threats scores for RMUs of each marine turtle species. (A) loggerheads (Caretta caretta), (B) green turtles (Chelonia mydas), (C) leatherbacks (Dermochelys coriacea, (D) hawskbills (Eretmochelys imbricata), (E) olive ridleys (Lepidochelys olivacea), (F) Kemp's ridleys (Lepidochelys kempii) and flatbacks (Natator depressus). Vertical...
Data
Scoring system for population size criterion in risk matrix. Numbers are average annual nesting females for the most recent survey data available. (DOCX)
Data
List of Regional Management Unit (RMU) codes used in Fig. 1. Species: Caretta caretta, loggerhead; Chelonia mydas, green turtle; Dermochelys coriacea, leatherback; Eretmochelys imbricata, hawksbill; Lepidochelys kempii, Kemp's ridley; Lepidochelys olivacea, olive ridley; Natator depressus, flatback. (DOCX)