Philippe S. Sabarros

Philippe S. Sabarros
Institute of Research for Development | IRD · UMR 248 MARBEC

PhD

About

58
Publications
11,354
Reads
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556
Citations
Additional affiliations
February 2007 - June 2010
University of Oslo
Position
  • PhD Student

Publications

Publications (58)
Article
Full-text available
Oceanic whitetip shark (Carcharhinus longimanus) is an important top predator in pelagic ecosystems currently classified as globally Critically Endangered by the International Union for the Conservation of Nature. This species is incidentally caught by fisheries targeting highly migratory tunas and billfishes throughout the Indian Ocean. Understand...
Article
Full-text available
Blue shark (Prionace glauca) is amongst the most abundant shark species in international trade, however this highly migratory species has little effective management and the need for spatio-temporal strategies increases, possibly involving the most vulnerable stage or sex classes. We combined 265,595 blue shark observations (capture or satellite ta...
Article
Recent comparative studies of billfishes (Istiophoridae and Xiphiidae) have provided evidence of differences in the form and function of the rostra (bill) among species. Here, we report the discovery of a new structure, lacuna rostralis, on the rostra of sailfish Istiophorus platypterus, which is absent on the rostra of swordfish Xiphias gladius, s...
Article
Elasmobranchs make up a significant part of bycatch in pelagic longline fisheries, whose induced mortality can be a major threat to endangered species. It is therefore crucial to understand the drivers of at-vessel mortality (AVM) for this fishing gear in order to enhance post-release survival. To this end, we analysed scientific data collected dur...
Article
Full-text available
Fisheries observer programs represent the most reliable way to collect data on fisheries bycatch. However, their limited coverage leads to important data gaps that preclude bycatch mitigation at the basin scale. Habitat models developed from available fisheries observer programs offer a potential solution to fill these gaps. We focus on tropical tu...
Article
Billfishes are well-known for their distinctive elongated rostra, a.k.a. bills. The functional significance of billfish rostra has been frequently discussed and the recent discovery of an oil gland (glandula oleofera) at the base of the rostrum in swordfish, Xiphias gladius , has added an interesting facet to this discussion regarding the potential...
Article
Full-text available
Despite bycatch of elasmobranch (sharks and rays) being a major concern in most fisheries worldwide, there is a lack of knowledge on their spatio-temporal species distribution, biology (life stage and sex-ratios), as well as their at-haulback mortality rate. Observer data from the French and Spanish tropical purse-seine tuna fisheries operating in...
Article
Full-text available
The EU project BIOFAD was launched in August 2017 and is coordinated by a Consortium comprising three European research centers: AZTI, IRD and IEO. The ISSF is also actively collaborating by providing the biodegradable materials needed to test biodegradable dFADs. This project is seeking to develop and implement the use of non-entangling and biodeg...
Article
Full-text available
Linking morphological differences in foraging adaptations to prey choice and feeding strategies has provided major evolutionary insights across taxa. Here, we combine behavioural and morphological approaches to explore and compare the role of the rostrum (bill) and micro-teeth in the feeding behaviour of sailfish (Istiophorus platypterus) and strip...
Conference Paper
Full-text available
The EU project BIOFAD was launched in August 2017. This 28-months EU project is coordinated by a Consortium comprising three European research centers: AZTI, IRD (Institut de recherche pour le développement) and IEO (Instituto Español de Oceanografía). The International Seafood Sustainability Foundation (ISSF) is also actively collaborating by prov...
Conference Paper
Full-text available
In this working paper, we address the ecosystem component consisted of "non-retained sharks and rays" to support the development of an ecosystem report card in the IOTC region. This group includes sharks and ray species that are not retained due to retention bans or due to their low or no commercial value. The interaction between these non-retained...
Conference Paper
Full-text available
In support of the IOTC ecosystem report card, we estimated several indicators which could be used to measure progress towards monitoring the impacts of IOTC fisheries on and the state of the "Food web/Trophic relationships" ecosystem component. An ecosystem approach requires understanding the ecological effects of removing all animals through fishi...
Conference Paper
Full-text available
Silky sharks (Carcharhinus falciformis) figure among the main pelagic shark species caught by the industrial tropical tuna purse-seine fisheries. However, this data was not used so far for estimating their population trends. In this study, using data from the European tropical tuna purse seine fishery, we provide an abundance trend for the silky sh...
Research
Full-text available
Using data from the French tropical tuna purse seine fishery, this study proposes a new method to derive an abundance index for silky shark's populations. Two models were used: the first one describes the dynamics of sharks associated to floating objects (FOBs) used by tuna purse seiners in a social and in a non-social case. The second one illustra...
Conference Paper
Full-text available
Observer programs have been implemented for many years in tuna purse seine fisheries to assess their impact on pelagic ecosystems by monitoring tuna discards and bycatch among which sensitive species such as sharks or rays. On board observers estimate discards using sampling and extrapolation methods when counting exhaustively is not possible. Howe...
Technical Report
Full-text available
This paper presents an update for the period 2008-2017 of the bycatch estimations for the European and Seychelles tuna purse seine fishery operating in the Indian Ocean. Bycatch data were collected by observers onboard. Given the situation of piracy in the area, the coverage of observers decreases progressively during the first part of the series,...
Article
Full-text available
Depredation in marine ecosystems is defined as the damage or removal of fish or bait from fishing gear by predators. Depredation raises concerns about the conservation of species involved, fisheries yield and profitability, and reference points based on stock assessment of depredated species. Therefore, the development of accurate indicators to ass...
Data
Review of the available literature about depredation impacting pelagic longline fisheries. Target species abbreviations: Billfish (BIL): Swordfish (SWO); Unidentified shark species (SHK); Tuna species (TUN). Predator species abbreviations: Killer whale (KW); False killer whale (FKW); Short-finned pilot whale (SFPW); Unidentified shark species (SHK)...
Data
Maximum DPUE. Maximum DPUE in number of depredated fish per 1000 hooks (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Standard deviation of DPUE. Standard deviation of DPUE in number of depredated fish per 1000 hooks (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Standard deviation of DR. Standard deviation of DR in % (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Coefficient of variation of DR. Coefficient of variation of DR in % (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Minimum DR. Minimum DR in % (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Mean DPUE. Mean DPUE in number of depredated fish per 1000 hooks (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Minimum DPUE. Minimum DPUE in number of depredated fish per 1000 hooks (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Mean DR. Mean DR in % (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Median DR. Median DR in % (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Maximum DR. Maximum DR in % (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Median DPUE. Median DPUE in number of depredated fish per 1000 hooks (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Data
Coefficient of variation of DPUE. Coefficient of variation of DPUE in number of depredated fish per 1000 hooks (left: 2004–2010, right: 2011–2015; blue: toothed whale depredation, green: shark depredation). (TIF)
Article
Full-text available
In order to comply with the different regulations and commitments requesting the presence of scientific observers onboard French purse seiners, and since it is not possible to embark more than one observer during a fishing trip, ORTHONGEL has imagined and implemented since July 2013 a program to facilitate and optimize the boarding of well-trained...
Conference Paper
Full-text available
Electronic monitoring system (EMS) was recently implemented on French tropical tuna purse seiners to complement observer program both in the Indian and Atlantic Oceans. The main objective was to test the efficiency and the potential of the EMS compared to regular observer programs. 'Mixed' trips involving both EMS and on-board observers were conduc...
Article
Full-text available
The costs and benefits of group living often depend on the spatial position of individuals within groups and the ability of individuals to occupy preferred positions. For example, models of predation events for moving prey groups predict higher mortality risk for individuals at the periphery and front of groups. We investigated these predictions in...
Article
Full-text available
The blue shark (Prionace glauca) is the most frequently captured shark in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. As part of cooperative scientific efforts for fisheries and biological data collection, information from fishery observers, scientific projects and surveys, and from recreational fisheri...
Technical Report
Full-text available
This paper presents an update for the period 2010-2016 of the bycatch estimations for the European tuna purse seine fishery operating in the Atlantic Ocean. Bycatch data were collected by observers onboard. Observer coverage increased progressively from 15 trips in 2010, to 114 and 107 trips in 2015 and 2016 respectively. Bycatch data, as collected...
Conference Paper
Full-text available
Observation data collected aboard fishing vessels are essential to describe the impact of fisheries on fish community. The Institut de Recherche pour le Développement (IRD, France) has been sending observers aboard tropical purse-seiners since 1995 in the Atlantic and Indian Oceans, and longliners since 2007 in the Indian Ocean. Since 2005, IRD is...
Conference Paper
Full-text available
Oceanic circulation structures nutrients distribution and affects primary productivity. Hydrodynamic features drive the distribution of intermediate trophic level species which aggregations commonly attract top predators. Blue shark (Prionace glauca, BSH) is the main bycatch species of Réunion Island pelagic longline fishery that mainly targets swo...
Article
Full-text available
Environmental change linked to climate and human activities may affect top predators via the food chain in marine systems. Understanding the functional link between resources and predator responses (e.g. foraging effort, reproductive success, population growth) is of crucial importance in the context of an ecosystem-based approach to fisheries. In...
Article
Full-text available
Using a multi-disciplinary approach, we evaluated the potential consequences of long-term contrasting prey availability on the condition Cape gannets Morus capensis. We compared breeding adults from a decreasing colony on Malgas Island off the west coast of South Africa, where the abundance of small pelagic fish has de-creased, with an increasing c...
Article
Full-text available
Oceanic mesoscale circulation is a crucial structuring force in the marine environment. Dynamic processes associated with eddies, such as eddy-induced upwelling or eddy-eddy interac- tion, drive the transport and distribution of nutrients that support the whole food chain, presumably through bottom-up processes. Eddies can shape the distribution of...
Article
Full-text available
Climate change and overfishing are increasingly causing unanticipated changes in marine ecosystems (e.g. shifts in species dominance). In order to understand and anticipate these changes, there is a crucial need for indicators that summarise large quantities of information into a few relevant and accessible signals. Seabirds have been suggested as...
Article
Full-text available
From 1997 to 2005, the distribution of sardine Sardinops sagax, an important prey item for four seabirds off South Africa, shifted 400 km to the south and east, influencing its availability to breeding birds. It became progressively less available to seabirds in the Western Cape Province, where the number of African penguins Spheniscus demersus bre...
Article
Population growth, and hence the population's persistence, is affected by several factors such as climate, species interaction, and harvesting pressure. Proper resource management requires an understanding of these factors. We apply techniques based upon age-structured population matrices to analyze estimated stock sizes derived from annual bottom...

Projects

Projects (4)
Project
The ASUR project (https://asur-allcut.com/) aims to study the post release mortality of some shark species (blue shark, oceanic white shark, shortfin mako, silky shark) in pelagic longline fisheries through the deployment of survival PAT and to develop an innovative device aiming to quickly release the individuals without endangering fishers
Project
Assess the post release mortality of the oceanic whitetip shark in the IOTC Area of Competence with the deployment of pop-up satellite tags (both archival and survival).