Pascale Chabanet | Université de la Réunion (original) (raw)
Papers by Pascale Chabanet
Journal of Fish Biology, Nov 1, 2008
This study shows how capture-mark-recapture (CMR) models can provide robust estimates of detectio... more This study shows how capture-mark-recapture (CMR) models can provide robust estimates of detection heterogeneity (sources of bias) in underwater visual-census data. Detection biases among observers and fish family groups were consistent between fished and unfished reef sites in Kenya, even when the overall level of detection declined between locations. Species characteristics were the greatest source of detection heterogeneity and large, highly mobile species were found to have lower probabilities of detection than smaller, site-attached species. Fish family and functional-group detectability were also found to be lower at fished locations, probably due to differences in local abundance. Because robust CMR models deal explicitly with sampling where not all species are detected, their use is encouraged for studies addressing reef-fish community dynamics.
Atoll research bulletin, 2013
All statements made in papers published in the Atoll Research Bulletin are the sole responsibilit... more All statements made in papers published in the Atoll Research Bulletin are the sole responsibility of the authors and do not necessarily represent the views of the Smithsonian Institution or of the editors of the Bulletin. Articles submitted for publication in the Atoll Research Bulletin should be original papers and must be made available by authors for open access publication. Manuscripts should be consistent with the "Author Formatting Guidelines for Publication in the Atoll Research Bulletin." All submissions to the Bulletin are peer reviewed and, after revision, are evaluated prior to acceptance and publication through the publisher's open access portal, Open SI (http://opensi.si.edu).
HAL (Le Centre pour la Communication Scientifique Directe), 2010
Acta Oecologica-international Journal of Ecology, Apr 1, 2016
Monitoring of coral reefs has become a major tool for understanding how they are changing, and fo... more Monitoring of coral reefs has become a major tool for understanding how they are changing, and for managing them in a context of increasing degradation of coastal ecosystems. The Global Coral Reef Monitoring Network (GCRMN) has near-global coverage, but there are few remote sites free of direct human impact that can serve as reference sites. This study provides baseline data for the French Iles Eparses in the Mozambique Channel, Western Indian Ocean (WIO), whose coral reefs are little known owing to their limited accessibility, and have been free from fishing pressure for over 20 years. Surveys of coral reef health and fish community structure were undertaken at four of the islands (Europa, Bassas da India, Juan de Nova and Glorieuses) in 2011e2013. Monitoring was conducted using standardized GCRMN methods for benthos and fish communities, at the highest taxonomic level. Benthic cover showed a latitudinal gradient, with higher coral cover and conversely lower algae cover (60% and 14% respectively) in the south of the Mozambique Channel. This could be due to the geomorphology of the islands, the latitudinal temperature gradient, and/or the history of chronic stress and bleaching events during the last decades. Fish also showed a latitudinal gradient with higher diversity in the north, in a center of diversity for the western Indian Ocean already recognized for corals. An exceptional biomass fish was recorded (approximately 3500 kg/ha excluding sharks, compared to a maximum of 1400 kg/ha elsewhere in the WIO). The presence of large predators and sharks in all the islands as well as the absence of fleshy benthic algae were indicators of the good health of the reef systems. Nevertheless, these islands are beginning to experience illegal fishing, particularly in the north of the Mozambique Channel, demonstrating their vulnerability to exploitation and the need to protect them as reference sites for coral reef studies, including of climate change impacts, for the region and globally.
Journal of Biogeography, Aug 5, 2020
Aim: The 'abundant centre' hypothesis states that species are more abundant at the centre of thei... more Aim: The 'abundant centre' hypothesis states that species are more abundant at the centre of their range. However, several recent large-scale studies have failed to find evidence for such a pattern. Here we used extensive global data of reef fishes to test the 'abundant centre' pattern, and to examine variation in the abundance patterns across species using life history and ecological traits. Location: Marine habitat at a global extent: from Indo-Pacific to Atlantic reefs. Methods: We used underwater visual estimates of fish abundance, containing 22,963 transects and 1,215 species. For each species we calculated the slope between abundance and distance to the range centre, with the range centre estimated using four different methods. We tested whether abundance patterns differ between the range core and margins using segmented regression. Meta-analytic methods were used to synthesize results across species, and to test whether species traits can explain variation in the fit to the pattern among species. Results: The method used to define the range centre had a large effect on the results. Nevertheless, in all cases we found large variation between species. Results of
HAL (Le Centre pour la Communication Scientifique Directe), 2020
HAL (Le Centre pour la Communication Scientifique Directe), Mar 20, 2014
International audienc
HAL (Le Centre pour la Communication Scientifique Directe), 2019
CBM - Cahiers de Biologie Marine, 2013
Europa is one of the Eparses Islands, French islands scattered in the Mozambique Channel. They ar... more Europa is one of the Eparses Islands, French islands scattered in the Mozambique Channel. They are isolated islands of coral origin, without permanent human population. This situation makes them good candidates to evaluate the evolution of biodiversity without direct anthropogenic influences. Knowledge is still scarce because their accessibility is limited. With the idea of classifying them as Marine Protected Areas, a management plan is required based on the coral reef communities. Among several aims, the program BioReCIE (Biodiversity, Resources and Conservation of Eparses Islands) was to complete the inventories of several marine groups, including the echinoderms, which had never been assessed before. In November 2011, a multidisciplinary team explored the reef slopes of the island by scuba diving down to 20 meters (10 sites), and the reef flats at low tide (14 sites, including the lagoon surrounded by mangrove), collecting and taking photos of the organisms which have been prese...
Western Indian Ocean journal of marine science, 2012
The Crustacea Decapoda of Europa Island have been inventoried during the BIORECIE fieldwork condu... more The Crustacea Decapoda of Europa Island have been inventoried during the BIORECIE fieldwork conducted from 7-12 November 2011. Previous records for Europa Island have been also compiled and an updated documented checklist of the species is proposed. In total, 175 decapods are reported for Europa Island, including 61 new records from this study. The fauna of Europa Island is mainly Indo-West Pacific in its composition. No endemic species have been recognized so far, but 15 species, such as Calcinus rosaceus , Ciliopagurus tricolor , Eriphia smithii or Grapsus fourmanoiri , are distinctive of the Western Indian Ocean region. A comparison with Mayotte Island, also recently inventoried for the decapods, shows that Europa Island fauna is slightly depauperate. This result is attributed to reduced size of the lagoon and mangroves as well as to the geographic isolation of the Island.
Fish and Fisheries, 2021
Current best‐practice policy recommendations for managing fish stocks are achieved by a mixture o... more Current best‐practice policy recommendations for managing fish stocks are achieved by a mixture of maintaining modest fishing mortality (restricting effort, times and gear), marine reserve networks and not subsidizing unprofitable fisheries. A seldom evaluated question is how effective these proposed approaches are for maintaining all fish stocks and biodiversity elements in marine seascapes? Both recommended and unrecommended fishing practices fragment habitats and reduce metapopulation connectivity with potentially unexpected seascape‐level consequences. To better understand these outcomes, we pooled and evaluated fish community data into two seascape groupings for comparisons of biomass and life‐history characteristics. These were remote baseline reefs (>9 hr from regional cities and >4 hr from human habitation, n = 584 locations) and those emulating best‐practice seascapes (BPS, n = 140). BPS were a mix of high‐compliance marine reserves (fishable biomass = 892 ± 696 (±SD)...
World Seas: an Environmental Evaluation, 2019
Abstract In the South Indian Ocean, French territories include Reunion (Mascarene archipelago), M... more Abstract In the South Indian Ocean, French territories include Reunion (Mascarene archipelago), Mayotte (Comoros archipelago) and the remote Iles Eparses in the Mozambique Channel (Glorieuses, Juan de Nova, Bassas da India, Europa), and Tromelin, North-East of Madagascar. Their coral reefs are varied, from 18 km2 of fringing reefs in Reunion to 1500 km2 of fringing, barrier and double barrier reefs in Mayotte, caye reefs in Glorieuses and Tromelin to atolls in Juan de Nova, Bassas da India and Europa. Pressures on them vary from 850,000 inhabitants in Reunion to no permanent inhabitants in Iles Eparses. Annual monitoring of Reunion and Mayotte shows a gradual decrease in coral cover and fish biomass, due to overfishing. Yet an exceptional biodiversity is recorded in Mayotte, mainly due to its geographical position at the center of the WIO coral triangle, and the variety of reef habitats. In the remote Iles Eparses, more recent monitoring showed a remarkable state of coral reefs and their exceptional fish biomass. These coral reefs are under human threats mainly due to coastal development and land-based pollution, except for Iles Eparses. Climate change has an impact through coral bleaching whose effects are stronger for reefs in the North of the Mozambique Channel. The impact of the 2016 bleaching event was variable on islands but most corals showed signs of resistance with a good recovery of coral colonies. In order to limit degradation and overexploitation of reef resources, national marine protected areas (MPAs) have been made in all French islands: 2007 in Reunion, 2010 in Mayotte, and 2012 in Glorieuses while all Iles Eparses have been under protection for more than 20 years. Despite this, Iles Eparses are beginning to suffer from illegal fishing, including collection of holothurians and perhaps shells, particularly since 2012. Long-term monitoring is essential to describe trends in coral communities in the context of increasing human impact and climate change.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2020
Reef fish biomass is increasingly recognized as a key indicator of fishery and biodiversity statu... more Reef fish biomass is increasingly recognized as a key indicator of fishery and biodiversity status linked to ecosystem integrity on coral reefs, and yet the evaluation of appropriate baselines for biomass, and what drives variation in potential baselines, is sparse. Variability in reef fishable biomass was assessed to test for the existence of baselines or benchmarks (B&Bs), based on field studies of 223 reef sites in remote uninhabited reefs, in high‐compliance closures of >5 km2, and among the increasing number of small and recent closures. The purpose of the study was to examine the effects of human habitation, travel time and distance to cities, habitat, depth, benthic cover, and environmental variables on fish B&Bs. There were large differences in the three categories of ‘no fishing’, with human habitation being the single best predictor of biomass. In remote areas without people (>9 hours of travel time), fish biomass had a mean of 2,450 kg ha–1 (95% confidence interval,...
Oral presentation about Can coral reef communities be used as indicators or proxies to assess eco... more Oral presentation about Can coral reef communities be used as indicators or proxies to assess ecological vulnerability of WIO small islands? The case of Glorieuses Island (Mozambic Channel, Indian Ocean)
Coral Reefs, 2015
Individual exposure to stressors can induce changes in physiological stress responses through mod... more Individual exposure to stressors can induce changes in physiological stress responses through modulation of the hypothalamic-pituitary-interrenal (HPI) axis. Despite theoretical predictions, little is known about how individuals will respond to unpredictable short-lived stressors, such as thermal events. We examine the primary neuroendocrine response of coral reef fish populations from the Îles Eparses rarely exposed to anthropogenic stress, but that experienced different thermal histories. Skunk anemonefish, Amphiprion akallopisos, showed different cortisol responses to a generic stressor between islands, but not along a latitudinal gradient. Those populations previously exposed to higher maximum temperatures showed greater responses of their HPI axis. Archive data reveal thermal stressor events occur every 1.92-6 yr, suggesting that modifications to the HPI axis could be adaptive. Our results highlight the potential for adaptation of the HPI axis in coral reef fish in response to a climate-induced thermal stressor.
Marine Biodiversity Records, 2013
An inventory has been made of the decapod fauna of the Glorieuses Islands, western Indian Ocean (... more An inventory has been made of the decapod fauna of the Glorieuses Islands, western Indian Ocean (WIO), following the BIORECIE 2 Expedition to the Islands, 5-17 December 2012. Field data are complemented by a review of taxonomic studies for these islands. Overall 157 species are now reported from the Glorieuses Islands, including 61 new records. The presence of the coconut crab, Birgus latro, is confirmed from these islands, for the first time since 1884, and the WIO distribution of this endangered species is updated, based on observations made in the region since 2006.
Journal of Fish Biology, Nov 1, 2008
This study shows how capture-mark-recapture (CMR) models can provide robust estimates of detectio... more This study shows how capture-mark-recapture (CMR) models can provide robust estimates of detection heterogeneity (sources of bias) in underwater visual-census data. Detection biases among observers and fish family groups were consistent between fished and unfished reef sites in Kenya, even when the overall level of detection declined between locations. Species characteristics were the greatest source of detection heterogeneity and large, highly mobile species were found to have lower probabilities of detection than smaller, site-attached species. Fish family and functional-group detectability were also found to be lower at fished locations, probably due to differences in local abundance. Because robust CMR models deal explicitly with sampling where not all species are detected, their use is encouraged for studies addressing reef-fish community dynamics.
Atoll research bulletin, 2013
All statements made in papers published in the Atoll Research Bulletin are the sole responsibilit... more All statements made in papers published in the Atoll Research Bulletin are the sole responsibility of the authors and do not necessarily represent the views of the Smithsonian Institution or of the editors of the Bulletin. Articles submitted for publication in the Atoll Research Bulletin should be original papers and must be made available by authors for open access publication. Manuscripts should be consistent with the "Author Formatting Guidelines for Publication in the Atoll Research Bulletin." All submissions to the Bulletin are peer reviewed and, after revision, are evaluated prior to acceptance and publication through the publisher's open access portal, Open SI (http://opensi.si.edu).
HAL (Le Centre pour la Communication Scientifique Directe), 2010
Acta Oecologica-international Journal of Ecology, Apr 1, 2016
Monitoring of coral reefs has become a major tool for understanding how they are changing, and fo... more Monitoring of coral reefs has become a major tool for understanding how they are changing, and for managing them in a context of increasing degradation of coastal ecosystems. The Global Coral Reef Monitoring Network (GCRMN) has near-global coverage, but there are few remote sites free of direct human impact that can serve as reference sites. This study provides baseline data for the French Iles Eparses in the Mozambique Channel, Western Indian Ocean (WIO), whose coral reefs are little known owing to their limited accessibility, and have been free from fishing pressure for over 20 years. Surveys of coral reef health and fish community structure were undertaken at four of the islands (Europa, Bassas da India, Juan de Nova and Glorieuses) in 2011e2013. Monitoring was conducted using standardized GCRMN methods for benthos and fish communities, at the highest taxonomic level. Benthic cover showed a latitudinal gradient, with higher coral cover and conversely lower algae cover (60% and 14% respectively) in the south of the Mozambique Channel. This could be due to the geomorphology of the islands, the latitudinal temperature gradient, and/or the history of chronic stress and bleaching events during the last decades. Fish also showed a latitudinal gradient with higher diversity in the north, in a center of diversity for the western Indian Ocean already recognized for corals. An exceptional biomass fish was recorded (approximately 3500 kg/ha excluding sharks, compared to a maximum of 1400 kg/ha elsewhere in the WIO). The presence of large predators and sharks in all the islands as well as the absence of fleshy benthic algae were indicators of the good health of the reef systems. Nevertheless, these islands are beginning to experience illegal fishing, particularly in the north of the Mozambique Channel, demonstrating their vulnerability to exploitation and the need to protect them as reference sites for coral reef studies, including of climate change impacts, for the region and globally.
Journal of Biogeography, Aug 5, 2020
Aim: The 'abundant centre' hypothesis states that species are more abundant at the centre of thei... more Aim: The 'abundant centre' hypothesis states that species are more abundant at the centre of their range. However, several recent large-scale studies have failed to find evidence for such a pattern. Here we used extensive global data of reef fishes to test the 'abundant centre' pattern, and to examine variation in the abundance patterns across species using life history and ecological traits. Location: Marine habitat at a global extent: from Indo-Pacific to Atlantic reefs. Methods: We used underwater visual estimates of fish abundance, containing 22,963 transects and 1,215 species. For each species we calculated the slope between abundance and distance to the range centre, with the range centre estimated using four different methods. We tested whether abundance patterns differ between the range core and margins using segmented regression. Meta-analytic methods were used to synthesize results across species, and to test whether species traits can explain variation in the fit to the pattern among species. Results: The method used to define the range centre had a large effect on the results. Nevertheless, in all cases we found large variation between species. Results of
HAL (Le Centre pour la Communication Scientifique Directe), 2020
HAL (Le Centre pour la Communication Scientifique Directe), Mar 20, 2014
International audienc
HAL (Le Centre pour la Communication Scientifique Directe), 2019
CBM - Cahiers de Biologie Marine, 2013
Europa is one of the Eparses Islands, French islands scattered in the Mozambique Channel. They ar... more Europa is one of the Eparses Islands, French islands scattered in the Mozambique Channel. They are isolated islands of coral origin, without permanent human population. This situation makes them good candidates to evaluate the evolution of biodiversity without direct anthropogenic influences. Knowledge is still scarce because their accessibility is limited. With the idea of classifying them as Marine Protected Areas, a management plan is required based on the coral reef communities. Among several aims, the program BioReCIE (Biodiversity, Resources and Conservation of Eparses Islands) was to complete the inventories of several marine groups, including the echinoderms, which had never been assessed before. In November 2011, a multidisciplinary team explored the reef slopes of the island by scuba diving down to 20 meters (10 sites), and the reef flats at low tide (14 sites, including the lagoon surrounded by mangrove), collecting and taking photos of the organisms which have been prese...
Western Indian Ocean journal of marine science, 2012
The Crustacea Decapoda of Europa Island have been inventoried during the BIORECIE fieldwork condu... more The Crustacea Decapoda of Europa Island have been inventoried during the BIORECIE fieldwork conducted from 7-12 November 2011. Previous records for Europa Island have been also compiled and an updated documented checklist of the species is proposed. In total, 175 decapods are reported for Europa Island, including 61 new records from this study. The fauna of Europa Island is mainly Indo-West Pacific in its composition. No endemic species have been recognized so far, but 15 species, such as Calcinus rosaceus , Ciliopagurus tricolor , Eriphia smithii or Grapsus fourmanoiri , are distinctive of the Western Indian Ocean region. A comparison with Mayotte Island, also recently inventoried for the decapods, shows that Europa Island fauna is slightly depauperate. This result is attributed to reduced size of the lagoon and mangroves as well as to the geographic isolation of the Island.
Fish and Fisheries, 2021
Current best‐practice policy recommendations for managing fish stocks are achieved by a mixture o... more Current best‐practice policy recommendations for managing fish stocks are achieved by a mixture of maintaining modest fishing mortality (restricting effort, times and gear), marine reserve networks and not subsidizing unprofitable fisheries. A seldom evaluated question is how effective these proposed approaches are for maintaining all fish stocks and biodiversity elements in marine seascapes? Both recommended and unrecommended fishing practices fragment habitats and reduce metapopulation connectivity with potentially unexpected seascape‐level consequences. To better understand these outcomes, we pooled and evaluated fish community data into two seascape groupings for comparisons of biomass and life‐history characteristics. These were remote baseline reefs (>9 hr from regional cities and >4 hr from human habitation, n = 584 locations) and those emulating best‐practice seascapes (BPS, n = 140). BPS were a mix of high‐compliance marine reserves (fishable biomass = 892 ± 696 (±SD)...
World Seas: an Environmental Evaluation, 2019
Abstract In the South Indian Ocean, French territories include Reunion (Mascarene archipelago), M... more Abstract In the South Indian Ocean, French territories include Reunion (Mascarene archipelago), Mayotte (Comoros archipelago) and the remote Iles Eparses in the Mozambique Channel (Glorieuses, Juan de Nova, Bassas da India, Europa), and Tromelin, North-East of Madagascar. Their coral reefs are varied, from 18 km2 of fringing reefs in Reunion to 1500 km2 of fringing, barrier and double barrier reefs in Mayotte, caye reefs in Glorieuses and Tromelin to atolls in Juan de Nova, Bassas da India and Europa. Pressures on them vary from 850,000 inhabitants in Reunion to no permanent inhabitants in Iles Eparses. Annual monitoring of Reunion and Mayotte shows a gradual decrease in coral cover and fish biomass, due to overfishing. Yet an exceptional biodiversity is recorded in Mayotte, mainly due to its geographical position at the center of the WIO coral triangle, and the variety of reef habitats. In the remote Iles Eparses, more recent monitoring showed a remarkable state of coral reefs and their exceptional fish biomass. These coral reefs are under human threats mainly due to coastal development and land-based pollution, except for Iles Eparses. Climate change has an impact through coral bleaching whose effects are stronger for reefs in the North of the Mozambique Channel. The impact of the 2016 bleaching event was variable on islands but most corals showed signs of resistance with a good recovery of coral colonies. In order to limit degradation and overexploitation of reef resources, national marine protected areas (MPAs) have been made in all French islands: 2007 in Reunion, 2010 in Mayotte, and 2012 in Glorieuses while all Iles Eparses have been under protection for more than 20 years. Despite this, Iles Eparses are beginning to suffer from illegal fishing, including collection of holothurians and perhaps shells, particularly since 2012. Long-term monitoring is essential to describe trends in coral communities in the context of increasing human impact and climate change.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2020
Reef fish biomass is increasingly recognized as a key indicator of fishery and biodiversity statu... more Reef fish biomass is increasingly recognized as a key indicator of fishery and biodiversity status linked to ecosystem integrity on coral reefs, and yet the evaluation of appropriate baselines for biomass, and what drives variation in potential baselines, is sparse. Variability in reef fishable biomass was assessed to test for the existence of baselines or benchmarks (B&Bs), based on field studies of 223 reef sites in remote uninhabited reefs, in high‐compliance closures of >5 km2, and among the increasing number of small and recent closures. The purpose of the study was to examine the effects of human habitation, travel time and distance to cities, habitat, depth, benthic cover, and environmental variables on fish B&Bs. There were large differences in the three categories of ‘no fishing’, with human habitation being the single best predictor of biomass. In remote areas without people (>9 hours of travel time), fish biomass had a mean of 2,450 kg ha–1 (95% confidence interval,...
Oral presentation about Can coral reef communities be used as indicators or proxies to assess eco... more Oral presentation about Can coral reef communities be used as indicators or proxies to assess ecological vulnerability of WIO small islands? The case of Glorieuses Island (Mozambic Channel, Indian Ocean)
Coral Reefs, 2015
Individual exposure to stressors can induce changes in physiological stress responses through mod... more Individual exposure to stressors can induce changes in physiological stress responses through modulation of the hypothalamic-pituitary-interrenal (HPI) axis. Despite theoretical predictions, little is known about how individuals will respond to unpredictable short-lived stressors, such as thermal events. We examine the primary neuroendocrine response of coral reef fish populations from the Îles Eparses rarely exposed to anthropogenic stress, but that experienced different thermal histories. Skunk anemonefish, Amphiprion akallopisos, showed different cortisol responses to a generic stressor between islands, but not along a latitudinal gradient. Those populations previously exposed to higher maximum temperatures showed greater responses of their HPI axis. Archive data reveal thermal stressor events occur every 1.92-6 yr, suggesting that modifications to the HPI axis could be adaptive. Our results highlight the potential for adaptation of the HPI axis in coral reef fish in response to a climate-induced thermal stressor.
Marine Biodiversity Records, 2013
An inventory has been made of the decapod fauna of the Glorieuses Islands, western Indian Ocean (... more An inventory has been made of the decapod fauna of the Glorieuses Islands, western Indian Ocean (WIO), following the BIORECIE 2 Expedition to the Islands, 5-17 December 2012. Field data are complemented by a review of taxonomic studies for these islands. Overall 157 species are now reported from the Glorieuses Islands, including 61 new records. The presence of the coconut crab, Birgus latro, is confirmed from these islands, for the first time since 1884, and the WIO distribution of this endangered species is updated, based on observations made in the region since 2006.