Proceedings of the Thirty-Second International Joint Conference on Artificial Intelligence
Biodiversity loss is taking place at accelerated rates globally, and a business-as-usual trajecto... more Biodiversity loss is taking place at accelerated rates globally, and a business-as-usual trajectory will lead to missing internationally established conservation goals. Biosphere reserves are sites designed to be of global significance in terms of both the biodiversity within them and their potential for sustainable development, and are therefore ideal places for the development of local solutions to global challenges. While the protection of biodiversity is a primary goal of biosphere reserves, adequate information on the state and trends of biodiversity remains a critical gap for adaptive management in biosphere reserves. Passive acoustic monitoring (PAM) is an increasingly popular method for continued, reproducible, scalable, and cost-effective monitoring of animal wildlife. PAM adoption is on the rise, but its data management and analysis requirements pose a barrier for adoption for most agencies tasked with monitoring biodiversity. As an interdisciplinary team of machine learni...
Pelagic elasmobranchs are key elements of oceanic ecosystems and must be preserved if marine trop... more Pelagic elasmobranchs are key elements of oceanic ecosystems and must be preserved if marine trophic networks are to be kept in balance. Yet, they face intense fishing pressure that has been threatening their populations worldwide. Ensuring proper conservation management of these taxa depends on a better understanding of the strategies they use to explore the pelagic realm and their contributions to trophic web structuring across the ocean column. This study aimed at examining relationships between vertical habitat use and trophic attributes among six sympatric pelagic elasmobranchs using satellite transmitting tags in the western equatorial South Atlantic Ocean. The vertical movements of 35 elasmobranch individuals were tracked during an overall total of 1911 days. Clear relationships between species’ feeding habits, maximum diving depths, and proportion of time spent either in epipelagic or in surface waters were evidenced by Bayesian generalized linear mixed models and multivaria...
Typical long-term shark control programs aim at reducing local populations of potentially aggress... more Typical long-term shark control programs aim at reducing local populations of potentially aggressive species (PAS) to mitigate shark peril, which is achieved by deploying mostly gillnets off hazardous beaches. However, such strategy produces serious environmental disturbance by inflicting severe mortality to sharks and to several harmless, frequently endangered taxa, including cetaceans, sirenians and chelonids. A different methodological approach combining bottom longlines and drumlines has shown comparably better results off Recife, northeastern Brazil. Since 1992 this region has been experiencing an abnormally high shark attack rate but the protective fishing strategy was implemented in 2004 only. Unlike traditional shark control programs, the Shark Monitoring Program of Recife (SMPR) aims at removing potentially aggressive sharks not from their populations but from the hazardous area instead, which is achieved by capturing, transporting and releasing sharks offshore. Between May...
[Settlement of the Caribbean spiny lobster, Panulirus argus on artificial substrates was studied ... more [Settlement of the Caribbean spiny lobster, Panulirus argus on artificial substrates was studied from September 2003 to April 2004 at Bimini, Bahamas. The small scale, shallowness, and distinctive current regime of Bimini make it a more readily interpretable recruitment system regarding species with complex life cycles. Spatiotemporal patterns of pueruli settlement on “Witham-type” collectors were examined monthly by sampling over three specific days scheduled around each new moon. Peak abundances of pueruli were found in September, November, and February, but with considerable spatial heterogeneity. The western portion of Bimini Lagoon, open to the ocean, revealed higher abundances of lobster larvae, while absence of pueruli at the broad eastern entrance, open to the shallow Great Bahama Bank, suggested little contribution to settlement in the Bimini nursery. This region apparently is primarily dependent on postlarvae supplied by the Gulf Stream. Pueruli settlement varied significantly over the three sampling days, occurring mostly 3 d before new moon, which differed from peak settlement times in other regional studies. Significantly smaller total lengths of postpueruli in the innermost section of the lagoon (i.e., the North Sound) suggest poorer environmental conditions at this site, probably reflecting poor food and shelter availability. Nevertheless, higher abundances of older juveniles in the North Sound demonstrated that this area has an ecologically important habitat for recruitment of spiny lobster to subsequent ontogenetic stages. The importance of recruitment processes for the successful management of this commercially exploited species is discussed. Entre Setembro de 2003 e Julho de 2004, foi estudado o assentamento dos estadios pos-larvares da lagosta Panulirus argus em substratos artificiais em Bimini, Bahamas. A dimensao, profundidade e regime de correntes de Bimini favorecem a interpretacao da dinâmica do recrutamento das especies com ciclos de vida complexos. A amostragem em tres dias especificos no periodo da lua nova permitiu identificar os padroes espaco-temporais do assentamento das pos-larvas em colectores do tipo “Witham”. Foram identificados picos de abundância em Setembro, Novembro e Fevereiro, apesar de se verificar uma grande heterogeneidade espacial. A zona ocidental da Lagoa de Bimini apresentou maiores abundâncias de recrutas, enquanto a quase inexistencia de pos-larvas na zona oriental sugere uma fraca contribuicao da mesma para o recrutamento bentonico desta especie. Aparentemente, o recrutamento de P. argus nesta regiao depende do influxo de poslarvas trazidas pela Corrente do Golfo. A abundância de pos-larvas variou bastante ao longo das tres amostragens mensais, ocorrendo principalmente tres dias antes da lua nova, ao contrario do indicado por outros estudos. Juvenis significativamente menores encontrados na zona mais interior da lagoa (i.e. o North Sound) sugerem fracas condicoes ambientais neste local, provavelmente reflectindo a indisponibilidade de alimento e de habitat adequado. No entanto, a maior abundância de juvenis tardios prova que o North Sound tem um papel importante no recrutamento desta especie para estadios ontogeneticos mais avancados. A importância dos processos de recrutamento para a optimizacao da gestao desta especie comercialmente valiosa e tambem discutida. , Settlement of the Caribbean spiny lobster, Panulirus argus on artificial substrates was studied from September 2003 to April 2004 at Bimini, Bahamas. The small scale, shallowness, and distinctive current regime of Bimini make it a more readily interpretable recruitment system regarding species with complex life cycles. Spatiotemporal patterns of pueruli settlement on “Witham-type” collectors were examined monthly by sampling over three specific days scheduled around each new moon. Peak abundances of pueruli were found in September, November, and February, but with considerable spatial heterogeneity. The western portion of Bimini Lagoon, open to the ocean, revealed higher abundances of lobster larvae, while absence of pueruli at the broad eastern entrance, open to the shallow Great Bahama Bank, suggested little contribution to settlement in the Bimini nursery. This region apparently is primarily dependent on postlarvae supplied by the Gulf Stream. Pueruli settlement varied significantly over the three sampling days, occurring mostly 3 d before new moon, which differed from peak settlement times in other regional studies. Significantly smaller total lengths of postpueruli in the innermost section of the lagoon (i.e., the North Sound) suggest poorer environmental conditions at this site, probably reflecting poor food and shelter availability. Nevertheless, higher abundances of older juveniles in the North Sound demonstrated that this area has an ecologically important habitat for recruitment of spiny lobster to subsequent ontogenetic stages. The importance of recruitment processes for the…
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand thei... more Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need t...
Longlines bearing "hook timers" (HTs) and alternating circle (15/0 and 17/0) and "J" (10/0) hooks... more Longlines bearing "hook timers" (HTs) and alternating circle (15/0 and 17/0) and "J" (10/0) hooks were employed off the coast of Brazil to measure differences in fishing mortality associated with hook type and on-hook time between capture and boarding. A total of 431 HTs were activated, revealing a clear pattern of the increased mortality rate of fishes associated with increased on-hook time. Swordfish had high mortality rates, unlike blue sharks, which had low mortality rates regardless of hook type and the location in which the hook was transfixed. The six species of tunas and billfishes examined in this study showed a strong association between hooking location and the animal's release condition, with reduced mortality associated with individuals hooked externally. Results suggest that knowledge of factors affecting the survival of pelagic fishes caught in longline fisheries may enable the development and adoption of fishing methods to reduce mortality of longline bycatch.
Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences reg... more Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences regarding shark attack hazard
Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences reg... more Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences regarding shark attack hazard
Tese dout., Ciencias do Mar, da Terra e do Ambiente (Ecologia Marinha), Faculdade de Ciencias e T... more Tese dout., Ciencias do Mar, da Terra e do Ambiente (Ecologia Marinha), Faculdade de Ciencias e Tecnologia, Univ. do Algarve, 2013
The present study aims at inferring linkages between the abundance of potentially dangerous shark... more The present study aims at inferring linkages between the abundance of potentially dangerous sharks (PDSs) and shark hazard, so as to derive information about the underlying processes of shark peril off Recife, Brazil. Fishery-independent longline and drumline data collected from May 2004 through December 2014 for Carcharhinus leucas and Galeocerdo cuvier measuring ≥109cm were considered for analysis. Generalised additive models showed that the frequency of shark bites was directly proportional to and followed the same seasonal trends as PDS abundance, meeting the hypothesis that higher shark abundance may result in an increased chance of a shark bite. However, the species-specific seasonality of bull and tiger sharks seemed to follow distinct patterns. This method was helpful in comparing the abundance dynamics of the PDSs caught by the local shark hazard-mitigation program with the distribution of shark bites, so as to infer whether the species involved in the incidents were being ...
Proceedings of the Thirty-Second International Joint Conference on Artificial Intelligence
Biodiversity loss is taking place at accelerated rates globally, and a business-as-usual trajecto... more Biodiversity loss is taking place at accelerated rates globally, and a business-as-usual trajectory will lead to missing internationally established conservation goals. Biosphere reserves are sites designed to be of global significance in terms of both the biodiversity within them and their potential for sustainable development, and are therefore ideal places for the development of local solutions to global challenges. While the protection of biodiversity is a primary goal of biosphere reserves, adequate information on the state and trends of biodiversity remains a critical gap for adaptive management in biosphere reserves. Passive acoustic monitoring (PAM) is an increasingly popular method for continued, reproducible, scalable, and cost-effective monitoring of animal wildlife. PAM adoption is on the rise, but its data management and analysis requirements pose a barrier for adoption for most agencies tasked with monitoring biodiversity. As an interdisciplinary team of machine learni...
Pelagic elasmobranchs are key elements of oceanic ecosystems and must be preserved if marine trop... more Pelagic elasmobranchs are key elements of oceanic ecosystems and must be preserved if marine trophic networks are to be kept in balance. Yet, they face intense fishing pressure that has been threatening their populations worldwide. Ensuring proper conservation management of these taxa depends on a better understanding of the strategies they use to explore the pelagic realm and their contributions to trophic web structuring across the ocean column. This study aimed at examining relationships between vertical habitat use and trophic attributes among six sympatric pelagic elasmobranchs using satellite transmitting tags in the western equatorial South Atlantic Ocean. The vertical movements of 35 elasmobranch individuals were tracked during an overall total of 1911 days. Clear relationships between species’ feeding habits, maximum diving depths, and proportion of time spent either in epipelagic or in surface waters were evidenced by Bayesian generalized linear mixed models and multivaria...
Typical long-term shark control programs aim at reducing local populations of potentially aggress... more Typical long-term shark control programs aim at reducing local populations of potentially aggressive species (PAS) to mitigate shark peril, which is achieved by deploying mostly gillnets off hazardous beaches. However, such strategy produces serious environmental disturbance by inflicting severe mortality to sharks and to several harmless, frequently endangered taxa, including cetaceans, sirenians and chelonids. A different methodological approach combining bottom longlines and drumlines has shown comparably better results off Recife, northeastern Brazil. Since 1992 this region has been experiencing an abnormally high shark attack rate but the protective fishing strategy was implemented in 2004 only. Unlike traditional shark control programs, the Shark Monitoring Program of Recife (SMPR) aims at removing potentially aggressive sharks not from their populations but from the hazardous area instead, which is achieved by capturing, transporting and releasing sharks offshore. Between May...
[Settlement of the Caribbean spiny lobster, Panulirus argus on artificial substrates was studied ... more [Settlement of the Caribbean spiny lobster, Panulirus argus on artificial substrates was studied from September 2003 to April 2004 at Bimini, Bahamas. The small scale, shallowness, and distinctive current regime of Bimini make it a more readily interpretable recruitment system regarding species with complex life cycles. Spatiotemporal patterns of pueruli settlement on “Witham-type” collectors were examined monthly by sampling over three specific days scheduled around each new moon. Peak abundances of pueruli were found in September, November, and February, but with considerable spatial heterogeneity. The western portion of Bimini Lagoon, open to the ocean, revealed higher abundances of lobster larvae, while absence of pueruli at the broad eastern entrance, open to the shallow Great Bahama Bank, suggested little contribution to settlement in the Bimini nursery. This region apparently is primarily dependent on postlarvae supplied by the Gulf Stream. Pueruli settlement varied significantly over the three sampling days, occurring mostly 3 d before new moon, which differed from peak settlement times in other regional studies. Significantly smaller total lengths of postpueruli in the innermost section of the lagoon (i.e., the North Sound) suggest poorer environmental conditions at this site, probably reflecting poor food and shelter availability. Nevertheless, higher abundances of older juveniles in the North Sound demonstrated that this area has an ecologically important habitat for recruitment of spiny lobster to subsequent ontogenetic stages. The importance of recruitment processes for the successful management of this commercially exploited species is discussed. Entre Setembro de 2003 e Julho de 2004, foi estudado o assentamento dos estadios pos-larvares da lagosta Panulirus argus em substratos artificiais em Bimini, Bahamas. A dimensao, profundidade e regime de correntes de Bimini favorecem a interpretacao da dinâmica do recrutamento das especies com ciclos de vida complexos. A amostragem em tres dias especificos no periodo da lua nova permitiu identificar os padroes espaco-temporais do assentamento das pos-larvas em colectores do tipo “Witham”. Foram identificados picos de abundância em Setembro, Novembro e Fevereiro, apesar de se verificar uma grande heterogeneidade espacial. A zona ocidental da Lagoa de Bimini apresentou maiores abundâncias de recrutas, enquanto a quase inexistencia de pos-larvas na zona oriental sugere uma fraca contribuicao da mesma para o recrutamento bentonico desta especie. Aparentemente, o recrutamento de P. argus nesta regiao depende do influxo de poslarvas trazidas pela Corrente do Golfo. A abundância de pos-larvas variou bastante ao longo das tres amostragens mensais, ocorrendo principalmente tres dias antes da lua nova, ao contrario do indicado por outros estudos. Juvenis significativamente menores encontrados na zona mais interior da lagoa (i.e. o North Sound) sugerem fracas condicoes ambientais neste local, provavelmente reflectindo a indisponibilidade de alimento e de habitat adequado. No entanto, a maior abundância de juvenis tardios prova que o North Sound tem um papel importante no recrutamento desta especie para estadios ontogeneticos mais avancados. A importância dos processos de recrutamento para a optimizacao da gestao desta especie comercialmente valiosa e tambem discutida. , Settlement of the Caribbean spiny lobster, Panulirus argus on artificial substrates was studied from September 2003 to April 2004 at Bimini, Bahamas. The small scale, shallowness, and distinctive current regime of Bimini make it a more readily interpretable recruitment system regarding species with complex life cycles. Spatiotemporal patterns of pueruli settlement on “Witham-type” collectors were examined monthly by sampling over three specific days scheduled around each new moon. Peak abundances of pueruli were found in September, November, and February, but with considerable spatial heterogeneity. The western portion of Bimini Lagoon, open to the ocean, revealed higher abundances of lobster larvae, while absence of pueruli at the broad eastern entrance, open to the shallow Great Bahama Bank, suggested little contribution to settlement in the Bimini nursery. This region apparently is primarily dependent on postlarvae supplied by the Gulf Stream. Pueruli settlement varied significantly over the three sampling days, occurring mostly 3 d before new moon, which differed from peak settlement times in other regional studies. Significantly smaller total lengths of postpueruli in the innermost section of the lagoon (i.e., the North Sound) suggest poorer environmental conditions at this site, probably reflecting poor food and shelter availability. Nevertheless, higher abundances of older juveniles in the North Sound demonstrated that this area has an ecologically important habitat for recruitment of spiny lobster to subsequent ontogenetic stages. The importance of recruitment processes for the…
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand thei... more Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need t...
Longlines bearing "hook timers" (HTs) and alternating circle (15/0 and 17/0) and "J" (10/0) hooks... more Longlines bearing "hook timers" (HTs) and alternating circle (15/0 and 17/0) and "J" (10/0) hooks were employed off the coast of Brazil to measure differences in fishing mortality associated with hook type and on-hook time between capture and boarding. A total of 431 HTs were activated, revealing a clear pattern of the increased mortality rate of fishes associated with increased on-hook time. Swordfish had high mortality rates, unlike blue sharks, which had low mortality rates regardless of hook type and the location in which the hook was transfixed. The six species of tunas and billfishes examined in this study showed a strong association between hooking location and the animal's release condition, with reduced mortality associated with individuals hooked externally. Results suggest that knowledge of factors affecting the survival of pelagic fishes caught in longline fisheries may enable the development and adoption of fishing methods to reduce mortality of longline bycatch.
Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences reg... more Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences regarding shark attack hazard
Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences reg... more Regional movements of the tiger shark, Galeocerdo cuvier, off northeastern Brazil: inferences regarding shark attack hazard
Tese dout., Ciencias do Mar, da Terra e do Ambiente (Ecologia Marinha), Faculdade de Ciencias e T... more Tese dout., Ciencias do Mar, da Terra e do Ambiente (Ecologia Marinha), Faculdade de Ciencias e Tecnologia, Univ. do Algarve, 2013
The present study aims at inferring linkages between the abundance of potentially dangerous shark... more The present study aims at inferring linkages between the abundance of potentially dangerous sharks (PDSs) and shark hazard, so as to derive information about the underlying processes of shark peril off Recife, Brazil. Fishery-independent longline and drumline data collected from May 2004 through December 2014 for Carcharhinus leucas and Galeocerdo cuvier measuring ≥109cm were considered for analysis. Generalised additive models showed that the frequency of shark bites was directly proportional to and followed the same seasonal trends as PDS abundance, meeting the hypothesis that higher shark abundance may result in an increased chance of a shark bite. However, the species-specific seasonality of bull and tiger sharks seemed to follow distinct patterns. This method was helpful in comparing the abundance dynamics of the PDSs caught by the local shark hazard-mitigation program with the distribution of shark bites, so as to infer whether the species involved in the incidents were being ...
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Papers by André Afonso