Comparative study of skipjack tuna Katsuwonus pelamis (Scombridae) fishery stocks from the South Atlantic and western Indian oceans
- Dahlet, Lol I, Downey-Breedt, Nicola, Arce, Gabriel, Sauer, Warwick H H, Gasalla, Maria A
- Authors: Dahlet, Lol I , Downey-Breedt, Nicola , Arce, Gabriel , Sauer, Warwick H H , Gasalla, Maria A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123988 , vital:35523 , https://doi.org/10.3989/scimar.04804.22C
- Description: Temporal and spatial fluctuations in the abundance of oceanic pelagic populations spread geographically around the globe are common (Cushing 1975). The causes of these fluctuations may be exogenous (environmental or anthropogenic) or endogenous to the organism (e.g. ontogenetic drivers) (Ricker 1954). This scenario applies to some tuna stocks, including the skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758), known as bonito-listrado in Brazil, katunkel, or ocean bonito in South Africa, and godhaa (bigger) or kadumas (smaller) skipjack in the Maldives. The skipjack belongs to the family Scombridae and inhabits tropical and subtropical areas of the globe. On average, 85% of skipjack catch occurs in waters warmer than 24°C (Fonteneau 2003). This resource is of particular importance, accounting for 57% of the global industrial tuna catch in 2016, and is mainly processed by the canning industry. Skipjack catches totaled 2.79 million t in 2016 (ISSF 2018), and currently 8.5% of worldwide catches are made by the pole-and line fleet. In Brazil and the Maldives, the resource is well-known. Catches in Brazil were seen to increase until 2014, while in the Maldives, 2006 marked the beginning of a strong and unsettling decline that continued until recent years. Off South Africa, skipjack catches are 1000 to 10000 times lower than those from Brazil and the Maldives, and the highest catches were recorded in 2012.
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- Authors: Dahlet, Lol I , Downey-Breedt, Nicola , Arce, Gabriel , Sauer, Warwick H H , Gasalla, Maria A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123988 , vital:35523 , https://doi.org/10.3989/scimar.04804.22C
- Description: Temporal and spatial fluctuations in the abundance of oceanic pelagic populations spread geographically around the globe are common (Cushing 1975). The causes of these fluctuations may be exogenous (environmental or anthropogenic) or endogenous to the organism (e.g. ontogenetic drivers) (Ricker 1954). This scenario applies to some tuna stocks, including the skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758), known as bonito-listrado in Brazil, katunkel, or ocean bonito in South Africa, and godhaa (bigger) or kadumas (smaller) skipjack in the Maldives. The skipjack belongs to the family Scombridae and inhabits tropical and subtropical areas of the globe. On average, 85% of skipjack catch occurs in waters warmer than 24°C (Fonteneau 2003). This resource is of particular importance, accounting for 57% of the global industrial tuna catch in 2016, and is mainly processed by the canning industry. Skipjack catches totaled 2.79 million t in 2016 (ISSF 2018), and currently 8.5% of worldwide catches are made by the pole-and line fleet. In Brazil and the Maldives, the resource is well-known. Catches in Brazil were seen to increase until 2014, while in the Maldives, 2006 marked the beginning of a strong and unsettling decline that continued until recent years. Off South Africa, skipjack catches are 1000 to 10000 times lower than those from Brazil and the Maldives, and the highest catches were recorded in 2012.
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Ecological connectivity between the areas beyond national jurisdiction and coastal waters: Safeguarding interests of coastal communities in developing countries
- Popova, Ekaterina, Vousden, David, Sauer, Warwick H H, Mohammed, Essam Y, Allain, Valerie, Downey-Breedt, Nicola, Fletcher, Ruth, Gjerde, Kristina M, Halpin, Patrick, Kelly, Stephen, Obura, David, Pecl, Gretta T, Roberts, Michael J, Raitsos, Dionysios E, Rogers, Alex, Samoilys, Melita, Sumaila , Ussif Rashid, Tracey, Sean, Yool, Andrew
- Authors: Popova, Ekaterina , Vousden, David , Sauer, Warwick H H , Mohammed, Essam Y , Allain, Valerie , Downey-Breedt, Nicola , Fletcher, Ruth , Gjerde, Kristina M , Halpin, Patrick , Kelly, Stephen , Obura, David , Pecl, Gretta T , Roberts, Michael J , Raitsos, Dionysios E , Rogers, Alex , Samoilys, Melita , Sumaila , Ussif Rashid , Tracey, Sean , Yool, Andrew
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124331 , vital:35594 , https://doi.10.1016/j.marpol.2019.02.050
- Description: The UN General Assembly has made a unanimous decision to start negotiations to establish an international, legally-binding instrument for the conservation and sustainable use of marine biological diversity within Areas Beyond National Jurisdiction (ABNJ). However, there has of yet been little discussion on the importance of this move to the ecosystem services provided by coastal zones in their downstream zone of influence. Here, we identify the ecological connectivity between ABNJ and coastal zones as critically important in the negotiation process and apply several approaches to identify some priority areas for protection from the perspective of coastal populations of Least Developed Countries (LDCs). Initially, we review the scientific evidence that demonstrates ecological connectivity between ABNJ and the coastal zones with a focus on the LDCs. We then use ocean modelling to develop a number of metrics and spatial maps that serve to quantify the connectivity of the ABNJ to the coastal zone. We find that the level of exposure to the ABNJ influences varies strongly between countries. Similarly, not all areas of the ABNJ are equal in their impacts on the coastline. Using this method, we identify the areas of the ABNJ that are in the most urgent need of protection on the grounds of the strength of their potential downstream impacts on the coastal populations of LDCs. We argue that indirect negative impacts of the ABNJ fishing, industrialisation and pollution, communicated via oceanographic, cultural and ecological connectivity to the coastal waters of the developing countries should be of concern.
- Full Text:
- Authors: Popova, Ekaterina , Vousden, David , Sauer, Warwick H H , Mohammed, Essam Y , Allain, Valerie , Downey-Breedt, Nicola , Fletcher, Ruth , Gjerde, Kristina M , Halpin, Patrick , Kelly, Stephen , Obura, David , Pecl, Gretta T , Roberts, Michael J , Raitsos, Dionysios E , Rogers, Alex , Samoilys, Melita , Sumaila , Ussif Rashid , Tracey, Sean , Yool, Andrew
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124331 , vital:35594 , https://doi.10.1016/j.marpol.2019.02.050
- Description: The UN General Assembly has made a unanimous decision to start negotiations to establish an international, legally-binding instrument for the conservation and sustainable use of marine biological diversity within Areas Beyond National Jurisdiction (ABNJ). However, there has of yet been little discussion on the importance of this move to the ecosystem services provided by coastal zones in their downstream zone of influence. Here, we identify the ecological connectivity between ABNJ and coastal zones as critically important in the negotiation process and apply several approaches to identify some priority areas for protection from the perspective of coastal populations of Least Developed Countries (LDCs). Initially, we review the scientific evidence that demonstrates ecological connectivity between ABNJ and the coastal zones with a focus on the LDCs. We then use ocean modelling to develop a number of metrics and spatial maps that serve to quantify the connectivity of the ABNJ to the coastal zone. We find that the level of exposure to the ABNJ influences varies strongly between countries. Similarly, not all areas of the ABNJ are equal in their impacts on the coastline. Using this method, we identify the areas of the ABNJ that are in the most urgent need of protection on the grounds of the strength of their potential downstream impacts on the coastal populations of LDCs. We argue that indirect negative impacts of the ABNJ fishing, industrialisation and pollution, communicated via oceanographic, cultural and ecological connectivity to the coastal waters of the developing countries should be of concern.
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Tools to enrich vulnerability assessment and adaptation planning for coastal communities in data-poor regions: application to a case study in Madagascar
- Cochrane, Kevern L, Rakotondrazafy, H, Aswani, Shankar, Chaigneau, Tomas, Downey-Breedt, Nicola, Lemahieu, Anne, Paytan, Adina, Pecl, Gretta T, Plagányi, Éva, Popova, Elizaveta, Van Putten, Ingrid E, Sauer, Warwick H H, Byfield, Val, Gasalla, Maria A, Van Gennip, Simon J, Malherbe, Willem, Rabary, Andriantsilavo, Rabeariso, Ando, Ramaroson, N, Randrianarimanana, V, Scott, Lucy E P, Tsimanaoraty, P M
- Authors: Cochrane, Kevern L , Rakotondrazafy, H , Aswani, Shankar , Chaigneau, Tomas , Downey-Breedt, Nicola , Lemahieu, Anne , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva , Popova, Elizaveta , Van Putten, Ingrid E , Sauer, Warwick H H , Byfield, Val , Gasalla, Maria A , Van Gennip, Simon J , Malherbe, Willem , Rabary, Andriantsilavo , Rabeariso, Ando , Ramaroson, N , Randrianarimanana, V , Scott, Lucy E P , Tsimanaoraty, P M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145347 , vital:38430 , DOI: 10.3389/fmars.2018.00505
- Description: Here we describe an interdisciplinary and multi-country initiative to develop rapid, participatory methods to assess the vulnerability of coastal communities and facilitate adaptation to climate change in data-poor regions. The methods were applied in Madagascar as a case study. The initiative centered on an exploratory research exercise in two communities in the south-west of Madagascar, a workshop held in Antananarivo in June 2016, combined with a component on communicating ocean science and climate change to stakeholders. It utilized innovative and rapid approaches to combine global and local skills and information on adaptation and resilience building, taking cognizance of national policies, and was based on the principles of a holistic, integrated and participatory approach. This paper summarizes the activities undertaken and assesses how effective they were in achieving the project goals, as well as presenting examples of the outputs obtained.
- Full Text:
- Authors: Cochrane, Kevern L , Rakotondrazafy, H , Aswani, Shankar , Chaigneau, Tomas , Downey-Breedt, Nicola , Lemahieu, Anne , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva , Popova, Elizaveta , Van Putten, Ingrid E , Sauer, Warwick H H , Byfield, Val , Gasalla, Maria A , Van Gennip, Simon J , Malherbe, Willem , Rabary, Andriantsilavo , Rabeariso, Ando , Ramaroson, N , Randrianarimanana, V , Scott, Lucy E P , Tsimanaoraty, P M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145347 , vital:38430 , DOI: 10.3389/fmars.2018.00505
- Description: Here we describe an interdisciplinary and multi-country initiative to develop rapid, participatory methods to assess the vulnerability of coastal communities and facilitate adaptation to climate change in data-poor regions. The methods were applied in Madagascar as a case study. The initiative centered on an exploratory research exercise in two communities in the south-west of Madagascar, a workshop held in Antananarivo in June 2016, combined with a component on communicating ocean science and climate change to stakeholders. It utilized innovative and rapid approaches to combine global and local skills and information on adaptation and resilience building, taking cognizance of national policies, and was based on the principles of a holistic, integrated and participatory approach. This paper summarizes the activities undertaken and assesses how effective they were in achieving the project goals, as well as presenting examples of the outputs obtained.
- Full Text:
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