Global trends of local ecological knowledge and future implications
- Aswani, Shankar, Lemahieu, Anne, Sauer, Warwick H H
- Authors: Aswani, Shankar , Lemahieu, Anne , Sauer, Warwick H H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70504 , vital:29668 , https://doi.org/10.1371/journal.pone.0195440
- Description: Local and indigenous knowledge is being transformed globally, particularly being eroded when pertaining to ecology. In many parts of the world, rural and indigenous communities are facing tremendous cultural, economic and environmental changes, which contribute to weaken their local knowledge base. In the face of profound and ongoing environmental changes, both cultural and biological diversity are likely to be severely impacted as well as local resilience capacities from this loss. In this global literature review, we analyse the drivers of various types of local and indigenous ecological knowledge transformation and assess the directionality of the reported change. Results of this analysis show a global impoverishment of local and indigenous knowledge with 77% of papers reporting the loss of knowledge driven by globalization, modernization, and market integration. The recording of this loss, however, is not symmetrical, with losses being recorded more strongly in medicinal and ethnobotanical knowledge. Persistence of knowledge (15% of the studies) occurred in studies where traditional practices were being maintained consiously and where hybrid knowledge was being produced as a resut of certain types of incentives created by economic development. This review provides some insights into local and indigenous ecological knowledge change, its causes and implications, and recommends venues for the development of replicable and comparative research. The larger implication of these results is that because of the interconnection between cultural and biological diversity, the loss of local and indigenous knowledge is likely to critically threaten effective conservation of biodiversity, particularly in community-based conservation local efforts.
- Full Text:
- Date Issued: 2018
- Authors: Aswani, Shankar , Lemahieu, Anne , Sauer, Warwick H H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70504 , vital:29668 , https://doi.org/10.1371/journal.pone.0195440
- Description: Local and indigenous knowledge is being transformed globally, particularly being eroded when pertaining to ecology. In many parts of the world, rural and indigenous communities are facing tremendous cultural, economic and environmental changes, which contribute to weaken their local knowledge base. In the face of profound and ongoing environmental changes, both cultural and biological diversity are likely to be severely impacted as well as local resilience capacities from this loss. In this global literature review, we analyse the drivers of various types of local and indigenous ecological knowledge transformation and assess the directionality of the reported change. Results of this analysis show a global impoverishment of local and indigenous knowledge with 77% of papers reporting the loss of knowledge driven by globalization, modernization, and market integration. The recording of this loss, however, is not symmetrical, with losses being recorded more strongly in medicinal and ethnobotanical knowledge. Persistence of knowledge (15% of the studies) occurred in studies where traditional practices were being maintained consiously and where hybrid knowledge was being produced as a resut of certain types of incentives created by economic development. This review provides some insights into local and indigenous ecological knowledge change, its causes and implications, and recommends venues for the development of replicable and comparative research. The larger implication of these results is that because of the interconnection between cultural and biological diversity, the loss of local and indigenous knowledge is likely to critically threaten effective conservation of biodiversity, particularly in community-based conservation local efforts.
- Full Text:
- Date Issued: 2018
Science in the service of society: Is marine and coastal science addressing South Africa's needs?
- Cochrane, Kevern L, Sauer, Warwick H H, Aswani, Shankar
- Authors: Cochrane, Kevern L , Sauer, Warwick H H , Aswani, Shankar
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126071 , vital:35847 , https://doi.10.17159/sajs.2019/4418
- Description: The modern world is confronted with many and diverse social and environmental challenges of high complexity. In South Africa, rapid and sustainable development is needed to address high levels of poverty and unemployment but this development has to take place in the context of an environment that is already severely impacted by human activities. Sound and relevant scientific input and advice, covering the full scope of each challenge, is essential for effective decisions and actions to address the needs. South Africa has the benefit of strong scientific capacity but the country’s National Development Plan reported that national research priorities were not always consistent with South Africa’s needs. We investigate the validity of that conclusion in the coastal and marine sciences by examining presentations made at the 2017 South African Marine Science Symposium on the theme of ‘Unlocking the ocean’s economic potential whilst maintaining social and ecological resilience’. Despite the theme, only 21% of the presentations were judged to be actionable and directly relevant to societal needs, as defined by the criteria used. Less than 7% were evaluated as being interdisciplinary within the natural sciences and approximately 10% were found to include both natural and human sciences. Poor representation by the human sciences was also noteworthy. This preliminary assessment highlights the need for an urgent review of the disciplinary representation and approaches in marine and coastal science in South Africa in the context of the priority practical needs of the country now and into the future.
- Full Text:
- Date Issued: 2019
- Authors: Cochrane, Kevern L , Sauer, Warwick H H , Aswani, Shankar
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126071 , vital:35847 , https://doi.10.17159/sajs.2019/4418
- Description: The modern world is confronted with many and diverse social and environmental challenges of high complexity. In South Africa, rapid and sustainable development is needed to address high levels of poverty and unemployment but this development has to take place in the context of an environment that is already severely impacted by human activities. Sound and relevant scientific input and advice, covering the full scope of each challenge, is essential for effective decisions and actions to address the needs. South Africa has the benefit of strong scientific capacity but the country’s National Development Plan reported that national research priorities were not always consistent with South Africa’s needs. We investigate the validity of that conclusion in the coastal and marine sciences by examining presentations made at the 2017 South African Marine Science Symposium on the theme of ‘Unlocking the ocean’s economic potential whilst maintaining social and ecological resilience’. Despite the theme, only 21% of the presentations were judged to be actionable and directly relevant to societal needs, as defined by the criteria used. Less than 7% were evaluated as being interdisciplinary within the natural sciences and approximately 10% were found to include both natural and human sciences. Poor representation by the human sciences was also noteworthy. This preliminary assessment highlights the need for an urgent review of the disciplinary representation and approaches in marine and coastal science in South Africa in the context of the priority practical needs of the country now and into the future.
- Full Text:
- Date Issued: 2019
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:
- Date Issued: 2019
- 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:
- Date Issued: 2019
The GULLS project: a comparison of vulnerabilities across selected ocean hotspots and implications for adaptation to global change
- Cochrane, Kevern L, Hobday, Alistair J, Aswani, Shankar, Byfield, Val, Dutra, Leo X, Gasalla, Maria A, Haward, Marcus, Paytan, Adina, Pecl, Gretta T, Popova, Katya, Sainulabdeen, Shyam S, Savage, Candida, Sauer, Warwick H H, van Putten, Ingrid E, Visser, Natascha, TG Team
- Authors: Cochrane, Kevern L , Hobday, Alistair J , Aswani, Shankar , Byfield, Val , Dutra, Leo X , Gasalla, Maria A , Haward, Marcus , Paytan, Adina , Pecl, Gretta T , Popova, Katya , Sainulabdeen, Shyam S , Savage, Candida , Sauer, Warwick H H , van Putten, Ingrid E , Visser, Natascha , TG Team
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422037 , vital:71906
- Description: The GULLS project, `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' has been underway since October 2014. The project has been investigating six regional `hotspots': marine areas experiencing rapid warming. These are south-east Australia, Brazil, India, Solomon Islands, South Africa, and the Mozambique Channel and Madagascar. Rapid warming could be expected to have social, cultural and economic impacts that could affect these countries in different ways and may already be doing so. GULLS has focused on contributing to assessing and reducing the vulnerability of coastal communities and other stakeholders dependent on marine resources and to facilitate adaptation to climate change and variability through an integrated and trans-disciplinary approach. It includes participants from Australia, Brazil, India, Madagascar, New Zealand, South Africa, the United Kingdom and the United States of America. The research programme has been divided into six inter-linked components: ocean models, biological and ecological sensitivity analyses, system models, social vulnerability, policy mapping, and communication and education. This presentation will provide a brief overview of each of these components and describe the benefits that have resulted from the collaborative and transdisciplinary approach of GULLS. Following the standard vulnerability elements of exposure, sensitivity and adaptive capacity, the vulnerabilities of coastal communities and other stakeholders dependent on marine resources in the five hotspots will be compared using a set of indicators derived and populated from results of the research programme. The implications of similarities and differences between the hotspots for adaptation planning and options will be described.
- Full Text:
- Date Issued: 2016
- Authors: Cochrane, Kevern L , Hobday, Alistair J , Aswani, Shankar , Byfield, Val , Dutra, Leo X , Gasalla, Maria A , Haward, Marcus , Paytan, Adina , Pecl, Gretta T , Popova, Katya , Sainulabdeen, Shyam S , Savage, Candida , Sauer, Warwick H H , van Putten, Ingrid E , Visser, Natascha , TG Team
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422037 , vital:71906
- Description: The GULLS project, `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' has been underway since October 2014. The project has been investigating six regional `hotspots': marine areas experiencing rapid warming. These are south-east Australia, Brazil, India, Solomon Islands, South Africa, and the Mozambique Channel and Madagascar. Rapid warming could be expected to have social, cultural and economic impacts that could affect these countries in different ways and may already be doing so. GULLS has focused on contributing to assessing and reducing the vulnerability of coastal communities and other stakeholders dependent on marine resources and to facilitate adaptation to climate change and variability through an integrated and trans-disciplinary approach. It includes participants from Australia, Brazil, India, Madagascar, New Zealand, South Africa, the United Kingdom and the United States of America. The research programme has been divided into six inter-linked components: ocean models, biological and ecological sensitivity analyses, system models, social vulnerability, policy mapping, and communication and education. This presentation will provide a brief overview of each of these components and describe the benefits that have resulted from the collaborative and transdisciplinary approach of GULLS. Following the standard vulnerability elements of exposure, sensitivity and adaptive capacity, the vulnerabilities of coastal communities and other stakeholders dependent on marine resources in the five hotspots will be compared using a set of indicators derived and populated from results of the research programme. The implications of similarities and differences between the hotspots for adaptation planning and options will be described.
- Full Text:
- Date Issued: 2016
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.
- Full Text:
- Date Issued: 2019
- 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.
- Full Text:
- Date Issued: 2019
Global proliferation of cephalopods
- Doubleday, Zoë A, Prowse, Thomas A A, Arkhipkin, Alexander, Pierce, Graham J, Semmens, Jayson, Steer, Michael, Leporati, Stephen C, Lourenço, Sílvia, Quetglas, Antoni, Sauer, Warwick H H, Gillanders, Bronwyn M
- Authors: Doubleday, Zoë A , Prowse, Thomas A A , Arkhipkin, Alexander , Pierce, Graham J , Semmens, Jayson , Steer, Michael , Leporati, Stephen C , Lourenço, Sílvia , Quetglas, Antoni , Sauer, Warwick H H , Gillanders, Bronwyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124560 , vital:35628 , https://doi.10.1016/j.cub.2016.04.002
- Description: Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2–4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment.
- Full Text:
- Date Issued: 2016
- Authors: Doubleday, Zoë A , Prowse, Thomas A A , Arkhipkin, Alexander , Pierce, Graham J , Semmens, Jayson , Steer, Michael , Leporati, Stephen C , Lourenço, Sílvia , Quetglas, Antoni , Sauer, Warwick H H , Gillanders, Bronwyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124560 , vital:35628 , https://doi.10.1016/j.cub.2016.04.002
- Description: Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2–4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment.
- Full Text:
- Date Issued: 2016
Modelling transport of inshore and deep-spawned chokka squid (Loligo reynaudi) paralarvae off South Africa: the potential contribution of deep spawning to recruitment
- Downey-Breedt, Nicola, Roberts, Michael J, Sauer, Warwick H H, Chang, N
- Authors: Downey-Breedt, Nicola , Roberts, Michael J , Sauer, Warwick H H , Chang, N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125183 , vital:35742 , https://doi.10.1111/fog.12132
- Description: The South African chokka squid, Loligo reynaudi, spawns both inshore (≤70 m) and on the mid-shelf (71–130 m) of the Eastern Agulhas Bank. The fate of these deep-spawned hatchlings and their potential contribution to recruitment is as yet unknown. Lagrangian ROMS-IBM (Regional Ocean Modelling System-Individual-Based Model) simulations confirm westward transport of inshore and deep-spawned hatchlings, but also indicate that the potential exists for paralarvae hatched on the Eastern Agulhas Bank deep spawning grounds to be removed from the shelf ecosystem. Using a ROMS-IBM, this study determined the transport and recruitment success of deepspawned hatchlings relative to inshore-hatched paralarvae. A total of 12 release sites were incorporated into the model, six inshore and six deep-spawning sites. Paralarval survival was estimated based on timely transport to nursery grounds, adequate retention within the nursery grounds and retention on the Agulhas Bank shelf. Paralarval transport and survival were dependent on both spawning location and time of hatching. Results suggest the importance of the south coast as a nursery area for inshore-hatched paralarvae, and similarly the cold ridge nursery grounds for deep-hatched paralarvae. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off the Tsitsikamma coast, and the beneficial currents during this period (as indicated by the model results) it can be concluded that deep spawning may at times contribute significantly to recruitment.
- Full Text:
- Date Issued: 2016
- Authors: Downey-Breedt, Nicola , Roberts, Michael J , Sauer, Warwick H H , Chang, N
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125183 , vital:35742 , https://doi.10.1111/fog.12132
- Description: The South African chokka squid, Loligo reynaudi, spawns both inshore (≤70 m) and on the mid-shelf (71–130 m) of the Eastern Agulhas Bank. The fate of these deep-spawned hatchlings and their potential contribution to recruitment is as yet unknown. Lagrangian ROMS-IBM (Regional Ocean Modelling System-Individual-Based Model) simulations confirm westward transport of inshore and deep-spawned hatchlings, but also indicate that the potential exists for paralarvae hatched on the Eastern Agulhas Bank deep spawning grounds to be removed from the shelf ecosystem. Using a ROMS-IBM, this study determined the transport and recruitment success of deepspawned hatchlings relative to inshore-hatched paralarvae. A total of 12 release sites were incorporated into the model, six inshore and six deep-spawning sites. Paralarval survival was estimated based on timely transport to nursery grounds, adequate retention within the nursery grounds and retention on the Agulhas Bank shelf. Paralarval transport and survival were dependent on both spawning location and time of hatching. Results suggest the importance of the south coast as a nursery area for inshore-hatched paralarvae, and similarly the cold ridge nursery grounds for deep-hatched paralarvae. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off the Tsitsikamma coast, and the beneficial currents during this period (as indicated by the model results) it can be concluded that deep spawning may at times contribute significantly to recruitment.
- Full Text:
- Date Issued: 2016
Governance mapping: a framework for assessing the adaptive capacity of marine resource governance to environmental change
- Dutra, Leo X C, Sporne, Ilva, Haward, Marcus, Aswani, Shankar, Cochrane, Kevern L, Frusher, Stewart, Gasalla, Maria A, Gianesella, Sônia M F, Grant, Tanith, Hobday, Alistair J, Jennings, Sarah, Plagányi, Éva, Pecl, Gretta T, Salim, Shyam S, Sauer, Warwick H H, Taboada, Manuela B, Van Putten, Ingrid E
- Authors: Dutra, Leo X C , Sporne, Ilva , Haward, Marcus , Aswani, Shankar , Cochrane, Kevern L , Frusher, Stewart , Gasalla, Maria A , Gianesella, Sônia M F , Grant, Tanith , Hobday, Alistair J , Jennings, Sarah , Plagányi, Éva , Pecl, Gretta T , Salim, Shyam S , Sauer, Warwick H H , Taboada, Manuela B , Van Putten, Ingrid E
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145336 , vital:38429 , DOI: 10.1016/j.marpol.2018.12.011
- Description: Marine social-ecological systems are influenced by the way humans interact with their environment, and external forces, which change and re-shape the environment. In many regions, exploitation of marine resources and climate change are two of the primary drivers shifting the abundance and distribution of marine living resources, with negative effects on marine-dependent communities. Governance systems determine ‘who’ makes decisions, ‘what’ are their powers and responsibilities, and ‘how’ they are exercised. Understanding the connections between the actors comprising governance systems and influences between governance and the environment is therefore critical to support successful transitions to novel forms of governance required to deal with environmental changes. The paper provides an analytical framework with a practical example from Vanuatu, for mapping and assessment of the governance system providing for management of coral reef fish resources. The framework enables a rapid analysis of governance systems to identify factors that can encourage, or hinder, the adaptation of communities to changes in abundance or availability of marine resources.
- Full Text:
- Date Issued: 2019
- Authors: Dutra, Leo X C , Sporne, Ilva , Haward, Marcus , Aswani, Shankar , Cochrane, Kevern L , Frusher, Stewart , Gasalla, Maria A , Gianesella, Sônia M F , Grant, Tanith , Hobday, Alistair J , Jennings, Sarah , Plagányi, Éva , Pecl, Gretta T , Salim, Shyam S , Sauer, Warwick H H , Taboada, Manuela B , Van Putten, Ingrid E
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145336 , vital:38429 , DOI: 10.1016/j.marpol.2018.12.011
- Description: Marine social-ecological systems are influenced by the way humans interact with their environment, and external forces, which change and re-shape the environment. In many regions, exploitation of marine resources and climate change are two of the primary drivers shifting the abundance and distribution of marine living resources, with negative effects on marine-dependent communities. Governance systems determine ‘who’ makes decisions, ‘what’ are their powers and responsibilities, and ‘how’ they are exercised. Understanding the connections between the actors comprising governance systems and influences between governance and the environment is therefore critical to support successful transitions to novel forms of governance required to deal with environmental changes. The paper provides an analytical framework with a practical example from Vanuatu, for mapping and assessment of the governance system providing for management of coral reef fish resources. The framework enables a rapid analysis of governance systems to identify factors that can encourage, or hinder, the adaptation of communities to changes in abundance or availability of marine resources.
- Full Text:
- Date Issued: 2019
Spatial description of hake-directed fishing activity off the west coast of South Africa
- Fairweather, T P, Booth, Anthony J, Sauer, Warwick H H, Leslie, R W
- Authors: Fairweather, T P , Booth, Anthony J , Sauer, Warwick H H , Leslie, R W
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127031 , vital:35945 , https://doi.10.2989/18142320609504129
- Description: Historically, the two species of Cape hakes Merluccius capensis and M. paradoxus off South Africa were commercially exploited exclusively by demersal trawling. In 1994, hake-directed demersal longline was introduced on an experimental basis, and in 1998 was initiated as a commercial fishing sector. The effect of a combined fleet composed of both trawlers and longliners on the Cape hake resource is not fully understood. Analysis of fishing intensity and catch-rate data revealed that the highest catch rates were found around the 400m and 500m isobaths for the trawl and longline fisheries respectively. Catch rates from both fishing sectors were also noted to be higher over sediments with a sand component. Differences between areas of the highest fishing intensity and highest catch rates were noted. In addition to other factors, it is suggested that a ‘friction of distance’ effect applies — vessels will trade-off higher catch rates with the increased costs associated with fishing in deeper waters.
- Full Text:
- Date Issued: 2010
- Authors: Fairweather, T P , Booth, Anthony J , Sauer, Warwick H H , Leslie, R W
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127031 , vital:35945 , https://doi.10.2989/18142320609504129
- Description: Historically, the two species of Cape hakes Merluccius capensis and M. paradoxus off South Africa were commercially exploited exclusively by demersal trawling. In 1994, hake-directed demersal longline was introduced on an experimental basis, and in 1998 was initiated as a commercial fishing sector. The effect of a combined fleet composed of both trawlers and longliners on the Cape hake resource is not fully understood. Analysis of fishing intensity and catch-rate data revealed that the highest catch rates were found around the 400m and 500m isobaths for the trawl and longline fisheries respectively. Catch rates from both fishing sectors were also noted to be higher over sediments with a sand component. Differences between areas of the highest fishing intensity and highest catch rates were noted. In addition to other factors, it is suggested that a ‘friction of distance’ effect applies — vessels will trade-off higher catch rates with the increased costs associated with fishing in deeper waters.
- Full Text:
- Date Issued: 2010
A change of the seaward boundary of Goukamma Marine Protected Area could increase conservation and fishery benefits
- Gotz, Albrecht, Kerwath, Sven E, Attwood, Colin G, Sauer, Warwick H H
- Authors: Gotz, Albrecht , Kerwath, Sven E , Attwood, Colin G , Sauer, Warwick H H
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123503 , vital:35449 , https://doi10.4102/sajs.v105i9/10.102
- Description: Goukamma Marine Protected Area (MPA) on the South African temperate South Coast has been shown to be effective in maintaining a spawning stock of roman, Chrysoblephus laticeps (Sparidae). The larval ecology and the oceanographic conditions in the area suggest a good potential for the enhancement of roman stocks outside the reserve through larval dispersal. A high rate of illegal fishing just inside the seaward boundary of the MPA could severely compromise its function. We suggest that a change of the seaward boundary of the reserve to coincide with a latitudinal line could increase its function as a harvest refuge for resident reef fishes such as roman, facilitate voluntary compliance and monitoring and prosecution of illegal fishing without a significant negative impact on the commercial linefishing fleet in the area. Simple adjustments such as the one proposed here could be attempted at a number of South African MPAs as they would be beneficial to achieve fishery and conservation goals alike.
- Full Text:
- Date Issued: 2009
- Authors: Gotz, Albrecht , Kerwath, Sven E , Attwood, Colin G , Sauer, Warwick H H
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123503 , vital:35449 , https://doi10.4102/sajs.v105i9/10.102
- Description: Goukamma Marine Protected Area (MPA) on the South African temperate South Coast has been shown to be effective in maintaining a spawning stock of roman, Chrysoblephus laticeps (Sparidae). The larval ecology and the oceanographic conditions in the area suggest a good potential for the enhancement of roman stocks outside the reserve through larval dispersal. A high rate of illegal fishing just inside the seaward boundary of the MPA could severely compromise its function. We suggest that a change of the seaward boundary of the reserve to coincide with a latitudinal line could increase its function as a harvest refuge for resident reef fishes such as roman, facilitate voluntary compliance and monitoring and prosecution of illegal fishing without a significant negative impact on the commercial linefishing fleet in the area. Simple adjustments such as the one proposed here could be attempted at a number of South African MPAs as they would be beneficial to achieve fishery and conservation goals alike.
- Full Text:
- Date Issued: 2009
Integrated genetic and morphological data support eco‐evolutionary divergence of Angolan and South African populations of Diplodus hottentotus
- Gwilliam, Michael P, Winkler, Alexander C, Potts, Warren M, Santos, Carmen V D, Sauer, Warwick H H, Shaw, Paul W, McKeown, Niall J
- Authors: Gwilliam, Michael P , Winkler, Alexander C , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124833 , vital:35702 , https://doi.10.1111/jfb.13582
- Description: The genus Diplodus presents multiple cases of taxonomic conjecture. Among these the D. cervinus complex was previously described as comprising three subspecies that are now regarded as separate species: Diplodus cervinus, Diplodus hottentotus and Diplodus omanensis. Diplodus hottentotus exhibits a clear break in its distribution around the Benguela Current system, prompting speculation that Angolan and South African populations flanking this area may be isolated and warrant formal taxonomic distinction. This study reports the first integrated genetic [mitochondrial (mt)DNA and nuclear microsatellite] and morphological (morphometric, meristic and colouration) study to assess patterns of divergence between populations in the two regions. High levels of cytonuclear divergence between the populations support a prolonged period of genetic isolation, with the sharing of only one mtDNA haplotype (12 haplotypes were fully sorted between regions) attributed to retention of ancestral polymorphism. Fish from the two regions were significantly differentiated at a number of morphometric (69·5%) and meristic (46%) characters. In addition, Angolan and South African fish exhibited reciprocally diagnostic colouration patterns that were more similar to Mediterranean and Indian Ocean congeners, respectively. Based on the congruent genetic and phenotypic diversity we suggest that the use of hottentotus, whether for full species or subspecies status, should be restricted to South African D. cervinus to reflect their status as a distinct species-like unit, while the relationship between Angolan and Atlantic–Mediterranean D. cervinus will require further demo-genetic analysis. This study highlights the utility of integrated genetic and morphological approaches to assess taxonomic diversity within the biogeographically dynamic Benguela Current region.
- Full Text:
- Date Issued: 2018
- Authors: Gwilliam, Michael P , Winkler, Alexander C , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124833 , vital:35702 , https://doi.10.1111/jfb.13582
- Description: The genus Diplodus presents multiple cases of taxonomic conjecture. Among these the D. cervinus complex was previously described as comprising three subspecies that are now regarded as separate species: Diplodus cervinus, Diplodus hottentotus and Diplodus omanensis. Diplodus hottentotus exhibits a clear break in its distribution around the Benguela Current system, prompting speculation that Angolan and South African populations flanking this area may be isolated and warrant formal taxonomic distinction. This study reports the first integrated genetic [mitochondrial (mt)DNA and nuclear microsatellite] and morphological (morphometric, meristic and colouration) study to assess patterns of divergence between populations in the two regions. High levels of cytonuclear divergence between the populations support a prolonged period of genetic isolation, with the sharing of only one mtDNA haplotype (12 haplotypes were fully sorted between regions) attributed to retention of ancestral polymorphism. Fish from the two regions were significantly differentiated at a number of morphometric (69·5%) and meristic (46%) characters. In addition, Angolan and South African fish exhibited reciprocally diagnostic colouration patterns that were more similar to Mediterranean and Indian Ocean congeners, respectively. Based on the congruent genetic and phenotypic diversity we suggest that the use of hottentotus, whether for full species or subspecies status, should be restricted to South African D. cervinus to reflect their status as a distinct species-like unit, while the relationship between Angolan and Atlantic–Mediterranean D. cervinus will require further demo-genetic analysis. This study highlights the utility of integrated genetic and morphological approaches to assess taxonomic diversity within the biogeographically dynamic Benguela Current region.
- Full Text:
- Date Issued: 2018
Phylogeny of the Sepia officinalis species complex in the eastern Atlantic extends the known distribution of Sepia vermiculata across the Benguela upwelling region
- Healey, Amy J E, McKeown, Niall J, Potts, Warren M, de Beer, Chénelle L, Sauer, Warwick H H, Shaw, Paul W
- Authors: Healey, Amy J E , McKeown, Niall J , Potts, Warren M , de Beer, Chénelle L , Sauer, Warwick H H , Shaw, Paul W
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125631 , vital:35802 , https://doi.10.2989/1814232X.2017.1371076
- Description: Accurate species identification and biogeographic characterisation are fundamental for appropriate management of expanding cephalopod fisheries. This study addresses this topic within the common cuttlefish Sepia officinalis species complex (S. officinalis, S. hierredda and S. vermiculata), with an emphasis on occurrence in African waters. Tissue samples from the currently presumed distributions of S. vermiculata and S. hierredda (from South Africa and Ghana/Angola, respectively) were sequenced for the cytochrome c oxidase subunit I (COI) and the cytochrome b (cytb) genes of the mitochondrial genome and then compared to existing S. officinalis sequences. Three highly divergent and reciprocally monophyletic clades, corresponding to S. officinalis, S. hierredda and S. vermiculata, were resolved, representing the first molecular confirmation of the distinct species status of S. hierredda and S. vermiculata. The sequences also revealed that, contrary to expectations based on presently published information, all samples from southern Angola were S. vermiculata. These results indicate that the range of S. vermiculata extends beyond the currently described northern limit and that S. hierredda and S. vermiculata may be indiscriminately harvested in Angolan waters. Finer-scale patterns within S. vermiculata phylogeography also indicate that the Benguela Current System and/or other environmental factors serve to isolate northern and southern stocks.
- Full Text:
- Date Issued: 2017
- Authors: Healey, Amy J E , McKeown, Niall J , Potts, Warren M , de Beer, Chénelle L , Sauer, Warwick H H , Shaw, Paul W
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125631 , vital:35802 , https://doi.10.2989/1814232X.2017.1371076
- Description: Accurate species identification and biogeographic characterisation are fundamental for appropriate management of expanding cephalopod fisheries. This study addresses this topic within the common cuttlefish Sepia officinalis species complex (S. officinalis, S. hierredda and S. vermiculata), with an emphasis on occurrence in African waters. Tissue samples from the currently presumed distributions of S. vermiculata and S. hierredda (from South Africa and Ghana/Angola, respectively) were sequenced for the cytochrome c oxidase subunit I (COI) and the cytochrome b (cytb) genes of the mitochondrial genome and then compared to existing S. officinalis sequences. Three highly divergent and reciprocally monophyletic clades, corresponding to S. officinalis, S. hierredda and S. vermiculata, were resolved, representing the first molecular confirmation of the distinct species status of S. hierredda and S. vermiculata. The sequences also revealed that, contrary to expectations based on presently published information, all samples from southern Angola were S. vermiculata. These results indicate that the range of S. vermiculata extends beyond the currently described northern limit and that S. hierredda and S. vermiculata may be indiscriminately harvested in Angolan waters. Finer-scale patterns within S. vermiculata phylogeography also indicate that the Benguela Current System and/or other environmental factors serve to isolate northern and southern stocks.
- Full Text:
- Date Issued: 2017
Genetic analysis reveals harvested Lethrinus nebulosus in the Southwest Indian Ocean comprise two cryptic species
- Healey, Amy J E, Gouws, Gavin, Fennessy, Sean T, Kuguru, Baraka, Sauer, Warwick H H, Shaw, Paul W, McKeown, Niall J
- Authors: Healey, Amy J E , Gouws, Gavin , Fennessy, Sean T , Kuguru, Baraka , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124538 , vital:35626 , https://doi.10.1093/icesjms/fsx245
- Description: This study initially aimed to investigate the genetic population/stock structuring of Lethrinus nebulosus in the Southwest Indian Ocean (SWIO) to inform management practices in light of emerging evidence of overharvesting of this species throughout its distribution. Adult samples were genotyped for 14 nuclear microsatellites and by sequencing fragments of the mtDNA control region and COI gene. A salient feature of the data was the congruent cyto-nuclear partitioning of samples into two high divergent, reciprocally monophyletic groups. This indicates that despite no a priori evidence, hitherto described L. nebulosus in the SWIO comprises two cryptic species that co-occur among southern samples. This intermingling indicates that, at least in southern samples, both species are being indiscriminately harvested, which may severely compromise sustainability. Limited microsatellite differentiation was detected within both species, though there was some evidence of isolation in the Mauritian population. In contrast, mtDNA revealed a pattern consistent with chaotic genetic patchiness, likely promoted by stochastic recruitment, which may necessitate a spatial bet-hedging approach to management to satisfy fishery management and conservation goals.
- Full Text:
- Date Issued: 2018
- Authors: Healey, Amy J E , Gouws, Gavin , Fennessy, Sean T , Kuguru, Baraka , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124538 , vital:35626 , https://doi.10.1093/icesjms/fsx245
- Description: This study initially aimed to investigate the genetic population/stock structuring of Lethrinus nebulosus in the Southwest Indian Ocean (SWIO) to inform management practices in light of emerging evidence of overharvesting of this species throughout its distribution. Adult samples were genotyped for 14 nuclear microsatellites and by sequencing fragments of the mtDNA control region and COI gene. A salient feature of the data was the congruent cyto-nuclear partitioning of samples into two high divergent, reciprocally monophyletic groups. This indicates that despite no a priori evidence, hitherto described L. nebulosus in the SWIO comprises two cryptic species that co-occur among southern samples. This intermingling indicates that, at least in southern samples, both species are being indiscriminately harvested, which may severely compromise sustainability. Limited microsatellite differentiation was detected within both species, though there was some evidence of isolation in the Mauritian population. In contrast, mtDNA revealed a pattern consistent with chaotic genetic patchiness, likely promoted by stochastic recruitment, which may necessitate a spatial bet-hedging approach to management to satisfy fishery management and conservation goals.
- Full Text:
- Date Issued: 2018
Population connectivity of an overexploited coastal fish, Argyrosomus coronus (Sciaenidae), in an ocean-warming hotspot
- Henriques, R, Potts, Warren M, Santos, Carmen V D, Sauer, Warwick H H, Shaw, Paul W
- Authors: Henriques, R , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H , Shaw, Paul W
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125720 , vital:35811 , https://doi.10.2989/1814232X.2018.1434090
- Description: Anthropogenic activities are recognised as causing significant impacts to marine systems at multiple levels, ranging from habitat disturbance (Pauly et al. 2005) to overfishing (Sala and Knowlton 2006) and loss of genetic diversity (Pinsky and Palumbi 2014). Exploitation and harvesting in particular are known to strongly influence fish populations and their associated ecosystems (Pauly et al. 2005), and in combination with ongoing climate change can have compound effects on the viability and long-term survival of marine fishes (Last et al. 2011). Species can react to the impacts of climate change either by shifting their distributional range or by adapting to changing conditions through individual ecological plasticity and/or local population adaptation (Briggs 2011; Last et al. 2011). However, since ecological plasticity and local adaptation have strong genetic components, overharvesting has the potential to impact the long-term adaptive ability of marine fishes by decreasing the extant genetic diversity (Allendorf et al. 2014). Therefore, understanding the impact of exploitation on genetic diversity and population substructuring is critical for predicting the likely consequences of continued exploitation and climate change.
- Full Text:
- Date Issued: 2018
- Authors: Henriques, R , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H , Shaw, Paul W
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125720 , vital:35811 , https://doi.10.2989/1814232X.2018.1434090
- Description: Anthropogenic activities are recognised as causing significant impacts to marine systems at multiple levels, ranging from habitat disturbance (Pauly et al. 2005) to overfishing (Sala and Knowlton 2006) and loss of genetic diversity (Pinsky and Palumbi 2014). Exploitation and harvesting in particular are known to strongly influence fish populations and their associated ecosystems (Pauly et al. 2005), and in combination with ongoing climate change can have compound effects on the viability and long-term survival of marine fishes (Last et al. 2011). Species can react to the impacts of climate change either by shifting their distributional range or by adapting to changing conditions through individual ecological plasticity and/or local population adaptation (Briggs 2011; Last et al. 2011). However, since ecological plasticity and local adaptation have strong genetic components, overharvesting has the potential to impact the long-term adaptive ability of marine fishes by decreasing the extant genetic diversity (Allendorf et al. 2014). Therefore, understanding the impact of exploitation on genetic diversity and population substructuring is critical for predicting the likely consequences of continued exploitation and climate change.
- Full Text:
- Date Issued: 2018
Incipient genetic isolation of a temperate migratory coastal sciaenid fish (Argyrosomus inodorus) within the Benguela Cold Current system
- Henriques, Romina, Potts, Warren M, Sauer, Warwick H H, Shaw, Paul W
- Authors: Henriques, Romina , Potts, Warren M , Sauer, Warwick H H , Shaw, Paul W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124710 , vital:35652 , https://doi.10.1080/17451000.2014.952309
- Description: The Benguela Cold Current system, located in the south-eastern Atlantic, features cold sea surface temperatures, bounded to the north and south by tropical currents (the Angola and Agulhas Currents, respectively) and a perennial upwelling cell off central Namibia that divides the region into two sub-systems with different characteristics (Shannon 1985; Hutchings et al. 2009). The colder sea surface temperatures of the Benguela Current have been considered an important biogeographic barrier, isolating tropical and warm-temperate fauna of the Atlantic and Indo-Pacific Oceans (Avise 2000; Floeter et al. 2008). However, recent studies revealed that other oceanographic features, such as the perennial upwelling cell, may also play an important role in shaping the population structure of warm temperate fish populations within the Benguela system, as complete disruption of gene flow was documented both in Lichia amia (Linnaeus, 1758) and Atractoscion aequidens (Cuvier, 1830) (Henriques et al. 2012, 2014). Little is known, however, regarding the influence of the Benguela system on genetic population connectivity of cold-water-tolerant species.
- Full Text:
- Date Issued: 2015
- Authors: Henriques, Romina , Potts, Warren M , Sauer, Warwick H H , Shaw, Paul W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124710 , vital:35652 , https://doi.10.1080/17451000.2014.952309
- Description: The Benguela Cold Current system, located in the south-eastern Atlantic, features cold sea surface temperatures, bounded to the north and south by tropical currents (the Angola and Agulhas Currents, respectively) and a perennial upwelling cell off central Namibia that divides the region into two sub-systems with different characteristics (Shannon 1985; Hutchings et al. 2009). The colder sea surface temperatures of the Benguela Current have been considered an important biogeographic barrier, isolating tropical and warm-temperate fauna of the Atlantic and Indo-Pacific Oceans (Avise 2000; Floeter et al. 2008). However, recent studies revealed that other oceanographic features, such as the perennial upwelling cell, may also play an important role in shaping the population structure of warm temperate fish populations within the Benguela system, as complete disruption of gene flow was documented both in Lichia amia (Linnaeus, 1758) and Atractoscion aequidens (Cuvier, 1830) (Henriques et al. 2012, 2014). Little is known, however, regarding the influence of the Benguela system on genetic population connectivity of cold-water-tolerant species.
- Full Text:
- Date Issued: 2015
Molecular genetic, life-history and morphological variation in a coastal warm-temperate sciaenid fish: evidence for an upwelling-driven speciation event
- Henriques, Romina, Potts, Warren M, Sauer, Warwick H H, Santos, Carmen V D, Kruger, Jerraleigh, Thomas, Jessica A, Shaw, Paul W
- Authors: Henriques, Romina , Potts, Warren M , Sauer, Warwick H H , Santos, Carmen V D , Kruger, Jerraleigh , Thomas, Jessica A , Shaw, Paul W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125252 , vital:35750 , http://dx.doi.10.1111/jbi.12829
- Description: The marine environment is punctuated by biogeographical barriers that limit dispersal and gene flow in otherwise widespread species (Teske et al., 2011a,b; Briggs & Bowen, 2012; Luiz et al., 2012). These barriers may be physical obstacles such as landmasses (e.g. Isthmus of Panama) or less intuitive features such as deep water (Lessios et al., 2003), freshwater outflows (Floeter et al., 2008) or oceanographic features (Shaw et al., 2004; Galarza et al., 2009; von der Heyden et al., 2011). Upwelling cells and sea surface temperature (SSTs) gradients in particular are known to disrupt gene flow, leading to divergence of allopatric populations and species (Waters & Roy, 2004; Teske et al., 2011a; Henriques et al., 2012, 2014, 2015). However, as oceanographic features are seldom permanent and frequently subject to considerable environmental variability, many barriers often permit some level of permeability to dispersal (Floeter et al., 2008). Other processes may influence the persistence of differentiated allopatric taxa across such physical barriers (Bradbury et al., 2008), with ecological divergence (and diversifying selection) being reported as a major evolutionary process influencing the biogeographical distributions of marine species (Pelc et al., 2009; Teske et al., 2011a; Gaither et al., 2015).
- Full Text:
- Date Issued: 2016
- Authors: Henriques, Romina , Potts, Warren M , Sauer, Warwick H H , Santos, Carmen V D , Kruger, Jerraleigh , Thomas, Jessica A , Shaw, Paul W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125252 , vital:35750 , http://dx.doi.10.1111/jbi.12829
- Description: The marine environment is punctuated by biogeographical barriers that limit dispersal and gene flow in otherwise widespread species (Teske et al., 2011a,b; Briggs & Bowen, 2012; Luiz et al., 2012). These barriers may be physical obstacles such as landmasses (e.g. Isthmus of Panama) or less intuitive features such as deep water (Lessios et al., 2003), freshwater outflows (Floeter et al., 2008) or oceanographic features (Shaw et al., 2004; Galarza et al., 2009; von der Heyden et al., 2011). Upwelling cells and sea surface temperature (SSTs) gradients in particular are known to disrupt gene flow, leading to divergence of allopatric populations and species (Waters & Roy, 2004; Teske et al., 2011a; Henriques et al., 2012, 2014, 2015). However, as oceanographic features are seldom permanent and frequently subject to considerable environmental variability, many barriers often permit some level of permeability to dispersal (Floeter et al., 2008). Other processes may influence the persistence of differentiated allopatric taxa across such physical barriers (Bradbury et al., 2008), with ecological divergence (and diversifying selection) being reported as a major evolutionary process influencing the biogeographical distributions of marine species (Pelc et al., 2009; Teske et al., 2011a; Gaither et al., 2015).
- Full Text:
- Date Issued: 2016
Planning adaptation to climate change in fast-warming marine regions with seafood-dependent coastal communities
- Hobday, Alistair J, Cochrane, Kevern, Howard, James, Aswani, Shankar, Byfield, Val, Duggan, Greg, Duna, Elethu, Dutra, Leo X, Frusher, Stewart D, Fulton, Elizabeth A, Gammage, Louise, Gasalla, Maria A, Griffiths, Chevon, Guissamulo, Almeida, Haward, Marcus, Jarre, Astrid, Jennings, Sarah M, Jordan, Tia, Joyner, Jessica, Ramani, Narayana K, Shanmugasundaram, Swathi L P, Malherbe, Willem, Ortega-Cisneros, Kelly, Paytan, Adina, Pecl, Gretta T, Plagányi, Éva E, Popova, Ekaterina E, Razafindrainibe, Haja, Roberts, Michael, Rohit, Prathiba, Sainulabdeen, Shyam S, Sauer, Warwick H H, Valappil, Sathianandan T, Zacharia, Paryiappanal U, Van Putten, E Ingrid
- Authors: Hobday, Alistair J , Cochrane, Kevern , Howard, James , Aswani, Shankar , Byfield, Val , Duggan, Greg , Duna, Elethu , Dutra, Leo X , Frusher, Stewart D , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah M , Jordan, Tia , Joyner, Jessica , Ramani, Narayana K , Shanmugasundaram, Swathi L P , Malherbe, Willem , Ortega-Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , Van Putten, E Ingrid
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125675 , vital:35806 , https://doi.10.1007/s11160-016-9419-0
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and codeveloping adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
- Authors: Hobday, Alistair J , Cochrane, Kevern , Howard, James , Aswani, Shankar , Byfield, Val , Duggan, Greg , Duna, Elethu , Dutra, Leo X , Frusher, Stewart D , Fulton, Elizabeth A , Gammage, Louise , Gasalla, Maria A , Griffiths, Chevon , Guissamulo, Almeida , Haward, Marcus , Jarre, Astrid , Jennings, Sarah M , Jordan, Tia , Joyner, Jessica , Ramani, Narayana K , Shanmugasundaram, Swathi L P , Malherbe, Willem , Ortega-Cisneros, Kelly , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva E , Popova, Ekaterina E , Razafindrainibe, Haja , Roberts, Michael , Rohit, Prathiba , Sainulabdeen, Shyam S , Sauer, Warwick H H , Valappil, Sathianandan T , Zacharia, Paryiappanal U , Van Putten, E Ingrid
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125675 , vital:35806 , https://doi.10.1007/s11160-016-9419-0
- Description: Many coastal communities rely on living marine resources for livelihoods and food security. These resources are commonly under stress from overfishing, pollution, coastal development and habitat degradation. Climate change is an additional stressor beginning to impact coastal systems and communities, but may also lead to opportunities for some species and the people they sustain. We describe the research approach for a multi-country project, focused on the southern hemisphere, designed to contribute to improving fishing community adaptation efforts by characterizing, assessing and predicting the future of coastal-marine food resources, and codeveloping adaptation options through the provision and sharing of knowledge across fast-warming marine regions (i.e. marine ‘hotspots’). These hotspots represent natural laboratories for observing change and concomitant human adaptive responses, and for developing adaptation options and management strategies. Focusing on adaptation options and strategies for enhancing coastal resilience at the local level will contribute to capacity building and local empowerment in order to minimise negative outcomes and take advantage of opportunities arising from climate change. However, developing comparative approaches across regions that differ in political institutions, socio-economic community demographics, resource dependency and research capacity is challenging. Here, we describe physical, biological, social and governance tools to allow hotspot comparisons, and several methods to evaluate and enhance interactions within a multi-nation research team. Strong partnerships within and between the focal regions are critical to scientific and political support for development of effective approaches to reduce future vulnerability. Comparing these hotspot regions will enhance local adaptation responses and generate outcomes applicable to other regions.
- Full Text:
- Date Issued: 2016
Socio-Economic and Environmental Challenges of Small-Scale Fisheries: Prognosis for Sustainable Fisheries Management in Lake Kariba, Zambia
- Imbwae, Imikendu, Aswani, Shankar, Sauer, Warwick H H
- Authors: Imbwae, Imikendu , Aswani, Shankar , Sauer, Warwick H H
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391422 , vital:68650 , xlink:href="https://doi.org/10.3390/su15043179"
- Description: The Lake Kariba fishery is of regional importance; it accounts for 35% of the total Zambian fish production. However, emerging evidence in the recent decades suggests that the fishery is facing socio-economic and environmental challenges. Using Ostrom’s framework for analysing socio-ecological systems, we examined the social, economic, and environmental problems faced by the fishing communities in Lake Kariba. The framework links various social, economic, and ecological factors to devise a sustainable fisheries management plan. A combination of survey questionnaires, focus group discussions, observations, and key informant interviews were used to assess this sustainability challenge. The data collected were subjected to bivariate and descriptive analysis. The results obtained did not show a significant decline in fish production over the past 13 years (R2 Linear = 0.119, p = 0.248). However, the experts and the fishers have reported declining trends in valuable fish species such as Oreochromis mortimeri, compounded by the increased fishing efforts (X2 = 180.14, p value = ˂ 0.00001). The key threats identified include: overfishing, weak institutions, and the introduction of invasive fish species such as Oreochromis niloticus. This situation has raised fears of fish depletion among the stakeholders. Based on these results, we recommend stronger institutional collaboration among the stakeholders in the riparian states and education that illustrates the global value of fisheries for food security and biodiversity conservation in pursuing the United Nations Sustainable Development Goals.
- Full Text:
- Date Issued: 2023
- Authors: Imbwae, Imikendu , Aswani, Shankar , Sauer, Warwick H H
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391422 , vital:68650 , xlink:href="https://doi.org/10.3390/su15043179"
- Description: The Lake Kariba fishery is of regional importance; it accounts for 35% of the total Zambian fish production. However, emerging evidence in the recent decades suggests that the fishery is facing socio-economic and environmental challenges. Using Ostrom’s framework for analysing socio-ecological systems, we examined the social, economic, and environmental problems faced by the fishing communities in Lake Kariba. The framework links various social, economic, and ecological factors to devise a sustainable fisheries management plan. A combination of survey questionnaires, focus group discussions, observations, and key informant interviews were used to assess this sustainability challenge. The data collected were subjected to bivariate and descriptive analysis. The results obtained did not show a significant decline in fish production over the past 13 years (R2 Linear = 0.119, p = 0.248). However, the experts and the fishers have reported declining trends in valuable fish species such as Oreochromis mortimeri, compounded by the increased fishing efforts (X2 = 180.14, p value = ˂ 0.00001). The key threats identified include: overfishing, weak institutions, and the introduction of invasive fish species such as Oreochromis niloticus. This situation has raised fears of fish depletion among the stakeholders. Based on these results, we recommend stronger institutional collaboration among the stakeholders in the riparian states and education that illustrates the global value of fisheries for food security and biodiversity conservation in pursuing the United Nations Sustainable Development Goals.
- Full Text:
- Date Issued: 2023
Transboundary Fisheries Management in Kavango–Zambezi Transfrontier Conservation Area (KAZA-TFCA): Prospects and Dilemmas
- Imbwae, Imikendu, Aswani, Shankar, Sauer, Warwick H H, Hay, Clinton
- Authors: Imbwae, Imikendu , Aswani, Shankar , Sauer, Warwick H H , Hay, Clinton
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391433 , vital:68651 , xlink:href="https://doi.org/10.3390/su15054406"
- Description: Inland fisheries in the Kavango–Zambezi Transfrontier Conservation Area (KAZA-TFCA) offer food security to the riverine communities across the region. They also contribute towards the attainment of the United Nations’ Sustainable Development Goals 1 and 15, which aim to alleviate poverty and maintain biodiversity conservation. Despite this significant role, the fisheries have suffered severe declines in the previous decades due to multiple factors, such as overfishing and poor legislation. Furthermore, climate change is exerting pressure by altering the ecology and productivity of the river systems. The unprecedented challenges of the COVID-19 pandemic have further constrained management efforts. Attempts to address these challenges have pointed towards transboundary fisheries management as a silver bullet in moving towards sustainable fisheries management. However, the implementation of this strategy in the region has encountered numerous roadblocks, thereby subjecting the river ecosystem to a wider environmental threat, with dire consequences on livelihoods. This paper reviews existing management and governance structures together with key informant interviews to elicit primary and secondary data essential for management at the regional level. The study identifies conflicting regulations, and inadequate policies and institutions across the region as major bottlenecks affecting the successful implementation of transboundary fisheries management. Finally, the paper offers some suggestions for the improvement of fisheries management in the region.
- Full Text:
- Date Issued: 2023
- Authors: Imbwae, Imikendu , Aswani, Shankar , Sauer, Warwick H H , Hay, Clinton
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391433 , vital:68651 , xlink:href="https://doi.org/10.3390/su15054406"
- Description: Inland fisheries in the Kavango–Zambezi Transfrontier Conservation Area (KAZA-TFCA) offer food security to the riverine communities across the region. They also contribute towards the attainment of the United Nations’ Sustainable Development Goals 1 and 15, which aim to alleviate poverty and maintain biodiversity conservation. Despite this significant role, the fisheries have suffered severe declines in the previous decades due to multiple factors, such as overfishing and poor legislation. Furthermore, climate change is exerting pressure by altering the ecology and productivity of the river systems. The unprecedented challenges of the COVID-19 pandemic have further constrained management efforts. Attempts to address these challenges have pointed towards transboundary fisheries management as a silver bullet in moving towards sustainable fisheries management. However, the implementation of this strategy in the region has encountered numerous roadblocks, thereby subjecting the river ecosystem to a wider environmental threat, with dire consequences on livelihoods. This paper reviews existing management and governance structures together with key informant interviews to elicit primary and secondary data essential for management at the regional level. The study identifies conflicting regulations, and inadequate policies and institutions across the region as major bottlenecks affecting the successful implementation of transboundary fisheries management. Finally, the paper offers some suggestions for the improvement of fisheries management in the region.
- Full Text:
- Date Issued: 2023
Social capital reduces vulnerability in rural coastal communities of Solomon Islands:
- Malherbe, Willem, Sauer, Warwick H H, Aswani, Shankar
- Authors: Malherbe, Willem , Sauer, Warwick H H , Aswani, Shankar
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150230 , vital:38951 , https://doi.org/10.1016/j.ocecoaman.2020.105186
- Description: Rural island communities are generally regarded as the most vulnerable groups affected by climate change. This perception arises due to them often being in less developed areas with high levels of exposure to stressors, while reportedly lacking the means to cope with these stressors. Studies which use developed-country yardsticks, such as those used in past IPCC-based assessments, when measuring vulnerability in less developed states will however inevitably over-pronounce its effects in such areas. The sustainable livelihoods approach provides an alternate means of determining vulnerability using capital assets such as social capital. The presence of these assets enables communities to pursue diverse livelihood strategies which ultimately serve to reduce their vulnerability. This study seeks to measure attributes of social capital in five marine dependent communities of Solomon Islands.
- Full Text:
- Date Issued: 2020
- Authors: Malherbe, Willem , Sauer, Warwick H H , Aswani, Shankar
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150230 , vital:38951 , https://doi.org/10.1016/j.ocecoaman.2020.105186
- Description: Rural island communities are generally regarded as the most vulnerable groups affected by climate change. This perception arises due to them often being in less developed areas with high levels of exposure to stressors, while reportedly lacking the means to cope with these stressors. Studies which use developed-country yardsticks, such as those used in past IPCC-based assessments, when measuring vulnerability in less developed states will however inevitably over-pronounce its effects in such areas. The sustainable livelihoods approach provides an alternate means of determining vulnerability using capital assets such as social capital. The presence of these assets enables communities to pursue diverse livelihood strategies which ultimately serve to reduce their vulnerability. This study seeks to measure attributes of social capital in five marine dependent communities of Solomon Islands.
- Full Text:
- Date Issued: 2020