Assessment and management of Cape horse mackerel<i>Trachurus capensis</i>off Namibia based on a fleet-disaggregated age-structured production model

Kirchner, Carola; Bauleth-D’Almeida, G; Wilhelm,

doi:10.2989/1814232x.2010.538144

Cited by 11 publications

(4 citation statements)

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“…T. trachurus is widely described throughout the NE Atlantic as far north as Norway and Iceland (Knijn et al ., ) as well as the Mediterranean basins (Fischer, ). Both species are of great commercial importance and are the most valuable horse mackerel species in these regions (Murta, ) as exemplified by the Namibian T. capensis fishery, which reports the highest biomass and catch of all fish species landed within the region and is the second highest economic contributor to Namibian fisheries (Kirchner et al ., ).…”

Section: Introductionmentioning

confidence: 99%

Genetic analysis provides insights into species distribution and population structure in East Atlantic horse mackerel (Trachurus trachurus and T. capensis)

Healey

Farthing

Nunoo

et al. 2020

Journal of Fish Biology

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Two sister species of horse mackerel (Trachurus trachurus and T. capensis) are described that are intensively harvested in East Atlantic waters. To address long‐standing uncertainties as to their respective geographical ranges, overlap and intraspecific population structure this study combined genetic (mitochondrial DNA and microsatellite) analysis and targeted sampling of the hitherto understudied West African coast. mtDNA revealed two reciprocally monophyletic clades corresponding to each species with interspecies nuclear differentiation supported by FST values. The T. trachurus clade was found across the north‐east Atlantic down to Ghana but was absent from Angolan and South African samples. The T. capensis clade was found only in South Africa, Angola and a single Ghanaian individual. This pattern suggests that both species may overlap in the waters around Ghana. The potential for cryptic hybridization and/or indiscriminate harvesting of both species in the region is discussed. For T. capensis mtDNA supports high gene flow across the Benguela upwelling system, which fits with the species' ecology. The data add to evidence of a lack of significant genetic structure throughout the range of T. trachurus though the assumption of demographic panmixia is cautioned against. For both species, resolution of stock recruitment heterogeneity relevant to fishery management, as well as potential hybridization, will require more powerful genomic analyses.

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Section: Introductionmentioning

confidence: 99%

Genetic analysis provides insights into species distribution and population structure in East Atlantic horse mackerel (Trachurus trachurus and T. capensis)

Healey

Farthing

Nunoo

et al. 2020

Journal of Fish Biology

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“…Industrial fishing in Namibia began in the 1950s, with fishing activities dominated by European fleets, especially for inshore pelagic fishing for the South African sardine (Sardinops sagax) and Cape anchovy (Engraulis encrasicolus) (Bianchi et al, 1999;Boyer et al, 2001;Kirchner et al, 2010). In 1969, the International Commission for the Southeast Atlantic Fisheries (ICSEAF) was established to control and regulate the harvesting of marine resources off the coasts of Namibia and South Africa, which was at the time open access (Bianchi et al, 1999;van der Westhuizen, 2001;Paterson et al, 2013).…”

Section: The Namibian Hake Trawl and Longline Fisherymentioning

confidence: 99%

Ocean and Marine Stewardship in Africa: The Marine Stewardship Council Certification in Namibia and The Gambia

Nyiawung

Erasmus²

2022

Front. Mar. Sci.

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Ocean and marine stewardship activities across different geographical areas contribute to global sustainability efforts, management, and conservation of ocean resources. The Marine Stewardship Council (MSC), through its sustainability standards and market-based mechanisms, rewards best practices for wild-caught seafood. To date, very few fisheries in Africa have participated in the MSC’s full assessment and obtained its certification. This paper explores the MSC certification scheme in the African continent by examining two case studies: the Namibian hake (Merluccius capensis and M. paradoxus) trawl and longline fishery and The Gambian sole bottom set gillnet fishery (Cynoglossus senegalenis and Synaptura cadenati). Drawing on document analysis, institutional ethnography, and extensive collaborative research with actors in these fisheries, we utilize three stewardship dimensions, i.e., Care-Knowledge-Agency, to qualitatively analyze how the MSC program provides an opportunity of actors to design ocean stewardship tools and promote fisheries sustainability in Africa. The Namibian fishery demonstrates a large-scale fishery with the adequate agency, technical knowledge, and interest in self-design improvements and stewardship, compared to The Gambian fishery, a small-scale fishery motivated to achieve certification but depends largely on external support to coordinate improvements and stewardship activities. The key motivation for Namibia and The Gambia actors to participate in the MSC’s assessment is the interest in increasing their international market access while ensuring ecosystem-based management and sustainability of the fisheries. Successful engagement with MSC requires establishing good governance structures, involvement of local actors, technical knowledge, and sufficient financial resources. The paper demonstrates the need for practitioners, government/market-actors, and academia to encourage sustainable seafood management in Africa by promoting various national and regional sustainability campaigns, environmental awareness programs and ocean stewardship initiatives.

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“…A large percentage of our survey participants (49.3%) earned a monthly salary of more than N$10 000, which might have influenced their choice of hake. Cape horse mackerel, the second most preferred marine fish species, is relatively inexpensive, readily available and is the highest species in Namibia in terms of landed volume (Kirchner et al, 2010;Kainge et al, 2020). The fish preferences were most likely influenced by affordability, the accessibility of particular fish species and the fish texture (Verbeke et al, 2007).…”

Section: Fish Preferences and Consumption Frequencymentioning

confidence: 99%

Public perceptions and factors affecting domestic marine fish consumption in Namibia, southwestern Africa

Erasmus¹,

Kadhila²,

Thyberg

et al. 2021

Regional Studies in Marine Science

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Using a web-based survey conducted among 2,481 Namibian, aged 18 years or older, the factors and motivations driving individuals' decisions on marine fish consumption, spatial fish consumption, and possible strategies to promote domestic marine fish consumption were explored. Most participants (97.9%) were aware of the importance of fish in the human diet, with many preferring hake (Merluccius capensis and M. paradoxus) (31.5%) and Cape horse mackerel (Trachurus capensis) (21.7%). Most respondents (64.1%) were poor fish consumers, consuming fish once a week or once a month. Participants claimed that they mostly purchased marine fish from retail fish shops (50.7%), wholesale fish companies (18.8%), and the Namibian Fish Consumption Promotion Trust (17.4%). Factors affecting marine fish affordability in Namibia were explained with a Logit Model, with age, education, gender, monthly income, and region of residence as the explanatory variables. Responses regarding fish affordability were principally driven by age, education, and monthly income (p < 0.05). The Khomas region purchased the most marine fish (60,764.8 weighted kg) in 2019. There was a consensus across all participants that regular fish consumption is beneficial to human health; however, participants listed affordability and accessibility of marine fish as critical constraints. Results indicate that Namibian marine fish consumption is poor and needs to be promoted. Results suggest ways to stimulate marine fish consumption locally and elsewhere to meet the UN Sustainable Development Goal 2 to end hunger and alleviate malnutrition.

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Assessment and management of Cape horse mackerelTrachurus capensisoff Namibia based on a fleet-disaggregated age-structured production model

Cited by 11 publications

References 11 publications

Genetic analysis provides insights into species distribution and population structure in East Atlantic horse mackerel (Trachurus trachurus and T. capensis)

Genetic analysis provides insights into species distribution and population structure in East Atlantic horse mackerel (Trachurus trachurus and T. capensis)

Ocean and Marine Stewardship in Africa: The Marine Stewardship Council Certification in Namibia and The Gambia

Public perceptions and factors affecting domestic marine fish consumption in Namibia, southwestern Africa

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