African Fisheries Research Articles

Stakeholders’ perceptions of the conservation and management of elasmobranchs in South Africa

Global shark populations are in serious decline, especially due to overexploitation through fisheries, whose impact is often increased by a lack of proper management regulations and enforcement. South Africa’s population of chondrichthyan fauna is one of the most diverse in the world, with high rates of endemic and imperiled elasmobranch species. South Africa has been lauded as a global leader in shark conservation through progressive management legislation, such as the 2013 National Plan of Action for the Conservation and Management of Sharks (NPOA-Sharks I). However, South Africa’s shark populations have continued to decline. This study aimed to survey stakeholders’ (students, academics, government representatives, conservationists, recreational anglers, commercial fishers, and tourism-related stakeholders) perspectives on the efficacy of NPOA-Sharks I in managing and enforcing fisheries regulations and to advise the 2022 NPOA-Sharks II approach concerning the conservation of South African elasmobranchs. A total of 89 stakeholders participated in an online questionnaire survey launched in 2021. Most stakeholders viewed the NPOA-Sharks I as somewhat appropriate, South Africa’s current exploitation of shark stocks as unsustainable and management and enforcement of regulations as inadequate. Commercial fishing and lack of enforcement were ranked as the two most pressing issues facing South Africa’s sharks. Similarly, the expert review panel found limited progress (<50%) made in the implementation of the NPOA-Sharks I concerning regulatory tools and sustainable management and called for improved monitoring, surveillance and enforcement of compliance regulations across fisheries as one of the top recommendations for immediate implementation in NPOA-Sharks II. However, the majority of action items under the “Sustainable Management” issue cluster in NPOA-Sharks II suggest a reassessment or reestablishment of existing regulations or the development of new regulatory tools with few specifics provided, reflective of a disconnect between what the lead government agency responsible for the management of South Africa’s sharks, the Department of Forestry, Fisheries and the Environment (DFFE), perceives to be effective and what stakeholders experience concerning shark conservation in South Africa. What was perceived by the national management agency as effective concerning shark conservation in South Africa was not necessarily experienced as such by the stakeholders. There is a need for increased collaboration among stakeholders and significant improvements in the practical management of South African fisheries for shark conservation, which is now also suggested in the NPOA-Sharks II.

Pathway to sustainability: the Marine Stewardship Council certification standard as an improvement framework for African fisheries

Fishery certification is increasingly employed as a multi-stakeholder, market-based mechanism to promote sustainability of fisheries. Preparing for, and achieving certification continues to deliver tangible improvements and benefits to fisheries, but the number of certified fisheries from Africa remains low. Some of the factors that constrain certification of fisheries in the region include limited data to assess and manage fisheries, the open access nature of many fisheries, overfishing, poor management, inadequate enforcement, and low demand for certified seafood. To overcome these constraints, several fisheries employ a “pathway to sustainability” approach that involves using the MSC fisheries standard as a framework for gap analysis, action planning, progress tracking and improvement. Certification may not always be the goal. This allows fisheries to make ongoing improvements over prior performance, regardless of whether they immediately achieve certification or not. Progress towards the desired goal, sustainable management, can be tracked over time. Some of the reported benefits include clarity of objectives, consolidation and focus of stakeholder efforts, participatory engagement, ability to attract resources for improvements, benchmarking of performance and, ultimately, improved environmental performance through better fisheries management. This paper discusses the uptake of this approach in Africa, by presenting case study fisheries from the continent. It outlines mechanisms through which these fisheries embarked on a pathway to sustainability using the MSC fisheries standard, and the outcomes from these initiatives. It highlights the successes and challenges associated with implementation. The paper concludes that the MSC standard and the improvements that it incentivizes can make a positive contribution to regional efforts to improve environmental sustainability, fisheries governance and consequently the socio-economic viability and resilience of fisheries in Africa.

Genetic identification and diversity of stocks of the African bonytongue, Heterotis niloticus (Osteoglossiformes: Arapaiminae), in Nigeria, West Africa

Inland fisheries are an important source of protein and income for people in Africa. Their sustainable management can greatly benefit from identification of regional genetic stocks and characterization of their genetic diversity, but such information is lacking for most African freshwater fisheries. The African bonytongue, Heterotis niloticus, is an important component of inland fisheries in West Africa. Nigeria has the largest fishery for African bonytongues, representing ~ 86% of the global total. Recent declines in yields at some Nigerian locations, however, suggest current levels of exploitation may be unsustainable. Habitat degradation also may be impacting some stocks. Despite its commercial and nutritional importance, the African bonytongue has been the subject of scant genetic research to support management. We examined patterns of genetic diversity in natural populations of H. niloticus at four locations in Nigeria, including Kainji Lake, a reservoir on the Niger River in north-central Nigeria, and three southern localities (Ethiope River, Igbokoda River, and Epe Lagoon), as well fish from the Ouémé River delta near Porto Novo, Benin. Eighty-five specimens were genotyped for nine microsatellite-loci. Genetic diversity estimates were highest at Kainji Lake, and substantially lower at southern localities. High levels of genetic differentiation were detected between samples from Kainji Lake and those from southern localities. Low, yet significant FST values were observed among samples from southern Nigerian localities that were more differentiated from the sample from nearby coastal Benin. We thus recommend that African bonytongues from the five locations be considered distinct genetic stocks and managed accordingly.

From the Atlantic Coast to Lake Tanganyika: Gill-Infecting Flatworms of Freshwater Pellonuline Clupeid Fishes in West and Central Africa, with Description of Eleven New Species and Key to Kapentagyrus (Monogenea, Dactylogyridae)

Simple SummarySardines and other herring-like fishes (Clupeidae) are well-known, mostly from open seas, and globally commercially important. Their freshwater representatives receive less attention. Tropical Africa harbours over 20 species of the latter, classified under Pellonulini. These small river and lake fishes sustain locally important fisheries and are sometimes exported (inter)nationally. There is little research on them, let alone their parasites. An abundant parasite group of African freshwater clupeids is monogenean flatworms infecting their gills. Since the discoveries of the first (1969) and second species (1973) systematics of these monogeneans was ignored until 2018, when they were classified under the new genus Kapentagyrus with three species from three pellonuline species. Here, we inspected the gills of 12 West and Central African pellonulines, 10 from which there were no known parasites. We discovered and described 11 new species of Kapentagyrus. They look highly similar; distinguishing them requires measuring parts of their attachment organ. This study more than quadruples the known species richness of Kapentagyrus, and almost quadruples the number of pellonuline species of which monogeneans are known. Monogeneans are suitable tags for the lifestyle and history of their hosts. Therefore, parasitological knowledge on these poorly studied fishes will contribute to understanding data-poor African fisheries.Unlike their marine counterparts, tropical freshwater clupeids receive little scientific attention. However, they sustain important fisheries that may be of (inter)national commercial interest. Africa harbours over 20 freshwater clupeid species within Pellonulini. Recent research suggests their most abundant parasites are gill-infecting monogenean flatworms within Kapentagyrus. After inspecting specimens of 12 freshwater clupeids from West and Central Africa, mainly sourced in biodiversity collections, we propose 11 new species of Kapentagyrus, which we describe using their haptoral and genital morphology. Because of their high morphological similarity, species delineation relies mostly on the morphometrics of anchors and hooks. Specifically, earlier, molecular taxonomic work indicated that the proportion between the length of the anchor roots, and between the hook and anchor length, is diagnostic. On average, about one species of Kapentagyrus exists per pellonuline species, although Pellonula leonensis harbours four species and Microthrissa congica two, while Microthrissa moeruensis and Potamothrissa acutirostris share a gill monogenean species. This study more than quadruples the number of known species of Kapentagyrus, also almost quadrupling the number of pellonuline species of which monogeneans are known. Since members of Kapentagyrus are informative about their hosts’ ecology, evolutionary history, and introduction routes, this enables a parasitological perspective on several data-poor African fisheries.

Expanding ocean observation and climate services to build resilience in West African fisheries

The Canary Current is a potential hotspot for climate change impacts on the oceans where 63 million people depend upon marine resources for national economies and livelihoods. Their unique vulnerability highlights the key roles of climate services and capacity building in order to develop effective adaptation measures. The Canary Current is a potential hotspot for climate change impacts on the oceans where 63 million people depend upon marine resources for national economies and livelihoods. Their unique vulnerability highlights the key roles of climate services and capacity building in order to develop effective adaptation measures.

Assessing South Africa’s Potential to Address Climate Change Impacts and Adaptation in the Fisheries Sector

The marine fisheries sector is one of the most important income sectors in South Africa and plays an important role in food security for small-scale and subsistence fishers. Climate-driven impacts have resulted in distribution shifts and declines in abundance of important fisheries targets, with negative consequences to the users dependent on these resources. The sustainability of the sector depends on its readiness to adapt to climate change. The inclusion of climate change impacts and adaptation in fisheries management documents in South Africa is essential to ensure adequate climate adaptation responses are implemented at the short- and long-term. This study aims to 1) determine if the relevant fisheries national management documents address climate change and adaptation, 2) determine if the relevant national climate change documents address climate change and adaptation in the fisheries sector and 3) evaluate the extent to which fisheries management documents address climate change and adaptation. A content analysis of fisheries management and climate change documents was carried out to determine if they incorporated information on climate change impacts and adaptation and marine fisheries respectively. Fisheries management documents were then screened against nine pre-determined criteria (or themes) based on climate change adaptation to determine the level of inclusion of best practice for climate change adaptation. Results indicate that climate change impacts and adaptation are rarely incorporated in the main fisheries management documents, except for the Climate Change Adaptation and Mitigation Plan for the agriculture, fisheries and forestry sectors. However, this document is still waiting to be adopted. The only direct reference identified in all the fisheries documents that supports climate change adaptation was ‘conservation and sustainable management of biodiversity’. With regards to indirect references to climate change adaptation, ‘equity,’ ‘participatory management,’ and ‘capacity building’ were most frequently incorporated in fisheries management documents. There is a need to explicitly incorporate information on climate change impacts and adaptation in South African fisheries management documents and increase the human and financial capacity at national institutions to ensure that the fisheries sector can adequately adapt to climate change.

Modeling the impacts of floating seaweeds on fisheries sustainability in Ghana

The ongoing Sargassum invasions in the Atlantic Ocean present both opportunities and threats to open-access fisheries. Due to the lack of entry and harvest regulations, West African fisheries are on the verge of collapse. Floating seaweeds can help rebuild fish stocks by enhancing fish growth and naturally reducing harvest by impeding fishing boats and gears. However, in high volumes, floating seaweeds can harm fish stocks and reduce landings. To improve fisheries sustainability, a policy prescribing the periodic removal of seaweeds should be anchored on a thorough understanding of the trade-offs between different levels of seaweed removal. We developed an agent-based model (ABM) to identify the optimal seaweed removal policy capable of maximizing fish stocks and landings in the long-term in Ghana’s marine fishery. Our policy experiments suggest that, by leaving behind 25% of relative seaweed biomass (i.e. seaweed biomass expressed as a percentage of carrying capacity) in each fishing zone every week after seaweed removal, fishery managers can take advantage of floating seaweeds to naturally regulate fishing mortality and maximize fish stocks and landings in the long-term. Our ABM can assist scientists interested in studying the long-term interactions between floating seaweeds and fisheries sustainability, and help fishery managers understand the potential of floating seaweeds to naturally regulate fishing pressure in developing countries where the lack of adequate employment opportunities outside fishing makes it difficult to address overfishing. Our ABM can also assist countries struggling with seaweed invasions to assess the impacts of different seaweed removal strategies on fisheries sustainability.

Accounting for linefish dependency in management of the South African small pelagic fishery

To further implement an ecosystem approach to management of the small pelagic fishery in South Africa, we attempted to develop functional relationships between spatialised time-series of the biomass of three small pelagic fish species and the catch per unit effort (CPUE) of four linefish species (i.e. species caught on hook and line, excluding longlines) that could be used to account for the forage needs of dependent predators. Granger causality tests indicated significant effects of anchovy Engraulis encrasicolus biomass on silver kob Argyrosomus inodorus and yellowtail Seriola lalandi CPUE, significant effects of sardine Sardinops sagax biomass on geelbek Atractoscion aequidens CPUE, but no significant effects of biomass of west coast redeye round herring Etrumeus whiteheadi and east coast redeye round herring Etruemus wongratanai on any linefish CPUE. Sequential t-test analysis of regime shift (STARS) indicated temporal matching in regimes between anchovy biomass east of Cape Agulhas (EoCA) and yellowtail west coast (west of Cape Point) CPUE, and between sardine biomass EoCA and geelbek southwest coast (Cape Point to Cape Infanta) CPUE. Convergent cross mapping found no causality for anchovy biomass EoCA on yellowtail west coast CPUE but causality in the reverse direction. A high degree of causality in both directions for sardine biomass EoCA and geelbek southwest coast CPUE was observed, indicating strong predator–prey interaction, and a highly significant linear relationship between sardine biomass EoCA in year n–1 and geelbek southwest coast CPUE in yearn was obtained. This functional relationship should be considered for inclusion as a proxy for ecosystem state in management procedures that adopt the ecosystem approach to fisheries for the South African small pelagic fishery.

Interannual monsoon wind variability as a key driver of East African small pelagic fisheries

Small pelagic fisheries provide food security, livelihood support and economic stability for East African coastal communities—a region of least developed countries. Using remotely- sensed and field observations together with modelling, we address the biophysical drivers of this important resource. We show that annual variations of fisheries yield parallel those of chlorophyll-a (an index of phytoplankton biomass). While enhanced phytoplankton biomass during the Northeast monsoon is triggered by wind-driven upwelling, during the Southeast monsoon, it is driven by two current induced mechanisms: coastal “dynamic uplift” upwelling; and westward advection of nutrients. This biological response to the Southeast monsoon is greater than that to the Northeast monsoon. For years unaffected by strong El-Niño/La-Niña events, the Southeast monsoon wind strength over the south tropical Indian Ocean is the main driver of year-to-year variability. This has important implications for the predictability of fisheries yield, its response to climate change, policy and resource management.

Total admissible catches and experimental fishing quotas in the pink lobster (Palinurus mauritanicus, Gruvel 1911) : a new opportunity for economic development in West Africa ?

Over the last thirty years, the poor state of certain fish stocks in the Large Marine Ecosystem of the Canary Current gradually revealed the limits of the West African fisheries management. The Ecosystem Approach advocated in Mauritania, calls to change the perception of fisheries management to incorporate participatory management considerations total admissible catches (TACs) and fishing quotas. An experiment around, a total allowable capture of 800 tons of pink lobster (Palinurus mauritanicus) is at the heart of this approach using methodological tools of analysis / assessment of the economic performance of crawfish exploratory fishery. Survey results show that during the period from February 2015 to January 2016, the fishery was based on a total of 23 vessels. 52% is held by Mauritanian and the rest is chartered with European (EU) ship owners. The capture of the Mauritanian fishery is significantly higher than that of the European Union, respectively 393 tons against 390 tons. 98% of the overall production volume is in live lobsters, mainly for the European market. This production generated sales of 4.26 billion MRO Affairs. Overall, experimental rock lobster industry is an important macroeconomic activity. The Turnover (CA) represents approximately 5% of revenue from exports of the Mauritanian Fish Marketing Company in 2015 (US $ 268 million) and 13% of fishing GDP in 2014 (33.47 billion MRO, BCM 2015). Over two thirds of this amount (3.62 billion MRO) is generated by the (VA) Added Value 85% of turnover. The VA created by Mauritanian operators is 10% more than the VA created by European operators. The Fixed Annual Costs and the Estimated Gross Excess (FACEGE) represents 1.3 MRO billion or 32% of sales. More than half (MRO 896.6 million) in FACEGE is generated by Mauritanian. Experimental lobster industry creates 557 direct and indirect jobs. These jobs represent 10% of the industrial fishing jobs, globally estimated at 3764 Live 2014. It is estimated that the Mauritanian segment creates 25% more jobs than the European segment. This assessment of socio-economic performance of the exploratory fishery in Mauritania lobster is a first step towards a deeper understanding of its cost structure and its dynamics, necessary for the management of TACs and fishing quotas.

Comparative production of fisheries yields and ecosystem overfishing in African Large Marine Ecosystems

Marine capture fisheries in African Large Marine Ecosystems (LMEs) are important from economic, cultural, social, and food provision perspectives. These African fisheries have a long history of high exploitation in the context of data-limited situations. There is a growing, global movement (both in terms of management requirements and scientific efforts) to develop measures of ecosystem overfishing (EOF) that detect overfishing of an entire ecosystem using readily available data and based on widely repeatable patterns. These EOF indicators extend the thinking beyond single stock overfishing to an entire ecosystem and are largely based on well-established trophic theory. Moreover, they need to be germane for data limited situations, easily interpretable, and simple to calculate. Here we introduce and present the results of several of these indicators—the Ryther index, Fogarty index, and Friedland index—as well as indices based on cumulative biomass-Trophic Level curve parameters for eight African LMEs. Significantly, all these EOF indicators also have thresholds beyond which EOF is indicated, particularly when coupled with other evidence. These thresholds were applied to the African LME EOF indicators to determine the degree to which EOF may be occurring. Five out of eight African LMEs exhibited symptoms of EOF, one with significant EOF, with at least one LME still currently experiencing EOF, and three more that may be close to EOF thresholds. One LME exhibited evidence of recovering trends. Additionally, EOF indicators detected changes in the LMEs five-ten years prior to major impacts that would be identified by piecing together fishing impacts on a stock-by-stock basis. We conclude that if EOF is detected, at the very least these relative simple measures should be monitored and means to mitigate total fishing pressure in an ecosystem should be explored.

The fisheries of Africa: Exploitation, policy, and maritime security trends

African maritime countries take the majority of their animal protein from fish. Bound with tradition and a promise of food and other values, African fisheries also provide a source of livelihood for over 35 million coastal fishers. Yet, as in many other regions of the world, the fishing sector is plagued with policy failures, and illegal activities. This paper summarizes the key points in the evolution of African fisheries in terms of exploitation, policy, and maritime security trends. It addresses how access to fishing by the small-scale sector is increasingly hindered by the increasing power and scope of an industrial fleet often involved in Illegal, Unreported, and Unregulated (IUU) fishing. It also discusses the impacts of ineffective enforcement against overexploitation and illegal fishing, piracy, human smuggling and climate-change risks for coastal communities, as well as policy measures and initiatives to reverse the existing trends.

Socializing the rain: human adaptation to ecological variability in a fishery, Mweru-Luapula, Zambia

&lt;p&gt;&lt;strong&gt;Abstract &lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Rainfall drives fishery fertility in Mweru-Luapula, thus rainfall variability contributes to frequent changes in fishing catches. Fishers and traders have adapted their institutions to this variable ecology in a variety of ways, including learning to read the fishery for productive periods and practicing multiple modes of income procurement. By accurately identifying inter-annual, inter-decadal, and longer spans of rainfall trends, future high and low yields can be forecast. This article presents and analyzes annual rainfall in the fishery from 1916-1992 and quantitative fish market data comprised of observed fish catch numbers by species in three markets from September 2004 to September 2005. It uses political ecology to better understand fish production, trade, and subsistence in this South-Central African freshwater fishery. We combine qualitative analysis of fisher and marketer perceptions of the fishery and knowledge of rainfall patterns to show how human behavior is not "tragically" driven, but instead based on the state of the ecological, sociocultural, and socioeconomic environment at a given time.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Keywords&lt;/strong&gt;: African freshwater fisheries, rainfall modeling, political ecology, Mweru-Luapula, Zambia, climate change&lt;/p&gt;

DNA barcoding of chondrichthyans in South African fisheries

South Africa has one of the highest chondrichthyan species diversities in the world, with more than 35% affected by regional fisheries. In order to evaluate the impact of these activities, accurate data on species occurrence is needed. Here, we tested a more robust identification approach of chondrichthyan species in South Africa by sequencing a subsample of specimens (n = 75) collected from different regional fisheries at the mitochondrial cytochrome c oxidase subunit I (COI) gene. Morphological identification of these specimens was evaluated through sequence similarity testing of barcoding sequences available in the Barcode of Life Data (BOLD) database. A total of 23 species from ten families of sharks, skates and rays were identified with an overall agreement of 73% between genetic identification and initial morphological identifications made in the field. Despite some limitations of the COI gene for species identity and the small number of samples analysed in the study, results suggest that a more integrated species identification approach of chondrichthyans can be used to assist conservation of chondrichthyans in South African fisheries.

Holistic assessment of Chwaka Bay's multi-gear fishery – Using a trophic modeling approach

Abstract East African coastal communities highly depend on marine resources for not just income but also protein supply. The multi-species, multi-gear nature of East African fisheries makes this type of fishery particularly difficult to manage, as there is a trade-off between maximizing total catch from all gears and species and minimizing overfishing of target species and the disintegration of the ecosystem. The use and spatio-temporal overlap of multiple gears in Chwaka Bay (Zanzibar) has led to severe conflicts between fishermen. There is a general concern of overfishing in the bay because of the widespread use of small mesh sizes and destructive gears such as dragnets and spear guns. We constructed an Ecopath food web model to describe the current trophic flow structure and fishing pattern of the bay. Based on this model, we explored the impact of different gears on the ecosystem and the fishing community in order to give advice for gear based management in the bay. Results indicate that Chwaka bay is a productive, shallow water system, with biomass concentrations around the first and second trophic level. The system is greatly bottom-up driven and dominated by primary producers and invertebrates. The trophic and network indicators as well as the community energetics characterize Chwaka Bay as relatively mature. Traps and dragnets have the strongest impact on the ecosystem and on the catches obtained by other gears. Both gears potentially destabilize the ecosystem by reducing the biomass of top-down controlling key species (including important herbivores of macroalgae). The dragnet fishery is the least profitable, but provides most jobs for the fishing community. Thus, a complete ban of dragnets in the bay would require the provision of alternative livelihoods. Due to the low resource biomass of fish in the bay and the indication of a loss of structural control of certain fish groups, Chwaka Bay does not seem to provide scope for further expansion of the fishery. Instead, we recommend an effort control of traps and a reduction in the use of dragnets, partially by redistributing them to the more profitable and less impacting gears (e.g. longlines, gillnets, handlines).

Analysis of bycatch in the South African midwater trawl fishery for horse mackerel Trachurus capensis based on observer data

The South African midwater trawl fishery targets adult horse mackerel Trachurus capensis. The bulk of the catch is taken by a single freezer-trawler, the biggest fishing vessel operating in South African waters. As fishing takes place off the south coast in ecologically sensitive areas, there are concerns about the potential impacts of this fishing operation on non-target species. Fishing behaviour and bycatch of this fishery from 2004 to 2014 were investigated by analysing observer records with regard to catch composition, volume and temporal and spatial patterns. The midwater trawl fishery was estimated to have caught 25 415 tonnes annually, with a bycatch of 6.9% of the total catch, by weight. There are species overlaps with various fisheries, namely the demersal trawl, small-pelagic, line, shark longline and squid fisheries, yet the total bycatch estimates from this fishery are generally small relative to catches taken in the target fisheries. Bycatch species with the highest average annual catches were chub mackerel Scomber japonicus, redeye roundherring Etrumeus whiteheadi, ribbonfish Lepidopus caudatus and hake Merluccius spp. Large-fauna bycatch species included sunfish Mola mola as well as a number of CITES II- and IUCN-listed species, such as Cape fur seal Arctocephalus pusillus, dusky shark Carcharhinus obscurus, smooth hammerhead shark Sphyrna zygaena and thresher sharks Alopias spp. The 97.9% observer coverage is high and the 6.9% bycatch rate low compared to other South African fisheries; however, due to the large size of the individual hauls (average of 46.3 t), the average sampling rate of 1.56% is low. Our analyses suggest that bycatch in the South African midwater trawl fishery has been lower than in other South African fisheries and similar fisheries elsewhere, but due to the combination of high catch volumes and low sampling rates, estimation errors for rare species are high and there is a substantial risk of incidental unmonitored bycatch of rare large fauna and aggregations of small fauna. This could be mitigated by spatio-temporal management of this fishery, to avoid fishing in high-risk areas, and the introduction of an electronic monitoring programme.

Climate change adaptation and the African fisheries: evidence from the UNFCCC National Communications

Climate change can cause significant (un)foreseen changes in the fisheries sector. However, adaptation has the potential to moderate some of the impacts. This paper explores the challenges faced by both freshwater and marine fisheries sector in addressing climate change and teases out intervention measures from 21 African countries. The paper uses document analysis and draws selected analysis parameters from the grounded theory. The data are obtained from the United Nations Framework Convention on Climate Change National Communication reports. Among the key adaptation measures emerging from the analysis are: fish breeding, integrated coastal management, putting in place appropriate policies, water and flood management as well as research and development. The study concludes that adaptation in the African fisheries sector should be prioritised, an aspect that could also apply elsewhere in the world to enhance food security.

Trends in Industrial and Artisanal Catch Per Effort in West African Fisheries

AbstractArtisanal fisheries are generally assumed to generate a lower fishing effort in comparison to the industrial sector. This study aims to comparing catch, fishing effort, and catch‐per‐unit‐of‐effort (CPUE) for each sector, using kWdays as a metric for fishing effort, and kg/kWdays for CPUE. The study, which covers West Africa (1950–2010), finds that the artisanal sector spends 4.7•109 kWdays/year versus 1.3•109kWdays/year by the industrial sector, due to increasing numbers and size of artisanal boats, which in Senegal and Ghana can exceed that of (smaller) industrial vessels. The artisanal total fishing effort increased by 10‐fold between 1950 and 2010, in contrast to a decrease in the industrial effort since the 1990s, which points to the occurrence of Malthusian overfishing, a form of fishing that favors excess labor instead of capital. This analysis finds that the CPUE declined by 1/3 since 1950 driven by a strong decline in the artisanal CPUE, which is 11 times lower than industrial CPUE. This confirms other indicators of decline of fish populations. This study calls for the prioritization of artisanal fisheries, with regard to management and data availability, but also as an important but unregulated sector, which contributes to overexploitation of fish stocks that are vital for communities in West Africa.

Ⅳ-2. アジア・アフリカを念頭に置いた水産物エコラベル構築の必要性

Ⅳ-2. アジア・アフリカを念頭に置いた水産物エコラベル構築の必要性

Mosquito Net Use in an Artisanal East African Fishery

AbstractWidespread, anecdotal reports of the use of bed nets designed for malaria control (“mosquito nets”) in artisanal fisheries have led to concern from health and natural resource management sectors. However, mosquito net fishing (MNF) may play an important role in the livelihoods of artisanal fishers, an aspect not yet investigated. At a coastal Kenyan site among Giriama fishers, nearly half of homesteads interviewed used mosquito nets as fishing gear, targeting juvenile fish and prawns for subsistence and sale. The majority of mosquito net (MN) fishers here were men, suggesting that the assumption that MNF is a female activity is not valid in this case. However, MN use for fishing at this site is unlikely to impact malaria protection as fishers used old or surplus nets. Respondents perceived both positive aspects of MNF (e.g., food and income) and negative aspects (e.g., impact on fishery). As mosquito nets are widely available, they may enable new entrants to access fisheries. There is a critical need to review current management responses, which predominately focus on banning the practice, and instead promote integrated strategies for sustainable livelihoods.