Fisheries in the Drylands of Sub-Saharan Africa – “Fish come with the rains”. Building resilience for fisheries-dependent livelihoods to enhance food security and nutrition in the drylands

Dryland areas cover more than half of sub-Saharan Africa and are home to nearly 50 percent of its populations, who depend on agriculture (including livestock, crops and fisheries) as their main livelihood strategy. Sporadic and irregular rainfall patterns are the most important environmental driver for these regions and water, in particular surface water, is the primary element of scarcity in drylands. Generally, dryland water bodies are unstable and strongly pulsed ecosystems owing to intermittent and largely unpredictable precipitation. Such systems are characterized by very productive and highly resilient, small opportunistic fish species with “boom and bust” fluctuation adapted to strong environmental disturbances, and are therefore difficult to overfish. As a result of high productivity, they can sustain very high yields in years of good rains, but being largely short-lived they also respond rapidly to environmental changes in hydrological regimes, which means that alternating periods of low productivity are inevitable. The focus of this review is to both document the general resilience of many fish resources to climatic variability − including their underestimation in livelihood importance, particularly in protracted crisis situations − and to enhance the potential supply of fish from dryland areas through improved use of the available water bodies, and in particular small reservoirs. The important role that small water bodies play in supplying essential micronutrients and protein to rural communities has largely been overlooked since the termination of the FAO/ALCOM (Aquaculture for Local Community Development) programme in 1998, although they are more productive on a per unit area basis than the large lakes and reservoirs and, when pooled, constitute a much larger area of water. Most of the fish production, however, is consumed locally and goes unrecorded in official catch statistics. By refocusing attention on the fish productivity of small water bodies and reservoirs in drylands, and in particular by integrating fisheries with developments in water harvesting, irrigation and improved water storage facilities, the potential to increase the role played by fish in the diets of dryland people, and to provide improved livelihood opportunities is great. The overall conclusion is that the potential for increasing fish production in dryland areas is significant, that the resources are highly resilient and productive, but that the general and increased unpredictability of the rainfall required to sustain surface water bodies creates uncertainties in annual production. That must be counteracted by an adaptive and diversified livelihood strategy.publishedVersio

Operational, environmental, and resource productivity factors driving spatial distribution of gillnet and longline fishers targeting Nile-perch (Lates niloticus), Lake Victoria

Operational and environmental factors limited available resource space of gillnet and longline fishers targeting Nile perch in the Speke gulf and open lake of southern Lake Victoria and drove their encounter rates with patches of fish resulting in gear specific distributional patterns. Catch-rate patterns were similar by region and gear: large (>50 cm) Nile-perch densities increased over distance from homeport and deeper in the water column while small Nile perch (<50 cm) densities decreased. Effects of season, (setting) depth and region were present but small and obscured by high variation in daily catch-rates and individual fisher strategies. Both fisheries distributed themselves over the size-productivity spectrum of Nile perch but reacted differently to patterns in size distribution of Nile perch: gillnetters focused more on numbers of productive juveniles between 30 and 60 cm at on average 5 km distance (59 min travel time) from homeport and longliners on larger sized 40–80 cm Nile perch deeper in the water column at 7 km (108 min). Sampled fishers likely were representative of most of the Nile perch fisheries. If so, this means that fishing pressure is mainly exerted on nearshore lake areas, and more lightly fished offshore areas may act as a refuge for adult Nile perch. Total catch-rates by gear were generally equalized over the resource space, increasing slightly with distance from homeport, according to ideal free distribution predictions. Nile perch fishers on Lake Victoria appear to distribute themselves according to the underlying productivity distribution of the resource within the constraints of their available resource space.</p

Fisheries, the inverted food pyramid

A global assessment of fishing patterns and fishing pressure from 110 different Ecopath models, representing marine ecosystems throughout the world and covering the period 1970–2007, show that human exploitation across trophic levels (TLs) is highly unbalanced and skewed towards low productive species at high TLs, which are around two TLs higher than the animal protein we get from terrestrial farming. Overall, exploitation levels from low trophic species were 40% of their production. Generally, well-managed fisheries from temperate ecosystems were more selectively harvested at higher exploitation rates than tropical and upwelling (tropical and temperate) fisheries, resulting in potentially larger long-term changes to the ecosystem structure and functioning. The results indicate a very inefficient utilization of the food energy value of marine production. Rebuilding overfished components of the ecosystem and changing focus to balancing exploitation across a wider range of TLs, i.e. balanced harvesting, has the potential to significantly increase overall catches from global marine fisheries

Maximizing fisheries yields while maintaining community structure

Under the ecosystem approach to fisheries, an optimal fishing pattern is one that gives the highest possible yield while having the least structural impact on the community. Unregulated, open-access African inland fisheries have been observed to sustain high catches by harvesting a broad spectrum of species and sizes, often in conflict with current management regulations in terms of mesh and gear regulations. Using a size- and trait-based model, we explore whether such exploitation patterns are commensurable with the ecosystem approach to fisheries by comparing the impacts on size spectrum slope and yield with the different size limit regimes employed in the Zambian and Zimbabwean sides of man-made Lake Kariba. Long-term multispecies data under fished and unfished conditions are used to compare and validate the model results. Both model and observations show that the highest yields and low structural impact on the ecosystem are obtained by targeting small individuals in the community. These results call for a re-evaluation of the size-based management regulations that are ubiquitous in most fisheries

Fisheries in the Drylands of Sub-Saharan Africa – “Fish come with the rains”. Building resilience for fisheries-dependent livelihoods to enhance food security and nutrition in the drylands

Dryland areas cover more than half of sub-Saharan Africa and are home to nearly 50 percent of its populations, who depend on agriculture (including livestock, crops and fisheries) as their main livelihood strategy. Sporadic and irregular rainfall patterns are the most important environmental driver for these regions and water, in particular surface water, is the primary element of scarcity in drylands. Generally, dryland water bodies are unstable and strongly pulsed ecosystems owing to intermittent and largely unpredictable precipitation. Such systems are characterized by very productive and highly resilient, small opportunistic fish species with “boom and bust” fluctuation adapted to strong environmental disturbances, and are therefore difficult to overfish. As a result of high productivity, they can sustain very high yields in years of good rains, but being largely short-lived they also respond rapidly to environmental changes in hydrological regimes, which means that alternating periods of low productivity are inevitable. The focus of this review is to both document the general resilience of many fish resources to climatic variability − including their underestimation in livelihood importance, particularly in protracted crisis situations − and to enhance the potential supply of fish from dryland areas through improved use of the available water bodies, and in particular small reservoirs. The important role that small water bodies play in supplying essential micronutrients and protein to rural communities has largely been overlooked since the termination of the FAO/ALCOM (Aquaculture for Local Community Development) programme in 1998, although they are more productive on a per unit area basis than the large lakes and reservoirs and, when pooled, constitute a much larger area of water. Most of the fish production, however, is consumed locally and goes unrecorded in official catch statistics. By refocusing attention on the fish productivity of small water bodies and reservoirs in drylands, and in particular by integrating fisheries with developments in water harvesting, irrigation and improved water storage facilities, the potential to increase the role played by fish in the diets of dryland people, and to provide improved livelihood opportunities is great. The overall conclusion is that the potential for increasing fish production in dryland areas is significant, that the resources are highly resilient and productive, but that the general and increased unpredictability of the rainfall required to sustain surface water bodies creates uncertainties in annual production. That must be counteracted by an adaptive and diversified livelihood strategy

Freshwater small pelagic fish and fisheries in the main African great lakes and reservoirs in relation to food security and nutrition

This paper reviews the status and importance of the freshwater small pelagic fish and fisheries for sustainable healthy livelihoods in Africa. The lack of recognition of the importance of small pelagic fish for the sustenance, livelihoods and public health has prevented the necessary investments for improving the quality, shelf life and public awareness of this vitally important resource. This FAO Technical Paper has been prepared to fill this gap and enable policymakers and development practitioners to design and implement more effective policies, strategies and programmes that will contribute to reducing the food insecurity that currently affect the people of the sub-Saharan Africa. The paper examines the biology and biological production of the most important pelagic species in the major lakes and reservoirs, as well as the impacts of environmental and climatic variation on stocks of these species. It discusses the various capture techniques and the potential for improving the fisheries and associated processing and national and regional trade within Africa

Uncertainty in catch and effort data of small- and medium-scale tuna fisheries in Indonesia : Sources, operational causes and magnitude

This study aims to identify the sources and magnitude of uncertainty in the collection and processing of catch and effort data of small- and medium-scale tuna fisheries in Indonesia, as well as the causes of uncertainty on an operational level. We identified possible sources of uncertainty through a literature review and interviews with experts. Next, we surveyed 40 small-scale (<10 GT) and medium-scale (10–100 GT) pole-and-line, purse-seine, longline and handline fishers in the oceanic fishing port Bitung, which has the largest number of tuna fisheries activities in eastern Indonesia, to estimate the magnitude of unreported catch of juvenile tuna, on-board consumption, home consumption and catch used as bait. We used logbook data from the fisheries submitted to the fishing port authorities to extrapolate survey results to the fishing port level. Uncertainties around unreported catches were due both to non-reporting by fishers to the fishing port authority and to flaws in data management in the data collection institution. After removing flaws in the logbook database we estimated that the catch by small- and medium-scale fishing vessels active in Indonesian waters could be about 33–38% higher than reported. The proportion of unreported catch, as well as the sources and range of uncertainty, varied according to the types of gear used. Finally, we discuss what aspects of data collection and processing should be improved at the fishing port level, including the identified sources of unreported catch and the processes leading to non-reporting. We hence provide a methodology for estimating unreported catches in small and medium-scale fisheries.</p

Freshwater small pelagic fish and fisheries in the main African great lakes and reservoirs in relation to food security and nutrition

This paper reviews the status and importance of the freshwater small pelagic fish and fisheries for sustainable healthy livelihoods in Africa. The lack of recognition of the importance of small pelagic fish for the sustenance, livelihoods and public health has prevented the necessary investments for improving the quality, shelf life and public awareness of this vitally important resource. This FAO Technical Paper has been prepared to fill this gap and enable policymakers and development practitioners to design and implement more effective policies, strategies and programmes that will contribute to reducing the food insecurity that currently affect the people of the sub-Saharan Africa. The paper examines the biology and biological production of the most important pelagic species in the major lakes and reservoirs, as well as the impacts of environmental and climatic variation on stocks of these species. It discusses the various capture techniques and the potential for improving the fisheries and associated processing and national and regional trade within Africa.publishedVersio

Uncertainty in catch and effort data of small- and medium-scale tuna fisheries in Indonesia : Sources, operational causes and magnitude

This study aims to identify the sources and magnitude of uncertainty in the collection and processing of catch and effort data of small- and medium-scale tuna fisheries in Indonesia, as well as the causes of uncertainty on an operational level. We identified possible sources of uncertainty through a literature review and interviews with experts. Next, we surveyed 40 small-scale (<10 GT) and medium-scale (10–100 GT) pole-and-line, purse-seine, longline and handline fishers in the oceanic fishing port Bitung, which has the largest number of tuna fisheries activities in eastern Indonesia, to estimate the magnitude of unreported catch of juvenile tuna, on-board consumption, home consumption and catch used as bait. We used logbook data from the fisheries submitted to the fishing port authorities to extrapolate survey results to the fishing port level. Uncertainties around unreported catches were due both to non-reporting by fishers to the fishing port authority and to flaws in data management in the data collection institution. After removing flaws in the logbook database we estimated that the catch by small- and medium-scale fishing vessels active in Indonesian waters could be about 33–38% higher than reported. The proportion of unreported catch, as well as the sources and range of uncertainty, varied according to the types of gear used. Finally, we discuss what aspects of data collection and processing should be improved at the fishing port level, including the identified sources of unreported catch and the processes leading to non-reporting. We hence provide a methodology for estimating unreported catches in small and medium-scale fisheries.</p