Aquaculture has a significant potential to contribute to the Sustainable Development Goals, such as reduced hunger, poverty, and improved human health and wellbeing [1
]. Fish provides 19% of the animal protein intake to people in Africa, and plays a unique role in providing a range of micronutrients and essential fatty acids [2
]. About 37% of Africa has been estimated to be suitable for rural fish farming and 43% for commercial fish production [6
Still, aquaculture production in Africa is very low compared to the other regions of the world, and contributed only with 2.5% of the global aquaculture production in 2016 [2
], and the slow progress of aquaculture development in Africa is something of a mystery [1
]. Despite extensive research and investments by governments and donors in the past five decades, aquaculture development in Sub-Saharan Africa (SSA) has had only limited success, and is still struggling to realize its high potential [1
Local government’s efforts to develop and implement sustainable and profitable aquaculture is constrained by large challenges, such as a lack of improved fish breeds, feeds, technical training, weak research capacity, inadequate human and financial resources, poor market infrastructure and access, and weak governance and regulations [1
However, aquaculture in SSA is currently undergoing an exciting phase of growth after numerous false starts, perhaps as a reaction to the high incidence of poverty, malnutrition, and unemployment [8
]. Also, stagnating catches of wild fish and an increasing food demand from a growing population have created a potential for aquaculture to supply the market with more fish [2
African aquaculture output has doubled in the past seven years and has experienced accelerated growth at 10% annually in the past decade (2006–2016) [2
]. Still, the current production of fish through aquaculture in Africa is low, and even an optimistic aquaculture growth scenario falls short of the trend for increasing demand of fish [2
Tanzania is the biggest fish consumer in East Africa (8.6 kg/capita and year) and fish is the main source of protein to nearly one-third of the country’s population [4
]. People derives more than 20% of their total animal protein intake from fish and seafood (2.2 g/capita/day) [4
]. Tanzania is currently mainly relying on inland fisheries from Lake Victoria (85%) and marine fisheries (14%) for its supply of fish. Only around 3%, or 10,000 tons of fish, is produced by aquaculture [7
]. Current trends indicate that fish catches from Lake Victoria are declining, and in order to maintain the present levels of fish consumption in Tanzania, considerable additional quantities of fish are required, either through increased aquaculture production or imports [4
Tanzania has great potential for aquaculture production [6
]. Its climate is overall good for farming of warm water fish species, including tilapia and African catfish, being the favored species for Tanzania’s lower- and middle-income classes [4
Considering the recent expansion of aquaculture in Tanzania and the expected increased demand for fish [9
], this study aims to make a first order assessment of the potential for freshwater fish farming activities in Tanzania. The study combines GIS spatial modelling with multi-criteria evaluation (MCE), and build on large quantitative datasets as well as more qualitative inputs from fish farmers and regional fisheries officers, to assess the opportunities and constraints for fresh water pond farming of fish in Tanzania.
The first continental assessment of aquaculture suitability in Africa incorporating a GIS methodology was developed by Kapetsky in 1994 [12
], which later was followed-up by a similar study in 1998 [6
]. In this study the suitability of two aquaculture models, representing small-scale and commercial pond farming of fish was assessed. This was done by assigning weights to selected criteria by pairwise comparing the criteria following the approach by Eastman et al. [13
], which built on the Analytical Hierarchy Process (AHP) developed by Saaty [14
]. Ssegane et al. [15
] did a similar aquaculture suitability assessment for Uganda, combining GIS spatial modelling and multi-criteria evaluation, including seven criteria. The assessment by Ssegane et al. [15
] followed a methodology similar to those found in Kapetsky [12
], Kapetsky and Nath [16
], and Aguilar-Manjarrez and Nath [6
], including criteria classification by thresholds into four suitability levels, and weight production following the AHP methodology by Saaty [14
Although our study builds on the overall methodology framework used in the studies above, our study provides the first assessment of the potential for fish pond farming in Tanzania combining GIS spatial modelling and stakeholder consultations.
The overall vision of the Ministry of Livestock and Fisheries in Tanzania is to develop an aquaculture sector that is commercially run, vibrant, diversified, and sustainable, using highly productive resources to ensure food security and nutrition, employment and improved income for the households and nation at large, while conserving the environment [17
]. Our study indicates that this can be achieved if Tanzania takes advantage of its diverse social-ecological conditions and identifies appropriate farming methods that meet the local conditions, in such a way that it promotes sustainable development, equity, and resilience of interlinked social and ecological systems. We think our study provide useful insights on this by combining GIS analyses with surveys or fish farmers and fisheries officers perceptions.
The study is delimited to mainland Tanzania (Figure 1
a), which is located just below the equator in East Africa, having a total land area of 947,303 km2
and a 1424 km long coastline [18
]. A larger part of the mainland is covered by an extensive plateau, with an altitude ranging between 1000 and 2000 m above mean sea level (MAMSL). The northern coast and southern part of the mainland is however characterized with a considerably flatter terrain, with an approximate altitude gradient between 50 and 500 MAMSL [19
]. Inland lakes have a total coverage of 59,000 km2
Tanzania’s total population was about 58 million people in 2019, with 65.5% living in rural areas and where small-scale agriculture is the major livelihood activity [20
]. Economic growth has contributed significantly to poverty reduction in recent years, although 28% of Tanzanians still remain below the nationally determined poverty line [21
]. In 2019, the country average annual temperature varied between 19.2 °C and 29.3 °C with an annual average total rainfall of 1284 mm [22
]. The amount of annual rainfall varies spatially, where the highest rate is found in the northern regions around Lake Victoria, with approximately 2500 mm, while the Central part is characterized by lower rates, approximately 550 mm [19
]. One-third of the crop land is devoted to maize, which accounts for 40% of caloric intake nationally [21
]. While increasing temperatures may benefit rainfed maize in the highlands, national production is projected to decrease 8–13% by 2050, due to increased heat stress, drying, erosion, and flood damage. Bean, sorghum, and rice yield projections follow similar trends, with decreases of 5–9% by 2050 [21
Aquaculture in Tanzania is currently mostly a small-scale activity and usually not practiced as a stand-alone economic activity, but rather as subsistence farming integrated with agricultural activities and rearing of livestock ([7
], Figure 1
In Tanzania the aquaculture sector consists of roughly 19,000 small-scale freshwater farmers and 1600 marine fish farmers (excluding seaweed farms) [4
]. Although the production of this practices is relative low, they are important in terms of food security and provide complementary animal protein and important nutrients [24
]. The low production makes it possible to rely on local resource as feed for the fish. Use of manure and agriculture waste help to increase the productions efficiency and enhance the fish yield without any increased production costs [11
International evidence also suggests that small-scale aquaculture can play a significant role in parallel to the development of commercial production that will catalyze the sector [25
]. Development of a viable smallholder sector has the potential to greatly improve livelihoods in the industry [3
]. In recent years there has been an increased demand for high-quality fish feeds and seeds, and there are now a small, but growing number of farmers, that operate their farms on a more commercial basis and are reaching high levels of production [7
]. In addition, cage farming in Lake Victoria has taken off, although at modest levels compared to the neighboring countries [7
Considering the recent expansion of aquaculture in Tanzania and the expected increased demand for fish [9
], this study makes a first order assessment of the suitability for freshwater aquaculture activities in Tanzania, with an aim to provide guidance on how aquaculture could be developed in Tanzania for an optimized and sustainable production of fish.
Our results indicate that there is a good potential for fish pond farming in Tanzania, but the sector, particularly commercial aquaculture, is still in its infancy, especially compared to countries in Asia, but also compared to countries like Egypt, Uganda, and Nigeria [1
]. Still, this only shows that the aquaculture experience from these countries could provide valuable guidance on how to further develop aquaculture in Tanzania. Some 80% of the regional fisheries officers said that fish farming had increased during the last 10 years, and that it was likely to expand in the coming 10 years, and overall the attitude among regional fisheries officers and local farmers to aquaculture was positive (Table 6
and Table 7
]). As the majority of the fish in Tanzania currently comes from Lake Victoria, with stagnating or even declining fish catches, partly due to overfishing and pollution, it can be expected that the demand for farmed fish will increase in the future [4
], which was confirmed by many of the regional fisheries officers. Still, even with an expansion in aquaculture it would be difficult to keep the currently low, but nutritionally important, per capita fish consumption in Tanzania at the same level as today [2
]. With a per capita fish consumption of 8.6 kg per year and a population growth of 3% [20
], the additional fish production required to maintain 2018′s level of fish consumption, would be some 110,000 tons in 2025. If only coming from aquaculture, this would imply a 10-fold increase of the current combined yield of marine and freshwater aquaculture or a 20-fold increase of the freshwater fish production. With a yield of 2–4 tons of fish per ha and year in extensive pond farming (cf. Table 7
]) this would require an additional area of 27,000–55,000 ha for pond farming.
Although this would be a major expansion of the aquaculture activities in Tanzania and require considerable investments in aquaculture [c.f. 4] the availability of suitable land would certainly not be a constraint according to our results. Around 60% of Tanzania, or 450,600 km2, is suitable for fish pond farming. The challenge would rather be to find ways to support an expansion that are designed to fit local conditions and that ensures a sustainable and efficient production of fish.
In terms of physical conditions water availability is the most limiting factor and assessed as being “suitable” in less than 30% of the country. This is much less than the almost 50% estimated by Manjarrez and Nath [6
], and may become even a more critical factor in the future with the ongoing impact from climate change [47
]. In the field survey of 89 small-scale farmers, water scarcity was seen as a serious problem among 45% of the farmers, and almost 30% of the farmers felt that the availability of water limited the adoption rate of fish pond farming [24
]. Moreover, more than 80% of the regional fisheries officers perceived water availability as the most important factor influencing on fish pond farming, and that water scarcity was a difficult challenge for current farming activities and for the future expansion of aquaculture (Figure 7
and Figure 9
). The majority of the officers felt that the availability of water was affected negatively by climate change and that this problem would increase in the coming 10 years (Table 6
). According to the regional fisheries officers the majority of the farmers currently extract their water from rivers (c.f. [11
], Table 7
), and more wells or canals were seen as an important way to expand aquaculture in the future ([24
], Figure 9
The correlation between water availability and number of fish ponds in the regions of Tanzania (Figure 6
a) confirms that water availability is an important factor determining the distribution of fish ponds. The highest number of fish farmers and ponds is found in Ruvuma, Njombe, Iringa, and Mbeya, which have suitable water conditions, despite they have some areas with suboptimal conditions in terms of soil, terrain, and temperature. Overall, one could expect that with increasing altitude the conditions for water availability improves, while the conditions for soil, terrain, and temperature get worse. Thus, in many cases farmers need to make a trade-off between these factors, and it seems as water is of highest priority, which could explain why the distribution of ponds was negatively correlated with the suitability score for soil and terrain (Figure 6
b). Still 70% Tanzania was estimated to have very suitable or suitable soil and terrain conditions. The corresponding estimate by Aguilar-Manjarrez and Nath [6
] was 90%, and these physical factors seem to be of less concern than water availability.
Some regions south of Lake Victoria were assessed as suitable for most of the criteria except water, and overall our results indicate that these regions are some of the most suitable areas for fish pond farming in Tanzania. Still, the current number of fish ponds in these regions (e.g., Shinyanga, Geita, Tabora and Simuyo) are low compared to the other regions (cf. Figure 1
b), which could be because fish catches from Lake Victoria have satisfied the demand for fish, or because of the suboptimal water conditions in these regions. However, with declining catches of wild fish, the fish demand could be expected to increase in the future, and some of these regions have extensive areas of small water bodies, which potentially could be used for irrigation and aquaculture purposes. Thus, with an improved access to water, these regions could provide potential areas for future aquaculture expansion. Overall, the irrigation potential in Tanzania is estimated at 29.4 million hectares [48
] and Tanzania is endowed with a high number of small natural and man-made lakes, rivers, and wetlands with a total area of 64,300 km2
], indicating considerable opportunities to expand aquaculture in areas with suboptimal rainfall.
Some of these regions, including Shinyanga, Tabora, Mwanza, Mbeya, and Rukwa, are also the most important rice-farming areas in Tanzania [48
], and a potential way to increase aquaculture in areas with limited access to water for ponds, could be to integrate rice farming with fish farming [49
]. Tanzania is the second largest producer of rice in Eastern and Southern Africa after Madagascar [51
]. In 2017/18, rice was cultivated on 1.1 million ha, and the area targeted for rice cultivation in 2030 is 2.2 million ha [48
Egypt has applied rice-fish farming successfully for many years, and fish production from rice field has been reported to contribute substantially to the country’s total aquaculture production [45
]. Integrated rice-fish farming experiments in Kenya with mixed sex tilapia (Oreochromis niloticus
) stocked at low densities (6000 fingerlings/ha) and African catfish, (Clarias gariepinus
) stocked at high densities (60,000 fingerlings/ha) resulted in average fish yields of 130 and 3370 kg/ha, respectively [49
]. Using a conservative low yield of 130 kg fish/ha and assuming that 30% of the 1.1 million ha of the rice fields in Tanzania would be converted to rice-fish farming practices, these rice fields could produce 43,000 tons of fish per year. This is four times higher than the current total production of fish from aquaculture and could help to supply a significant part of Tanzania’s fish demand in the future. A yield of 130 kg fish/ha is very similar to the reported catch of wild aquatic animals from rice fields in Cambodia [52
], and as indicated by the experiments in Kenya, the yield could probably be substantially higher with an increased fish stocking density.
Most farmers in Tanzania, view aquaculture as a low investment, low-risk complement to agriculture, and the cost of constructing earthen fish ponds is seen as a major constraint to fish pond farming by many farmers [24
]. Raising fish in rice fields would however minimize the investment costs, and could provide an attractive alternative for the farmers to diversify their crop production. Fish from the rice fields would increase the availability of animal protein and improve the nutrition of the rural population.
As most farmers practice small-scale farming and use manure and agriculture waste to enhance the pond productivity and feed the fish (Table 7
), the availability of manure and agriculture waste could be a critical factor for a sustained fish production. Still our analysis shows that this probably is not a major constraint in large parts of Tanzania, which is similar to the results by Aguilar-Manjarrez and Nath [6
], who estimated that 70% of Tanzania was either very suitable (40%) or suitable (30%) in terms of availability of agriculture inputs. However, the availability of high-quality fish feed was seen as a major challenge for a further expansion of aquaculture, as most fisheries officers expected that future aquaculture would increasingly target commercial fish production for markets rather than for home consumption.
A recent survey of small-scale pond farmers showed that approximately 40% of their production were used for home consumption and that 60% were sold [24
]. This corresponds well with the regional fisheries officers’ view that the main benefits from aquaculture are that it provides an extra income and food security to the farmers (Figure 11
). The survey with 89 farmers showed that poor fish farmers consumed a larger proportion of their pond harvest compared to better-off farmers, indicating that fish farming contributes more to food security in low-income households as compared to high-income households [24
]. The sold fish can provide some important cash and also create an incentive for some famers to transform into more business-oriented aquaculture [cf. 1]. These small-scale entrepreneurs could play an important role in helping to expand aquaculture production in Tanzania, by for example creating an increased demand for high-quality fish seeds and feeds [23
Similar to the findings by Aguilar-Manjarrez and Nath [6
], most of Tanzania was either suitable or moderately suitable in terms of farm-gate sales. According to our analysis farm-gate sales are higher in rural areas with high population densities, such as the regions around Lake Victoria, than in less densely populated areas, such as central and southern Tanzania. Thus, a moderate suitability in terms of water availability in some of these northern regions, could tentatively be compensated by a slightly more commercially oriented aquaculture targeting local markets and farm-gate sales, where an increased income could help farmers to afford pumping water to their ponds.
The northern parts have also a more developed infrastructure, which further would enhance the access to local markets. The fish from Lake Victoria over the years has helped to develop markets and, as indicated by the regional fisheries officers, the increased demand for fish in combination with declining catches of fish in these areas, could help in the establishment of more commercially oriented fish farming. Although access to fish markets was not seen as a critical factor for current fish farming activities, dominated by small-scale subsistence pond farming, regional fisheries officers believed that this would be more important in coming years, when small-scale commercial fish farming would become more common (Figure 12
Combining all criteria considered in this study, 46% and 54% of Tanzania was assessed to be suitable and moderately suitable for small-scale subsistence fish pond farming, respectively. The regions that were most suitable were located around Lake Victoria and along the coast, and were in general not those areas that currently have most fish farms. One reason for this could be that the fish demand in these regions has been satisfied with wild fish from the ocean and Lake Victoria. However, declining catches of wild fish followed by an increased demand for fish could stimulate an expansion of aquaculture activities. Aguilar-Manjarrez and Nath [6
] estimated that 93% of Tanzania was either very suitable (43%) or suitable (50%) for subsistence fish pond farming and there are many regions with a good combination of the criteria included in our analysis, but with slightly different comparative strength. This provides an opportunity to design future aquaculture activities in Tanzania, that builds on and meets the local conditions and demands of the different regions.
More remote rural areas with suitable environmental conditions, but less direct access to markets and road networks, such as parts of Katavi, Iringa, Mbeya Njombe, Singida, and Lindi, could be well suited for upgraded small-scale subsistence aquaculture, which, according to the regional fisheries officers, currently is applied by the majority of the aquaculture farmers in Tanzania [7
]. Although these systems often have a low productivity, they are important in terms of food security and provide complementary animal protein and important nutrients ([1
], Figure 5
). The low scale of production and comparatively low production costs make these systems less dependent on well-established fish-markets and infrastructure. Although only half of the crop is sold, either due to lack of access to wealthier markets or out of a need to meet more local food security priorities, it generates a small, but important amount of cash for emergencies, school fees, etc., [1
As they operated on a low scale, they can rely on local available resources and are often integrated with the other agriculture activities [11
]. Use of manure and agriculture waste to provide feed to the fish increases the recycling within the system, and has in many studies shown to increase the production efficiency and enhance the fish yield, without any increased production costs [10
]. The fish pond provides nutrients and water to the crops and provide a buffer against periods of droughts, which could expect to increase with future climate change.
Thus, small-scale integrated fish farming, such as integrated rice-fish or vegetable-fish farming, could be an important way to increase fish production and the diversity of local farming activities in rural areas of Tanzania [cf. 10, 11, 45]. Diversification of crops and secured water, would help small-scale farmers to become more resilient to environmental change by for example balancing economic losses on seasonal cropland. They provide a design that can operate in more remote areas, and has been shown to enhance poor farmers’ livelihoods for decades. They have very low or even positive environmental impact and have often a positive social impact through enhanced food security, water availability, and poverty alleviation, and should therefore continue to be an important part of Tanzania’s future aquaculture portfolio, even if there are other aquaculture methods that could provide higher financial gains and export earnings.
Although only a minority of the small-scale farmers may have the means or skills to transform into more business-oriented aquaculture, these farmers can still play an important role in the future expansion of the aquaculture sector in Tanzania. International evidence suggests that small-scale aquaculture can catalyze the sector [7
] in parallel to the development of larger commercial production, and according to Hishamunda and Ridler [25
], small-scale farmers will be critical in contributing to an economic growth of the aquaculture sector in Sub-Saharan countries such as Tanzania. These farmers already have a practical experience of aquaculture operations, which still is scarce in Tanzania. They influence on other farmers and help create an increased demand for improved quality of fish seeds and feeds. This demand creates incitements to establish fish hatcheries and feed factories, which according to the fisheries officers currently are increasing in numbers in Tanzania in areas with available infrastructure and markets, such as around Dar es Salaam, Pwani, Mwanza, Ruwuma, and Mbeya [c.f. 9]. Areas similar to these are likely to become important hubs for a transformative change of the aquaculture sector in Tanzania in the future.
About 82% of the regional fisheries officers thought that small-scale commercial aquaculture production or cage farming would be the dominant farming practice in the coming 10 years (Figure 12
), and the opportunities for an increased profit was seen as an important reason for an expansion in aquaculture production, boosted by increasing demands for fish and declining yields of wild fish (Figure 11
). With an increased cash flow, these farmers will be better suited to overcome some physical constraints, such as water shortage and non-optimal soil conditions, by for example pumping water and building concrete ponds. This may make the farmers less vulnerable to environmental changes, but at the same time more dependent on a stable cash flow, which also means that these farms need to be situated close to fish markets and in areas with good infrastructure, including road networks. These farmers become increasingly constrained by high costs for feed, fingerlings, and transportation and lack of marketing infrastructure [1
]. Thus, a decreased vulnerability to environmental conditions could easily be substituted for an increased vulnerability to financial market fluctuations, which in a way would make aquaculture operations more complex, demanding a good understanding of both farming techniques and financial management, which would exclude many local farmers. These challenges were confirmed by both farmers and regional fisheries officers, who said that improved extension services and better technical know-how were among the most important factors to facilitate an expansion of aquaculture in the future ([24
], Figure 9
). The presence of aquaculture expertise and previous development projects on aquaculture were also seen as main reasons, by the regional fisheries officers, why certain regions, despite suboptimal conditions for some of the suitability criteria for fish farming, such as soil and terrain in Ruvuma and Njombe, had more aquaculture farms than others.
According to our analysis urban and semi-urban areas would be the most suitable areas for this kind of more business-oriented aquaculture, which currently is happening in for example Dar es Salaam. Our field survey showed that pond farming in Dar es-Salaam was conducted in concrete ponds, fish fingerlings were stocked in comparatively high stocking densities and most fish farmers used commercial fish feeds and hired labor (Table 7
). Thus, compared to more remote and rural areas these farms are operated in a more business-oriented manner, which requires a different set of skills as compared to subsistence farming, and where most of the yield are sold for cash. Our survey shows that 70% of the fish farmers in Dar es Salaam, while less that 20% of the rural fish farmers had more than 14 years of education, respectively (Table 7
). Moreover, the motivation to farm fish differed, where small-scale subsistence farmers primarily sought food security and farm diversification, while the commercial farmers sought cash, often at the expense of diversity and, sometimes, sustainability [1
Also regions around Lake Victoria could be well suited for more business-oriented aquaculture. Fish from the lakes have created fish markets, and the declining catches of wild fish could potentially increase the demand for farmed fish [4
]. The lakes also provide opportunities to establish fish cage farming, which now is quite common in Lake Victoria and has also been introduced since a few years back in Lake Tanganyika. According to the regional fisheries officers, cage farming was believed to become the dominant future aquaculture systems in some regions around Lake Victoria (Mwanza, Mara and Geita), and in Ruvuma, probably because of the comparatively high availability of fish feed producers, hatcheries, and experienced fish farmers. Fish cage farming tend to be more capital demanding than pond farming and is often not an option for local farmers. They are often run as large-scale business operations, where the produced fish primarily target urban and international markets. Thus, the demand for good infrastructure and for high-quality input of fish fry and commercial fish feed is high for these activities and they aim for a high production, which could generate a high revenue and contribute to an economic growth in Tanzania.
However, there is a need to be cautious as an increased scale of production often is followed by an increased risk to exceed the carrying capacity of the supporting environment. If this happens it could easily be followed by environment and social impacts. Much fish feed, feces, and antibiotics are lost from fish cages, directly into the lake environment, which could contribute to an increased pollution of the aquatic environment. Lake Victoria is already suffering from many pollutants and any additional pollution load should be minimized [46
]. Also escapes of fish from the cages could have negative impact on the native fish populations, which was seen as the main environmental drawback from aquaculture by the regional fisheries officers (Table 6
). Local farmers are often excluded from these operations and the fish are often sold far from the production site, creating fewer local benefits while still potentially creating negative local impacts. Thus, it is important that social and environmental consequences of these activities are closely monitored to ensure a sustainable and equity production of fish that contribute to both economic growth, social justices, and environmental qualities.
Increased aquaculture production could provide a potential solution to declining catches of wild fish and increased demand for fish in Tanzania. In this study we have assessed the suitability for subsistence and commercial fish pond farming, which are the dominant fish farming practices in Tanzania, by applying a combination of GIS spatial modeling with multi-criteria evaluation. GIS modeling made it possible to use large spatial data sets to analyze how a combination of criteria, related to the environment, land uses, and infrastructure, affected the suitability for fish pond farming in different parts of Tanzania. The importance of these criteria was decided through multi-criteria evaluations and analytical hierarchy processes, building on field interviews and questionnaires with fish farmers and fisheries officers, which provided means to include different stakeholders’ knowledge in the overall GIS assessments, and also to validate the GIS spatial modelling results. The combination of GIS modeling and stakeholder consultations, building on both quantitative and qualitative data, helped to provide policy-relevant results, such as maps and compilation of stakeholder’s perceptions. Still aquaculture involves a diverse set of biological, environmental, and socioeconomic parameters, and an assessment of the suitability of aquaculture is a complex task, with several factors potentially affecting the results, and our study should be seen as a first-order assessment that hopefully can provide some guidance for the future development of aquaculture in Tanzania.
Our results indicate that there is a good potential for aquaculture in Tanzania. About 60% of Tanzania was assessed as being suitable and 40% as moderately suitable for small-scale subsistence pond farming. The corresponding figures for medium-scale commercial farming, which most regional fisheries officers saw as the dominating farming method in ten years, were 53% and 47% respectively
In terms of physical conditions water availability was the most limiting factor for pond farming, which was confirmed by both farmers and regional fisheries officers, and assessed as being “suitable” in only 28% of the country. This area is likely to become smaller in the future, due to climate change.
Around 80% of Tanzania was seen as either very suitable or suitable in terms of water temperature, soil, and terrain and the most suitable conditions were found south of Lake Victoria and along the coast in eastern Tanzania, while the least suitable conditions were found at high altitudes.
The availability of farm inputs (agriculture waste and manure) for small-scale pond farming was overall good (26% very suitable and 32% suitable), but high-quality fish feed was seen as a constraint to aquaculture development, both by farmers and regional fisheries officers.
The suitability in terms of farm-gate sales and local markets was overall good, and primarily located in areas with high population densities. Overall, the market potential for fish in Tanzania was high. This is mainly due to the fast-growing Tanzanian population and increased buying power combined with decreasing supply of wild fish.
Currently small subsistence pond farming is the dominating aquaculture practice in Tanzania. Although these systems often have a low productivity, they have very low or even positive environmental impact and have often a positive social impact through enhanced food security, water availability, and poverty alleviation. If integrated with other crops they provide means for livelihood diversification and water security and can help farmers to become more resilient to environmental change, including climate change. The low scale of production and comparatively low production costs make these systems less dependent on well-established fish-markets and infrastructure, and they provide a design that can operate in more remote areas, and we believe that that these systems should continue to be an important part of Tanzania’s aquaculture portfolio.
Still the majority of the regional fisheries officers saw medium-scale commercial farming as the dominating fish farming method in ten years. An expansion of these activities could certainly make a significant contribution to the aquaculture development in Tanzania, not only providing financial gains and export earnings, but also stimulating the production of high-quality fish feeds and seeds. With increased access to high-quality fish seeds, feeds, and markets, more people, including local fish-farmers, could see aquaculture as a business opportunity, tentatively contributing to a transformative change of the aquaculture sector in Tanzania.
We believe that such a change should meet the vision of The Ministry of Livestock and Fisheries and be developed in the context of local conditions, where aquaculture is seen as a part of an integrated social ecological system. Our analysis shows that conditions in Tanzania vary and that this provides opportunities to develop aquaculture in Tanzania sustainably, by encouraging farming practices that are designed to fit local conditions and to meet local demands. In this way aquaculture could be developed to contribute to both economic growth, social justices, and environmental qualities.