Daniel Jamu - Academia.edu (original) (raw)

Papers by Daniel Jamu

Research paper thumbnail of A preliminary study on the feasibility of using fenced brushparks for fish production in Lake Chilwa, Malawi

Research paper thumbnail of IAA Production Systems in Malawi

Research paper thumbnail of Responsible aquaculture can aid food problems

Research paper thumbnail of WorldFish Centre. Impact of the development and dissemination of integrated aquaculture-agriculture technologies in Malawi

International research on natural resource management: advances in impact assessment, 2007

This chapter presents an ex post impact assessment of the development and dissemination of small-... more This chapter presents an ex post impact assessment of the development and dissemination of small-scale integrated aquaculture-agriculture (IAA) technologies in Malawi over more than 15 years by the WorldFish Centre and its national and international partners. The results indicate that the adoption of IAA technology in Malawi has improved total farm productivity by 10%, increased per hectare farm income by 134% and total farm income by 61%, and improved the technical efficiency of farming by almost 40%. In addition, the increased per capita consumption of fresh fish by about 208% and per capita consumption of dried fish by about 21% have resulted in an enhanced consumption of protein-rich foods. IAA has improved the sustainability and environment of the adopters' farms, reduced nitrogen loss by half and improved nitrogen use efficiency. The development and dissemination of IAA technologies in Malawi have also institutionalized the natural resource management approach within the M...

Research paper thumbnail of Culture-based production systems: Options for the chambo in Lake Malawi and Lake Malombe

Research paper thumbnail of Synthesis of aquaculture policy and development approaches in Africa

The WorldFish Center was tasked to undertake a study to access, collate and develop background ma... more The WorldFish Center was tasked to undertake a study to access, collate and develop background materials to produce an internationally linked and Africa-wide perspective on sectorally relevant policy issues. The specific objective of the study was to assess and define conditions and impact pathways, in Africa or elsewhere, where markets, policies, resources and technologies have combined to promote steady and sustainable growth of aquaculture, and where have been clear direct impacts on food supply, income, employment and consumption opportunities, as well as increase in supply that has led to stabilised prices. The study was also aimed at providing guidelines for scaling up the implementation of the synthesis study via Afri-FishNet (CAADP Fish Expert Pools) at the national and regional levels.

Research paper thumbnail of Influence of water quality parameters on Opsaridium microlepis (Günther 1864) catches in the Linthipe River catchment, central Malawi

Research paper thumbnail of Mitigation of food insecurity and poverty: the role of integrated agriculture — aquaculture (IAA) systems in Malawi

Research paper thumbnail of Land use and cover changes in the Likangala catchment of the Lake Chilwa basin, Malawi: implications for managing a tropical wetland

African Journal of Aquatic Science, Aug 1, 2003

ABSTRACT

Research paper thumbnail of A Farmer-participatory approach to aquaculture technology development & dissemination

Uganda Journal of Agricultural Sciences, 2004

Research paper thumbnail of Land use and cover changes in the Likangala catchment of the Lake Chilwa basin, Malawi: implications for managing a tropical wetland

African Journal of Aquatic Science, 2003

ABSTRACT

Research paper thumbnail of Changes in fish species diversity, size structure and distribution in the trawlable demersal zones of Lake Malawi, Malawi

A study was conducted to assess temporal and spatial changes in the trawlable demersal zones of L... more A study was conducted to assess temporal and spatial changes in the trawlable demersal zones of Lake Malawi. Data from surveys conducted in 1998 and 2020 targeting 120 stations covering a surface area of 9,647.97km2 was used. Trawling speed of Research Vessel Ndunduma was restricted to 4.6km/hr. Length frequency distribution was modelled with the probability density function for determining the likelihoods in the gamma distribution. Parameters for modal length and logistic modelling were guessed and Solver in Microsoft Excel 2021 was used to generate the best of fit values through iteration with GRG Nonlinear approach. The study determined fish diversity using the Shannon and Weiner relationship. The recent survey recorded fewer fish species (149) against 158 sampled in the previous survey. The overall catch rates in 2020 and 1998 ranged from 3.8kg/0.5hr to 2003.8kg/0.5hr and 28.7 kg/0.5 to 1,884.3 kg/0.5hr, respectively. Overall fish density in the 2020 and 1998 surveys was calcula...

Research paper thumbnail of Integrated agriculture-aquaculture production systems in southern Malawi

<title>Abstract</title> <p>Southern Malawi is characterized by the Rift valley ... more <title>Abstract</title> <p>Southern Malawi is characterized by the Rift valley and the Shire Highlands, which are dominated by the Zomba and Mulanje plateaux, and the Kirk Range. These mountainous areas are a source of various rivers and streams, which support small-scale integrated agriculture-aquaculture systems (IAA). The IAA systems were introduced to Malawi in 1986 by the WorldFish Center when a range of IAA technologies were developed and disseminated to farmers. The most common IAA system consists of fishponds, vegetables, fish, rice and irrigated maize. This system is practised by over 2,000 farmers in southern Malawi. The number of farmers practising this system has grown by 25% per year over the past 5 years because of the impact that this system has on household food security, income and environmental sustainability. Farmers practising IAA achieve yields of over 1,500 kg ha<sup>-1</sup> yr<sup>-1</sup> extrapolated from 450 m<sup>2</sup> ponds compared with 900 kg ha<sup>-1</sup> yr<sup>-1</sup> for non-integrated farms and twice as much annual household income (US$ 270) than non-IAA farms.</p>

Research paper thumbnail of Ecosystem approach

Research paper thumbnail of Natural resource-based livelihoods in the context of climate change in the Lake Chilwa Basin

Research paper thumbnail of Reconciling livelihoods and aquatic ecosystem resilience in the lakes of Malawi

Journal of Great Lakes Research, 2011

Research paper thumbnail of Investigations on the use of on-farm resources as pond inputs to culture Tilapia rendalli and Oreochromis shiranus on smallholder farms in rural Malawi

Aquaculture, 1993

... to culture Tilapia rendalli and Oreochromis shiranus on smallholder farms in rural Malawi* Fr... more ... to culture Tilapia rendalli and Oreochromis shiranus on smallholder farms in rural Malawi* Fredson JKT Chikafumbwa, Barry A. Costa-Pierce, Daniel M. Jamu, Winston K. Kadongola ... Martinez-Palacios, CA, Galvan Cruz, R., Olvera Novoa, MA and Chavez-Martinez, C., 1988. ...

Research paper thumbnail of Ten-year simulations of organic matter concentrations in tropical aquaculture ponds using the multiple pool modeling approach

Aquacultural Engineering, 2001

ABSTRACT The accumulation rate of organic matter has been used to develop guidelines on sediment ... more ABSTRACT The accumulation rate of organic matter has been used to develop guidelines on sediment management in tropical aquaculture ponds. However, there is conflicting evidence as to the rate of sediment organic matter accumulation and whether steady state concentrations are achieved in the short term (&lt;10 years) in aquaculture ponds. A simulation study using the multiple pool modeling approach (Multi-G model) was conducted to determine the long-term dynamics of sediment organic matter and to establish whether steady state concentrations could be achieved in tropical aquaculture ponds. The Multi-G model, which recognizes the existence of different organic matter pools, each with its own decay rate constant was run as a sub-model of an integrated aquaculture–agriculture system (IAAS) model. The simulation study was conducted for representative management scenarios for new integrated ponds receiving artificial feed, chicken manure, or a combination of chicken manure and crop wastes. The model was run for 10 years using a 0.125 day time step, and each year&#39;s simulation consisted of a wet and a dry season, and fallow periods between crops that totalled 121 days for the year. Pond sediment organic matter concentrations increased over time for all input regimes in the following order: chicken manure×plant waste &gt;chicken manure &gt;artificial feed. Simulated organic matter concentration decreased in the first 4–5 years in ponds receiving chicken manure and artificial feed. Contrary to predictions of models that used a single decay rate constant for the organic matter, steady state sediment organic matter were not achieved within the first 5 years of production. These results were consistent with those obtained from long term sediment organic matter experiments in tropical aquaculture ponds. The results show that the multiple pool modeling approach may be more applicable to the simulation of pond sediment organic matter dynamics than those that assume organic matter to consist of a single pool decaying at a single rate.

Research paper thumbnail of Abundance and distribution of fish in the lower Mnembo River, Malawi-Mozambique

African Journal of Ecology, 2007

... semble moins souffrir de l&amp;amp;#x27;influence des populations humaines, avec la grand... more ... semble moins souffrir de l&amp;amp;#x27;influence des populations humaines, avec la grande abondance de Barbus et une présence affirmée des espèces de ... It is suspected that the Mnembo which flows from Mozambique is the lake&amp;amp;#x27;s major source of water (Jamu, Delaney &amp;amp;amp; Campbell, 2006 ...

Research paper thumbnail of Relationship between Secchi disk visibility and chlorophyll a in aquaculture ponds

Research paper thumbnail of A preliminary study on the feasibility of using fenced brushparks for fish production in Lake Chilwa, Malawi

Research paper thumbnail of IAA Production Systems in Malawi

Research paper thumbnail of Responsible aquaculture can aid food problems

Research paper thumbnail of WorldFish Centre. Impact of the development and dissemination of integrated aquaculture-agriculture technologies in Malawi

International research on natural resource management: advances in impact assessment, 2007

This chapter presents an ex post impact assessment of the development and dissemination of small-... more This chapter presents an ex post impact assessment of the development and dissemination of small-scale integrated aquaculture-agriculture (IAA) technologies in Malawi over more than 15 years by the WorldFish Centre and its national and international partners. The results indicate that the adoption of IAA technology in Malawi has improved total farm productivity by 10%, increased per hectare farm income by 134% and total farm income by 61%, and improved the technical efficiency of farming by almost 40%. In addition, the increased per capita consumption of fresh fish by about 208% and per capita consumption of dried fish by about 21% have resulted in an enhanced consumption of protein-rich foods. IAA has improved the sustainability and environment of the adopters' farms, reduced nitrogen loss by half and improved nitrogen use efficiency. The development and dissemination of IAA technologies in Malawi have also institutionalized the natural resource management approach within the M...

Research paper thumbnail of Culture-based production systems: Options for the chambo in Lake Malawi and Lake Malombe

Research paper thumbnail of Synthesis of aquaculture policy and development approaches in Africa

The WorldFish Center was tasked to undertake a study to access, collate and develop background ma... more The WorldFish Center was tasked to undertake a study to access, collate and develop background materials to produce an internationally linked and Africa-wide perspective on sectorally relevant policy issues. The specific objective of the study was to assess and define conditions and impact pathways, in Africa or elsewhere, where markets, policies, resources and technologies have combined to promote steady and sustainable growth of aquaculture, and where have been clear direct impacts on food supply, income, employment and consumption opportunities, as well as increase in supply that has led to stabilised prices. The study was also aimed at providing guidelines for scaling up the implementation of the synthesis study via Afri-FishNet (CAADP Fish Expert Pools) at the national and regional levels.

Research paper thumbnail of Influence of water quality parameters on Opsaridium microlepis (Günther 1864) catches in the Linthipe River catchment, central Malawi

Research paper thumbnail of Mitigation of food insecurity and poverty: the role of integrated agriculture — aquaculture (IAA) systems in Malawi

Research paper thumbnail of Land use and cover changes in the Likangala catchment of the Lake Chilwa basin, Malawi: implications for managing a tropical wetland

African Journal of Aquatic Science, Aug 1, 2003

ABSTRACT

Research paper thumbnail of A Farmer-participatory approach to aquaculture technology development & dissemination

Uganda Journal of Agricultural Sciences, 2004

Research paper thumbnail of Land use and cover changes in the Likangala catchment of the Lake Chilwa basin, Malawi: implications for managing a tropical wetland

African Journal of Aquatic Science, 2003

ABSTRACT

Research paper thumbnail of Changes in fish species diversity, size structure and distribution in the trawlable demersal zones of Lake Malawi, Malawi

A study was conducted to assess temporal and spatial changes in the trawlable demersal zones of L... more A study was conducted to assess temporal and spatial changes in the trawlable demersal zones of Lake Malawi. Data from surveys conducted in 1998 and 2020 targeting 120 stations covering a surface area of 9,647.97km2 was used. Trawling speed of Research Vessel Ndunduma was restricted to 4.6km/hr. Length frequency distribution was modelled with the probability density function for determining the likelihoods in the gamma distribution. Parameters for modal length and logistic modelling were guessed and Solver in Microsoft Excel 2021 was used to generate the best of fit values through iteration with GRG Nonlinear approach. The study determined fish diversity using the Shannon and Weiner relationship. The recent survey recorded fewer fish species (149) against 158 sampled in the previous survey. The overall catch rates in 2020 and 1998 ranged from 3.8kg/0.5hr to 2003.8kg/0.5hr and 28.7 kg/0.5 to 1,884.3 kg/0.5hr, respectively. Overall fish density in the 2020 and 1998 surveys was calcula...

Research paper thumbnail of Integrated agriculture-aquaculture production systems in southern Malawi

<title>Abstract</title> <p>Southern Malawi is characterized by the Rift valley ... more <title>Abstract</title> <p>Southern Malawi is characterized by the Rift valley and the Shire Highlands, which are dominated by the Zomba and Mulanje plateaux, and the Kirk Range. These mountainous areas are a source of various rivers and streams, which support small-scale integrated agriculture-aquaculture systems (IAA). The IAA systems were introduced to Malawi in 1986 by the WorldFish Center when a range of IAA technologies were developed and disseminated to farmers. The most common IAA system consists of fishponds, vegetables, fish, rice and irrigated maize. This system is practised by over 2,000 farmers in southern Malawi. The number of farmers practising this system has grown by 25% per year over the past 5 years because of the impact that this system has on household food security, income and environmental sustainability. Farmers practising IAA achieve yields of over 1,500 kg ha<sup>-1</sup> yr<sup>-1</sup> extrapolated from 450 m<sup>2</sup> ponds compared with 900 kg ha<sup>-1</sup> yr<sup>-1</sup> for non-integrated farms and twice as much annual household income (US$ 270) than non-IAA farms.</p>

Research paper thumbnail of Ecosystem approach

Research paper thumbnail of Natural resource-based livelihoods in the context of climate change in the Lake Chilwa Basin

Research paper thumbnail of Reconciling livelihoods and aquatic ecosystem resilience in the lakes of Malawi

Journal of Great Lakes Research, 2011

Research paper thumbnail of Investigations on the use of on-farm resources as pond inputs to culture Tilapia rendalli and Oreochromis shiranus on smallholder farms in rural Malawi

Aquaculture, 1993

... to culture Tilapia rendalli and Oreochromis shiranus on smallholder farms in rural Malawi* Fr... more ... to culture Tilapia rendalli and Oreochromis shiranus on smallholder farms in rural Malawi* Fredson JKT Chikafumbwa, Barry A. Costa-Pierce, Daniel M. Jamu, Winston K. Kadongola ... Martinez-Palacios, CA, Galvan Cruz, R., Olvera Novoa, MA and Chavez-Martinez, C., 1988. ...

Research paper thumbnail of Ten-year simulations of organic matter concentrations in tropical aquaculture ponds using the multiple pool modeling approach

Aquacultural Engineering, 2001

ABSTRACT The accumulation rate of organic matter has been used to develop guidelines on sediment ... more ABSTRACT The accumulation rate of organic matter has been used to develop guidelines on sediment management in tropical aquaculture ponds. However, there is conflicting evidence as to the rate of sediment organic matter accumulation and whether steady state concentrations are achieved in the short term (&lt;10 years) in aquaculture ponds. A simulation study using the multiple pool modeling approach (Multi-G model) was conducted to determine the long-term dynamics of sediment organic matter and to establish whether steady state concentrations could be achieved in tropical aquaculture ponds. The Multi-G model, which recognizes the existence of different organic matter pools, each with its own decay rate constant was run as a sub-model of an integrated aquaculture–agriculture system (IAAS) model. The simulation study was conducted for representative management scenarios for new integrated ponds receiving artificial feed, chicken manure, or a combination of chicken manure and crop wastes. The model was run for 10 years using a 0.125 day time step, and each year&#39;s simulation consisted of a wet and a dry season, and fallow periods between crops that totalled 121 days for the year. Pond sediment organic matter concentrations increased over time for all input regimes in the following order: chicken manure×plant waste &gt;chicken manure &gt;artificial feed. Simulated organic matter concentration decreased in the first 4–5 years in ponds receiving chicken manure and artificial feed. Contrary to predictions of models that used a single decay rate constant for the organic matter, steady state sediment organic matter were not achieved within the first 5 years of production. These results were consistent with those obtained from long term sediment organic matter experiments in tropical aquaculture ponds. The results show that the multiple pool modeling approach may be more applicable to the simulation of pond sediment organic matter dynamics than those that assume organic matter to consist of a single pool decaying at a single rate.

Research paper thumbnail of Abundance and distribution of fish in the lower Mnembo River, Malawi-Mozambique

African Journal of Ecology, 2007

... semble moins souffrir de l&amp;amp;#x27;influence des populations humaines, avec la grand... more ... semble moins souffrir de l&amp;amp;#x27;influence des populations humaines, avec la grande abondance de Barbus et une présence affirmée des espèces de ... It is suspected that the Mnembo which flows from Mozambique is the lake&amp;amp;#x27;s major source of water (Jamu, Delaney &amp;amp;amp; Campbell, 2006 ...

Research paper thumbnail of Relationship between Secchi disk visibility and chlorophyll a in aquaculture ponds

Research paper thumbnail of The natural history and fisheries ecology of Lake Chilwa, southern Malawi

Lancet, 2011

Lake Chilwa produces between zero and 24,000 metric tons of fish per year, making it one of the m... more Lake Chilwa produces between zero and 24,000 metric tons of fish per year, making it one of the most productive but variable lakes in Africa. The size of the lake varies seasonally and among years, sometimes drying completely. Its surrounding wetland and floodplain provide habitat for a diversity of birds and economically valuable grasses and reeds. When the lake has water, there is considerable activity on its shores and temporary fishing villages spring up. People move in and out of the lake basin in concert with these seasonal and longer term changes. This paper examines the environmental dynamics of Lake Chilwa and its surrounding wetlands, presents an overview of the socio-economic context of the area and discusses threats to this resilient system that might occur as a result of climate change. We conclude that management of Lake Chilwa must place the lake in the wider economic and ecological system in which it is situated. Ultimately, land-use practices within the basin present more of a threat to the resilience of the fishery and people's livelihoods than overfishing or a strict focus on the lake's resources. These perspectives present significant challenges to conventional fisheries governance.