Browsing by Author "Nguyen, T.T.T."

Now showing 1 - 4 of 4

Alien Species in Aquaculture and Biodiversity: A Paradox in Food Production
(AMBIO: A Journal of the Human Environment, 2009) de Silva, S.S.; Nguyen, T.T.T.; Turchini, G.M.; Amarasinghe, U.S.; Abery, N.W.
Aquaculture is seen as an alternative to meeting the widening gap in global rising demand and decreasing supply for aquatic food products. Asia, the epicenter of the global aquaculture industry, accounts for over 90% of the global aquaculture production quantity and about 80% of the value. Asian aquaculture, as with global aquaculture, is dependent to a significant extent on alien species, as is the case for all the major food crops and husbanded terrestrial animals. However, voluntary and or accidental introduction of exotic aquatic species (alien species) is known to negatively impact local biodiversity. In this relatively young food production industry, mitigating the dependence on alien species, and thereby minimizing potential negative impacts on biodiversity, is an imperative for a sustainable future. In this context an attempt is made in this synthesis to understand such phenomena, especially with reference to Asian inland finfish, the mainstay of global aquaculture production. It is pointed out that there is potential for aquaculture, which is becoming an increasingly important food production process, not to follow the past path of terrestrial food crops and husbanded animals in regard to their negative influences on biodiversity.
An evaluation of the role and impacts of alien finfish in Asian inland aquaculture
(Aquaculture Research, 2006) de Silva, S.S.; Nguyen, T.T.T.; Abery, N.W.; Amarasinghe, U.S.
Asia dominates global aquaculture production accounting for over 80% of the total and the mainstay in Asian aquaculture is finfish. Over the years, Asia has experienced a number of inter-continental and intra-continental transfers/introductions/translocation of finfish species, between nations and watersheds, beyond their natural range of distribution, primarily for aquaculture development. In this article all such species are referred to as alien species. An attempt is made to evaluate the importance of the production of alien species in selected Asian nations, using statistics of the Food and Agriculture Organization. Also, negative effects, if any, based on literature surveys, of alien species in relation to displacement of indigenous species, and on biodiversity and/or genetic diversity together with associated pathogen transfers are evaluated. The major alien species, based on their significance to Asian inland aquaculture considered, are the tilapias, catfish, Chinese and Indian major carps and common carp. It is estimated that currently alien species account for nearly 12% of the cultured finfish production (2.6 million tonnes) in Asia, valued at US$ 2.59 billion, and the contribution exceeds 40% when Asian countries excluding China are taken into consideration. Inland finfish aquaculture in some Asian nations, such as Indonesia and the Philippines, is predominated by alien species, and in some others, e.g. Bangladesh and India, the contribution from alien species has been increasing steadily. It is suggested that overall alien finfish species have done little ecological harm to native flora and fauna. However, in the wake of increasing anthropogenic development taking place in watersheds the resulting environments are often made unconducive to indigenous species but not to some alien species, thereby potentially and indirectly making the latter invasive.
Better-practice approaches for culture-based fisheries development in Asia
(Australian Centre for International Agricultural Research, 2006) de Silva, S.S.; Amarasinghe, U.S.; Nguyen, T.T.T.
Enhancing Rural Farmer Income through Fish Production:Secondary use of water resources in Sri Lanka and elsewhere
(Success Stories in Asian Aquaculture, 2009) Amarasinghe, U.S.; Nguyen, T.T.T.
The inland fishery of Sri Lanka has been essentially a capture fishery from major and medium scale irrigation reservoirs. However, small-sized (<100 ha) minor irrigation reservoirs are also frequent in the country. Naturally, these water bodies are incapable of supporting self-recruiting fisheries, but can be utilized to enhance the fish production significantly through development of culture-based fisheries (CBF), without causing impediment on their primary use . CBF in village reservoirs of Sri Lanka is a communal activity, and the water bodies used for this purpose are rural, thus benefiting rural communities by augmenting their traditional means of incomes and also increased food-fish availability. CBF is a non-water consumptive secondary activity that brings into play communities that were not engaged in fishery-related activities previously. It is also environmentally friendly, as the only external input is the seed stock. CBF is a present day paradigm of ecosystem-based aquaculture. CBF has developed as a result of coordinated efforts of a multitude of stakeholders, working in unison, resulting in developing and improving the knowledge base, facilitating required legislative change, such as in the case of amendment of the Agrarian Development Act, and issue of a governmental decree permitting and encouraging CBF in Sri Lanka and community organizations. CBF is a sustainable activity that also impinges on bringing better harmony amongst rural communities. Most importantly, CBF brought about socio-economic benefits to the rural communities. In a similar vein, CBF activities are being adopted in the mountainous region of Northern Vietnam, and in reservoir coves and flood plain depressions in Lao PDR, with results complimentary to those from Sri Lanka. In all the instances, CBF activities have been sustainable with a strong community-based management strategy driving it. In all the countries, rural farming communities are adopting CBF in suitable water bodies with resulting improved income generation and food-fish availability to the rural communities.