ReviewCan “Integrated Multi-Trophic Aquaculture (IMTA)” adapt to climate change in coastal Bangladesh?
Introduction
Bangladesh is one of the most suitable countries in the world for coastal aquaculture because of its favorable biophysical resources and agro-climatic conditions. Its coastal aquaculture sector is dominated by export-oriented freshwater prawn (Macrobrachium rosenbergii) and saltwater shrimp (Penaeus monodon) farming,1 both known as “white gold” because of their export value (Islam, 2009, Ahmed, 2013). The coastal aquaculture sector has become a multimillion dollar industry in Bangladesh due to huge demand for prawn and shrimp in global markets, particularly the European Union and the United States of America (USA). In 2014–2015,2 Bangladesh earned US$506 million from exporting prawn and shrimp (FRSS, 2016). Thus, prawn and shrimp farming play an important role in the economy of Bangladesh.
Despite economic benefits, the culture of prawn and shrimp in coastal Bangladesh has recently been threatened by climate change that could have severe effects on export earnings and further consequences for the economy of Bangladesh (Ahmed, 2013, Ahmed et al., 2014, Ahmed and Diana, 2015a, Ahmed and Diana, 2015b). According to the Global Climate Risk Index, Bangladesh was ranked 1st in 2012 among countries vulnerable to climate change while it is ranked 6th in 2016 (Harmeling and Eckstein, 2012, Kreft et al., 2015). Considering vulnerability of social-ecological systems in coastal Bangladesh to the effects of climate change on prawn and shrimp farming, adaptation strategies must be developed. Adapting coastal aquaculture to climate change will require a combination of strategies and policies.
One of the adaptation strategies to climate change is “Integrated Multi-Trophic Aquaculture (IMTA)” (Sreejariya et al., 2011, Chung et al., 2013, Geere, 2014, Clements and Chopin, 2016). IMTA is a process of growing different species of finfish and shellfish with seaweeds from different trophic levels in an integrated farm. IMTA is a practice in which the by-products from one species are recycled to become inputs (feed, nutrients) for another. The principle of IMTA is the co-cultivation of fed fish, organic extractive species, and inorganic extractive species (Troell et al., 2009, Chopin, 2011, Chopin et al., 2012). The concept of IMTA is to create balanced systems for environmental sustainability, economic viability, and social acceptability (Barrington et al., 2009). IMTA is currently operated in over 40 countries on experimental and commercial basis, including Canada, Chile, China, Japan, the USA, and many European countries (Chopin, 2011). In Bangladesh, IMTA has taken recent consideration for research and development to diversify production (Sarker et al., 2014, Kibria, 2016).
This review paper illustrates the impacts of climate change on coastal aquaculture in Bangladesh. Considering the effects of climate change on coastal aquaculture, this article identifies the opportunities and challenges for the development of IMTA in coastal Bangladesh. The aim of this paper is to highlight key issues in developing IMTA as an adaptation strategy to climate change.
Section snippets
Coastal Bangladesh: land of multiple disasters
Bangladesh is one of the most disaster-prone countries in the world because of its geographical location (Fig. 1). Bangladesh is considered as “nature's laboratory on disasters” due to existing most climatic threats. Coastal Bangladesh is subject to seasonal changes in climatic conditions. The increasing risk from a combination of climatic variables, including: (1) cyclone, (2) drought, (3) flood, (4) rainfall, (5) salinity, (6) sea level rise, and (7) sea surface temperature (Ahmed et al., 2013
Revolutionary development of coastal aquaculture
As part of agricultural development in coastal Bangladesh, prawn and shrimp farming were initiated in the 1970s and began to expand rapidly in the 1980s. Since the 1980s, prawn and shrimp culture have undergone a revolutionary development in coastal Bangladesh (Azad et al., 2009, Ahmed, 2013). Thousands of farmers have converted their low-lying rice fields to prawn and shrimp farms, locally known as “gher”. The practice of prawn and shrimp intercropping6
Culture species
In coastal Bangladesh, IMTA would be a novel process of growing different fed fish (shrimp, finfish) and shellfish with seaweeds in an integrated farm (Fig. 4). In IMTA systems, fed fish can be placed at the upper and middle trophic levels while organic extractive species (mussels) at the middle and bottom level so that they can consume particulate organic nutrients (waste feed and faeces). Seaweeds could be placed a little far away of fed and organic extractive species so that they can consume
Environmental benefits
The development of IMTA in coastal Bangladesh could bring a wide range of environmental benefits, which in turn may help to tackle climate change (Fig. 5). IMTA would reduce ecological effects on natural resources as the adoption of IMTA in coastal Bangladesh can be an approach for biodiversity conservation and ecosystem services. IMTA could offer a balanced ecosystem approach that will benefit the environment and society (Chopin, 2011).
Shrimp culture in open-water IMTA can be environmentally-
Challenges for IMTA
In spite of potential benefits and adaptation to climate change, the development of IMTA in coastal Bangladesh could face various social, economic, technological, and environmental challenges. IMTA is a rather new feature of the aquaculture industry in Bangladesh, and thus, social acceptability is a prerequisite for its development (Barrington et al., 2010). The adoption of IMTA in coastal Bangladesh could face various social conflicts including theft, robbery, and vandalism, and thus, negative
Conclusions
The coastal aquaculture sector in Bangladesh is particularly vulnerable to climate change. Different climatic variables, including cyclone, drought, flood, rainfall, salinity, sea level rise, and sea surface temperature have had adverse effects on land-based prawn and shrimp farming. Open-water IMTA could be developed to cope with the challenges of vulnerability to the effects of climate change on coastal aquaculture. There are great opportunities for the development of IMTA in coastal
Acknowledgments
The study was supported through the Alexander von Humboldt Foundation, Germany. The study was a part of the first author's research work under the Georg Forster Research Fellowship by the Alexander von Humboldt Foundation at the Leibniz Center for Tropical Marine Ecology (ZMT), Bremen, Germany and part of the second author’s long term involvement in rural Bangladesh. Earlier draft of this paper was presented at the ZMT seminar in April 2015. Thanks to André Klicpera for drawing IMTA figure. We
References (109)
Linking prawn and shrimp farming towards a green economy in Bangladesh: confronting climate change
Ocean Coast. Manag.
(2013)- et al.
Coastal to inland: expansion of prawn farming for adaptation to climate change in Bangladesh
Aquac. Rep.
(2015) - et al.
Threatening “white gold”: impacts of climate change on shrimp farming in coastal Bangladesh
Ocean Coast. Manag.
(2015) - et al.
Prawn postlarvae fishing in coastal Bangladesh: challenges for sustainable livelihoods
Mar. Policy
(2010) - et al.
The impact of climate change on prawn postlarvae fishing in coastal Bangladesh: socioeconomic and ecological perspectives
Mar. Policy
(2013) - et al.
Stratigraphic evolution of the late Holocene Ganges-Brahmaputra lower delta plain
Sediment. Geol.
(2003) Mangrove forests: resilience, protection from tsunamis, and responses to global climate change
Estuar. Coast. Shelf Sci.
(2008)- et al.
Restocking and stock enhancement of coastal fisheries: potential, problems and progress
Fish. Res.
(2006) - et al.
Long term water level and surface temperature changes in the lagoons of the southern and eastern Baltic
Oceanologia
(2011) - et al.
Farmer's perception and adaptation practices to cope with drought: perspectives from Northwestern Bangladesh
Int. J. Disaster Risk Reduct.
(2012)
Carbon emissions and the drivers of deforestation and forest degradation in the tropics
Curr. Opin. Environ. Sustain.
Bioremediation efficiency of Gracilaria verrucosa for an integrated multi-trophic aquaculture system with Pseudosciaena crocea in Xiangshan harbor, China
Aquaculture
From pond to plate: towards a twin-driven commodity chain in Bangladesh shrimp aquaculture
Food Policy
Development of an integrated multi-trophic aquaculture (IMTA) system for tropical marine species in southern cebu, Central Philippines
Aquac. Rep.
Towards an ecosystem approach to aquaculture: assessment of sustainable shellfish cultivation at different scales of space, time and complexity
Aquaculture
Impacts of shrimp farming in Bangladesh: challenges and alternatives
Ocean Coast. Manag.
Rapid rise in effective sea-level in southwest Bangladesh: its causes and contemporary rates
Glob. Planet. Change
Overcoming the impacts of aquaculture on the coastal zone
Ocean Coast. Manag.
Absorption efficiency of blue mussels (Mytilus edulis and M. trossulus) feeding on Atlantic salmon (Salmo salar) feed and fecal particulates: implications for integrated multi-trophic aquaculture
Aquaculture
A review of the main bacterial fish diseases in mariculture systems
Aquaculture
Seaweed cultivation in Bangladesh: problems and potentials
Kasetsart Univ. Fish. Res. Bull.
Fishing for prawn larvae in Bangladesh: an important coastal livelihood causing negative effects on the environment
Ambio
Rice-fields to prawn farms: a blue revolution in southwest Bangladesh?
Aquac. Int.
Community-based climate change adaptation strategies for integrated prawn-fish-rice farming in Bangladesh to promote social-ecological resilience
Rev. Aquac.
Carbon cycling and storage in mangrove forests
Annu. Rev. Mar. Sci.
Coastal aquaculture development in Bangladesh: unsustainable and sustainable experiences
Environ. Manag.
Integrated multi-trophic aquaculture (IMTA) in marine temperate waters
Social aspects of the sustainability of integrated multi-trophic aquaculture
Aquac. Int.
Managing Seagrasses for Resilience to Climate Change
Progression of the integrated multi-trophic aquaculture (IMTA) concept and upscaling of IMTA systems towards commercialization
Aquac. Eur.
Open-water integrated multi-trophic aquaculture: environmental biomitigation and economic diversification of feed aquaculture by extractive aquaculture
Rev. Aquac.
Coastal Fishers' Livelihood in Peril: Sea Surface Temperature and Tropical Cyclones in Bangladesh
Installing kelp forests/seaweed beds for mitigation and adaptation against global warming: Korean project overview
ICES J. Mar. Sci.
The impacts of deep-sea fisheries on benthic communities: a review
ICES J. Mar. Sci.
Ocean acidification and marine aquaculture in North America: potential impacts and mitigation strategies
Rev. Aquac.
Science and Innovation for Development
A global dataset of Palmer drought severity index for 1870–2002: relationship with soil moisture and effects of surface warming
J. Hydrometeorol.
Cyclones in a changing climate: the case of Bangladesh
Clim. Dev.
Climate Change, Soil Salinity, and the Economics of High-yield Rice Production in Coastal Bangladesh
Responsible aquaculture in 2050: valuing local conditions and human innovations will be key to success
BioScience
National Plan for Disaster Management 2010–2015
National Fish Week 2014 Compendium
National Fish Week 2016 Compendium
Mangroves among the most carbon-rich forests in the tropics
Nat. Geosci.
The role of coastal plant communities for climate change mitigation and adaptation
Nat. Clim. Change
Desert in the Delta: a Report on the Environmental, Human Rights and Social Impacts of Shrimp Production in Bangladesh
The World's Mangroves1980–2005
The State of World Fisheries and Aquaculture: Contributing to Food Security and Nutrition for All
Potential impacts of global climate change on freshwater fisheries
Rev. Fish Biol. Fish.
Polyculture of tilapia penaeid shrimp
Glob. Aquac. Advocate
Cited by (23)
Coastline protection and restoration: A comprehensive review of China's developmental trajectory
2024, Ocean and Coastal ManagementIdentifying the interfaces between perceived multi-hazards and socio-ecological risks to strengthen local adaptations
2024, Journal of Environmental ManagementIntegration of multitrophic aquaculture approach with marine energy projects for management and restoration of coastal ecosystems of India
2022, Ecological EngineeringCitation Excerpt :Each IMTA component/module's spatial location depends on many variables such as ocean currents, depth, location, and climate of the target area. However, rather than seaweed, upper and middle water depths generally constitute fish habitats, whereas the habitats of organic extractive species are present in the middle and bottom waters (Ahmed and Glaser, 2016). The implementation of IMTA projects decreases waste and increases the productivity of cultivated species (Chopin et al., 2008).
Cumulative climatic stressors strangles marine aquaculture: Ancillary effects of COVID 19 on Spanish mariculture
2022, AquacultureCitation Excerpt :For that apart of the current lines of research in aquaculture are directed towards systems that favour the development of more sustainable aquaculture, seeking alternative sources of protein for feed supply, diversifying alternative sources of protein for feed supply, diversifying cultivable species of lower trophic level and implementing more environmentally friendly, such as integrated multi-trophic aquaculture systems (IMTA; Bostock et al., 2010; FAO, 2009). IMTA could provide a wide range of environmental services (Ahmed and Glaser, 2016), for example, reducing eutrophication risk because the dissolved nutrients provided by fish farming could be indirectly transfer to the filter feeders though primary producers (Sanz-Lazaro and Sanchez-Jerez, 2020). Developing IMTA models can provide quantitative tools for the development and management of these production systems (Ren et al., 2012) may help to design farming systems that are more resilient to climate change.
Evaluating the contribution of diversified shrimp-rice agroecosystems in Bangladesh and West Bengal, India to social-ecological resilience
2017, Ocean and Coastal ManagementCitation Excerpt :Carbon sequestration rates for integrated agriculture-aquaculture systems were estimated at 21.2 t ha−1 y−1 but it was noted that practices such as pond sediment removal could release greenhouse gases (Ahmed et al., 2017). If carbon sensitive management strategies could be widely instigated, diversified shrimp-rice agroecosystems could bolster blue carbon capture and storage, contributing to climate change mitigation (Ahmed and Glaser, 2016a, 2016b). Technology adoption by farmers may be motivated by production enhancement (yield and quality), efficiency gains (per unit input, labour or land) and resistance and resilience (to pests, weeds, drought or water-logging).