Digital library

  • Integrated mariculture - A global review

    While the concept and practice of integrated aquaculture is well-known in inland environments particularly in Asia, in the marine environment, it has been much less reported. However, in recent years the idea of integrated aquaculture has been often considered a mitigation approach against the excess nutrients/organic matter generated by intensive aquaculture activities particularly in marine waters. In this context, integrated multitrophic aquaculture (IMTA) has emerged, where multitrophic refers to the explicit incorporation of species from different trophic positions or nutritional levels in the same system. Integrated marine aquaculture can cover a diverse range of co-culture/ farming practices, including IMTA, and even more specialized forms of integration such as mangrove planting with aquaculture, called aquasilviculture. Integrated mariculture has many benefits, among wich bioremediation is one of the most relevant, and yet is not valued in its real social and economic potential although the present document provides some initial economic estimates for the integration benefits derived from bioremediation. Reducing risks is also an advantage and profitable aspect of farming multiple species in marine environments (as in freshwaters): a diversified product portfolio increases the resilience of the operation, for instance when facing changing prices for one of the farmed species or the accidental catastrophic destruction of a crop. Yet such perspectives are far from been considered in mariculture where, on the contrary, there is a tendency to monoculture.

    Modern integrated mariculture systems must be developed in order to assist sustainable expansion of the sector in coastal and marine ecosystems thus responding to the global increase for seafood demand but with a new paradigm of more efficient food production systems. Successful integrated mariculture operations must consider all relevant stakeholders into its development plan government, industry, academia, the general public and non-governmental organizations must work together and the role of integrated mariculture within integrated coastal zone management plans must be clearly defined.

    There is a need to facilitate commercialization and promote effective legislation for the support and inclusion of integrated mariculture through adequate incentives particularly considering the reduction of environmental costs associated to monoculture farming. Bioremediation of fed aquaculture impacts through integrated aquaculture is a core benefit but the increase of production, more diverse and secure business, and larger profits should not be underestimated as additional advantages.

    In many cases, more research is needed to further integrated mariculture – particularly regarding the technical implementation of a farm. At this level, an important issue is to adopt adequate management practices that avoid or reduce the likelihood of disease transmission within and between aquaculture facilities or to the natural aquatic fauna. Also, careful consideration should be paid to the selection of species used in polyculture or integrated multitrophic aquaculture to reduce potential stress and suffering of culture individuals. Integrated aquaculture should be looked upon as a very important tool to facilitate the growth of marine aquaculture and promote sustainable development

    Author(s): Doris Soto

  • Integrated mariculture: asking the right questions

    Reducing negative environmental impacts from aquaculture activities is a key issue for ensuring long-term sustainability of the industry. This study examines the major findings and methodology aspects from 28 peer-reviewed studies on marine aquaculture systems integrating fed and extractive organisms. All studies include seaweeds as extractive organisms. The main objective was to analyse the degree of relevance these findings have for large-scale implementation of integrated mariculture practices, and to identify necessary research areas for a future research agenda.The following directions for future research were identified: (1) understand in detail the important biological/biochemical processes in closed recirculating and open seaweed culture systems; (2) conduct research into these advanced aquaculture technologies at scales relevant to commercial implementation or suitable for extrapolation; (3) broaden the focus to include factors affecting seaweed growth and uptake capacity; (4) improve experimental design for statistical calculations; (5) attain a detailed understanding of the temporal variability in seaweed-filtered mariculture systems; (6) define numerical design parameters critical for engineers in designing commercial recirculation systems with seaweed filters; (7) study the influences of location-specific parameters, such as latitude, climate and local seaweed strains/species, on seaweed filter performance; (8) include economic components, considering the added value of seaweeds, and feasibility aspects; (9) analyse the role and function of integrated aquaculture practices for improved environmental, economic, and social acceptability within the broader perspective of integrated coastal management initiatives; and (10) develop educational, training and financial incentive approaches to transfer these novel and somewhat complex technologies of integrated mariculture from the scientists to the industry.

    Author(s): Yarish, Charles N. Kautsky, A.H. Buschmann, T. Chopin, A. Neori, C. Halling, M. Troell

  • Integrated multi-trophic aquaculture (IMTA) in marine temperate waters

    What is important is that the appropriate organisms are chosen based on the functionsthey have in the ecosystem, their economic value or potential, and their acceptance byconsumers. While IMTA likely occurs due to traditional or incidental, adjacent cultureof dissimilar species in some coastal areas (Troellet al., 2003), deliberately designedIMTA sites are, at present, less common. Moreover, they are presently simplifiedsystems, like fish/seaweed/shellfish. In the future, more advanced systems with severalother components for different functions, or similar functions but different size rangesof organic particles, will have to be designed (Chopin, 2006).The aim is to increase long-term sustainability and profitability per cultivation unit(not per species in isolation as is done in monoculture), as the wastes of one crop (fedanimals) are converted into fertilizer, food and energy for the other crops (extractiveplants and animals), which can in turn be sold on the market. Feed is one of the coreoperational costs of finfish aquaculture operations. Through IMTA, some of thefood, nutrients and energy considered lost in finfish monoculture are recaptured andconverted into crops of commercial value, while biomitigation takes place. In this wayall the cultivation components have an economic value, as well as a key role in servicesand recycling processes of the system, the harvesting of the three types of cropsparticipating in the export of nutrients outside of the coastal ecosystem.IMTA is considered more sustainable than the common monoculture systems – thatis a system of aquaculture where only one species is cultured – in that fed monoculturestend to have an impact on their local environments due to their dependence ofsupplementation with an exogenous source of food and energy without mitigation(Chopinet al., 2001). For some twenty years now, many authors have shown that thisexogenous source of energy (e.g. fish food) can have a substantial impact on organicmatter and nutrient loading in marine coastal areas (Gowen and Bradbury, 1987; Folkeand Kautsky, 1989; Chopinet al., 1999; Cromey, Nickell and Black, 2002), affectingthe sediments beneath the culture sites and producing variations in the nutrientcomposition of the water column (Chopinet al., 2001).

    Author(s):

  • Integrated Multi-Trophic Aquaculture - Ancient, Adaptable Concept Focuses On Ecological Integration

    In integrated multi-trophic aquaculture, farmers combine the cultivation of fed species such as finfish or shrimp with extractive seaweeds, aquatic plants and shellfish and other invertebrates that recapture organic and inorganic particulate nutrients for their growth. Such systems take advantage of synergistic interactions among species while biomitigation takes place for greater environmental and economic stability, as well as societal acceptability. Culture organisms must be chosen based on their complementary functions in the ecosystem, as well as economic potential.

    Author(s): Thierry Chopin

  • Integrated Multi-Trophic Aquaculture Part I. Responsible Practice Provides Diversified Products, Biomitigation

    Integrated multi-trophic aquaculture involves cultivating fed species with extractive species that  utilize the inorganic and organic wastes from aquaculture for their growth. The mix of organisms of different trophic levels mimics the functioning of natural ecosystems. All the cultivation components have commercial value, as well as key roles in recycling processes and biomitigating services. Some of the externalities of fed monoculture are internalized, increasing the overall sustainability and long-term profitability of aquaculture farms.

    Author(s): Thierry Chopin, Max Troell, Gregor K. Reid, Duncan Knowler, Shawn M. C. Robinson, Amir Neori, Alejandro H. Buschmann, Shaojun Pang

  • Integrated Multi-Trophic Aquaculture Part II. Increasing IMTA Adoption

    Integrated multi-trophic aquaculture involves cultivating fed species with extractive species that utilize wastes from aquaculture for their growth. All components  have commercial value, as well as roles in biomitigating. The IMTA concept  should also be understood within an integrated land/coastal aquaculture ecosystem  approach. Regulatory frameworks and financial incentives may be required  to fully realize the benefits of IMTA systems. Differentiation of IMTA products through traceability and ecolabeling will be key in their promotion.

    Author(s): Thierry Chopin, Max Troell, Gregor K. Reid, Duncan Knowler, Shawn M. C. Robinson, Amir Neori, Alejandro H. Buschmann, Shaojun Pang

  • Integrated Offshore Aquaculture for Industrialization in Korea

    Due to the high demand for live fish, Korea already retains an advanced infrastructure for production and transportation for live fish consumption. With its considerable production
    costs, however, as well as prevalent consumer anxiety relating to environmental pollution and diseases, the conventional (inshore) aquaculture method has been proven to be inefficient from a commercial point of view.

    Author(s): Yoon Kil Lee

  • INTEGRATED PRODUCTION OF ALGAL BIOMASS

    Applied research is increasingly defined within a context of sustainability and ecological modernisation. Within this remit, recent developments in algal biotechnology are considered to hold particular promise in integrating aspects of bioremediation and bioproduction. However, there are still a number of engineering and biological bottlenecks related to large scale production of algae; including requirements to reduce both capital expenditure (CAPEX) and operational expenditure (OPEX). One potential avenue to reduce these costs is via feedstock substitution and resource sharing; often described as industrial symbiosis. Such an approach has the benefit of providing both environmental and economic benefits as part of an ‘eco-biorefinery’. This thesis set out to investigate and address how best to approach some of the cost related bottlenecks within the algal industry, through a process of industrial integration and novel system design. The doctorate focussed on applications within a Northern European context and was split into four research topics. The first and second parts identified a suitable algal strain and were followed by the characterisation of its growth on wastewater; with the findings showing Chlorella sorokiniana (UTEX1230) capable of robust growth and rapid inorganic nutrient removal. The third part detailed the design, construction and validation of a lower cost and fully scalable modular airlift (ALR) photobioreactor, suitable amongst other applications for use within wastewater treatment. This work concluded with a pilot scale deployment of a 50 L ALR system. The fourth research section detailed the costs of ALR construction and operation at a wastewater treatment works, with a particular focus on the benefits that can be derived by industrial symbiosis. The thesis concludes with an appraisal of the ALR design and considers the potential for the technology, particularly within a wastewater treatment role. A final consideration is given to the practicalities of developing the algal industry within the UK in the short to medium term.

    Author(s): Alessandro Marco Lizzul

  • Integrating filamentous ‘green tide’ algae into tropical pond-based aquaculture

    ‘Green tide’ algae bloom in eutrophic environments with fast growth rates and efficient nutrient uptake. These same characteristics are sought after for algae in integrated aquaculture systems. We examined the effect of two key variables, salinity and total ammonia nitrogen (TAN), on the growth of three filamentous ‘green tide’ algae, Cladophora coelothrix, Chaetomorpha indica and Ulva sp. Survival and growth were first determined across the extremes of salinity in ponds (0 to 45‰). Subsequently, the interactive effects of salinity (15, 36 and 45‰) and TAN (0–700 µmol l−1) were quantified using a factorial design. All species have a broad tolerance to salinity (ranging from 5 to 45‰) with each having a different optimum for growth (C. coelothrix 30‰, C. indica 20‰ and Ulva sp. 15‰). A significant interaction (salinity⁎TAN⁎species) further demonstrated that responses vary between algae. C. indica and Ulva sp. have their highest growth rates of ~14% day−1 and ~25% day−1 respectively at higher TAN levels (>70 µmol l−1) but at different salinities. Growth of C. coelothrix was optimum at lower TAN levels (35 µmol l−1) and 36‰, but surprisingly was inhibited at the highest TAN. C. coelothrix and C. indica were also cultured in an operational bioremediation pond. High growth rates of C. coelothrix were maintained in situ (~6% day−1), while C. indica performed poorly. Finally, TAN removal rates were calculated using natural densities and in situ growth rates demonstrating that ‘green tide' algae have broad application across the environmental variables that characterize tropical pond-based aquaculture.

    Author(s): Pedro H. de Paula Silva, Shannon McBride, Rocky de Nys, Nicholas A. Paul

  • INTEGRATING SEAWEEDS INTO MARINE AQUACULTURE SYSTEMS: A KEY TOWARD SUSTAINABILITY

    The rapid development of intensive fed aquaculture (e.g. finfish and shrimp) throughout the world is associated with concerns about the environmental impacts of such often monospecific practices, especially where activities are highly geographically concentrated or located in suboptimal sites whose assimilative capacity is poorly understood and, consequently, prone to being exceeded. One of the main environmental issues is the direct discharge of significant nutrient loads into coastal waters from open-water systems and with the effluents from land-based systems. In its search for best management practices, the aquaculture industry should develop innovative and responsible practices that optimize its efficiency and create diversification, while ensuring the remediation of the consequences of its activities to maintain the health of coastal waters. To avoid pronounced shifts in coastal processes, conversion, not dilution, is a common-sense solution, used for centuries in Asian countries. By integrating fed aquaculture (finfish, shrimp) with inorganic and organic extractive aquaculture (seaweed and shellfish), the wastes of one resource user become a resource (fertilizer or food) for the others. Such a balanced ecosystem approach provides nutrient bioremediation capability, mutual benefits to the cocultured organisms, economic diversification by producing other value-added marine crops, and increased profitability per cultivation unit for the aquaculture industry. Moreover, as guidelines and regulations on aquaculture effluents are forthcoming in several countries, using appropriately selected seaweeds as renewable biological nutrient scrubbers represents a cost-effective means for reaching compliance by reducing the internalization of the total environmental costs. By adopting integrated polytrophic practices, the aquaculture industry should find increasing environmental, economic, and social acceptability and become a full and sustainable partner within the development of integrated coastal management frameworks.

    Author(s): Yarish, Charles Chris Neefus, Jose Zertuche, George P. Kraemer, Amir Neori, Nils Kautsky, Max Troell, Christina Halling, Alejandro H. Buschmann, Thierry Chopin

Pages