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

Integrated multi-trophic aquaculture (IMTA) in marine temperate waters 39
the carriage!). R&D should be conducted in a scientific manner to obtain and keep
credibility and validity. If not properly carried out, it could lead to questionable data,
unfounded speculations and biased conclusions. Consequently, one has to recognize
that R&D is a full component of any economic development plan. One should
also not forget that R&D is only justified if a “C” (commercialisation) comes next;
unfortunately, there is frequently a major gap between R&D and C, often because the
appropriate funding structures and incentives are not in place to take a R&D project
to a C reality.
One must also understand that the performance evaluation of IMTA systems requires
a different approach from the typical linear growth models used for monoculture over
the last decades, without consideration of the environmental and social costs. Five-year
profitability models, with the goal of reaching maximal performance for each cultured
species in isolation, should be replaced by optimized, long-term and sustainable bioeconomic
models in which the yield per unit resource input is evaluated.
Finally, let us not forget that we are still in the infancy of modern intensive
aquaculture and that some agricultural practices have taken centuries to develop into
better, not yet best, management practices.
CONCLUSIONS AND RECOMMENDATIONS
The aquaculture ecological, engineering, economic and social challenges remaining to
be solved are for some maybe daunting. However, the goal is to develop modern IMTA
systems, which are bound to play a major role worldwide in sustainable expansions
of the aquaculture operations of tomorrow, within a balanced ecosystem approach, to
respond to a worldwide increasing seafood demand with a new paradigm in the design
of the most efficient food production systems.
Most of the countries with coastlines in temperate regions of the globe have some level
of aquaculture ongoing, although very few, with the exception of Canada, Chile, South
Africa, the United Kingdom, Ireland, the United States of America and China, have
ongoing IMTA systems near or at commercial scale. IMTA has enormous potential for
growth in all the countries discussed. Several countries have active research programs
gaining knowledge about their regions potential for development of IMTA, while other
countries have made no direct groundwork toward the development of IMTA.
Genera of particular interest and those with high potential for development in
IMTA systems in marine temperate waters include:
- Laminaria, Saccharina, Sacchoriza, Undaria, Alaria, Ecklonia, Lessonia, Durvillaea,
Macrocystis, Gigartina, Sarcothalia, Chondracanthus, Callophyllis, Gracilaria,
Gracilariopsis, Porphyra, Chondrus, Palmaria, Asparagopsis and Ulva (seaweeds),
- Haliotis, Crassostrea, Pecten, Argopecten, Placopecten, Mytilus, Choromytilus and
Tapes (molluscs),
- Strongylocentrotus, Paracentrotus, Psammechinus, Loxechinus, Cucumaria, Holothuria,
Stichopus, Parastichopus, Apostichopus and Athyonidium (echinoderms),
- Nereis, Arenicola, Glycera and Sabella (polychaetes),
- Penaeus and Homarus (crustaceans), and
- Salmo, Oncorhynchus, Scophthalmus, Dicentrarchus, Gadus, Anoplopoma,
Hippoglossus, Melanogrammus, Paralichthys, Pseudopleuronectes and Mugil (fish).
This is based on established husbandry practices, habitat appropriateness,
biomitigation ability and the economic value of these species.
In order to ensure the expansion of IMTA in these regions several steps should be
taken where appropriate. These include:
1) Establishing the economic and environmental value of IMTA systems and their
co-products – seaweeds and invertebrates can be very profitable cultured species,
not only for their services as effluent biomitigators, but also as differentiated
premium cash crops diversifying the aquaculture sector and reducing risks.