where for the first time kelp species were tested in an IMTA approach offshore with
partners from the offshore wind industry. Future multi-use development will require
a great deal of coordination between offshore energy industries, the commercial
offshore aquaculture sector, research institutions and international government
agencies in order to be successful.
Both seed recruitment and growing and fattening phases are subject to changes
in environmental conditions: mussel seed recruitment requires in most of the cases a
natural settlement of the larvae on the collection systems, unlike, for instance, in the
fish farming industry, where juveniles are bred in hatcheries. As for the feeding of
the mussels, it also relies on naturally occurring phytoplankton present in the water
column, as opposed to fish that are fed with manufactured fishmeal. In this sense
mussel aquaculture depends highly on environmental determinants and their temporal variability. Chile that produces roughly 240,000 t of Mytilus chilensis per
year experienced a crisis in 2009 when the phytoplankton concentrations decreased
to such an extent that mussel growth came to a standstill (Serramalera 2015).
Projected climate change poses multiple risks to mussel farming because of the
increased frequency of extreme events that might lie outside the realm of present
day experience (Serramalera 2015; Adger et al. 2005; Searle and Rovira 2008).
Natural variation in seed collection is inevitable. Environmental temperature for
example has an impact on the egg quality and quantity produced by the female
broodstock (Bayne et al. 1978) but also on the primary productivity which can have
a major impact on larval development and survival. Predation on larvae also can
vary significantly between years and is unpredictable. For example, in 2012 Chile
found itself in a critical situation when spatfall in the mussel production areas was
very poor for unexplained reasons (Carrasco et al. 2014).
Production of bivalves in hatcheries is a valid alternative and technically very
feasible but it is not economically viable to produce hatchery seed of mussels in
Europe currently because of the low market prices of the end-product. Production of
triploid mussels may offer an interesting alternative, as is currently the case for the
cupped oyster Crassostrea gigas, because this technique may also induce faster
growth and lead to year-round supply (since the animals do not reproduce).
The IMTA multi-crop diversification approach (fish, seaweeds and invertebrates)
could be an economic risk mitigation and management option to address pending
climate change and coastal acidification impacts (Chopin 2015; Clements and
Chopin 2016). Multi-species and multi-use systems could not only bring increased
profitability per operation/cultivation unit, but also environmental sustainability and
societal acceptability.
References
Abreu, M. H., Pereira, R., Yarish, C., Buschmann, A. H., & Sousa-Pinto, I. (2011b). IMTA with
Gracilaria vermiculophylla: Productivity and nutrient removal performance of the seaweed in a
land-based pilot scale system. Aquaculture, 312, 77–87.
58
B.H. Buck et al.
partners from the offshore wind industry. Future multi-use development will require
a great deal of coordination between offshore energy industries, the commercial
offshore aquaculture sector, research institutions and international government
agencies in order to be successful.
Both seed recruitment and growing and fattening phases are subject to changes
in environmental conditions: mussel seed recruitment requires in most of the cases a
natural settlement of the larvae on the collection systems, unlike, for instance, in the
fish farming industry, where juveniles are bred in hatcheries. As for the feeding of
the mussels, it also relies on naturally occurring phytoplankton present in the water
column, as opposed to fish that are fed with manufactured fishmeal. In this sense
mussel aquaculture depends highly on environmental determinants and their temporal variability. Chile that produces roughly 240,000 t of Mytilus chilensis per
year experienced a crisis in 2009 when the phytoplankton concentrations decreased
to such an extent that mussel growth came to a standstill (Serramalera 2015).
Projected climate change poses multiple risks to mussel farming because of the
increased frequency of extreme events that might lie outside the realm of present
day experience (Serramalera 2015; Adger et al. 2005; Searle and Rovira 2008).
Natural variation in seed collection is inevitable. Environmental temperature for
example has an impact on the egg quality and quantity produced by the female
broodstock (Bayne et al. 1978) but also on the primary productivity which can have
a major impact on larval development and survival. Predation on larvae also can
vary significantly between years and is unpredictable. For example, in 2012 Chile
found itself in a critical situation when spatfall in the mussel production areas was
very poor for unexplained reasons (Carrasco et al. 2014).
Production of bivalves in hatcheries is a valid alternative and technically very
feasible but it is not economically viable to produce hatchery seed of mussels in
Europe currently because of the low market prices of the end-product. Production of
triploid mussels may offer an interesting alternative, as is currently the case for the
cupped oyster Crassostrea gigas, because this technique may also induce faster
growth and lead to year-round supply (since the animals do not reproduce).
The IMTA multi-crop diversification approach (fish, seaweeds and invertebrates)
could be an economic risk mitigation and management option to address pending
climate change and coastal acidification impacts (Chopin 2015; Clements and
Chopin 2016). Multi-species and multi-use systems could not only bring increased
profitability per operation/cultivation unit, but also environmental sustainability and
societal acceptability.
References
Abreu, M. H., Pereira, R., Yarish, C., Buschmann, A. H., & Sousa-Pinto, I. (2011b). IMTA with
Gracilaria vermiculophylla: Productivity and nutrient removal performance of the seaweed in a
land-based pilot scale system. Aquaculture, 312, 77–87.
58
B.H. Buck et al.