biomass produced is a renewable protein-enriched feed for
other species, for the production of biofuels or fertilizer
(Wuang et al. 2016; Czyrnek-Delêtre et al. 2017; Adeniyi
et al. 2018). Generally, this algal biomass is characterized by
production of high value polysaccharides (Azevedo et al.
2015). While, released organic particles can be consumed by
species such as filter feeders (Handå et al. 2012a). Mussels
grown in aquaculture and conventional mussels grown at
these IMTA sites show no discernible difference; however,
meat yield in IMTA mussels is higher (Handå et al. 2012b).
Then algae and bivalves provide bioremediatives services,
the integrated system transforms “waste” into a valuable resource (Hussenot and Richard 2009).
Advantages and Inconvenient of Integrated
Aquaculture
Integrated aquaculture has both economic and environmental
benefits (Burns et al. 2014; Ferreira et al. 2014),it increases the
social acceptability of fish farming systems (Nobre et al. 2010;
Alexander et al. 2016a, b; Biswas et al. 2020) and AMTI
farms give producers the green label (Troell et al. 2009; van
Osch et al. 2017). It increases long-term viability and profitability per crop unit not per species, which is the case for
monocultures (Xie et al. 2013; Gambelli et al. 2019),up to
80% of the overall economic gains on the transition to
IMTA (Edwards 2015; Ankamah-Yeboah et al. 2016). Some
countries require relocation of farm sites every few years to
reduce benthic impacts (Kletou et al. 2018) and the IMTA has
the potential to reduce sediment enrichment (Ying et al. 2018).
In addition, IMTA is considered to be an adaptation strategy to
climate change based on the ecosystem approach (Ahmed and
Glaser 2016). Thus,sustainable mariculture could be developed through IMTA (Di Marco et al. 2017; Biermann and
Geist 2019), and the implementation of IMTA in Sanggou
Bay China confirm this hypothesis, it has increased economic
benefits, sustained environmental quality, created new jobs
and led to innovations in farming techniques, it is considered
as the biggest and the most successful case of IMTA in the
world (Fang et al. 2016).
Using high algae densities over a large area can also change
current local patterns and at night time decrease oxygen concentrations around the cages thus putting fish in a stressful
situation (Engström-Öst and Isaksson 2006; Milhazes-Cunha
and Otero 2017; Rodríguez-Martínez et al. 2019).
The difficulty of analyzing the complex interactive processes that link biomass to nutrient absorption, Handå et al.
(2012b) and Irisarri et al. (2015) have shown that mussels near
salmon farms use feed particles more efficiently than fecal
matter, while feed waste represents less than 5% and they
prefer to feed on seston around cages (especially diatoms) that
have been induced by the high nutrient content. IMTA engenders an increase in cumulative energy demand, which has an
impact on climate change (Chary et al. 2020),also, the limitation of engineering progress (Alexander et al. 2016a, b;
Kleitou et al. 2019) and the absence of an internationally recognized standard (Yu et al. 2017),in addition, the failure to
have appropriate marketing strategies (Sicuro 2019), these
are the obstacles that slow down the development of IMTA.
Offshore Mariculture
In response to increasing demand for seafood and global food
security concerns, while at the same time relieving pressure on
coastal ecosystems and wild fisheries, offshore mariculture
offers a promising alternative for minimizing aquaculture’s
potentially adverse environmental and socio-economic impacts (Thomas et al. 2019). Offshore mariculture defined as
occurring at more than to 2 km, from the coast in water depths
>50 m and under the influence of powerful hydrodynamic
energy (waves, ocean swells, ocean currents and strong
winds) (Lovatelli et al. 2013), but based on actual practice
and practicable method of mooring and costs, the depth
thresholds for conventional sea cages are approximately 25
to 100 m (Chu et al. 2020). All farmed species are candidates
for offshore mariculture except crustacean which are farmed
in inland ponds (Lovatelli et al. 2013).
Offshore sites allow more sea surface area and generally
better water quality, which is necessary to boost the
production of healthy organisms, Muñiz et al. (2019) and
Barillé et al. (2020) found that offshore sites had better growth
potential for oysters and mussels, as well as a better
biochemical composition, than intertidal sites. Di Trapani
et al. (2014) results’s showed a better economic profitability
of offshore farm versus inshore one, mainly due to better feed
conversion ratio and to a higher fish density, as well as good
market price (Kim et al. 2012; Thomas et al. 2019). According
to (Lester et al. 2018) study, farming only a very small total
area in open ocean (50 km
2
), could produce a total amount of
seafood that exceeds all U. S mariculture production combined and wild fishery landings.
van den Burg et al. (2017) have identified a total of 105
hazards for offshore exploitations, classified into six categories: (a) operational, (b) economic and political, (c) financial,
(d) environmental, (e) socio-economic and (f) health and safety, which regulatory and financial conditions are perceived as
a stronger barrier facing offshore expansion, whereas technical, environmental, and market conditions were generally
judged to be conducive or manageable by farmers
(Fairbanks 2016), whereas negative ecological impacts of offshore mariculture were weaknesses trough hydrodynamic
conditions (Froehlich et al. 2017; Lacson et al. 2019), the best
way to increased returns in offshore farms or to reduce coast
due to exploitation was combining mariculture with offshore
renewable energy production (wind energy or wave energy),
Thalassas
other species, for the production of biofuels or fertilizer
(Wuang et al. 2016; Czyrnek-Delêtre et al. 2017; Adeniyi
et al. 2018). Generally, this algal biomass is characterized by
production of high value polysaccharides (Azevedo et al.
2015). While, released organic particles can be consumed by
species such as filter feeders (Handå et al. 2012a). Mussels
grown in aquaculture and conventional mussels grown at
these IMTA sites show no discernible difference; however,
meat yield in IMTA mussels is higher (Handå et al. 2012b).
Then algae and bivalves provide bioremediatives services,
the integrated system transforms “waste” into a valuable resource (Hussenot and Richard 2009).
Advantages and Inconvenient of Integrated
Aquaculture
Integrated aquaculture has both economic and environmental
benefits (Burns et al. 2014; Ferreira et al. 2014),it increases the
social acceptability of fish farming systems (Nobre et al. 2010;
Alexander et al. 2016a, b; Biswas et al. 2020) and AMTI
farms give producers the green label (Troell et al. 2009; van
Osch et al. 2017). It increases long-term viability and profitability per crop unit not per species, which is the case for
monocultures (Xie et al. 2013; Gambelli et al. 2019),up to
80% of the overall economic gains on the transition to
IMTA (Edwards 2015; Ankamah-Yeboah et al. 2016). Some
countries require relocation of farm sites every few years to
reduce benthic impacts (Kletou et al. 2018) and the IMTA has
the potential to reduce sediment enrichment (Ying et al. 2018).
In addition, IMTA is considered to be an adaptation strategy to
climate change based on the ecosystem approach (Ahmed and
Glaser 2016). Thus,sustainable mariculture could be developed through IMTA (Di Marco et al. 2017; Biermann and
Geist 2019), and the implementation of IMTA in Sanggou
Bay China confirm this hypothesis, it has increased economic
benefits, sustained environmental quality, created new jobs
and led to innovations in farming techniques, it is considered
as the biggest and the most successful case of IMTA in the
world (Fang et al. 2016).
Using high algae densities over a large area can also change
current local patterns and at night time decrease oxygen concentrations around the cages thus putting fish in a stressful
situation (Engström-Öst and Isaksson 2006; Milhazes-Cunha
and Otero 2017; Rodríguez-Martínez et al. 2019).
The difficulty of analyzing the complex interactive processes that link biomass to nutrient absorption, Handå et al.
(2012b) and Irisarri et al. (2015) have shown that mussels near
salmon farms use feed particles more efficiently than fecal
matter, while feed waste represents less than 5% and they
prefer to feed on seston around cages (especially diatoms) that
have been induced by the high nutrient content. IMTA engenders an increase in cumulative energy demand, which has an
impact on climate change (Chary et al. 2020),also, the limitation of engineering progress (Alexander et al. 2016a, b;
Kleitou et al. 2019) and the absence of an internationally recognized standard (Yu et al. 2017),in addition, the failure to
have appropriate marketing strategies (Sicuro 2019), these
are the obstacles that slow down the development of IMTA.
Offshore Mariculture
In response to increasing demand for seafood and global food
security concerns, while at the same time relieving pressure on
coastal ecosystems and wild fisheries, offshore mariculture
offers a promising alternative for minimizing aquaculture’s
potentially adverse environmental and socio-economic impacts (Thomas et al. 2019). Offshore mariculture defined as
occurring at more than to 2 km, from the coast in water depths
>50 m and under the influence of powerful hydrodynamic
energy (waves, ocean swells, ocean currents and strong
winds) (Lovatelli et al. 2013), but based on actual practice
and practicable method of mooring and costs, the depth
thresholds for conventional sea cages are approximately 25
to 100 m (Chu et al. 2020). All farmed species are candidates
for offshore mariculture except crustacean which are farmed
in inland ponds (Lovatelli et al. 2013).
Offshore sites allow more sea surface area and generally
better water quality, which is necessary to boost the
production of healthy organisms, Muñiz et al. (2019) and
Barillé et al. (2020) found that offshore sites had better growth
potential for oysters and mussels, as well as a better
biochemical composition, than intertidal sites. Di Trapani
et al. (2014) results’s showed a better economic profitability
of offshore farm versus inshore one, mainly due to better feed
conversion ratio and to a higher fish density, as well as good
market price (Kim et al. 2012; Thomas et al. 2019). According
to (Lester et al. 2018) study, farming only a very small total
area in open ocean (50 km
2
), could produce a total amount of
seafood that exceeds all U. S mariculture production combined and wild fishery landings.
van den Burg et al. (2017) have identified a total of 105
hazards for offshore exploitations, classified into six categories: (a) operational, (b) economic and political, (c) financial,
(d) environmental, (e) socio-economic and (f) health and safety, which regulatory and financial conditions are perceived as
a stronger barrier facing offshore expansion, whereas technical, environmental, and market conditions were generally
judged to be conducive or manageable by farmers
(Fairbanks 2016), whereas negative ecological impacts of offshore mariculture were weaknesses trough hydrodynamic
conditions (Froehlich et al. 2017; Lacson et al. 2019), the best
way to increased returns in offshore farms or to reduce coast
due to exploitation was combining mariculture with offshore
renewable energy production (wind energy or wave energy),
Thalassas