193
aquarium should be enforced to obtain the best results. While culturing in ponds,
water inlet and outlet filters of appropriate sizes should be used to prevent predator
inputs and cuttlefish outputs. In addition, net barriers should be used for preventing cuttlefish capture by birds. Since these ponds are dynamic ecological systems,
with proper fauna and flora, the use of oxygenators to efficiently supersaturate
the rearing water is recommended. This might be performed either by mechanical
movement (paddles) or by oxygen injection and will be particularly important at
high water temperatures, in very productive waters and especially during nighttime, when microalgae also consume oxygen.
The pros and cons of using either tanks or ponds are presented in Table 11.4.
11.6.2 Density
Published information provides data regarding density in either open, semi-open and
closed systems. As in other life stages, considering not only densities but also the
Table 11.4 Pros and cons of tanks versus earthen ponds
Variables
Tanks
Earthen ponds
Temperature
Only controlled in semi-open and
closed seawater systems
Not controlled
Salinity
Only controlled in semi-open and
closed seawater systems
Not controlled or hard and expensive
to control
Dissolved oxygen Fully controlled
Controlled through the use of aerators
but primary productivity may generate spikes of lower oxygen during
the night
Nitrogenous
compounds
Controlled in open and semi-open
systems
Controlled in ponds with water renewal
Density/biomass Fully controlled
Hard to control due to water turbidity
Mortality/
cannibalism
Fully controlled
Hard to control due to water turbidity
Food/feeding
hierarchies
Controlled
Controlled
Predators
None
Require bird nets, filters of appropriate
size in inlet water supply, if water
renewal is used
System setup and
maintenance
Logistics, time consuming and
expensive in setup Maintenance
is time consuming
Expensive in pond setup. Low expenses
during maintenance
Filters inlet/outlet Inlet filters in water of the facilities are expensive and require
logistics and maintenance. Outlet
filters used to prevent escape of
animals
Inlet filters to prevent entrance of
natural predators. Outlet filters to
prevent escape of animals. Both are
time consuming
Type of culture
Intensive and semi-intensive
Intensive, semi-intensive and extensive
Type of integrated
aquaculture
Water used for growth of micro or
macroalgae after leaving the tank
Pond used for bivalves and water used
for micro or macroalgae after leaving the pond
11 Sepia officinalis
aquarium should be enforced to obtain the best results. While culturing in ponds,
water inlet and outlet filters of appropriate sizes should be used to prevent predator
inputs and cuttlefish outputs. In addition, net barriers should be used for preventing cuttlefish capture by birds. Since these ponds are dynamic ecological systems,
with proper fauna and flora, the use of oxygenators to efficiently supersaturate
the rearing water is recommended. This might be performed either by mechanical
movement (paddles) or by oxygen injection and will be particularly important at
high water temperatures, in very productive waters and especially during nighttime, when microalgae also consume oxygen.
The pros and cons of using either tanks or ponds are presented in Table 11.4.
11.6.2 Density
Published information provides data regarding density in either open, semi-open and
closed systems. As in other life stages, considering not only densities but also the
Table 11.4 Pros and cons of tanks versus earthen ponds
Variables
Tanks
Earthen ponds
Temperature
Only controlled in semi-open and
closed seawater systems
Not controlled
Salinity
Only controlled in semi-open and
closed seawater systems
Not controlled or hard and expensive
to control
Dissolved oxygen Fully controlled
Controlled through the use of aerators
but primary productivity may generate spikes of lower oxygen during
the night
Nitrogenous
compounds
Controlled in open and semi-open
systems
Controlled in ponds with water renewal
Density/biomass Fully controlled
Hard to control due to water turbidity
Mortality/
cannibalism
Fully controlled
Hard to control due to water turbidity
Food/feeding
hierarchies
Controlled
Controlled
Predators
None
Require bird nets, filters of appropriate
size in inlet water supply, if water
renewal is used
System setup and
maintenance
Logistics, time consuming and
expensive in setup Maintenance
is time consuming
Expensive in pond setup. Low expenses
during maintenance
Filters inlet/outlet Inlet filters in water of the facilities are expensive and require
logistics and maintenance. Outlet
filters used to prevent escape of
animals
Inlet filters to prevent entrance of
natural predators. Outlet filters to
prevent escape of animals. Both are
time consuming
Type of culture
Intensive and semi-intensive
Intensive, semi-intensive and extensive
Type of integrated
aquaculture
Water used for growth of micro or
macroalgae after leaving the tank
Pond used for bivalves and water used
for micro or macroalgae after leaving the pond
11 Sepia officinalis