Sea Turtle Husbandry
427
16.8 ROUTINE CLEANING
16.8.1 TURTLES
Every other day, each tank is completely drained, rinsed with freshwater and
refilled with fresh seawater. Every inside surface of the tank and rearing containers
is hosed off. The turtles are sprayed with freshwater directly on all exposed
surfaces, with particular emphasis on the carapace to remove any loose algae or
molting carapace material. For the first 90 days, one-half city water pressure
(approximately 30 psi) is used when spraying the turtles. After 90 days, the turtles
are sprayed with full city water pressure (approximately 60 psi). Turtles are out
of water for up to 30 min every other day during the cleaning process, but are not
allowed to dry. Prolonged periods out of the water will cause carapace desiccation
leading to scute peeling. Damage to carapace from desiccation may provide an
entry path for bacterial and fungal infection. Small loggerheads are more sensitive
to desiccation and scute peeling than Kemp’s ridleys, greens, or hawksbills.
Although wild sea turtles naturally display varying degrees of epibiota, captivereared turtles are susceptible to heavy and rapid biofouling, requiring periodic
removal. Typically, captive and wild pelagic turtles lack access to a substrate on
which to scrape away accumulating epibiota. Epibiotic buildup leads to hydrodynamic drag and increased weight, and can potentially impact swimming performance. Epibiotic buildup may also create a medium for bacterial and fungal
infection. Smaller turtles may be more sensitive to buildup than larger turtles,
especially hatchlings. In the wild, algae and settling larvae are possibly kept in
check and removed from pelagic turtles by epibiotic crabs (Frick et al., 2000), a
relationship that is most likely absent in the captive environment. Algae must be
mechanically removed from captive turtles with scrub brushes. Nylon bristle
brushes are disinfected prior to use and between each tank or group of turtles in
a solution of bleach (sodium hypochlorite 2%) (1:4) or chlorhexidine (2% chlorhexidine gluconate) (1:4) followed by a freshwater rinse. Every effort is made to
maintain the integrity of the independent environment in each tank by reducing
the chance of cross contamination.
16.8.2 REARING CONTAINERS
Uneaten food and waste that has settled on the bottom of the tank is directed
by hose nozzle manipulation and city water pressure (60 psi) to the drain. To
facilitate cleaning the raceway bottom, crates are moved along a polyvinyl
chloride (PVC) support rack, which keeps the crates off the tank bottom (Caillouet, 2000). Cages are suspended off the bottom to facilitate cleaning and can
be moved to gain access to the tank bottom. Once a month the inside tank
surfaces and racks are hand scrubbed with a Scotchbrite-type nylon abrasive
pad. Hand scrubbing is preferred to high-pressure washing. High-pressure washing tends to atomize waste material, creating a potential airborne tank-to-tank
contamination problem. High-pressure washing (1500–1800 psi) may be used
after tanks are disinfected.
1123_C16 Page 427 Tuesday, November 12, 2002 8:28 AM
427
16.8 ROUTINE CLEANING
16.8.1 TURTLES
Every other day, each tank is completely drained, rinsed with freshwater and
refilled with fresh seawater. Every inside surface of the tank and rearing containers
is hosed off. The turtles are sprayed with freshwater directly on all exposed
surfaces, with particular emphasis on the carapace to remove any loose algae or
molting carapace material. For the first 90 days, one-half city water pressure
(approximately 30 psi) is used when spraying the turtles. After 90 days, the turtles
are sprayed with full city water pressure (approximately 60 psi). Turtles are out
of water for up to 30 min every other day during the cleaning process, but are not
allowed to dry. Prolonged periods out of the water will cause carapace desiccation
leading to scute peeling. Damage to carapace from desiccation may provide an
entry path for bacterial and fungal infection. Small loggerheads are more sensitive
to desiccation and scute peeling than Kemp’s ridleys, greens, or hawksbills.
Although wild sea turtles naturally display varying degrees of epibiota, captivereared turtles are susceptible to heavy and rapid biofouling, requiring periodic
removal. Typically, captive and wild pelagic turtles lack access to a substrate on
which to scrape away accumulating epibiota. Epibiotic buildup leads to hydrodynamic drag and increased weight, and can potentially impact swimming performance. Epibiotic buildup may also create a medium for bacterial and fungal
infection. Smaller turtles may be more sensitive to buildup than larger turtles,
especially hatchlings. In the wild, algae and settling larvae are possibly kept in
check and removed from pelagic turtles by epibiotic crabs (Frick et al., 2000), a
relationship that is most likely absent in the captive environment. Algae must be
mechanically removed from captive turtles with scrub brushes. Nylon bristle
brushes are disinfected prior to use and between each tank or group of turtles in
a solution of bleach (sodium hypochlorite 2%) (1:4) or chlorhexidine (2% chlorhexidine gluconate) (1:4) followed by a freshwater rinse. Every effort is made to
maintain the integrity of the independent environment in each tank by reducing
the chance of cross contamination.
16.8.2 REARING CONTAINERS
Uneaten food and waste that has settled on the bottom of the tank is directed
by hose nozzle manipulation and city water pressure (60 psi) to the drain. To
facilitate cleaning the raceway bottom, crates are moved along a polyvinyl
chloride (PVC) support rack, which keeps the crates off the tank bottom (Caillouet, 2000). Cages are suspended off the bottom to facilitate cleaning and can
be moved to gain access to the tank bottom. Once a month the inside tank
surfaces and racks are hand scrubbed with a Scotchbrite-type nylon abrasive
pad. Hand scrubbing is preferred to high-pressure washing. High-pressure washing tends to atomize waste material, creating a potential airborne tank-to-tank
contamination problem. High-pressure washing (1500–1800 psi) may be used
after tanks are disinfected.
1123_C16 Page 427 Tuesday, November 12, 2002 8:28 AM