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The Biology of Sea Turtles, Vol. II
permitted a variety of bacterial infections, including Salmonella , Escherichia coli ,
Citrobacter , and Moraxella spp. They concluded that Gram-negative bacterial infections caused systemic illness and death following the severe infestation by spirorchid
cardiovascular flukes. Glazebrook and Campbell (1990) found cardiovascular flukes
in green, loggerhead, and hawksbill turtles in the U.S., India, Pakistan, and Australia,
as well as a variety of gastrointestinal (GI) flukes, barnacles, and mites. In that study,
heart fluke infestations resulted in cases of bronchopneumonia and septicemia–toxemia, whereas all heavy infestations of cardiovascular flukes were associated with
severe debilitation, generalized muscle wastage, and thickening and hardening of
the walls of the major cardiac blood vessels.
6.3.4.2 GTFP
The epidemic of GTFP that has arisen over the last 15–20 years is of great concern.
First recorded in the 1930s in the Florida Keys in a few green turtles, it appeared
to increase in the 1960s and is now pandemic, with infection rates in some habitats
of more than 70% (Aguirre and Lutz, in press). GTFP has been reported in every
major ocean basin that is home to green sea turtles (Herbst, 1994). The rapid
spread of this disease is exemplified by the record of its occurrence in the Indian
River Lagoon on Florida’s east coast. The first case in the Indian River was reported
in 1982, and by late 1985 more than 50% of C. mydas captured in the lagoon had
fibropapillomas (Herbst, 1994); current infection rates are approximately 67%
(Hirama and Ehrhart, 2002). Although many turtles with GTFP will not die of the
disease per se, the tumors, which may range up to more than 30 cm in diameter,
interfere with normal functioning, cause physical weakening, and expose the
carrier to other threats (Figure 6.3). Cutaneous tumors increase drag and may
interfere with vision; large tumors could thus severely hamper the victim’s ability
to swim and dive; escape predation; and locate, capture, and swallow food. Internal
tumors may affect organ function, digestion, buoyancy, cardiac function, and
respiration (Herbst, 1994; Work and Balazs, 1999). Turtles with fibropapillomas
are also more likely to become entangled in monofilament line or other debris
(Witherington and Ehrhart, 1989). Turtles with advanced GTFP are chronically
stressed. Those with large numbers of tumors are hypoferremic, anemic, and
hypoproteinemic, and are in advanced stages of acidosis and calcium–phosphorus
imbalance (Aguirre and Balazs, 2000). These symptoms, of course, may have
additional effects on turtles: animals already in ion imbalance may be less able
to handle additional osmotic stresses induced by cold stunning, for example,
whereas anemic animals will have a lower oxygen-carrying capacity for diving,
and would be more severely incapacitated if caught in a net or trawl. There is also
likely to be a debilitating synergism between GTFP and spirorchidiasis; many
animals suffer from both infections simultaneously, and many pathological outcomes are similar (Aguirre et al., 1998).
Although it initially appeared that GTFP was confined to green sea turtles, in
which it is most prevalent, recent studies have found GTFP in loggerhead (Herbst,
1994), olive ridley (Aguirre et al., 1999), Kemp’s ridley (Harshbarger, 1991), flatback
(Limpus and Miller, 1994), and possibly leatherback turtles (Huerta et al., 2000).
1123 book.book Page 176 Monday, November 11, 2002 11:11 AM
The Biology of Sea Turtles, Vol. II
permitted a variety of bacterial infections, including Salmonella , Escherichia coli ,
Citrobacter , and Moraxella spp. They concluded that Gram-negative bacterial infections caused systemic illness and death following the severe infestation by spirorchid
cardiovascular flukes. Glazebrook and Campbell (1990) found cardiovascular flukes
in green, loggerhead, and hawksbill turtles in the U.S., India, Pakistan, and Australia,
as well as a variety of gastrointestinal (GI) flukes, barnacles, and mites. In that study,
heart fluke infestations resulted in cases of bronchopneumonia and septicemia–toxemia, whereas all heavy infestations of cardiovascular flukes were associated with
severe debilitation, generalized muscle wastage, and thickening and hardening of
the walls of the major cardiac blood vessels.
6.3.4.2 GTFP
The epidemic of GTFP that has arisen over the last 15–20 years is of great concern.
First recorded in the 1930s in the Florida Keys in a few green turtles, it appeared
to increase in the 1960s and is now pandemic, with infection rates in some habitats
of more than 70% (Aguirre and Lutz, in press). GTFP has been reported in every
major ocean basin that is home to green sea turtles (Herbst, 1994). The rapid
spread of this disease is exemplified by the record of its occurrence in the Indian
River Lagoon on Florida’s east coast. The first case in the Indian River was reported
in 1982, and by late 1985 more than 50% of C. mydas captured in the lagoon had
fibropapillomas (Herbst, 1994); current infection rates are approximately 67%
(Hirama and Ehrhart, 2002). Although many turtles with GTFP will not die of the
disease per se, the tumors, which may range up to more than 30 cm in diameter,
interfere with normal functioning, cause physical weakening, and expose the
carrier to other threats (Figure 6.3). Cutaneous tumors increase drag and may
interfere with vision; large tumors could thus severely hamper the victim’s ability
to swim and dive; escape predation; and locate, capture, and swallow food. Internal
tumors may affect organ function, digestion, buoyancy, cardiac function, and
respiration (Herbst, 1994; Work and Balazs, 1999). Turtles with fibropapillomas
are also more likely to become entangled in monofilament line or other debris
(Witherington and Ehrhart, 1989). Turtles with advanced GTFP are chronically
stressed. Those with large numbers of tumors are hypoferremic, anemic, and
hypoproteinemic, and are in advanced stages of acidosis and calcium–phosphorus
imbalance (Aguirre and Balazs, 2000). These symptoms, of course, may have
additional effects on turtles: animals already in ion imbalance may be less able
to handle additional osmotic stresses induced by cold stunning, for example,
whereas anemic animals will have a lower oxygen-carrying capacity for diving,
and would be more severely incapacitated if caught in a net or trawl. There is also
likely to be a debilitating synergism between GTFP and spirorchidiasis; many
animals suffer from both infections simultaneously, and many pathological outcomes are similar (Aguirre et al., 1998).
Although it initially appeared that GTFP was confined to green sea turtles, in
which it is most prevalent, recent studies have found GTFP in loggerhead (Herbst,
1994), olive ridley (Aguirre et al., 1999), Kemp’s ridley (Harshbarger, 1991), flatback
(Limpus and Miller, 1994), and possibly leatherback turtles (Huerta et al., 2000).
1123 book.book Page 176 Monday, November 11, 2002 11:11 AM