Incidental catching of Turtles

Each of the methods of fishing outlined is known to be responsible for the incidental catching of a large number of turtles.

Long term studies on the incidental catching of turtles on long lines has shown that, though some turtles may be incidentally snagged on the hooks, most are hooked in the oesophagous, stomach or mouth as they swallow the fish bait. This is usually mackeral Scomber scombrus or Scomber japonicus or flying squid (Todarodes sagittatus) (MUNTINGH 1988; PANOU 1988). It is likely that this mostly affects Caretta caretta.

Three fishing hooks and line found in the oesophagous of a stranded loggerhead turtle: the cause of death to the stranding. Photo: C.Morris 1996 - Kefalonia

In the case of Trawl-nets, the turtles are "scooped-up" by the net. Having entered the net they very rarely find a way out due to the sheer size of the trawl. In a similar way, those turtles which come into contact with a drift-net are dragged along by it. The contact with the net may entangle the turtle's flippers or lead to disorientation. Death normally occurs due to drowning, even though turtles can remain submerged for many hours when not disturbed. Even if the turtle is not dead when discarded it can often die as a result of anoxic brain damage.

Hawksbill sea turtle strangled in line and netting. Photo: Sea Turtle Stranding and Salvage Network