references
GREAT BARRIER REEF
// Outlook Report 2014
29
• While the ecological risk of trawl fisheries to large sharks and rays has been significantly reduced through the introduction of mandatory excluder devices, many smaller species of sharks and rays remain in the bycatch of prawn and scallop trawlers (Section 5.4.3).9,201 There is limited information on the distribution and habitat use of either the pelagic or deep-water shark species of the Region.191 Deep-water species of sharks and rays have lower growth rates, later age at maturity, and live longer than both shelf and pelagic species, meaning their populations will take longer to recover from exploitation or other factors causing declines.119
2.4.10 Sea snakes
There are 16 species of sea snakes recorded in the Region with 14 species maintaining permanent breeding populations.202 In general, sea snake species richness declines from north to south.203 While the broad distributions have been documented203,204, information about the distribution and abundance of individual sea snake species is limited, in part due to logistical difficulties associated with counting sea snakes.205 Hence, there is little information and no regular monitoring of population trends. The trawl fishery continues to interact with and cause mortality to sea snakes. Of the large number of sea snakes caught as trawl bycatch each year (estimated to be over 100,000), it is estimated that about 26 per cent die.204 Reduction in trawl fisheries effort (Section 5.4) and management initiatives promoting the adoption of fisheye bycatch reduction devices are likely to have reduced impacts on some sea snakes. Two species of sea snakes, the ornate reef sea snake and the elegant sea snake, have been identified as being at high risk to the impacts of otter trawling, and two species, the spectacled sea snake and the smallheaded sea snake, as at intermediate risk.9,204
A large number of sea snakes are caught as bycatch.
Sixteen species of sea snakes are recorded in the Region
© Matt Curnock
2.4.11 Marine turtles