Effects of chemicals from longline baits on the biting behaviour of loggerhead sea turtles

Published source details Piovano S., Farcomeni A. & Giacoma C. (2012) Effects of chemicals from longline baits on the biting behaviour of loggerhead sea turtles. African Journal of Marine Science, 34, 283-287.
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This study is summarised as evidence for the following.

	Action	Category
	Use a different bait type: Sea turtles Action Link

Use a different bait type: Sea turtles

A controlled study in 2001–2010 in sea water test tanks in Italy (Piovano et al. 2012) found that loggerhead turtles Caretta caretta were less likely to bite at mackerel Scomber scomber bait than squid Ilex argentinus bait, and that this varied with the size of the turtle. Overall, turtles were less likely to bite at mackerel bait (biting at mackerel: 23% frequency) than squid (biting at squid: 60% frequency), but more likely to bite at mackerel than no bait (5–8% frequency). Smaller turtles were more likely to bite at mackerel bait and larger turtles were more likely to bite at squid bait (data reported as statistical model outputs). Whole mackerel and squid were selected as bait as these are commonly used in longline fisheries. Individual turtles (30 in total) were presented with bait of the same species (13 mackerel tests; 20 squid tests) and no bait in three different coloured sacks and their response was recorded on a portable video camera. Three turtles were tested using both bait types. Attempts to bite a sack were considered proof of biting behaviour. Turtles were wild caught individuals who had been in the rescue centre for <4 months and were considered fit to be released.

(Summarised by: Katie Sainsbury)