Results

Do seal-safe pingers increase depredation in seals?

Pingers did not have a visible effect on the amount of bait taken from stations. However, the general engagement rate was very low (about 14%) which means that even though no effect is visible, we cannot say with confidence that these pingers don’t increase depredation.

Do seal-safe pingers reduce porpoise bycatch?

The model showed that pingers had a significant effect on bycatch and helped reduce it. The model also showed that the ICES area in which the fishing activity took place had an effect on bycatch. Soak time (the amount of time a net spends in the water) and the length of the net also had a significant impact on bycatch.

Graph depicting the average (+/- SE) number of porpoises bycaught in each ICES fishing area, depending on which pinger was used on the nets.

The height of the net and the year in which the data was collected did not affect bycatch according to the model. However, it’s interesting to see that some years have higher bycatch when pingers were in use, which is unexpected.

Graph depicting the average (+/- SE) number of porpoises bycaught in each year, depending on the type of pinger used.

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