Continuing with the tori line experiments in the pelagic longline fishery, I headed back to sea but this time aboard the RS Aldebran, Uruguay’s research vessel.
On this last trip we spent 20 days at sea, with a short break at the start due to a faulty hydraulic pump forcing us to return briefly back to port. We headed out into awful weather, with the whole crew suffering seasickness but after three days the ocean settled down and we were able to begin working under more comfortable conditions.
The vessel set eight fishing lines, each as the sun was setting. Of these, four were set using a tori line and four without, as stipulated under the experimental design. These sets reaffirmed how effective a tori line can be on reducing seabird interactions, as we unfortunately caught some birds during the sets with no tori line whereas we caught no birds during the sets with a tori line.
Despite the occasional entanglement, which can happen when the tori line crosses over the main fishing line in pelagic longline fisheries, this mitigation measure worked well at reducing the possibility of seabirds accessing baited hooks.
We believe that we have advanced, from a point when we had no evidence to show that tori lines were an effective measure in pelagic longline fisheries, to the current situation where we have the data to prove it. Now we just need to make some improvements to help prevent entanglements between the tori line and the fishing gear.
We also compared the interaction between the seabirds and the fishing gear as the fishing line is set, during the short period of light available before nightfall. This information provides further evidence as to how the tori lines force the seabirds away from the baited hooks.
After the initial bad luck of the weather conditions, we put in some good work to obtain these results and everything started going well for us. However, once I was dropped back in port, the luck turned against the crew on the next trip as a fire broke out in the engine room. They were able to put the fire out rapidly, but it took them two days to repair the engines and get the vessel back to port, so while I was lucky, it was another difficult day at sea for the crew.