Posted By Dave Itano
29 May 2012
David Itano is a fisheries research associate with the Pelagic Fisheries Research Program at the University of Hawaii and is currently serving as a principal investigator during the western and central Pacific Ocean cruise of the ISSF #BycatchProject. He is currently onboard the Cape Finisterre, a 1500 GRT tuna purse seine tuna fishing vessel operating in the western Pacific.
We have been out to sea for just under a week and have already made five sets and started a variety of experiments, making many interesting observations. Where to start? We are currently working in the southern Tokelau zone and adjacent high seas area. Each day starts at 0400 when Mike Tallarida (navigator) runs up on one of our FADs while Captain John Crisci makes an initial assessment of the FAD school with sonar and echo sounder.
Some of the buoys have integrated sonar on them that can give an indication of fish abundance even before we arrive. Estimates before arriving, on arrival and throughout the fishing process are being recorded against the actual catch loaded. This data will eventually be compared to what is estimated onboard by the observer and what is ultimately unloaded at the cannery at the completion of the cruise. Information like this may someday be useful for avoiding areas of high bycatch or small sized tuna. Ferral Lasi from SPC has been busy conducting simultaneous ”spill” sampling with precise measurement and identification of every fish brailed into a special sampling bin with generous assistance from the crew.
Stepping back a bit, life onboard the Cape Finisterre is unbelievable to us (in a good way), especially when compared to the living conditions we havebecome used to on small longline and pole and line boats when conducting high seas research on other projects. The food is restaurant quality, varied and essentially unlimited; accommodations are cool, clean and comfortable and we enjoy excellent cooperation from the officers and crew. We are making them do things and are doing things onboard that they never dreamed of and they seem to be taking it all in stride and are very interested in our work.
As catch is being brailed onboard five to six tons at a time, it is loaded into a sorting hopper on deck where all non-target fish are released. This is SOP for this vessel and should be for all fleets. Our observer from the WCPFC Regional Observer Program via the National Fisheries Authority of PNG enumerates the fate and condition of all catch and bycatch; including tuna stored in the fish wells, other fish that are released and fish kept for onboard consumption. We have been pleasantly surprised at how little bycatch these rafts are carrying and how some of this so called ”bycatch” of mahi mahi and wahoo is utilized for immediate consumption by the cosmopolitan crew that hails from the Philippines, China, Ecuador, Panama, Samoa, Solomon Islands, Tonga, Tuvalu and of course, San Diego, California.
During the set Melanie Hutchinson has been busy taking and analyzing blood samples from silky sharks to determine stress levels and post-release survival that will also be determined by tagging and releasing sharks with special “survival” tags that upload data to satellite and back to the scientists. Jeff Muir and I have also been busy tagging bigeye tuna with sonic transmitters that send depth and presence/absence data to acoustic receivers mounted underneath the drifting FADs. This acoustic monitoring system is a great way to gather detailed information on the depth distribution and FAD residence patterns of all the tuna species and other fish species that frequent FADs.
This morning started with a nice 45 ton FAD set of good sized skipjack with a mix of small and large yellowfin. Jeff and I dove inside the net making observations of the behavior of tuna and bycatch as they were free-swimming in the net. Fascinating segregation of species by size were noted and hundreds of digital photographs and lots of video were taken. I’ve done a lot of bluewater diving, but this was the most incredible experience of my diving career. More of that later. This should do for an initial message from the scientists onboard and crew of the Cape Finisterre.