Browsing by Author "Dickson, Jonathan O."
Book chapterJO Dickson & RV Ramiscal - In T Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of AgricultureTest fishing for the giant squid Thysanoteuthis rhombus using large jigs was conducted in selected areas around Alabat Island, Quezon Province from May 1991 to October 1992. A total of 92 fishing days and 425.3 fishing hours were successfully completed and 1,650 jigs were set. The total catch was 82 giant squids of total weight 412 kg. Catch per unit effort was on average 0.02 kg/jig-hour or 5 squids/100 jigs, but higher from July to September. Capture of the giant squid by jigs was very seasonal, only from June to October. During these months, fish aggregating shelters were installed to catch pelagic fishes, and these shelters may have attracted the giant squid to Calauag Bay. The sample of 82 giant squids adds considerable information to the biology of this species in Philippine waters. The smallest specimen, caught in August 1991, was 23 cm in mantle length and 750 g in weight. The largest specimen, caught in September 1992, was a male 69 cm in mantle length and 10.3 kg in weight. Of the 66 specimens examined, 31 were males and 35 were females. About 52% of the specimens were sexually mature, 30% were maturing, and the rest were immature. Of the 61 stomachs dissected, 20 were empty, six were full or 3/4 full, and the rest were in between. The giant squid was a fish eater, almost all stomachs containing fish bones, spines, scales, or digested fish meat.
The squid fishery in Carigara Bay, Samar: catch of Photololigo duvaucelii by squid jigs and Sepioteuthis lessoniana by hanging squid pot JO Dickson & BR Ricafrente - In T Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of AgricultureThe squid fishery in Carigara Bay used the following gears: hanging squid pots, squid jigs, drive-in net, and spear by slingshot. Hanging squid pot operations were concentrated in the municipal waters of Capoocan and Carigara and targeted Sepioteuthis lessoniana. During the one-week survey in Carigara Bay, 705 hanging squid pots with markers were found offshore of barangays Culasian, Pinamopoan, Cabul-an and Talarian, all in Capoocan town. Other operators in Carigara, Babatngon, Barugo, and San Miguel towns hung their squid pots from fish shelters (arong) offshore of Carigara and Capoocan towns. Test fishing operations were conducted in Carigara Bay from January to December 1992 using the hanging squid pot, squid jigs, and a squid cast net. A 16 hp motorized boat F/B Ellah Meh was used during the fishing operations. A total of 162 days test fishing with 15 hanging squid pots yielded 125.7 kg of the longfin squid Sepioteuthis 1essoniana. Sixty nights of fishing with the ordinary squid jig yielded 97 kg of Indian squid Photololigo duvaucelii. Two test fishing operations with the squid cast net yielded no squid at all. The S. lessoniana (75-500 g body weight) caught by pots were larger than the P. duvaucelii (7-270 g) caught by jigs.