Effect of shelter acclimation on the post-release movement and putative predation mortality of hatchery-reared black-spot tuskfish Choerodon schoenleinii, determined by acoustic telemetry

In this study, the effect of shelter acclimation on the post-release movement and putative predation mortality of hatchery-reared black-spot tuskfish Choerodon schoenleinii was examined using acoustic telemetry. We acclimated four 1-year-old fish to shelters in cages before release and compared their movements with six nonacclimated fish. Since it was not possible to compare the behavioral pattern between the former and the latter fish due to the short periods the latter fish were available to be monitored, we also compared their movements with those of large nonacclimated fish that were less likely to be preyed upon. Sixty-seven percent of the nonacclimated fish showed atypical movements before the signals ceased to be detected, a pattern that suggested a predation event had occurred, whereas none of the acclimated and large nonacclimated fish showed the atypical movements. In addition, the probability of detection cessation was about 13 times lower in the acclimated than nonacclimated fish. The signal detection patterns suggest that the acclimated fish utilized night-time shelters from the first night after release, while the large nonacclimated fish started to utilize shelters several days after release. Therefore, it is likely that the shelter acclimation enhanced the shelter utilization by tuskfish, possibly decreasing post-release predation mortality

Diel behavioral pattern of hatchery-reared black-spot tuskfish determined by acoustic telemetry in the natural environment and video observation in a fish tank

December 15-17, 2007, Royal Phuket City Hotel, Phuket, ThailandDiel behavioral pattern of hatchery-reared black-spot tuskfish was examined by acoustic telemetry in the natural environment and video observation in a fish tank. Nine tuskfish were monitored using acoustic telemetry for 150 days; five fish were observed in a fish tank for 2 days. In the acoustic telemetry tracking, tuskfish moved horizontally and vertically during the day; they stayed still at night. The tuskfish tended to utilize depths near the bottom both during the day and night. In the video observation, the tuskfish tended to move actively and sweep sand at bottom during the day; they tended to stay still in the crater they made during the night. These results indicated that tuskfish might make their night-time resting house by sweeping sand near structures and forage benthic preys during the day, and rest in the resting house at night

Successful spontaneous nesting of the hawksbill turtle (Eretmochelys imbricate) at Yaeyama Station, National Center for Stock Enhancement, Japan

Organized by Graduate School of Informatics, Kyoto University ; JSPS Bangkok Liaison Office ; Japanese Society of Bio-logging Science ; Informatics Research Center for Development of Knowledge Society InfrastructureDecember 13-14, 2005, Siam City Hotel, Bangkok, ThailandWith a view to the conservation of the natural stock of the hawksbill turtle (Eretmochelys imbricata), we carried out studies on the propagation techniques of this species. This paper deals with the spontaneous nesting of this species under rearing conditions. Adult turtles that were captured off Ishigaki Island between 1999 and 2002 were brought to the center by licensed fishermen. One adult male and three mature females were selected from 29 turtles and they were stocked in a 250kL tank that was connected to a sandy beach for nesting. The females were examined by ultrasonography throughout experimental period. The mean diameter of the follicles ranged from 1.4 - 1.7 cm from January to April; and gradually increased to 3.0 cm from which shelled eggs were laid. The shelled eggs were first observed on 2nd June 2004, but were not observed after September. In contrast, non nesting individuals had not possessed shelled eggs during the experimental period. These results indicate that the formation of shelled eggs is an indicator of nesting. The first nesting was observed on 7th June, with a total of 7 nestlings observed until September. A total of 894 eggs were obtained from two females

RESENT STATUS ON REARING AND RELEASING STUDIES OF SEA TURTLES IN JAPAN SEA-FARMING ASSOCIATION

Southeast Asia Sea Turtle Associative ResearchBangkok, Thailand, 16-19 December 2002Hatchlings of loggerhead turtle Caretta caretta in 46.7mm on average (range : 41.0-49.0mm) of standard straight carapace length (SCL) and 22.6g on average (range : 17.4-24.5g) of body weight (BW) were transported from Nagoya Port Aquarium to Yaeyama station in July 1999. The hatchlings grew up to be 756.5mm on average (range : 708-855mm) SCL and 58.2kg on average (range : 46.3-71.2) BW for three years after hatchlings. The growth performance of these species are 0.3kg/month (in the 1st year), 1.2kg/month (in the 2nd year), and 3.3kg/month (in the 3rd year), respectively. A two and half years old loggerhead turtle in 649mm SCL and 43.1kg BW tagged with satellite tracking device on the carapace was released at Yaeyama station (24°N, 124°E) in January 2002. The data of the present position was collected through the Argos system. The turtle was at 36°N, 152°E in the end of December, 2002

MIS 7 interglacial sea-surface temperature and salinity reconstructions from a southwestern subtropical Pacific coral

We generated a 5.5-yr snapshot of biweekly-to-monthly resolved time series of carbon and oxygen isotope composition (δ13C and δ18O) and Sr/Ca and Mg/Ca from annually banded aragonite skeleton of a ~197ka pristine Porites coral collected at Niue Island

Stable oxygen isotope record and Sr/Ca ratios of corals from IODP Holes M0009D and M0023A

We present monthly resolved records of strontium/calcium (Sr/Ca) and oxygen isotope (d18O) ratios from well-preserved fossil corals drilled during the Integrated Ocean Drilling Program (IODP) Expedition 310 'Tahiti Sea Level' and reconstruct sea surface conditions in the central tropical South Pacific Ocean during two time windows of the last deglaciation. The two Tahiti corals examined here are uranium/thorium (U/Th)-dated at 12.4 and 14.2 ka, which correspond to the Younger Dryas (YD) cold reversal and the Bølling-Allerød (B-A) warming of the Northern Hemisphere, respectively. The coral Sr/Ca records indicate that annual average sea surface temperature (SST) was 2.6-3.1 °C lower at 12.4 ka and 1.0-1.6 °C lower at 14.2 ka relative to the present, with no significant changes in the amplitude of the seasonal SST cycle. These cooler conditions were accompanied by seawater d18O (d18Osw) values higher by ~0.8 per mill and ~0.6 per mill relative to the present at 12.4 and 14.2 ka, respectively, implying more saline conditions in the surface waters. Along with previously published coral Sr/Ca records from the island [Cohen and Hart (2004), Deglacial sea surface temperatures of the western tropical Pacific: A new look at old coral. Paleoceanography 19, PA4031, doi:10.1029/2004PA001084], our new Tahiti coral records suggest that a shift toward lower SST by ~1.5 °C occurred from 13.1 to 12.4 ka, which was probably associated with a shift toward higher d18Osw by ~0.2 per mill. Along with a previously published coral Sr/Ca record from Vanuatu [Corrège et al. (2004), Interdecadal variation in the extent of South Pacific tropical waters during the Younger Dyras event. Nature 428, 927-929], the Tahiti coral records provide new evidence for a pronounced cooling of the western to central tropical South Pacific during the Northern Hemisphere YD event