From Demography of Marine Turtles in the Nearshore Environments of the Northern Mariana Islands, an open access article in this issue. Clockwise from bottom left: nearshore capture locations in relation to benthic habitat of ( A) Saipan, (B) Tinian, and (C ) Rota, and (D) an image of the free diver hand capturing a juvenile green turtle. Green and orange dots depict capture locations for green and hawksbill turtles, respectively. Shading indicates benthic habitat.
This quarter’s issue of Pacific Science includes Demography of Marine Turtles in the Nearshore Environments of the Northern Mariana Islands, an open-access article; and an online-only supplemental for Methods for Measuring Bird-Mediated Seed Rain: Insights from a Hawaiian Mesic Forest.
The open-access article examines honu:
In the western Pacific, green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) sea turtles are listed as Endangered under the U.S. Endangered Species Act (ESA). Population data are limited for both species throughout the entire region and particularly in the Philippine Sea. This study characterizes size class distribution, growth rates, habitat use, behavior, diet, and site fidelity of foraging aggregations of green and hawksbill turtles in nearshore habitats of Saipan, Tinian, and Rota in the Commonwealth of the Northern Mariana Islands (CNMI ). Between August 2006 and February 2014, we captured 642 turtles (493 green and 36 hawksbill turtles). … This is the first study within the CNMI to report on morphometric data and diet composition of marine turtles. These results provide an assessment of green and hawksbill turtle population demographics and habitat use in the CNMI.
Adult specimens of Eriocheir ogasawaraensis, endemic to the Ogasawara Islands, collected in March, 2004, in Chichi-jima, Ogasawara, Japan, in dorsal view: female, 82 mm in carapace width (upper), male, 81 mm in carapace width (lower). Kobayashi and Satake in this issue compare the morphology of this endemic crab to that of its ontinental congener, the Japanese mitten crab, Eriocheir japonica, finding differences in sexual dimorphism. Photo: Satoshi Kobayashi.
This quarterly issue of Pacific Science explores new research about Pacific crabs, fish, plankton, birds, grass, frogs, and eels.
The opening article examines fish in the aftermath of the 2011 Tohoku 9.0 magnitude earthquake and tsunami at the Fukushima Daiichi Nuclear Power Plant. From the abstract:
Thirteen commonly consumed types of fish caught in the North Pacific and locally available in Hawai‘i were analyzed using gamma spectroscopy to measure Fukushima-derived and historic 134Cs and 137Cs isotopes. All fish samples had detectable 137Cs above 95% confidence intervals. Three out of the thirteen samples had 134Cs, an isotope indicative of Fukushima releases, detected above 95% confidence intervals. The highest 134Cs and 137Cs concentration in the examined species was in ‘ahi tuna, carrying 0.10 ± 0.04 Bq/ kg and 0.62 ± 0.05 Bq/ kg, respectively. Other samples with 134Cs activities found above their 2-sigma uncertainty were albacore tuna and swordfish. Historic and Fukushima-derived contributions were evaluated, and in several samples the Fukushima-derived radiocesium dominated the total radiocesium inventory with up to 61% contribution. All activities were below derived intervention limits of 1,200 Bq/ kg, and the doses to humans from consuming the fish attributable to radiocesium were 0.02 – 0.2 μ Sv, in comparison to 6 – 20 μ Sv contributed by the natural 40K present in the same fish.
Scholarly articles in this issue: