Pacific Science Volume 54, Number 4, 2000

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Pacific Science is a quarterly publication devoted to the biological and physical sciences of the Pacific Region.

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    54: Index - Pacific Science
    (University of Hawai'i Press, 2000)
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    Stratigraphy and Whole-Rock Amino Acid Geochronology of Key Holocene and Last Interglacial Carbonate Deposits in the Hawaiian Islands
    (University of Hawai'i Press, 2000-10) Hearty, Paul J. ; Kaufman, Darrell S. ; Olson, Storrs L. ; James, Helen F.
    We evaluated the utility of whole-rock amino acid racemization as a method for the stratigraphic correlation and dating of carbonate sediments in the Hawaiian Islands. D-alloisoleucine/L-isoleucine (A/I) ratios were determined for carbonate sand and sandstone samples from 25 localities in the archipelago. The superposition of A/I ratios within stratigraphic sections and the regional concordance of ratios within geological formations support the integrity of the method. To correlate the A/I ratios with an absolute chronology, comparisons were made with previously published uranium series dates on corals and with 14C dates on carbonate sand and organic material, including several new dates reported herein. The A/I mean from four marine isotope stage (MIS) 5e U-series calibration sites was 0.505 ± 0.027 (n = 11), and 12 "test sites" of previously uncertain or speculative geochronological age yielded an A/I mean of 0.445 ± 0.058 (n = 17). Similarly, extensive Holocene dunes on Moloka'i and Kaua'i were correlated by a mean A/I ratio of 0.266 ± 0.022 (n = 8) and equated with a 14C bulk sediment mean age of 8600 yr B.P. Our results indicate that the eolian dunes currently exposed in various localities in the Islands originated primarily during two major periods of dune formation, the last interglacial (MIS 5e) and the early Holocene (MIS 1). MIS 5e and MIS 1 A/I ratios from the Hawaiian Islands show close agreement with previous whole-rock studies in Bermuda and the Bahamas. We discuss these results in terms of their relevance to models of lithospheric flexure and to imposing constraints on the time frame for the extinction of fossil birds.
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    Notes on Status and Ecology of the Endangered Hawaiian Annual Awiwi, Centaurium sebaeoides (Gentianaceae)
    (University of Hawai'i Press, 2000-10) Medeiros, Arthur C. ; Chimera, Charles G. ; Loope, Lloyd L. ; Joe, Stephanie M. ; Krushelnycky, Paul D.
    The annual, endemic, coastal herb Centaurium sebaeoides is the only native Hawaiian species in the gentian family. The U.S. Fish and Wildlife Service listed it as Endangered under the Endangered Species Act on 29 October 1991. Before surveys reported here, the total population of this species statewide was estimated at 80-110 individuals in eight populations. During counts made in April and May 1997, following ample winter rains, 12 populations of C. sebaeoides with a total of 6300-6600 plants were noted on five islands (Kaua'i, O'ahu, Lana'i, Moloka'i, and Maui). Five populations were mapped with a global positioning system and counted; in the remaining seven populations, the numbers of individuals were estimated. More recent surveys in 1998-1999 estimated a total of only 60-80 individuals at all sites. Such dramatic population fluctuations are believed to be related to the sporadic occurrence of winter rains. Threats that further contribute to the rarity of the species include (1) displacement and overtopping by salt-tolerant nonnative woody species, especially Casuarina spp., (2) trampling and erosion of habitat by ungulates, and (3) damage caused by off-road vehicles.
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    Notes on the Identity of Small, Brown, Unpatterned Indo-Pacific Moray Eels, with Descriptions of Three New Species (Anguilliformes: Muraenidae)
    (University of Hawai'i Press, 2000-10) Bohlke, Eugenia B.
    Eight species of Indo-Pacific morays, including three new species, are described and discussed. Most are plain brown and have unpatterned body coloration (one with small dark spots); they are small to moderate-sized species and possess fewer than 150 vertebrae. They include Gymnothorax atolli (pietschmann, 1935); Gymnothorax australicola Lavenberg, 1992; Gymnothorax herrei Beebe & Tee-Van, 1933; Gymnothorax panamensis (Steindachner, 1876); Gymnothorax pindae Smith, 1962; Gymnothorax pseudoherrei Bohlke, n. sp.; Gymnothorax kontodontos Bohlke, n. sp.; and Gymnothorax microstictus Bohlke, n. sp.
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    Occurrence of a Rare Squaloid Shark, Trigonognathus kabeyai, from the Hawaiian Islands
    (University of Hawai'i Press, 2000-10) Wetherbee, Bradley M. ; Kajiura, Stephen M.
    The first occurrence of the rare viper shark, Trigonognathus kabeyai, from the central Pacific Ocean is reported. Morphometries are compared between this specimen and the type specimens from Japan, and this specimen differs from the types in only a few measurements. The poor preservation of this specimen precluded examination of internal anatomy.
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