Pacific Science Volume 59, Number 4, 2005
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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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ItemIndex to Volume 59(University of Hawaii Press, 2005-10)
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ItemAssociation affairs(University of Hawaii Press, 2005-10)
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ItemHelminth records from eleven species of Emoia (Sauria: Scincidae) from Oceania(University of Hawaii Press, 2005-10)As part of an ongoing study of the biogeography of helminth parasites of lizards from Oceania, 53 specimens of Emoia (11 species) were examined, as follows: E. atrocostata, E. boettgeri, E. caerulocauda, E. cyanogaster, E. cyanura, E. impar, E. nigra, E. nigromarginata, E. ponapea, E. sanfordi, E. trossula. One species of Digenea, Paradistomoides gregarium, and six species of Nematoda, Hedruris hanleyae, Maxvachonia chabaudi, Parapharyngodon maplestoni, Physalopteroides arnoensis, Spauligodon gehyrae, and Moaciria sp. indet., were found. These helminths have been reported previously from other lizard species. Seventeen new host records and eight new locality records are reported.
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ItemA new species of Glossodoris (Mollusca: Nudibranchia), of the Glossodoris atromarginata color group, from Indonesia(University of Hawaii Press, 2005-10)A new species, Glossodoris tibboeli Valdés & Adams, is described based on three specimens collected from Para Island and several others observed at Para, Kahakitang, and Mahengetang Islands, north of Sulawesi, Indonesia. The species is characterized by being starkly opaque white, with a dark brown, irregular dorsal strip extending from the rhinophores to the gill. Because of the coloration and external morphology the new species is compared with members of the Glossodoris atromarginata (Cuvier, 1804) color group, from which it differs by lacking a dark line around the mantle margin. The radulae of all members of the G. atromarginata color group are similar but differ from that of the new species in lacking rachidian teeth.
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ItemFalse killer whale dorsal fin disfigurements as a possible indicator of long-line fishery interactions in Hawaiian Waters(University of Hawaii Press, 2005-10)Scarring resulting from entanglement in fishing gear can be used to examine cetacean fishery interactions. False killer whales (Pseudorca crassidens) are known to interact with the Hawai'i-based tuna and swordfish long-line fishery in offshore Hawaiian waters. We examined the rate of major dorsal fin disfigurements of false killer whales from nearshore waters around the main Hawaiian Islands to assess the likelihood that individuals around the main islands are part of the same population that interacts with the fishery. False killer whales were encountered on 11 occasions between 2000 and 2004, and 80 distinctive individuals were photographically documented. Three of these (3.75%) had major dorsal fin disfigurements (two with the fins completely bent over and one missing the fin). Information from other research suggests that the rate of such disfigurements for our study population may be more than four times greater than for other odontocete populations. We suggest that the most likely cause of such disfigurements is interactions with longlines and that false killer whales found in nearshore waters around the main Hawaiian Islands are part of the same population that interacts with the fishery. Two of the animals documented with disfigurements had infants in close attendance and were thought to be adult females. This implies that even with such injuries, at least some females may be able to produce offspring, despite the importance of the dorsal fin in reproductive thermoregulation.
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ItemMain diatom taxa in the natural diet of juvenile Haliotis fulgens and H. corrugata (Mollusca: Gastropoda) in Bahía Tortugas and Bahía Asunción, B.C.S., México(University of Hawaii Press, 2005-10)To determine the main diatom taxa found in the natural diet of Haliotis fulgens Philippi (green abalone) and H. corrugata Wood (pink abalone) juvenile specimens and loose rocks were collected from different depths at two sites in Bahía Tortugas and Bahía Asunción, Baja California Sur. Overall 113 benthic diatom species were identified, and 98 taxa were recorded in the gut contents of both abalone species. Out of these 32 were not observed in the surrounding flora. Most diatom taxa were epiphytic forms, including the abundant taxa found in the gut contents of young abalone: Berkeleya fennica, Cocconeis speciosa, Cocconeis costata var. pacifica, Gomphonemopsis pseudexigua, Grammatophora marina, Navicula parva, Tabularia investiens, and Thalassionema nitzschioides. This somewhat re-flected the structure of the diatom assemblages in the rocky habitat: few abundant taxa and many rare or uncommon ones, with heterogeneous values of diversity (H') that ranged between 1.1 and 4.2 in the gut contents and from 2.83 to 3.91 in the surrounding flora. New records for the area include Cocconeis pseudomarginata, C. maxima (common), Licmosoma sp., Ardissonia formosa (rare), and the colonial form Berkeleya fennica (abundant), all found within the gut contents of abalone. The actual and potential diet of young abalone on the coast of Baja California Sur is extended to 235 taxa. The abundant taxa occurred frequently in clumps of numerous individuals in the gut contents, often still attached to algal tissue. The results of this investigation suggest that the importance of diatoms in the diet of larger juvenile abalone merits reassessment.
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ItemTemporal variation in photosynthetic pigments and UV-absorbing compounds in shallow populations of two Hawaiian reef corals(University of Hawaii Press, 2005-10)As we seek to understand the physiological mechanisms of coral bleaching, it is important to understand the background temporal variation in photosynthetic pigments and photoprotective compounds that corals exhibit. In this study, reef flat populations of two hermatypic coral species, Montipora capitata (Dana, 1846) and Porites compressa Dana, 1846, were sampled monthly in Kane'ohe Bay, Hawai'i, from January 1998 to March 1999. Surface ultraviolet radiation (UVR) was measured continually during this time period at the same location. High-performance liquid chromatography (HPLC) analysis of photosynthetic pigments and mycosporine-like amino acids (MAAs) revealed temporal changes in concentrations and proportions of these compounds in tissues of both species of coral. Chlorophyll a (chl a), chlorophyll c2 (chl c2), peridinin, and diadinoxanthin concentrations changed on a skeletal weight (M. capitata) or surface area (P. compressa) basis, significantly correlating with seasonal changes in solar input (number of days from the winter solstice). In P. compressa, diadinoxanthin increased in proportion to the total pigment pool during summer months, suggesting an up-regulation of a xanthophyll cycle. In M. capitata, the ratio of chl a: chl c2 decreased during winter months, suggesting photoacclimation to lower light levels. It is surprising that there was not a clear seasonal pattern in total MAA concentration for either species, with the exception of shinorine in P. compressa. The relative stability of MAA concentrations over the course of the year despite a pronounced seasonal trend in UVR suggests either that MAAs are not performing a photoprotective role in these species or that concentrations are kept at a threshold level in the presence of a dynamic light environment.
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ItemComposition and abundance of Benthic Macrofauna of a tropical sea-grass bed in North Queensland, Australia(University of Hawaii Press, 2005-10)The aims of this study were to characterize the functional composition of benthic macrofauna of a tropical sea-grass bed and to determine temporal variations in abundance of benthic macrofauna in relation to environmental factors such as sea-grass biomass, temperature, salinity, and sediment type. Benthic macrofaunal composition and abundance were investigated by core sampler during April 1999, October 1999, March 2000, and August 2000 at three stations within a sea-grass bed at Cockle Bay in North Queensland, Australia. A total of 110 species of benthic macrofauna was collected. Polychaetes were the most abundant group (37 species; 52% of total macrofaunal numbers; 47% of biomass) followed by amphipods (27 species; 35% of total numbers). Decapods were also important, with 28 species contributing 31% of total macrofaunal biomass. Other miscellaneous groups were tanaids, isopods, and ophiuroids. Most amphipods (65%) and decapods (90%) were epifaunal, but polychaetes were equally represented by epifauna and infauna. Temporal variation in both species composition and abundance was large: the peak number of benthic macrofauna occurred in April 1999 and March 2000, and biomass was highest in April 1999. Benthic macrofauna numbers as well as biomass were lowest in August 2000. These temporal patterns of abundance of benthic macrofauna appeared to correlate closely with temporal variation of sea-grass biomass. In addition, the factors of life cycle and predation by common fish species may be indirectly associated with these patterns of macrofaunal abundance.
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ItemPre-mining pattern of soils on Nauru, Central Pacific(University of Hawaii Press, 2005-10)The environment of Nauru, a raised atoll located in the central Pacific Ocean (0° 32' S, 166° 56' W), was devastated by mining of phosphate "rock" during the twentieth century. Some 100 million tonnes of phosphate material has been removed, leaving more than 80% of the island as a dolomite pinnacle-dominated karrenfeld. Based on fieldwork examining sites unmined at that time, laboratory studies on undisturbed profiles, aerial photographs, and old mining maps, a picture of what the soil pattern on Nauru was before mining has been developed. Four major soil associations were identified: the coastal fringe carbonate-dominated soils set on a recent fringing reef; deep and relatively deep phosphate-dominated soils free of substantial influence from the underlying dolomite pinnacles occurring on the NE, NW, SE, and SW sectors of the uplifted section of the island (known locally as "Topside"); a complex set of soils found on Topside and on the scarp where the pinnacle influence is important but containing some deep soils where phosphate material accumulated between the pinnacles; and a complex set of soils in low-lying areas around the old lagoon at Buada. Distribution of soils is discussed and physical, chemical, and mineralogical properties of the soils are presented. Soils were basically AC profiles, with coarse textures, free drainage, and limited moisture-retention capacities. Organic matter accumulated to various depths from about 5 to 50 cm. Soil pH was generally above 6, cation exchange capacities were closely aligned to organic matter contents, but trace element deficiencies would have been common. Cadmium concentrations were relatively high in Nauru soils. The soils are likely to have been of limited fertility, with moisture being a major limitation in many years. Classification of the soils indicated a dominance of Ustropepts and Ustolls, with smaller areas of Ustipsamments and Ustorthents, and very small areas of soils showing aquic features. The postmining situation is also discussed; only very limited areas of three of the original soil associations remain (the relatively deep profiles free of pinnacle influence have completely disappeared). Limitations to rehabilitation are also briefly reviewed.
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ItemDecline of a population of wild seeded breadfruit (Artocarpus mariannensis) on Guam, Mariana Islands(University of Hawaii Press, 2005-10)Seeded breadfruit (Artocarpus mariannensis) was historically a dominant tree in native forests on Guam and Rota in the Mariana Islands. Censuses conducted during 1989-1999 showed a large decline in the population of this species in northernmost Guam, with the number of trees at one study area decreasing from 549 to 190 trees, or 65.4%. Mean annual decline rates were far higher from 1989 to 1996 (9.2% per year) than from 1996 to 1999 (2.6% per year). Size structure of the population was strongly skewed toward larger trees, with 83.3% of measured individuals having trunk diameters ranging from 31 to 70 cm. Virtually no seedlings or saplings were present. Experiments at this site revealed high rates of fallen seed and fruit consumption and browsing on seedlings by introduced Philippine deer (Cervus mariannus) and feral pigs (Sus scrofa). In contrast, breadfruit populations elsewhere on Guam and Rota exhibited much less mortality. One population in an area without deer and pigs displayed considerable regeneration and a size structure composed mainly of younger plants. The decline of A. mariannensis in northern Guam appeared to be caused primarily by a combination of high mortality associated with an unusually severe typhoon season in 1992 and a nearly complete lack of recruitment due to excessive seed predation and herbivory by deer and pigs. Ungulate control is strongly urged to restore populations of A. mariannensis and other native plants, and to prevent further alteration of Guam's forests.