Effects of Water Removal on a Hawaiian Stream Ecosystem
Robert A. Kinzie III, Charles Chong, Julia Devrell, Dan Lindstrom, and Reuben Wolff
Abstract: A 3-year study of Wainiha River on Kaua‘i, Hawai‘i, was carried out to determine the impact that water removal had on key stream ecosystem parameters and functions. The study area included a diversion dam for a hydroelectric plant that removes water at an elevation of 213 m and returns it to the stream about 6 km downstream at an elevation of 30 m. There were two highelevation sites, one with undiverted flow and one with reduced flow, and two low-elevation sites, one with reduced flow and one with full flow restored. Monthly samples were taken of instream and riparian invertebrates and plants. When samples from similar elevations were compared, dewatered sites had lower concentrations of benthic photosynthetic pigments than full-flow sites, and benthic ash-free dry mass (AFDM) was higher at the two low-elevation sites regardless of flow. Benthic chlorophyll a (chl a) and AFDM were higher in summer months than in the winter. Benthic invertebrate abundance was highest at the full-flow, low-elevation site and benthic invertebrate biomass was highest at the full-flow, high-elevation site. Season had only marginal effects on abundance and biomass of benthic invertebrates. Diversity of benthic invertebrates was higher at the more-downstream sites. Abundance of drifting invertebrates was highest at the site above the diversion dam and generally higher in winter than in summer months. Biomass of drifting invertebrates was also highest at the above-dam site but there was little seasonal difference. Almost all parameters measured were lowest at the site just downstream of the diversion dam. The biotic parameters responded only weakly to flows that had occurred up to 1 month before the measurements were made. Flow, elevation, and season interact in complex ways that impact ecosystem parameters and functions, but water diversion can override all these environmental factors.
Baseline Climatology of Viti Levu (Fiji) and Current Climatic Trends
Melchior Mataki, Kanayathu C. Koshy, and Murari Lal
Abstract: In this paper we characterize the climate at Nadi and Suva in Fiji from 1961 to the present, providing a picture of ongoing climate trends. The focus is on surface observations of air temperature and rainfall, although some information on South Pacific Ocean climate is also discussed, given its relevance for Fiji. Our findings suggest that surface air temperatures have registered increasing trends at both Suva and Nadi (the two observatory sites in Fiji identified as Weather Observing Stations under the global network of the World Meteorological Organization) during the period 1961–2003. There has been a steady increase in the number of days per year with warmer nighttime temperatures in recent decades. The rise in annual mean surface air temperature over Suva was ~1.2 °C over the 43-yr period considered here (at a significantly increasing rate of 0.25 °C per decade, which is 1.5 times higher than the trends in global average temperature increase during the past century). The rate of increase in annual mean surface air temperature at Nadi was 0.07 °C per decade. No trend in annual mean rainfall has been observed, however, at either of the locations. Significant interannual variability in annual as well as summer rainfall observed at both sites (including extreme rainfall events during the 43-yr period) can largely be attributed to El Niño–Southern Oscillation (ENSO) events and intraseasonal oscillations in the mean position of the South Pacific Convergence Zone.
Vertebrates of Tetepare Island, Solomon Islands
John L. Read and Katherine Moseby
Abstract: Tetepare is the largest unlogged and uninhabited lowland rain-forest island in the South Pacific and is being managed primarily for conservation. An inventory was conducted, and 25 reptile, 4 frog, 76 bird, and 13 mammal species were recorded from Tetepare, including several birds and turtles of international conservation significance. Their relative abundance and local names were collected to assist landowners in attracting researchers and ecotourists and also to develop a conservation management plan for Tetepare.
Marine Algae of French Frigate Shoals, Northwestern Hawaiian Islands: Species List and Biogeographic Comparisons
Peter S. Vroom, Kimberly N. Page, Kimberly A. Peyton, and J. Kanekoa Kukea-Shultz
Abstract: French Frigate Shoals represents a relatively unpolluted tropical Pacific atoll system with algal assemblages minimally impacted by anthropogenic activities. This study qualitatively assessed algal assemblages at 57 sites, thereby increasing the number of algal species known from French Frigate Shoals by over 380% with 132 new records reported, four being species new to the Hawaiian Archipelago, Bryopsis indica, Gracilaria millardetii, Halimeda distorta, and an unidentified species of Laurencia. Cheney ratios reveal a truly tropical flora, despite the subtropical latitudes spanned by the atoll system. Multidimensional scaling showed that the flora of French Frigate Shoals exhibits strong similarities to that of the main Hawaiian Islands and has less commonality with that of most other Pacific island groups.
A Vermetid Gastropod with Complex Intracapsular Cannibalism of Nurse Eggs and Sibling Larvae and a High Potential for Invasion
Megumi F. Strathmann and Richard R. Strathmann
Abstract: A vermetid gastropod, previously unreported from the Pacific Ocean, was found at O‘ahu, Hawai‘i, in aquariums at the Kewalo Marine Laboratory, in fouling communities on docks, and on intertidal and shallow subtidal coral rubble. It also occurs on coral rubble in Florida. Eggs, or nurse eggs, and early embryos are about 100 µm in diameter. Young are brooded in 1–13 stalked capsules attached inside the tubular shell. Intracapsular development involves an unusual complex adelphophagy (sibling cannibalism). Most eggs are nondeveloping nurse eggs. Ten to 20 eggs develop into apparently normal small veligers. Of these most arrest as small veligers, but a few grow to hatch as large pediveligers or juveniles. The species has a high potential for invasion and establishment following maritime transport or natural rafting. Protected intracapsular development ends with the release of crawling hatchlings that also produce mucous threads on which they can drift. Juveniles settle readily on hard substrata. An apparent rarity or absence of males suggests long-term sperm storage, hermaphroditism, or parthenogenesis, any of which could aid colonization. Adults and juveniles occur in fouling communities and can survive extended periods in still seawater and at low food levels. The species’ global distribution and history of invasions are unknown. We predict widespread distribution and invasions in warm waters.
Anguilla marmorata (Giant Mottled Eel) Discovered in a New Location: Natural Range Expansion or Recent Human Introduction
Alex Handler and Shelley A. James
Abstract: Freshwater eels in the family Anguillidae spend a majority of their adult life in freshwater but migrate to the ocean to spawn and die. Because freshwater eels are believed to have a long larval period in the open ocean, it is unclear how the present global distribution of species arose. A stock of freshwater eels of the family Anguillidae was found on Palmyra Atoll in the central Pacific Ocean, in June 2003. In October 2003, a single eel specimen was caught using a hand net from this small group of eels on Palmyra Atoll. Morphological and molecular characters (12S and 16S mitochondrial rRNA and cytochrome b mtDNA sequences) were used to identify the species as Anguilla marmorata Quoy & Gaimard. The discovery of these eels on Palmyra supports the hypothesis of natural range expansion from the Indo-Pacific eastward to the Galápagos through the Line Islands, but further analysis of oceanic currents and more variable genes are required to assess whether humans are involved in the recent spread of Anguilla marmorata to these new locations.
Bryoliths (Bryoza) in the Gulf of California
D. W. James, M. S. Foster, and J. O’Sullivan
Abstract: Populations of Diaperoforma californica (d’Orbigny) bryoliths were discovered in rhodolith beds, a sand habitat, and on a cobble bottom in the Gulf of California, Mexico, the first known observation of a modern free-living cyclostome bryozoan in the Northern Hemisphere. Densities ranged from a mean of 9.2 to 22.6 individuals/0.06 m2. Bryoliths from the deepest site were irregularly shaped and had the highest variation in shape; those from shallow sites were spheroidal. Water motion and bioturbation move the bryoliths and may determine their morphology. Schizomavella robertsonae (Soule, Soule & Chaney) bryoliths also occurred occasionally in one rhodolith bed sampled. Fossilized bryolith specimens of the cyclostome Diaperoforma californica (d’Orbigny) were found in a Pleistocene deposit near modern habitats.
A New Genus and Species of Diplodactylid Gecko (Reptilia: Squamata: Diplodactylidae) from Northwestern New Caledonia
Aaron M. Bauer, Todd Jackman, Ross A. Sadlier, and Anthony H. Whitaker
Abstract: A new genus and species of diplodactylid gecko, Oedodera marmorata Bauer, Jackman, Sadlier & Whitaker, is described from low-elevation maquis habitat near Paagoumène in the northwest of the Province Nord, New Caledonia. The new gecko is a robust form that is superficially similar to members of the genus Bavayia Roux but differs in several digital characteristics, the presence of a patch (versus 1–2 rows) of precloacal pores, and a uniquely swollen neck. In addition, molecular data indicate that the new form is the basal member of the entire radiation of New Caledonian diplodactylids. The new species is at risk due to wildfires, introduced predators and perhaps competitors, and planned mine development into part of its range.
A New Species of Extinct Parrot (Psittacidae: Eclectus) from Tonga and Vanuatu, South Pacific
David W. Steadman
Abstract: A new extinct species of parrot, Eclectus infectus Steadman, is described from 21 bones from archaeological (late Holocene) and paleontological (late Pleistocene) sites on three islands in the Kingdom of Tonga, with limited referred material (ulna, tibiotarsus) from a late Holocene archaeological site on Malakula, Vanuatu. Probably, therefore, the range of E. infectus also included at least the intervening island group of Fiji. The extinction of E. infectus occurred since the arrival of people in this region ca. 3,000 yr ago and presumably was due to human impact. A single, very fragmentary parrot tibiotarsus from Rota (Mariana Islands) may pertain to an indeterminate species of Eclectus. The only extant species of Eclectus is E. roratus, which occurs from the Solomon Islands westward to the Moluccas. Eclectus infectus provides the first evidence of the genus east of the Solomon Islands, although its biogeographic implications are not unique. Within Oceania (outside New Zealand and the Hawaiian Islands), human activities have eliminated the easternmost species in at least 17 other genera of land birds.
Pacific Science Association