Human Impacts on Fluxes of Nutrients and Sediment in Waimanalo Stream, O‘ahu, Hawaiian Islands
Edward A. Laws and Lisa Ferentinos
Abstract: Waimanalo Stream, on the windward side of the island of O‘ahu in the Hawaiian Islands, has been greatly altered by human activities. Native riparian vegetation has been removed along much of the course of the stream, and significant sections of the stream have been hardened to control flooding. Absence of shade from riparian vegetation has allowed California grass (Brachia mutica), wild sugarcane (Saccharum officinarum), and other vegetation to proliferate in the stream channel. Some reaches of the stream more closely resemble a wetland than a natural watercourse. During fair weather and moderate storms, this vegetation effectively traps sediment. During a year when rainfall was [nearly equal to] 40% below average, dissolved N and P accounted for most of the N and P transported by the stream. N and P content of the suspended solids was comparable with that of terrestrial organic matter, but with a slightly lower N/P ratio, probably due to the high iron content of Hawaiian soils. Concentration of suspended solids in the stream was only about 4% of the average concentration in fluvial systems that discharge to the ocean. Base flow accounted for about 32% of the P, 58% of the suspended solids, and 96% of the N transported by the stream. The very high contribution of base flow to the N flux was apparently related to contamination of shallow groundwater in the lower reach of one tributary, in which nitrate N concentrations during base flow were about 7 mg liter–1. Flux of N in the stream was comparable with the amount of N produced by livestock waste in this predominantly agricultural watershed. Cesspool seepage and/or leaching of N from animal waste into shallow groundwater and seepage of that groundwater into the stream may account for the anomalously high N loading to the stream. Absence of a similarly high P flux probably reflects the high iron content of Hawaiian soils, which effectively immobilize P in groundwater.
First Record of a Rhizosolenia debyana Bloom in the Gulf of California, México
Ismael Gárate-Lizárraga, David A. Siqueiros-Beltrones, and Verónica Maldonado-López
Abstract: A bloom of the diatom Rhizosolenia debyana H. Peragallo was observed in the southwestern Gulf of California. This bloom was estimated to be about 22 km long and represents the first record of this species for the area. Total abundance of R. debyana ranged from 2,576,000 to 3,684,000 cells liter–1. Chlorophyll a concentrations ranged from 17.15 to 41.45 mg/m3. Rhizosolenia debyana has a tropical and subtropical distribution.
Movement Patterns of Dark-Rumped Petrels and Newell’s Shearwaters on the Island of Hawai‘i
Robert H. Day, Brian A. Cooper, and Richard J. Blaha
Abstract: We studied movements and distribution and abundance of endangered Dark-rumped Petrels (‘Ua‘u; Pterodroma phaeopygia sandwichensis Ridgway) and threatened Newell’s Shearwaters (‘A‘o; Puffinus auricularis newelli Henshaw) on the island of Hawai‘i in May–June 2001 and 2002. We recorded radar targets of either species at 14 of the 18 sites but recorded no birds visually at any site. Movement rates of petrels and shearwaters were very low (0–3.2 targets/hr) over all except one of the sites (Waipi‘o Valley; 25.8 targets/hr). We saw radar targets moving from shortly after sunset throughout the rest of the sampling, suggesting that both petrels and shearwaters were present. The highest movement rates occurred 1–2 hr after sunset, when primarily Newell’s Shearwaters are flying. The timing of evening movements suggests that Dark-rumped Petrels fly over the northern and southern parts of the island and may dominate on Mauna Loa and Mauna Kea. In contrast, the timing suggests that Newell’s Shearwaters fly over essentially the entire island (except in the southwestern part, where no birds appear to occur), dominate numerically in the Kohala Mountains, and occur in low numbers on Mauna Loa, in the Puna District, and on the northern slopes of Mauna Kea. Evening flight directions were predominantly inland at all sites except four. The limited radar data suggest that a substantial population change did not occur in the Puna District from 1995 to 2001–2002.
Rediscovery of Blackburnia anomala (Blackburn) (Coleoptera: Carabidae), in East Maui, Hawai‘i after an 107-year Hiatus
D. A. Polhemus, Curtis P. Ewing, R. Takumi, and James K. Liebherr
Abstract: The highly distinctive and diverse, native Hawaiian carabid beetle fauna includes a suite of species not recently observed in nature. These are predominantly historical residents of the mesic Acacia koa forest formation. We report rediscovery of one of these species, Blackburnia anomala (Blackburn) (Coleoptera: Carabidae), in the shrubland formation near Paliku Cabin, and in koa forest of Kaupo Gap. Prior records of B. anomala are limited to the leeward edges of historical koa forest near Olinda, on the northwest slope of Haleakala. Rediscovery on the far southeastern side of Haleakala Crater in similar, though conserved habitats, suggests that other long-missing koa-associates may persist in similar situations on Haleakala.
Helminths of the Ezo Brown Frog, Rana pirica (Ranidae) from Hokkaido Island, Japan
Stephen R. Goldberg and Charles R. Bursey
Abstract: Rana pirica, endemic to Hokkaido Island, Japan, was examined for helminths. One species of Monogenea, Polystoma ozakii, two species of Nematoda, Oswaldocruzia socialis and Rhabdias nipponica, and one species of Acanthocephala, Acanthocephalus lucidus, were found. Rana pirica represents a new host record and Hokkaido Island a new locality record for O. socialis, R. nipponica and A. lucidus. None of the helminths found in this study are restricted to Hokkaido Island.
Wood Anatomy of Hawaiian and New Guinean Species of Tetramolopium (Asteraceae): Ecological and Systematic Aspects
Sherwin Carlquist and Timothy K. Lowrey
Abstract: Qualitative and quantitative features are reported for five Hawaiian and one New Guinean species of Tetramolopium. Tetramolopium humile differs from the other Hawaiian species in its numerous narrow vessels, numerous vasicentric tracheids, and wide rays. Although these features are adaptive in the dry alpine localities of T. humile, they would be adaptive also in the remaining species, which are from dry to moderately dry lowland localities. Thus, one can consider these features of T. humile as systematic indicators. The wood of T. pumilum (New Guinea) has distinctive wide, tall rays that may be related to the short stems in this species; T. pumilum has wood more mesomorphic than that of any of the Hawaiian species. Within Hawaiian Tetramolopium, wood anatomy correlates with dryness of habitat. The species of Tetramolopium studied have highly xeromorphic wood in comparison to woods of dicotyledons at large.
Phylogeny and Biogeography of Pacific Rubus subg. Idaeobatus (Rosaceae) Species: Investigating the Origin of the Endemic Hawaiian Raspberry R. macraei
Clifford W. Morden, Donald E. Gardner, and Dana A. Weniger
Abstract: The endemic Hawaiian raspberries, Rubus hawaiensis and R. macraei (both subg. Idaeobatus), had been thought to be closely related species until recent molecular studies demonstrated otherwise. These studies suggest that they are the products of separate colonizations to the Hawaiian islands. Affinities of R. hawaiensis to R. spectabilis of western North America were clearly confirmed. However, no clear relation to R. macraei has been published. This study was initiated to examine species of subg. Idaeobatus from the surrounding Pacific region as well as species from other subgenera to better evaluate biogeographic and phylogenetic affinities of R. macraei by means of chromosome analysis and molecular data using the chloroplast gene ndhF. Results show that R. macraei clusters in a clade with species of blackberries, subg. Rubus, and of these it is most closely linked to R. ursinus. Chromosomally, R. macraei is 2n = 6x = 42, a number that would be a new report for subg. Idaeobatus. However, polyploidy is common in subg. Rubus. Analyses indicate that R. macraei and R. hawaiensis are derived from separate colonizations from North America and that similarities between them are due to convergent evolutionx in the Hawaiian environment.
Morphological and Genetic Variation in the Endemic Seagrass Halophila hawaiiana (Hydrocharitaceae) in the Hawaiian Archipelago
Karla J. McDermid, Monica C. Gregoritza, Jason W. Reeves, and D. Wilson Freshwater
Abstract: The endemic seagrass, Halophila hawaiiana Doty and Stone, is found in discrete populations throughout the Hawaiian Archipelago. Morphological characteristics of plants from Midway Atoll, Pearl and Hermes Reef, Kaua‘i, O‘ahu, Moloka‘i, and Maui were measured and compared. Striking variation in leaf length, leaf width, leaf length to width ratio, and internode length was evident among the 18 collection sites sampled at depths ranging from 0.32 m to 18 m. DNA sequence analyses of a chloroplast-genome, single-base repeat locus in ramets from nine different collections found only two repeat haplotypes. Repeat haplotypes were fixed at all collection sites and for all islands except O‘ahu.
Charcoal Stratigraphies for Kaua‘i and the Timing of Human Arrival
Lida Pigott Burney and David A. Burney
Abstract: Evidence from microscopic charcoal particle stratigraphy is presented from nine locations distributed throughout Kaua‘i in the Hawaiian Islands, including windward and leeward coastal sites and interior bogs at elevations ranging up to 1220 m. The overall trends are comparable to those reported for other mesic tropical island areas lacking strong seasonality, beginning with a general dearth of charcoal in sediments that predate evidence for humans on the island, followed by an increase of an order of magnitude or more at a time that probably represents first human presence at the site. In most cases, this initial peak or plateau of increased charcoal from presumably anthropogenic sources is followed by a prehistoric decrease and a second peak after European contact. Charcoal evidence presented here suggests a human presence in leeward coastal areas beginning ca. 830 ± 50 yr BP (1050–1095, 1140–1280 cal yr AD). One windward site, Limahuli Bog, may show charcoal evidence for humans as early as 1470 ± 60 yr BP (440–670 cal yr AD), but resolution is poor in the upper part of this core. Charcoal and sedimentological evidence suggests that Hawaiians were constructing fishponds as early as about eight centuries ago, and that the massive stoneworks forming the Alekoko or Menehune Fishpond, probably the largest prehistoric stone structure in the Hawaiian Islands, may have been completed by 580 ± 30 yr BP (1305–1420 cal yr AD). Charcoal peaks in prehuman times, particularly at 3800 ± 40 yr BP (4080–4290 cal yr BP), may be associated with prolonged drought conditions. Charcoal particles are virtually absent from the late Pleistocene sediments collected from interior bogs.
Pacific Science Association