Harvesting Impacts and Invasion by an Alien Species Decrease Estimates of Black Coral Yield off Maui, Hawai'i [Access article in PDF] Subject Headings:
Coral fisheries -- Enviromental aspects -- Hawaii -- Maui.
Introduced organisms -- Hawaii -- Maui.
For over 40 yr, the black coral fishery in Hawai'i has been managed
successfully. However, three new developments now threaten sustainability of
the resource. First, harvesting pressure on increasingly smaller colonies of both
species of commercial black coral (Antipathes dichotoma Pallas and Antipathes
grandis Verrill) has increased. Since 1976, the biomass of black coral in the
overall bed off Maui, Hawai'i, has decreased by about 25%. Second, at depths
between 80 and 110 m off Maui an alien species, Carijoa riisei (Duchassaing &
Michelotti), has overgrown large areas of the substratum as well as many adult
colonies of both species of commercial black coral. This invasion may be contributing
to a decrease in the recruitment of both species of black coral at shallower
depths. Third, increasing sales of black coral jewelry in recent years is also
placing more demand on the resource. Taken together, these trends suggest a
need for more stringent regulations, including a larger size (height) limit, a reduction
in the maximum sustained yield, and possible reassessment of the economics
of the fishery. Adoption of these or other measures would help to extend
and ensure continued sustainability of the black coral fishery in Hawai'i and
long-term conservation of the resource.
Cook, Robert P.
Macrofauna of Laufuti Stream, Taú, American Samoa, and the Role of Physiography in its Zonation [Access article in PDF] Subject Headings:
Zoogeography -- American Samoa -- Laufuti Stream.
Biogeomorphology -- American Samoa -- Laufuti Stream.
Laufuti Stream, on the island of Taú , American Samoa, is a complex
interrupted perennial stream, consisting of three accessible sections, lower
Laufuti (perennial), middle Laufuti (intermittent), and upper Laufuti (perennial),
and the inaccessible falls zone, a series of four sheer, intermittent waterfalls
separating lower Laufuti from middle Laufuti. The macrofauna consists primarily
of amphidromous species that are relatively common and widespread in
the tropical Pacific. However, in comparison with stream communities on Tutuila,
Laufuti is unusual. Its shrimp community is more diverse and abundant,
dominated by Macrobrachium latimanus, a species neither widespread nor abundant
on Tutuila. It also supports a relatively diverse, alien-free freshwater fish
community of six species representing three families, Gobiidae, Eleotridae, and
Anguillidae, including Anguilla megastoma, a species of limited occurrence on
Tutuila. The fish community of Laufuti is similar to that of other tropical Pacific
high-island streams in terms of dominant families, but zonation of macrofauna
differs. There are no euryhaline fish species, and only Anguilla megastoma
occurs above the falls zone. There are seven species of shrimps in lower Laufuti,
but only Macrobrachium lar and M. latimanus occur above the falls zone. The
severe dispersal barrier represented by the falls zone plus the absence of estuarine
conditions, both products of the islands' geologic history, have produced a
pattern of species distributions unlike that of most other tropical Pacific high
Specimens of Hormophysa cuneiformis ( J. Gmelin) P. Silva, collected by
R. E. DeWreede in July 1968 and by the author in January 1971 from Palau, are
documented for the first time and represent the first collections of a member of
the family Cystoseiraceae from Micronesia. A single specimen 6 cm tall of H.
cuneiformis was collected 4.5 yr later in July 1975 on a reef bench tide pool at
Pagan Island in the Northern Mariana Islands by R. Rechebei and was reported
in a floristic account of the Chlorophyta and Phaeophyta of the Northern Mariana
Islands in 1977. Specimens of this large and conspicuous brown alga have
not been reported previously from Palau nor other islands in Micronesia.
Price, Jonathan Paul.
Topographic History of the Maui Nui Complex, Hawai'i, and Its Implications for Biogeography [Access article in PDF] Subject Headings:
Hawaii -- Historical geography.
Biogeography -- Hawaii.
The Maui Nui complex of the Hawaiian Islands consists of the islands
of Maui, Moloka'i, Lana'i, and Kaho'olawe, which were connected as a single
landmass in the past. Aspects of volcanic landform construction, island subsidence,
and erosion were modeled to reconstruct the physical history of this
complex. This model estimates the timing, duration, and topographic attributes
of different island configurations by accounting for volcano growth and subsidence,
changes in sea level, and geomorphological processes. The model indicates
that Maui Nui was a single landmass that reached its maximum areal extent
around 1.2 Ma, when it was larger than the current island of Hawai'i. As subsidence
ensued, the island divided during high sea stands of interglacial periods
starting around 0.6 Ma; however during lower sea stands of glacial periods,
islands reunited. The net effect is that the Maui Nui complex was a single large
landmass for more than 75% of its history and included a high proportion of
lowland area compared with the contemporary landscape. Because the Hawaiian
Archipelago is an isolated system where most of the biota is a result of in situ
evolution, landscape history is an important determinant of biogeographic patterns.
Maui Nui's historical landscape contrasts sharply with the current landscape
but is equally relevant to biogeographical analyses.
Gray, Blair E.
Smith, Abigail M.
Mineralogical Variation in Shells of the Blackfoot Abalone, Haliotis iris (Mollusca: Gastropoda: Haliotidae), in Southern New Zealand [Access article in PDF] Subject Headings:
Paua -- New Zealand -- Anatomy.
The New Zealand blackfoot abalone, Haliotis iris Gmelin, is among
the few gastropods that precipitate both calcite and aragonite in their shells. The
location, composition, and thickness of these mineral layers may affect color,
luster, and strength of the shell, which is locally important in jewelry manufacture.
Skeletal mineralogy and shell structure of H. iris from three southern
New Zealand locations were determined using X-ray diffractometry, scanning
electron micrography, and mineral staining. In H. iris an outer calcitic layer is
separated from an inner aragonitic surface by both calcified and noncalcified
organic layers running longitudinally through the shell. Skeletal mineralogy
within individual shells varies from 29 to 98% aragonite, with older shell having
significantly higher aragonite content than young sections. Variation within
populations ranges from 40 to 98% aragonite, and among three populations
from 34 to 98% aragonite. Shell thickness, too, varies within individual shells
from 0.2 to 4.2 mm, with a significant positive relationship with age. Withinpopulation
variation in shell thickness ranges from 2.1 to 5.4 mm, with no
significant difference in shell thickness variation among populations. The high
degree of variability within and among individual shells suggests that it is
essential to test replicate samples from individual mollusk shells, especially when
they have complex bimineral structure.
This study documents a total of 321 fishes in 64 families occurring at
Wake Atoll, a coral atoll located at 19° 17' N, 166° 36' E. Ten fishes are listed
by genus only and one by family; some of these represent undescribed species.
The first published account of the fishes of Wake by Fowler and Ball in 1925
listed 107 species in 31 families. This paper updates 54 synonyms and corrects
20 misidentifications listed in the earlier account. The most recent published
account by Myers in 1999 listed 122 fishes in 33 families. Our field surveys add
143 additional species records and 22 new family records for the atoll. Zoogeographic
analysis indicates that the greatest species overlap of Wake Atoll fishes
occurs with the Mariana Islands. Several fish species common at Wake Atoll are
on the IUCN Red List or are otherwise of concern for conservation. Fish populations
at Wake Atoll are protected by virtue of it being a U.S. military base
and off limits to commercial fishing.
Trianni, Michael S.
Bryan, Patrick G.
Survey and Estimates of Commercially Viable Populations of the Sea Cucumber Actinopyga mauritiana (Echinodermata: Holothuroidea), on Tinian Island, Commonwealth of the Northern Mariana Islands [Access article in PDF] Subject Headings:
Actinopyga mauritiana -- Population viability analysis -- North Mariana Islands -- Tinian.
Trepang fisheries -- North Mariana Islands -- Tinian.
A survey was conducted in 1997 to assess commercially viable populations
of the surf redfish, Actinopyga mauritiana, and establish a harvest quota
for those populations on the island of Tinian. A simple random sampling approach
was employed using circular plots as samples. Outer reef flat and reef
slope habitats were sampled, producing a total of 333 samples over a 2-month
period, with a preharvest population estimate of 71,034. A harvest quota of
17,893 surf redfish was established due to stock depletions on both Rota and
Saipan, uncertainty of the density required to ensure successful reproduction of
the species, and high degree of uncertainty in the population estimates. It was
determined that a stratified sampling approach utilizing either simple proportional
or optimal allocation would have resulted in more precise estimates, and
these approaches are favored for any future survey work. Population estimates
should be revised when more accurate estimates of A. mauritiana habitats become
Temporal Variation in Forest Bird Survey Data from Tutuila Island, American Samoa [Access article in PDF] Subject Headings:
Bird surveys -- American Samoa -- Tutuila Island.
Birds -- Counting -- American Samoa -- Tutuila Island.
Avian census data from tropical Pacific islands often are limited to
brief, one-time surveys. These efforts yield information about species' presence
and distribution but reveal little about variation in abundance through time.
This variation may be important for refining and optimizing survey methods
and, in turn, assessing habitat preferences, population status, activity patterns, or
the impact of disturbance on the abundance and distribution of island birds. The
objective of this study was to determine if intra- or interannual patterns exist in
the recorded abundance of resident land birds. Forest birds on Tutuila Island,
American Samoa, were surveyed each month from 1992 to 1996 at 35 stations
on six transects distributed around the island. We used multiple regression
techniques to determine that seasonal patterns in detected abundance exist in
several species, most notably the Purple-capped Fruit-dove, Ptilinopus porphyraceus,
and the Wattled Honeyeater, Foulehaio carunculata. Intraannual patterns
may be associated with seasonally variable vocalizations or with concentrations
of birds at particular resources. Interannual trends in abundance were not islandwide
for any native species during the study period; they were localized and
as such may be attributable to small-scale changes in habitat rather than to
overall changes in population size. The results of this study, especially that the
abundance of nonmigratory island birds is seasonally variable, reinforce the importance
of year-round monitoring in the study and conservation of Pacific
Albert L. Tester Memorial Symposium (28th : 2003 : University of Hawaii at Manoa)
Abstracts of Papers, Twenty-eighth Annual Albert L. Tester Memorial Symposium, 16-17 April 2003 [Access article in PDF] Subject Headings: