Consuming Diversity: Analysis of Seasonal Catch Patterns in Multispecies Artisanal Reef Fisheries in North Sulawesi, Eastern Indonesia
M. Tokeshi, S. Arakaki, and J. R. P. Daud, 1–13
Despite the socioeconomic as well as ecological importance of smallscale fisheries in developing countries, there is a dearth of information on the state of artisanal fisheries in different regions of the tropical Indo-Pacific. In this study, catch patterns in small-scale artisanal fisheries within an area of high marine biodiversity in the western Pacific were analyzed using data gathered directly from the main fish market in Manado, North Sulawesi, eastern Indonesia. Of a total of 350 species identified among harvested fishes, the majority of species (ca. 90%) were closely associated with shallow reef habitats (<50 m), and open/deep-water species constituted a small proportion. There was a clear preponderance of relatively small (<50 cm) fish species among marketed fishes, with a steep decline in abundance of larger species, suggesting the possibility of overfishing. Faunal complementarity or distinctness between wet (November – March) and dry (April – October) season was lower for reef-associated fishes than for nonreef ones, reflecting the less-targeted nature of reef fisheries. Although relative catch patterns were broadly similar between wet and dry season, variability in catches as expressed by the variance of the truncated lognormal model was smaller in reef-associated than in nonreef species, indicating existence of year-round, relatively stable fishery activity centered on shallow reef environments. This finding points to the importance of reef habitats and their associated fish faunas for the artisanal fisheries of the tropical western Pacific.
Quantitative Analysis of Distribution of Lutjanus Fishes (Perciformes: Lutjanidae) by Market Surveys in the Ryukyu Islands, Okinawa, Japan
Tamaki Shimose and Atsushi Nanami, 15–22
Distribution patterns of Lutjanus fishes (Perciformes: Lutjanidae) in the Ryukyu Islands, Okinawa, Japan, were quantitatively investigated by fish market surveys in Okinawa Island (26° N, 127° E) and Ishigaki Island (24° N, 124° E). At Okinawa and Ishigaki, totals of 296 and 326 ports × days surveys recorded 8,866 and 8,246 individual Lutjanus fishes, respectively, of 19 species. Frequency of occurrence and number landed for some commercial Lutjanus species were different between the two islands during comparison within the same gear type. Five species (e.g., L. fulviflammus, L. gibbus) that were common (>1.0% in frequency of occurrence) at both islands were thought to have main distribution from south of the Ryukyu Islands to around Okinawa Island. Two species (L. decussatus, L. rivulatus) that were common at Ishigaki and not at Okinawa were thought to have main distribution from south of the Ryukyu Islands to around Ishigaki Island. Three species (e.g., L. bengalensis, L. stellatus) that were not common at both islands were thought to have main distribution outside the Ryukyu Islands. The remaining five species (e.g., L. malabaricus, L. vitta) were common at Okinawa but not at Ishigaki, despite the fact they are widely distributed in the area south of the Ryukyu Islands. This distribution pattern looks discontinuous and implies that the environments around Ishigaki Island are not preferable for nursery grounds or adult habitats of these species. Both qualitative (only presence or absence) and quantitative descriptions of the distribution will facilitate understanding of their biogeography.
Spatial and Temporal Variation in Rocky Intertidal Communities along the Main Hawaiian Islands
Traci Erin Cox, Joanna Philippoff, Erin Baumgartner, Chela J. Zabin, and Celia M. Smith, 23–45
Thirteen benthic rocky intertidal communities were quantitatively assessed on Maui, Moloka‘i, O‘ahu, and Hawai‘i Island between the years 2004 and 2007. Our goals were to test for differences in invertebrate and macroalgal abundance and composition to understand how these tropical communities are organized. Percentage cover surveys revealed a diverse intertidal system with 49 macroalgal, 1 cyanobacterial, and 31 invertebrate taxa. Shores were frequently dominated by a few macroalgae and mollusks, and at two sites these organisms were distributed in discrete vertical bands. Common intertidal taxa included the introduced alga Acanthophora spicifera; species in the macroalgal genera Padina, Sargassum, and Laurencia; turf forms of algae; and the mollusks Siphonaria normalis, Nerita picea, and species of littorine snails. Multivariate statistics found community structure to vary among sites and years, but there was lack of evidence for island-specific or substratum-specific assemblages. SIMPROF analysis revealed support for 11 different types of structure. This first description of community-level patterns at multiple intertidal sites along the Main Hawaiian Islands documents substantial spatial variation both among and within shores, as well as substantial temporal variation for select sites. These findings are in contrast to the characterization of a homogeneous tropical system and thus suggest that biotic and abiotic factors in the Main Hawaiian Islands act on a local scale to drive structure.
Treefall Gap Dynamics in a Tropical Rain Forest in Papua New Guinea
Arison Arihafa and Andrew L. Mack, 47–58
Treefall gaps play important roles in tropical rain-forest ecology. But studies rely increasingly on models, remote sensing, and a few intensively studied research sites, mostly in the neotropics. We studied the basic parameters of gap dynamics (size, causes, and frequency) of treefall gaps in a lower montane primary forest on the southern flank of the central range of Papua New Guinea. We found 40 treefall gaps formed on 10.4 km of transect sampled annually over 3 yr. Mean proportion of forest under new gaps was 0.015/yr. Mean area of treefall gaps ≤1 yr old was 312 m2, and gap area was positively correlated with diameter of the fallen tree. Mostly only large trees (diameter at breast height [DBH] x̄ = 53 cm) fell as snapped (n = 23) or uprooted (n = 17), creating both single (n = 34) and multiple (n = 6) treefall gaps. There was no strong directionality in the bearings of treefalls. This study provides some of the first information on gap dynamics in Papua New Guinea, where such data can be used to inform sustainable forestry harvesting practices.
Potential Classical Biological Control of Invasive Himalayan Yellow Raspberry, Rubus ellipticus (Rosaceae)
Kai Wu, Ted D. Center, Chunhua Yang, Jun Zhang, Jialiang Zhang, and Jianqing Ding, 59–80
Rubus ellipticus is one of the world’s worst invasive alien species. It is a serious problematic weed in Hawai‘i and has naturalized in many other countries. Biological control is being considered as a means to suppress it by introducing natural enemies from Asia, its native region. In this paper, we report 62 herbivorous insect species in 22 families that were collected on R. ellipticus during 2006 – 2010 in China. Two leaf-rolling moth species, Epinotia ustulana and Epiblema tetragonana; two warty beetle species, Chlamisus setosus and Chlamisus sp.; two flea beetle species in the genus Chaetocnema; four unidentified weevil species; five unidentified buprestids; one pyralid species; and one sawfly species were considered important. We also report results of preliminary host-range determinations for some of them. In addition, we summarize the literature on natural enemies associated with Rubus species in Asia, which encompasses 50 arthropod species in 14 families and 63 fungi species in 18 orders.
Land Snails from Archaeological Sites in the Marshall Islands, with Remarks on Prehistoric Translocations in Tropical Oceania
Carl C. Christensen and Marshall I. Weisler, 81–104
We report the recovery of 11 taxa of nonmarine mollusks from archaeological sites on Majuro, Maloelap, and Ebon Atolls, Republic of the Marshall Islands. Pupina complanata (Pupinidae), Omphalotropis fragilis (Assimineidae), Truncatella guerinii (Truncatellidae), Lamellidea pusilla and Pacificella variabilis (Achatinellidae), Gastrocopta pediculus (Gastrocoptidae), Nesopupa sp. (Vertiginidae), “Succinea” sp. (Succineidae), Allopeas gracile (Subulinidae), and Liardetia samoensis (Helicarionidae) arrived in these islands prehistorically; Liardetia sculpta (Helicarionidae) has not yet been recovered from levels of confirmed prehistoric age. Pupina complanata, O. fragilis, and probably also Nesopupa sp., and “Succinea” sp. are Micronesian endemics. All other species are widely distributed in Micronesia and Polynesia and (except for the strand-line species T. guerinii) were undoubtedly translocated to the Marshall Islands by the prehistoric voyages of Pacific islanders. The precise role of human transport in the dispersal of the Micronesian endemics remains unclear, but because these atolls have been emergent for a mere 3,000 yr or so, human transport is likely in view of the known rarity of natural interarchipelagic dispersal of nonmarine mollusks.
Seasonal Life Cycle of Zatypota albicoxa (Hymenoptera: Ichneumonidae), an Ectoparasitoid of Parasteatoda tepidariorum (Araneae: Theridiidae), in Southwestern Japan
Keizo Takasuka and Kazuhiro Tanaka, 105–111
The seasonal life cycle of Zatypota albicoxa, an ectoparasitoid of the house spider, Parasteatoda tepidariorum, was examined in Tōon, in warm-
temperate southwestern Japan. The larvae were found all year round, but eggs, pupal cocoons, and adults were found only from March to November. In winter, only the medium second-instar larvae were found, suggesting that they are in diapause state. Seasonal occurrence of each developmental stage in the field indicated that this parasitoid produces more than four generations per year. The life cycle in Tōon is substantially similar to that in Hirosaki, in cool-temperate northern Japan, but some of the traits differed geographically. Occurrence of newly formed pupal cocoons was 2 months earlier and length of the season for growth and reproduction was 4 months longer in Tōon than in Hirosaki. Appearance of the pupal cocoon is more or less coincident with the period when monthly mean temperatures reach around 10°C. The observed geographical difference in the seasonal life cycle may be due to the difference in local climatic conditions, but not to a difference in seasonal host availability.
Eight species of silica-scaled chrysophytes were observed from collections made between December 1988 and February 1989. The species are cosmopolitan with the exception of one new species, Paraphysomonas preisigii Wujek, described here. Siliceous scales of the colorless free-living flagellate Gyromitus disomatus were also observed.
Reptiles of Sorol Atoll, Yap, Federated States of Micronesia
Donald W. Buden, 119–128
Fourteen species of reptiles (two turtles, five geckos, six skinks, one monitor lizard) are recorded in the first herpetological survey of Sorol Atoll, Federated States of Micronesia (FSM). Most of the species are widespread in the western Pacific and often well beyond. Emoia boettgeri is endemic to the Caroline and Marshall Islands and is at the western limits of its range on Sorol Atoll, and E. atrocostata, which is widely distributed in Indo-Australia and the western Pacific, is near the eastern edge of its range in the Caroline Islands on Sorol. Emoia caeruleocauda and E. impar are the most common lizards on the islands where they were recorded, and Lepidodactylus moestus was the most widely encountered, being recorded on four of the six islands. An abundance of turtle tracks on the beaches of nearly all the islands suggests that Sorol Atoll is an important sea turtle nesting site in the FSM. The monitor lizard, Varanus indicus, frequently feeds on turtle eggs on Sorol Island, where it was introduced during the Japanese administration, but it has not spread to the other islands on the atoll.
Observation of an Attack by a Cookiecutter Shark (Isistius brasiliensis) on a White Shark (Carcharodon carcharias)
Mauricio Hoyos-Padilla, Yannis P. Papastamatiou, John O’Sullivan, and Christopher
G. Lowe, 129–134
Cookiecutter sharks (Isistius brasiliensis) are known to attack a wide array of large animals including pelagic fishes, cetaceans, and pinnipeds. Here we add another top predator, the white shark (Carcharodon carcharias), to the list of potential victims. A subadult male white shark off Guadelupe Island, Mexico, was observed with a fresh cookiecutter shark bite next to its mouth, as well as a second crescent-shaped scar. A subadult male white shark was tracked in the same location and showed diel changes in depth, with the shark occupying shallow water (<50 m) at night, which may be when white sharks overlap with the vertical distribution of cookiecutter sharks. This further indicates that the majority of co-occurring marine top predators can be targeted by cookiecutter sharks.