The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2002

Called for by the U.S. Coral Reef Task Force’s (USCRTF) National Action Plan to Conserve Coral Reefs, this is the first biennial report on the condition of coral reefs. It is the scientific baseline for subsequent reports on the health of U.S. coral reef ecosystems that are to be used by NOAA and others to evaluate the efficacy of coral reef conservation and management practices. The National Oceanic and Atmospheric Administration’s National Ocean Service led the development of this report. It was authored by 38 experts and supported by 79 contributors from government agencies and non-governmental organizations across the nation and internationally. Over 100 Task Force members and other notable scientists have reviewed this document

Seagrass community composition and biomass at Nahpali Island,

Abstract-The seagrass community off the barrier reef island of Nahpali, Pohnpei State, Federated States of Micronesia, was sampled in August 1996 to determine species composition and above-ground biomass. Three species were found: Cymodocea rotundata, Enhalus acoroides, and Thalassia hemprichii. This is the first time that C. rotundata has been recorded for Pohnpei. There were differences in the distribution relative to distance from shore for these seagrass species. Enhalus acoroides at this site showed significantly lower mean biomass (4.95 g dry weight/ m 2 ) than the other two species (C. rotundata 42.53 g dry weight/ m 2 , T. hemprichii 21.86 g dry weight/ m 2 )

The effect of causeway construction on seagrass meadows in the Western Pacific – a lesson from the ancient city of Nan Madol, Madolenihmw, Pohnpei, FSM

Two seagrass meadow sites were chosen at Nan Madal adjacent to the now permeable remnants of an ancient causeway constructed 500 to 700 years ago: one immedlately on the shoreward side of the causeway, and one immediately on the seaward side. The shoreward site had greater seagrass cover, canopy height, algal abundance, and epiphyte abundance and lower species diversity (both seagrass and macro-algae), as well as muddier sediments than the seaward site. The abundance of associated fauna did not appear to differ between sites, although the composition of the faunal communities was different. On the seaward site, average epiphyte cover was less than onetenth the epiphyte cover of that on the shoreward side. Halimeda species were the most common algae on the seaward side, while on the shoreward side Hypnea species were dominant. Cymodocea rotundata was the dominant seagrass species (54% of seagrass cover) on the seaward site, but was absent on the shoreward site, which was dominated by Thalassia hemprichii (84%) and Enhalus acoroides (16%). There was no difference in salinity between the two sites. Sediments had a higher proportion of fine mud shoreward. The beche-de-mer, Holothuria atra, was common on the seaward side of the causeway, but not on the shoreward side. The causeway is open to water flow at all tide heights and does not appear to influence water height in any way. The effects of even this simple permeable barrier on seagrass meadows are evident and include differences in seagrass species, algal species, and fauna. We discuss the management lesson from this historic location for present-day Pacific island causeway developments

Dimethylsulfoniopropionate in six species of giant clams and the evolution of dimethylsulfide after death

Author Posting. © National Research Council Canada, 2004. This article is posted here by permission of National Research Council Canada for personal use, not for redistribution. The definitive version was published in Canadian Journal of Fisheries and Aquatic Sciences 61 (2004): 758-764, doi:10.1139/F04-029.Substantial accumulation of dimethylsulfoniopropionate (DMSP) is documented in tissues of all six of the common species of giant clams (Tridacnidae). Results include measures of DMSP concentrations in siphonal mantle, byssal mantle, adductor muscle, and gill tissues obtained by gas chromatography of alkalized extracts plus evidence of DMSP from mass spectrometry. Formation of dimethylsulfide (DMS) by tissues after death is documented. The tridacnid clams maintain symbiotic associations with populations of dinoflagellates, which live within the enlarged siphonal mantle. We postulated that because of their association with dinoflagellates, the clams would chronically accumulate DMSP to high concentrations. Our results show that DMSP occurs at over 30 mmol·kg–1 in many tissues of tridacnid clams (sometimes 50–60 mmol·kg–1), meaning that these clams accumulate DMSP to the highest documented tissue concentrations in the animal kingdom. DMSP at such concentrations could affect multiple properties and functions. Our particular interest for this research was to assess whether postmortem breakdown of DMSP is responsible for the rapid development of potent off-odors and off-tastes that have blocked the commercial success of giant clam aquaculture. High concentrations of DMS produced in the day after death probably account for the peculiar perishability of giant clam tissues.This study was funded by the Comer Science and Education Foundation, Michigan Sea Grant, and Woods Hole Oceanographic Institution Sea Grant

Coral Records of the 1990s in the Tropical Northwest Pacific: ENSO, Mass Coral Bleaching, and Global Warming

The decade of the 1990s was very likely the warmest of the second millennium. The 1990s was also characterized by one of the strongest El Niño-Southern Oscillation (ENSO) events of the twentieth century, which occurred in 1997-1998 and was followed by worldwide mass coral bleaching. In this study, we examined the signal-recording ability of Porites spp. corals by comparing high-resolution coral oxygen isotope (δO) records from the northwestern Pacific with instrumental records of these profound events of the 1990s. Temporal changes in coral skeletal δO records from Ishigaki Island, Japan, showed good agreement with instrumental records of sea-surface temperature (SST) because the effect of seasonal and interannual variations in salinity on the δO of seawater in that region was relatively small. In the northwestern equatorial Pacific, the cooler SST and relative drought-characterizing El Niño events were particularly well recorded by corals from the Philippines. These conditions were also faithfully recorded as distinct positive anomalies in coral δO records from Chuuk Atoll and Pohnpei Island in Micronesia. Bleached Porites spp. corals from Ishigaki Island, as well as corals from Pandora Reef of the Great Barrier Reef, Australia, showed a growth gap, indicating a substantial decrease in skeletogenesis during the 1997-1998 mass bleaching event. At Ishigaki Island and the Pacific side of the Philippine Islands, a decreasing trend in δO was found even over the relatively short period between 1980 and 2000 which may indicate an SST rise and/or surface-water freshening related to global warming. Our results demonstrate the potential of coral isotope records to serve as indicators of climatic change in the tropical and subtropical waters of the northwestern Pacific, where the number of coral records is still limited