Baselines and benchmarks (B&Bs) are needed to evaluate the ecological status and fisheries potential of coral reefs. B&Bs may depend on habitat features and energetic limitations that constrain biomass within the natural variability of the environment and fish behaviors. To evaluate if broad B&Bs exist, we compiled data on the biomass of fishes in similar to 1000 reefs with no recent history of fishing in 19 ecoregions. These reefs spanned the full longitude and latitude of Indian and Pacific Ocean reefs and included older high-compliance fisheries closures (>15 yr closure) and remote reef areas (>9 h travel time from fisheries markets). There was no significant change in biomass over the 15 to 48 yr closure period but closures had only similar to 40% of the biomass (740 kg ha(-1), lower confidence interval [LCI] = 660 kg ha(-1), upper confidence interval [UCI] = 810 kg ha(-1), n = 157) of remote tropical reefs (1870 [1730, 2000] kg ha(-1), n = 503). Remote subtropical reefs had lower biomass (950 [860, 1040] kg ha(-1), n = 329) than tropical reefs. Closures and remote reef fish biomass responded differently to environmental variables of coral cover, net primary productivity, and light, indicating that remote reefs are more limited by productivity and habitat than closures. Closures in fished seascapes are unlikely to achieve the biomass and community composition of remote reefs, which suggests fisheries benchmarks will differ substantially from wilderness baselines. A fishery benchmark (B-0) of similar to 1000 kg ha(-1) adjusted for geography is suggested for fisheries purposes. For ecological purposes, a wilderness baseline of similar to 1900 kg ha(-1) is appropriate for including large and mobile species not well protected by closures.

Widespread declines among many coral reef fisheries have led scientists and managers to become increasingly concerned over the extinction risk facing some species. To aid in assessing the extinction risks facing coral reef fishes, large-scale censuses of the abundance and distribution of individual species are critically important. We use fisheries-independent data collected as part of the NOAA Pacific Reef Assessment and Monitoring Program from 2000 to 2009 to describe the range and density across the US Pacific of coral reef fishes included on The International Union for the Conservation of Nature’s (IUCN) 2011 Red List of Threatened Species. Forty-five species, including sharks, rays, groupers, humphead wrasse (Cheilinus undulatus), and bumphead parrotfish (Bolbometopon muricatum), included on the IUCN List, were recorded in the US Pacific Islands. Most species were generally rare in the US Pacific with the exception of a few species, principally small groupers and reef sharks. The greatest diversity and densities of IUCN-listed fishes were recorded at remote and uninhabited islands of the Pacific Remote Island Areas; in general, lower densities were observed at reefs of inhabited islands. Our findings complement IUCN assessment efforts, emphasize the efficacy of large-scale assessment and monitoring efforts in providing quantitative data on reef fish assemblages, and highlight the importance of protecting populations at remote and uninhabited islands where some species included on the IUCN Red List of Threatened Species can be observed in abundance.

Sharks and other large predators are scarce on most coral reefs, but studies of their historical ecology provide qualitative evidence that predators were once numerous in these ecosystems. Quantifying density of sharks in the absence of humans (baseline) is, however, hindered by a paucity of pertinent time-series data. Recently researchers have used underwater visual surveys, primarily of limited spatial extent or nonstandard design, to infer negative associations between reef shark abundance and human populations. We analyzed data from 1607 towed-diver surveys (>1 ha transects surveyed by observers towed behind a boat) conducted at 46 reefs in the central-western Pacific Ocean, reefs that included some of the world's most pristine coral reefs. Estimates of shark density from towed-diver surveys were substantially lower (<10%) than published estimates from surveys along small transects (<0.02 ha), which is not consistent with inverted biomass pyramids (predator biomass greater than prey biomass) reported by other researchers for pristine reefs. We examined the relation between the density of reef sharks observed in towed-diver surveys and human population in models that accounted for the influence of oceanic primary productivity, sea surface temperature, reef area, and reef physical complexity. We used these models to estimate the density of sharks in the absence of humans. Densities of gray reef sharks (Carcharhinus amblyrhynchos), whitetip reef sharks (Triaenodon obesus), and the group all reef sharks increased substantially as human population decreased and as primary productivity and minimum sea surface temperature (or reef area, which was highly correlated with temperature) increased. Simulated baseline densities of reef sharks under the absence of humans were 1.12.4/ha for the main Hawaiian Islands, 1.22.4/ha for inhabited islands of American Samoa, and 0.92.1/ha for inhabited islands in the Mariana Archipelago, which suggests that density of reef sharks has declined to 310% of baseline levels in these areas.

Comparable information on the status of natural resources across large geographic and human impact scales provides invaluable context to ecosystem-based management and insights into processes driving differences among areas. Data on fish assemblages at 39 US flag coral reef-areas distributed across the Pacific are presented. Total reef fish biomass varied by more than an order of magnitude: lowest at densely-populated islands and highest on reefs distant from human populations. Remote reefs (<50 people within 100 km) averaged ~4 times the biomass of “all fishes” and 15 times the biomass of piscivores compared to reefs near populated areas. Greatest within-archipelagic differences were found in Hawaiian and Mariana Archipelagos, where differences were consistent with, but likely not exclusively driven by, higher fishing pressure around populated areas. Results highlight the importance of the extremely remote reefs now contained within the system of Pacific Marine National Monuments as ecological reference areas.

Atoll Research Bulletin, no. 585. Inshore Fishes of Howland Island, Baker Island, Jarvis Island, Palmyra Atoll, and Kingman Reef.

Coral reefs in Micronesia and American Samoa appear to be amongst the most resilient in the world, despite numerous on-going threats; There has been considerable recovery of reefs in western Micronesia (especially Palau) that were devastated during the massive coral bleaching in 1998; The more remote islands support thriving communities of large reef fishes due to limited fishing pressures and habitat degradation; Fish populations around major population centres show clear signs of over-fishing with few large fish observed because of fishing pressure, particularly spear-fishers using scuba; Management and monitoring efforts are on-going throughout the region and numerous effective initiatives are promoting recovery of damaged coral reefs as well as the conservation of healthy ones; Lack of enforcement continues to be one of the major hindrances to effective resource management outcomes and more support is necessary.

The nature and degree of impact of ship groundings on coral reefs and subsequent recovery is not well understood. Disturbed benthic and associated fish assemblages may take years-decades to return to pre-impact levels or may attain alternate stable states. Rose Atoll, a small, remote coral atoll in the central South Pacific, was impacted by a major ship grounding and associated contaminant spill in October 1993. Coral reef fish assemblages were quantitatively surveyed at the site of impact and compared to other nearby sites along the western outer reef slope in August 1995, February 2002, February 2004, and March 2006. In 1995, herbivorous surgeonfishes dominated the site, likely attracted to the early algal blooms. During 2002-2006, both numbers and biomass of pooled herbivorous fishes were significantly greater at the wreck site than at the other reef-slope survey sites. This greater abundance, where some corroding steel debris remained, was associated with significantly greater substratum cover by opportunistic algae (both turf and cyanobacteria). Thus, more than 13 yrs later, the grounding of this ship is still impacting algal growth and herbivorous reef-fish populations. While continued ecosystem monitoring at Rose Atoll is necessary for a full understanding of recovery rates by fish assemblages from such major anthropogenic disturbances, in the event of future groundings, containment of the contaminant spill and prompt removal of all metallic debris is recommended to preserve ecosystem integrity.

SUMMARY Humans can impact coral reef fishes directly by fishing, or indirectly through anthropogenic degradation of habitat. Uncertainty about the relative importance of those can make it difficult to develop and build consensus for appropriate remedial management. Relationships between fish assemblages and human population density were assessed using data from 18 locations widely spread throughout the Main Hawaiian Islands (MHI) to evaluate the significance of fishing as a factor potentially driving fish trends on a regional scale. Fish biomass in several groups was negatively correlated with local human population density and a number of lines of evidence indicate that fishing was the prime driver of those trends. First, declines were consistently evident among fish groups targeted by fishers, but not among lightly fished or non-target groupings, which indicates that declines in target groups were not simply indicative of a general decline in habitat quality along human population gradients. Second, proximity to high human populations was not associated with low fish biomass where shoreline structure prevented ready access by fishers. Relatively remote and inaccessible locations within the MHI had 2.1–4.2 times the biomass of target fishes compared to accessible and populous locations, and may therefore function as partial refugia. However, stocks in those areas were clearly far from pristine, as biomass of large predators was more than an order of magnitude lower than at more intact ecosystems elsewhere in the Pacific.

Effective conservation requires rigorous baselines of pristine conditions to assess the impacts of human activities and to evaluate the efficacy of management. Most coral reefs are moderately to severely degraded by local human activities such as fishing and pollution as well as global change, hence it is difficult to separate local from global effects. To this end, we surveyed coral reefs on uninhabited atolls in the northern Line Islands to provide a baseline of reef community structure, and on increasingly populated atolls to document changes associated with human activities. We found that top predators and reef-building organisms dominated unpopulated Kingman and Palmyra, while small planktivorous fishes and fleshy algae dominated the populated atolls of Tabuaeran and Kiritimati. Sharks and other top predators overwhelmed the fish assemblages on Kingman and Palmyra so that the biomass pyramid was inverted (top-heavy). In contrast, the biomass pyramid at Tabuaeran and Kiritimati exhibited the typical bottom-heavy pattern. Reefs without people exhibited less coral disease and greater coral recruitment relative to more inhabited reefs. Thus, protection from overfishing and pollution appears to increase the resilience of reef ecosystems to the effects of global warming.

Ecological aspects of coral patch reefs were studied from 1��1 to 1��� in Welles Harbor, Midway Atoll. Water temperatures varied from 1�oC in February to ��oC in August. Sizes of reefs studied were described by mean area (59 m�), mean volume (�� m�), vertical relief (<1 m), and inter-reef isolation (100 m). Considerable temporal change in reef size occurred due to large winter swells shifting bottom sand. Six common species accounted for 70% of all individual fish visually censused over 4 years. Overall fish assemblage composition ranged from 11 to 46 fish/10 m �, fromto 1� species. Numerical abundance and species richness for all fish (pooled) strongly correlated with physical reef substrate characteristics of area, volume, and vertical relief during summer. Species diversity (H') was not correlated with the substrate variables, suggesting similarity in the structure of fish communities among different sizes of patch reefs. Daily surveillance for presence of large transient taxa suggested that visits by sharks, large jacks, monk seals, sea turtles, and dolphins were infrequent. Density estimates were made for all conspicuous invertebrate megafauna during initial and final assessments. Six common taxa provided �0% of these counts; nearly half were sea urchins. Percent cover also was recorded for coral and algal species on the patch reefs. Cover by live coral was low (about �%) and dominated by a few species. Mean algal cover ranged from �� to ��%. Such information on ecological characteristics of reefs may aid in understanding complex ecological processes and provides an earlier reference for current ecosystem studies.

1. American Samoa Department of Marine and Wildlife Resources 2. Coral Reef Initiative, American Samoa Coral Reef Advisory Group 3. University of Hawaii, Hawaii Institute of Marine Biology 4. NOAA, Pacific Islands Fisheries Science Center, Coral Reef Ecosystem Division 5. The Joint Institute for Marine and Atmospheric Research 6. American Samoa Environmental Protection Agency 7. National Park Service 8. NOAA National Centers for Coastal Ocean Science, Hollings Marine Lab 9. CNMI, Division of Environmental Quality 10. Mappamondo GIS 11. American Samoa Department of Commerce 12. NOAA Coral Reef Watch 12. U.S. Geological Survey, National Wildlife Health Center, Hawaii Field Office The State of Coral Reef Ecosystems of American Samoa

INTRODUCTION AND SETTING This report is an assessment of the status of coral reef ecosystems in Guam from 2002 to 2004. Data on coral reef ecosystems were synthesized from assessments and monitoring programs conducted by local and federal organizations. Included in the report are assessments of the environmental and anthropogenic stressors affecting coral reefs, information on data gathering activities and the condition of coral reef ecosystem resources, a description of current conservation management activities, and overall conclusions and recommendations to monitor and manage coral reef ecosystems better in the future.

The community of demersal, resident reef fishes of the Northwestern Hawaiian Islands was studied to determine the various roles of fishes within the piscivorous trophic subweb. Relative abundance estimates for 160 fish species were made on the basis of extensive visual censuses and four chemical collections. Diet information was collected by gut analysis of 52 piscivorous species from 16 families. Twenty species were termed major piscivores and 32 minor piscivores. Twelve to 31% of the biomass of the entire fish community at the four chemical stations was piscivorous. The Apogonidae, Labridae, Mullidae, Scorpaenidae, Pomacentridae, Holocentridae and Gobiidae were the most important prey families, providing over 70% of all prey. The families producing largest piscivorous impacts were the Muraenidae, Synodontidae, Congridae, Labridae, Scorpaenidae, Holocentridae, Priacanthidae and Cirrhitidae. Several families contained a number of intermediate level species whose combination of relatively high abundance, moderate degree of piscivory, and substantial vulnerability to predation gave them a wide trophic scope and an important place in the total trophic activity. The quantitative approach used here to analyze community trophics by estimating predation by and upon whole interacting populations offers promise for improved understanding of these complex systems.

Sharks (Carcharhinidae) and jacks (Carangidae) were surveyed using towed divers at the atolls and banks of the Northwestern Hawaiian Islands (NWHI) during annual surveys from �000 to �00�. We compared numerical and biomass densities of these predators among reefs, among habitats within atolls (forereef, backreef, channel, and lagoon) and banks (insular and exposed), and mapped the spatial distribution of predators at the reefs where they were most abundant. Shark and jack densities were both very high at two of the three pinnacles in the chain, Necker and Gardner Pinnacle. Otherwise, shark densities were highest at Maro Reef and Midway Atoll, and jack densities were highest at Pearl and Hermes Atoll and Lisianksi-Neva Shoals. Galapagos sharks (Carcharhinus galapagensis) and gray reef sharks (C. amblyrhynchos) were observed most frequently in forereef habitats within atolls, and on exposed reefs within banks. Whitetip reef sharks (Triaenodon obesus) showed no significant habitat preferences on either atolls or banks. Giant trevally (Caranx ignobilis), bluefin trevally (C. melampygus), and amberjack (Seriola dumerili) were most frequently observed in forereef habitats within atolls, although the difference was significant only for amberjack. Jack densities were similar on exposed and insular reefs within banks. Maps of the spatial distribution of Galapagos sharks at Maro Reef and Midway Atoll and giant and bluefin trevally at Pearl and Hermes and Lisianski Island-Neva Shoals showed localized hotspots (areas of high density) within these habitats. We conclude that towed-diver surveys provide an effective method to assess shark and jack populations at the remote, expansive atolls and banks of the NWHI. Continued tow surveys will enable us to monitor the status of these important apex predators in an ecosystem relatively undisturbed by humans.