Flora and Vegetation of Clipperton (La Passion) Atoll, North-Eastern Pacific Ocean: Three Centuries of Changes and Recent Plant Dynamics

The terrestrial flora and vegetation of Clipperton (La Passion) atoll, a very remote and small (170 ha of land) French island located in the North-Eastern Pacific Ocean, at ca. 1,000 km west of the Mexican coast, have dramatically changed during the past three centuries. This paper, based on historical testimonies, previously published floristic studies, and an extensive plant inventory conducted during the “International Scientific Expedition PASSION 2015”, show that the atoll has experienced particularly active and rapid vegetation dynamics with alternating plant cover expansion and regression phases. Our results provide the first comprehensive assessment of vegetation cover and vascular plant species distribution based on georeferenced data and mapped with GIS software, as well as the first record of two newly established non-native weeds. The current composition and abundance of native and alien vascular plant communities (15 species including only 4 native taxa) appear to depend not only on abiotic factors (e.g. substrate and climatic events) but also on biotic interactions with animal communities (e.g. native seabirds and crabs). Anthropogenic activities and disturbances (e.g. coconut palm, pig, rat and weed introductions) that have occurred in the past 100 years have also played an important role in explaining the past and current floristic changes.

Stomatopod Crustaceans from Mayotte Island (Crustacea, Hoplocarida)

A collection of stomatopods assembled during the KUW 2009 expedition to Mayotte Island and deposited in the Muséum national d’Histoire naturelle Paris is studied with a review of previous records from Comoros and Mayotte Island. In total 14 species are recognized 3 of them being new records for this region. A brief comparison with other regions studied for stomatopods indicates that sampling is still insufficient in Comoros and Mayotte and that dozens of species remain to be inventoried in that region.

Carbonate Beach Sand of Abaiang Atoll, Kiribati: Geochemistry, Biogenic Sources, and Properties

Sandy beaches are critical resources for low-lying Pacific atoll communities, providing protection during storms, and land area for many coastal villages. Information on the nature of atoll beach sediment, its geochemistry and composition, can help to establish priorities to effectively protect the sources of Pacific island beach sediment. To understand sand sources, this study evaluated its physical characteristics including grain-size, geochemistry and composition, from windward and leeward beach profiles around Abaiang Atoll, Kiribati. Beach sand was >99% carbonate, averaging 37% coral fragments, 30% mollusc shells, 12% foraminifera, and 20% calcareous algae. Significant differences were found between reef and lagoonal sites in proportions of coral and mollusc fragments and foraminifera tests, with lagoon beaches having higher mollusc and coral proportions and lower foraminifera relative to reef beaches. This is attributed to high foraminiferal productivity offshore of reef beaches, and taphonomic durability of coral fragments in longshore drift into the lagoon. Mean sediment diameter increased from the upper to lower beaches at all sites, but fine sediment was lacking, attributed to its dissolution by rainfall and groundwater outflow. Geochemical analysis showed a mean of 84% Ca-Mg carbonates, of which 80% was calcium carbonate. There was no significant difference in the mean calcium percentage or calcium carbonate composition of the sediment between lagoon and reef beach sediment sources. Magnesium and magnesium carbonate content were significantly higher at reef sites relative to lagoon sites, attributed to higher proportions of foraminifera. Sediment-producing near shore habitats are critical to village protection through provision of beach sand, and this study shows the need to better conserve and manage coral reefs and habitats such as lagoon seagrass beds, to ensure continued atoll beach sand supply.

Los Roques and Las Aves Archipelagos, Venezuela: A Marine Ecological and Conservation Reconnaissance of Two Little-Known Southeastern Caribbean Oceanic Archipelagos

The Los Roques and Las Aves oceanic coral reef archipelagos of Venezuela lie in a biogeographically unique and biologically diverse area of the Caribbean and possess extensive coral reefs, seagrass beds, mangroves and shallow macroalgae meadows. The geographic location of these archipelagos safeguards them from most Western Atlantic hurricane damage as well as the most severe Caribbean coral bleaching episodes. While the Aves islands remain uninhabited and are an area of low accessibility, Los Roques has been a managed national park since 1972. We here present an updated synthesis of recent research for these archipelagos as an aid to scientists and conservationists interested in these island groups for which no recent ecological reviews are available. Los Roques has been much better documented than Las Aves and is the largest coral reef marine protected area of Venezuela. It has about 1,500 inhabitants living principally from tourism and fisheries. Studies show that Los Roques possesses fish populations that suffer comparatively less fishing pressure and may serve as a rare benchmark for pristine fish communities elsewhere in the Caribbean. It has also successfully maintained its importance to seabird colonies for the last five decades, notwithstanding serious marine park funding and staffing shortages. A new baseline biological inventory for Las Aves is particulary critical considering the fragmentary information available for this archipelago. The relatively intact and resilient oceanic coral reef systems of Los Roques and Las Aves are of regionally significant conservation value and deserve much more conservation and biodiversity attention than so far accorded.

Ecological Changes in the Coral Reef Communities of Indonesia's Bali Barat National Park, 2011–2016

The coral reefs of Bali Barat National Park, one of Indonesia’s oldest marine protected areas, are known for their high biodiversity and excellent sport diving; however, stressors such as destructive fishing practices, elevated water temperatures, damage from anchors and careless visitors have been observed on these reefs for decades. The purpose of this study was to document and quantify changes in the fish and stony coral community structure of reefs within and outside the boundaries of Bali Barat National Park from 2011 to 2016, including its most popular dive site, Menjangan Island. The results provide further knowledge about the reefs of NW Bali and the efficacy of current management practices, and they will inform management decisions for locally managed reef stewardship programs. Between 2011 and 2016 the reefs of NW Bali lost 44.4% of their living coral cover, declining from 36% to 20% overall cover. Mortality was principally attributed to thermal bleaching caused by persistently high sea temperatures, which peaked in January 2016 at 32.2°C, coinciding with the third documented global bleaching event. Approximately one third of all stony corals were found to be bleached or recently dead. Despite the decline in coral cover, stony coral genus richness remained unchanged, with 56 genera recorded in both years, representing a combined total of 59 distinct genera. Mean fish biomass at Menjangan Island increased, with herbivorous fish biomass quadrupling, presumably due to decreased fishing effort at the island. The abundance of fish at all sites—both inside and outside the park—more than doubled, indicating a predominance of small fish at sites where fish biomass did not correspondingly rise. Crown-of-thorns starfish (Acanthaster planci), not observed on transects in 2011, were found in 2016 in areas of relatively high disturbance from marine recreation and possible eutrophication from shrimp farm effluent and mainland runoff. Patterns of coral cover and damage, fish abundance and biomass, and lost fishing gear suggest that management activities inside and outside the park have reduced ecological damage. Local community conservation groups are practicing one or more of the following at Menjangan Island and in some of the locally managed conservation areas: installing moorings, removing coral predators (crown-of-thorns starfish and Drupella snails), reducing fishing pressure, securing live coral fragments back onto the reef and planting mangroves. These nature groups are raising community awareness about the importance of NW Bali’s marine ecology to their economic and cultural wellbeing.