Journal of the Marine Biological Association of the United Kingdom

The island of Bonaire is a long-established Marine Protected Area (MPA), the reefs of which were extensively mapped in the early 1980s. Satellite remote sensing techniques were used to construct reef maps for 2008–2009. Metrics describing the spatial structure of coral habitat at the landscape scale – including coral cover, fragmentation, patch size and connectivity between patches – were calculated and compared between these two time periods. Changes were evaluated in and out of the MPAs and in areas exposed and sheltered from storm damage. Overall, coral cover has declined during the past three decades, being replaced by sand, but the decline has not been as drastic as elsewhere in the Caribbean. Fragmentation of the reef habitat has occurred, resulting in smaller and more disparate patches, but these changes were not associated with exposure along the coastline. However, total coral cover was maintained in sheltered areas, whereas it declined along exposed shorelines. Human protection of reefs by marine reserves had variable effects on coral cover and fragmentation. One of two no-diving marine reserves showed increases in coral cover accompanied by decreases in the number of patches of coral and an increase in the size of individual patches over the time period, while the second reserve exhibited the opposite trend. Advances in satellite remote sensing techniques allow for a more rapid assessment of changes in reefs at the landscape level, which can be used to identify spatial changes in the reef environment, including areas of coral decline.

The oceans have shown a recent rapid and accelerating rise in temperature with, given the close link between temperature and marine organisms, pronounced effects on ecosystems. Here we describe for the first time a globally synchronous pattern of pulsed short period (~1 year long) emanations of warm sea surface temperature anomalies from tropical seas towards the poles on the shelf/slope with an intensification of the warming after the 1976/1977, 1986/1987 and 1997/1998 El Niños. On the eastern margins of continents the anomalies propagate towards the poles in part by largely baroclinic boundary currents, reinforced by regional atmospheric warming. The processes contributing to the less continuous warm anomalies on western margins are linked to the transfer of warmth from adjacent western boundary currents. These climate induced events show a close parallelism with the timing of ecosystem changes in shelf seas, important for fisheries and ecosystem services, and melting of sea-ice.

Abstract:

Aruba is one of the most densely populated islands in the Caribbean. However, very little is known about its cetaceans. In 2010 and 2011, a total of 19721 km (1686 h) boat-based surveys over nearshore transects resulted in 117 positively-identified sightings comprising eight species. New records are also added for one of three previously-documented species. Five additional species were documented from strandings or reports by others. This brings the total number of cetacean species identified in Aruban waters to 16, of which nine are authenticated here for the first time. Atlantic spotted dolphin (Stenella frontalis (N 1⁄4 59) and bottlenose dolphin (Tursiops truncatus) (N 1⁄4 33) were the most frequently observed species, with sightings of both year-round, followed by spinner dolphin (S. longirostris) and false killer whale (Pseudorca crassidens). Additional species recorded are pantropical spotted dolphin (S. attenuata), striped dolphin (S. coeruleoalba), common dolphin (Delphinus capensis), rough-toothed dolphin (Steno bredanensis), short-finned pilot whale (Globicephala macrorhynchus), killer whale (Orcinus orca), Risso’s dolphin (Grampus griseus), humpback whale (Megaptera novaeangliae), Bryde’s/Eden’s whale (Balaenoptera brydei/edeni), sperm whale (Physeter macrocephalus) and an unidentified beaked whale (Mesoplodon sp.). All cetaceans were sighted within 22 km of the coast in relatively shallow waters. Sighting rate was low (0.69 cetacean sightings per 100 km). Sightings of calves and neonates indicate that Aruba may be a nursing or breeding area for some species. The presence of several species of cetaceans in Aruba’s coastal waters year-round indicates that status and threat assessments are needed to protect them.