The long-term response of coral reefs to climate change depends on the ability of reef-building coral symbioses to adapt or acclimatize to warmer temperatures, but there has been no direct evidence that such a response can occur. Here we show that corals containing unusual algal symbionts that are thermally tolerant and commonly associated with high-temperature environments are much more abundant on reefs that have been severely affected by recent climate change. This adaptive shift in symbiont communities indicates that these devastated reefs could be more resistant to future thermal stress, resulting in significantly longer extinction times for surviving corals than had been previously assumed.

Extreme concentration of marine biodiversity and exploitation of marine resources in the Coral Triangle pose challenges to biogeographers and resource managers. Comparative phylogeography provides a powerful tool to test biogeographic hypotheses evoked to explain species richness in the Coral Triangle. It can also be used to delineate management units for marine resources. After about a decade of phylogeographical studies, patterns for the Coral Triangle are emerging. Broad connectivity in some species support the notion that larvae have maintained gene flow among distant populations for long periods. Other phylogeographic patterns suggest vicariant events resulting from Pleistocene sea level fluctuations, which have, at least occasionally, resulted in speciation. Divergence dates ranging back to the Miocene suggest that changing land configurations may have precipitated an explosion of species diversification. A synthesis of the marine phylogeographic studies reveals repeated patterns that corroborate hypothesized biogeographic processes and suggest improved management schemes for marine resources.

We studied the effects of herbivory, fertilization and their interaction on algal succession on dead coral surfaces and the condition of live coral colonies. We used replicate open, closed, fertilized, and unfertilized cages in a 2-factor, 2-level design, sampled 7 times over a 49 d summer period at an offshore reef atoll lagoon in Belize. Herbivory negatively influenced algal biomass, whereas nutrients positively influenced wet but not dry or decalcified measures. Total and turf algal cover were positively influenced by nutrients and negatively by herbivory. Biomass was more strongly influenced by herbivory than fertilization, and the opposite was true for cover. Brown frondose algal cover was negatively influenced by both herbivory and nutrients, whereas red frondose algal cover was negatively affected by herbivory but unaffected by nutrients. There were more algal taxa and higher dominance in low compared to high herbivory treatments. In contrast to the relative dominance model (RDM), we found that turf algae did best under conditions of low herbivory and high nutrients, and also dominated high herbivory and low nutrient conditions, whereas frondose brown algae did best under low herbivory and low nutrient conditions, and appeared to be inhibited by high nutrients. Stony corals did sufficiently well in all conditions such that it was not possible to determine their optimal conditions, but elevated nutrients may provide resistance to end-of-summer bleaching by increasing the standing densities of algal symbionts. There were no detectable changes in symbiont community composition with all symbionts being members of Symbiodinium clade A. Coral mortality and low herbivory are most likely to be responsible for the high levels of brown frondose algae reported on these patch reefs.

The world is in the midst of a biodiversity crisis, threatening essential goods and services on which humanity depends. While there is an urgent need globally for biodiversity research, growing obstacles are severely limiting biodiversity research throughout the developing world, particularly in southeast Asia. Facilities, funding, and expertise are often limited throughout this region, reducing the capacity for local biodiversity research. Although western scientists generally have more expertise and capacity, international research has sometimes been exploitative "parachute science," creating a culture of suspicion and mistrust. These issues, combined with misplaced fears of biopiracy, have resulted in severe roadblocks to biodiversity research in the very countries that need it the most. Here, we present an overview of challenges to biodiversity research and case studies that provide productive models for advancing biodiversity research in developing countries. Key to success is integration of research and education, a model that fosters sustained collaboration by focusing on the process of conducting biodiversity research as well as research results. This model simultaneously expands biodiversity research capacity while building trust across national borders. It is critical that developing countries enact policies that protect their biodiversity capital without shutting down international and local biodiversity research that is essential to achieve the long-term sustainability of biodiversity, promoting food security and economic development.

Survival trajectories for coral reefs under climate change may depend in part on shifts in the composition of their algal symbiont communities (Symbiodinium spp.). Shifts favoring thermotolerant symbionts have been recorded in response to mass bleaching events but rarely tracked through time. A 10 yr monitoring study of Symbiodinium in a variety of Kenyan corals assessed their variability through time, across coral taxa and between sites, and their relationship to environmental conditions. Coral genera varied significantly in their propensity to host thermotolerant symbionts of Symbiodinium clade D, with some genera becoming dominated by clade D at annual maximum temperatures of 32°C but others showing clade D only rarely at 35°C. High annual maximum temperatures, high standard deviation, positive skewness and positive kurtosis characterized sites where clade D was common. In corals whose symbiont communities were thermally labile (e.g. Pocillopora) an increase in maximum annual temperature from 30 to 35°C resulted in 3-to 4-fold increases in dominance by clade D. There was no directional change in symbiont communities over the study period, but there was evidence for a ~6 yr decline in the incidence of mixed (C + D) communities following the 1998 bleaching event. These data illustrate how acute and chronic thermal stress caused by oceanographic and tidal oscillations interact to produce highly dynamic symbiotic communities. The clade D niche is a function of the environment and host taxon and, through a variety of mechanisms, is expected to expand with climate warming. Corals from warm and variable conditions represent conservation priorities because they establish a niche for these symbionts in contemporary reef environments.

Surveys of microsatellite variation show that genetic diversity has largely recovered in two reef-building corals, Pocillopora damicornis and Seriatopora hystrix (Scleractinia: Pocilloporidae), on reefs which were decimated by the eruption of the volcano Krakatau in 1883. Assignment methods and gene flow estimates indicate that the recolonization of Krakatau occurred mainly from the closest upstream reef system, Pulau Seribu, but that larval input from other regions has also occurred. This pattern is clearer in S. hystrix, which is traditionally the more dispersal-limited species. Despite these observed patterns of larval dispersal, self-recruitment appears to now be the most important factor in supplying larvae to coral populations in Krakatau. This suggests that the colonization of devastated reefs can occur quickly through larval dispersal; however, their survival requires local sources of larvae for self-recruitment. This research supports the observation that the recovery of genetic diversity in coral reef animals can occur on the order of decades and centuries rather than millennia. Conservation measures aimed at sustaining coral reef populations in Krakatau and elsewhere should include both the protection of upstream source populations for larval replenishment should disaster occur as well as the protection of large adult colonies to serve as local larval sources.

No abstract

We report the development of 10 polymorphic molecular markers containing short tandem repeats in the cosmopolitan reef-building coral, Pocillopora damicornis, an important model species for coral health, physiology, ecology, and genetics. The availability of polymorphic DNA markers in P. damicornis can act as impetus for investigations into inheritance and population genetics, as well as novel investigations into host-symbiont ecology and evolution. Coral bleaching and gene flow studies performed with these markers can have direct conservation implications.