Interaction between the El Nino and Indian Ocean dipole ocean-atmosphere quasi-periodic oscillations produced one of the warmest seawater temperatures on record in 1998. During the warm northeast ...monsoon in March and April, Kenya's shallow coral reefs experienced water temperatures between 30 and 31 degree C and low winds. This caused large-scale bleaching of hard and soft corals at the end of March, which extended into the cooler months of May and June. Direct observations of coloration in the Mombasa Marine National Park found that the coral genera Acropora, Millepora, Pocillopora, branching Porites and Stylophora showed rapid bleaching and high mortality by the end of May 1998. Other hard coral genera that bleached significantly included Echinopora, Favia, Favites, Galaxea, Hydnophora, Goniopora, Leptoria, Montipora, Platygyra and massive Porites, but mortality was variable among these genera. Astreopora, Coscinarea, Cyphastrea and Pavona were the least responsive genera, with some paling, but little evidence of full bleaching or significant mortality. We compared changes in reef ecology in four national parks (protected from fishing) with four non-park areas (heavy fishing) to determine how coral mortality and herbivory interact under the two management regimes. One year after the bleaching, sites in the national parks experienced 88 and 115% increases in turf and fleshy algal cover, respectively, while reefs outside the parks had a 220% increase in fleshy algal cover with no appreciable change in turf-forming algal cover. There was, however, high spatial variation and no statistically significant difference in the change in fleshy algal cover between sites in and out of the national parks. The number of coral genera per transect at each site decreased significantly 31 and 44% in and out of the national parks respectively. Larger-scale search sampling to determine the presence/absence of genera in study sites found consistent losses of coral genera from sites, but produced smaller differences than the line-transect method, suggesting that some general persisted, but at very low population densities and small colony sizes.
We evaluated and compared the influence of the largest temperature anomaly in recent history, the 1997–1998 El Niño–Indian Ocean Dipole anomaly that killed half of the corals in the Indian Ocean, ...with a nearly coincident increase in fisheries management restrictions on coral reef fisheries in southern Kenya. Seawater temperatures, benthic primary producers, and fishing effort and catch rate and income time series collected over the 1993–2012 period were evaluated using time series and variable cointegration methods. An observed decline and subsequent increase in catch rates was closely associated with the implementation of increasing fisheries restrictions and was not predictably cointegrated with the temperature or the primary producer’s time series. This may have occurred because the disturbance was pulsed with a limited 6 yr impact on the primary producers and the fishery was heavily utilized and composed of fastgrowing generalist species with broad diet and habitat needs. Consequently, under these conditions, promoting fisheries restrictions is expected to attenuate the predicted declines in fish catches projected by global warming.
Results are presented for the LEND instrument onboard LRO for the detection of local spots of suppression and excess of epithermal neutron emission at the lunar poles. Twelve local Neutron ...Suppression Regions (NSRs) and Neutron Excess Regions (NERs) are detected. It is shown using the data from the LOLA and Diviner instruments that six NSRs have the empirical property “less local irradiation and lower temperature – fewer local neutrons.” These NSRs may be identified with spots of water‐ice rich permafrost on the Moon. It is shown that detected NSRs are include in both permanently shadowed and illuminated areas, and they are not coincident with Permanently Shadowed Regions (PSRs) at the bottom of polar craters, as has been commonly expected before LEND presented neutron data with high spatial resolution.
Key Points
Neutron suppression regions and neutron excess regions discovered
Empirical law
Water‐ice rich permafrost spots may be identified with these regions on the Moon
In shallow-water systems, fisheries management influences herbivory, which mediates ecosystem processes by regulating algal biomass, primary production, and competition between benthic organisms, ...such as algae and corals. Sea urchins and herbivorous fishes (scrapers, grazers, browsers) are the dominant herbivores in Kenya’s fringing coral reef and their grazing influences coral–macroalgal dynamics and dominance. Using experimental substrata and grazer exclusions, we tested the hypothesis that herbivores differentially affect algal composition and succession using 3 levels of fisheries management: fished reefs, community-managed closures (<10 yr old, <0.5 km²), and government-managed closures (20 to 40 yr old, 5 to 10 km²). In fished reefs and government closures, herbivores facilitated maintenance of early successional algal species, such as turfs, associated with sea urchins in the former and scraping fishes in the latter. Crustose coralline algae were only abundant in government closures, and video recordings showed that fish grazing was greatest at these sites, most notably for parrotfishes (scrapers). A combination of sea urchins and small grazing and detritivorous fishes was present in community closures, which allowed macroalgae to quickly develop from turf into early then late successional stages. These reefs may represent an intermediate or transitional system of herbivore dominance characterized by macroalgae. Consequently, reefs in heavily fished seascapes initially protected from fishing may require additional management efforts to facilitate the recovery of larger-bodied scraping fishes, including bans on capturing parrotfishes and restricting gear (e.g. spearguns) that target these species.
The literature on coral reefs and human resource use or fishing is reviewed less from the perspective of summarizing findings but more from the sociological perspective of what scientists chose to ...study, publish, and cite in journal articles. The motivation was to determine if coral reef science is generating information needed to solve the coral reef climate and fisheries crisis that has been publicized in many of the highest visibility and cited publications. The social-ecological system of coral reefs involves the environment, the ecosystem, human harvesting and social organization and the policies that arise from their interaction. Regardless of the focus and findings of any science investigation on this system, recommendations for management are limited, and include restrictions on space, time of use, effort, gear, species, size, and gender. Evaluating the scientific journal literature in the
Scopus database on these restrictions indicates a disparity in focus for both publications and citations. The greatest number of scientists and citations are focused on spatial closures and fishing effort, effort seen as the problem and closures the solution. The other restrictions, that represent less extreme forms of management and have lower short-term social costs and trade offs, are not well studied and, when studied, investigated by either a small group of associated colleagues or transient one-publication investigators. When the values, selectivity, and incentives of scientists conflict with resource users desires for knowledge, incentives, and profits the resulting divide can weaken the social relevance and applicability of science and delay real-world problem solving. Societal engagement, acceptance, objectivity, and finding solutions are likely to increase if scientific effort is spread more evenly across this full spectrum of management restrictions and more components of the social-ecological system.
► Coral reef scientist’s focus for study and citation is marine reserves. ► Fishing effort is viewed as the problem and reserves as the solution. ► Conflict exists between incentives for scientists and the needs of resource users. ► Progress towards solving the coral reef crises is slowed by these conflicts. ► The solution is to spread research effort over more social-ecological problems.
► Explores the transformation to devolved resource governance in three east African countries. ► Drivers for change appeared to be donor driven in all three cases. ► The governance transformation has ...provided resource users with more say in how resources are managed. ► Accountability, however, is often upward to governments rather than downward to local actors. ► Adaptive experimentation with regulations has helped to change the mental models of resource users.
Communities are increasingly empowered with the ability and responsibility of working with national governments to make decisions about marine resources in decentralized co-management arrangements. This transition toward decentralized management represents a changing governance landscape. This paper explores the transition to decentralisation in marine resource management systems in three East African countries. The paper draws upon expert opinion and literature from both political science and linked social-ecological systems fields to guide exploration of five key governance transition concepts in each country: (1) drivers of change; (2) institutional arrangements; (3) institutional fit; (4) actor interactions; and (5) adaptive management. Key findings are that decentralized management in the region was largely donor-driven and only partly transferred power to local stakeholders. However, increased accountability created a degree of democracy in regards to natural resource governance that was not previously present. Additionally, increased local-level adaptive management has emerged in most systems and, to date, this experimental management has helped to change resource user's views from metaphysical to more scientific cause-and-effect attribution of changes to resource conditions.
Coral reefs are among the most species-rich and threatened ecosystems on Earth, yet the extent to which human stressors determine species occurrences, compared with biogeography or environmental ...conditions, remains largely unknown. With ever-increasing human-mediated disturbances on these ecosystems, an important question is not only how many species can inhabit local communities, but also which biological traits determine species that can persist (or not) above particular disturbance thresholds. Here we show that human pressure and seasonal climate variability are disproportionately and negatively associated with the occurrence of large-bodied and geographically small-ranging fishes within local coral reef communities. These species are 67% less likely to occur where human impact and temperature seasonality exceed critical thresholds, such as in the marine biodiversity hotspot: the Coral Triangle. Our results identify the most sensitive species and critical thresholds of human and climatic stressors, providing opportunity for targeted conservation intervention to prevent local extinctions.
Long-term changes in coral cover for the Caribbean and the Pacific/Southeast Asia regions (PSEA) have proven extremely useful in assessing the main drivers, magnitude and timescales of change. The ...one major coral reef region where such assessments have not been made is the Indian Ocean (IO). Here, we compiled coral cover survey data from across the IO into a database of ~2,000 surveys from 366 coral reef sites collected between 1977 and 2005. The compilation shows that the 1998 mass coral bleaching event was the single most important and widespread factor influencing the change in coral cover across the region. The trend in coral cover followed a step-type function driven by the 1998 period, which differs from findings in the Caribbean and the PSEA regions where declines have been more continuous and mostly began in the 1980s. Significant regional variation was observed, with most heterogeneity occurring during and after 1998. There was a significant relationship between cover and longitude for all periods, but the relationship became stronger in the period immediately after 1998. Before 1998, highest coral cover was observed in the central IO region, while this changed to the eastern region after 1998. Coral cover and latitude displayed a significant U-shaped relationship immediately after 1998, due to a large decrease in cover in the northern-central regions. Post-1998 coral cover was directly correlated to the impact of the disturbance; areas with the lowest mortality having the highest cover with India–Sri Lanka being an outlier due to its exceptionally high recovery. In 1998, reefs within Marine Protected Areas (MPAs) were more heavily impacted than unmanaged reefs, losing significantly greater total cover. MPA recovery was greater such that no differences were observed by 2001–2005. This study indicates that the regional patterns in coral cover distribution in the IO are driven mainly by episodic and acute environmental stress.
The size, density and biomass of coral reef fish in 4 fully closed marine protected areas (MPAs) with different ages were studied over a 17 yr period. Space-for-time substitution samples were ...available for a period of 4 yr before, and 36 yr after the closure. Both the height of the size structure graph (which is a value of overall abundance–biomass) and the assemblage biomass graph are convex polynomials with a maximum biomass of 1200 kg ha–1at 22 yr. This suggests that full recovery of coral reef fish assemblages in terms of abundance–biomass is considerably longer than generally believed. Beyond 25 yr, there can be a small loss in biomass, which we suggest is due to reduced net primary production associated with the increased abundance of calcifying algae attributable to intense grazing. Size spectra slopes were variable at all times, changed quickly, and were probably influenced by local environmental conditions, which made concise predictions for equilibrium coral reef size structure rather difficult.
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