Comparing bleaching and mortality responses of hard corals between southern Kenya and the Great Barrier Reef, Australia

We compared the bleaching and mortality response (BMI) of 19 common scleractinian corals to an anomalous warm-water event in 1998 to determine the degree of variation between depths, sites, and regions. Mombasa corals experienced a greater temperature anomaly than those on the Great Barrier Reef (GBR) sites and this was reflected in the greater BMI response of most taxa. Comparing coral taxa in different sites at the same depth produced high correlation coefficients in the bleaching response in Kenya at 2 m (r=0.86) and GBR at 6 m depth sites (r=0.80) but less in the GBR for shallow 2 m sites (r=0.49). The pattern of taxa susceptibility was remarkably consistent between the regions. Coral taxa explained 52% of the variation in the response of colonies to bleaching between these two regions (Kenya BMI=0.90 GBR BMI+26; F(1,19) - 18.3; p < 0.001; r2 = 0.52). Stylophora and Pocillopora were consistently susceptible while Cyphastrea, Goniopora Galaxea and Pavona were resistant in both regions. Three taxa behaved differently between the two regions; Acropora, and branching Porites were both moderately affected on the GBR but were highly affected in Kenya while the opposite was true for Pavona. These results suggest that a colonies response to bleaching is phylogenetically constrained, emphasizing the importance of features of the host's physiology or morphology in determining the response to thermal stress.     

Management of the Kenyan coast

We describe the changes in the management of marine resources in Kenya from traditional management, through the era of marine protected areas and the fisheries sector, towards the initial developments of an integrated coastal area management system, which has only been active since the early 1990s. The first meetings between sectors were held in the mid-1990s where the responsibilities of management were agreed upon and from which a number of memorandums were initiated as part of the integrative process that was lead by the Coast Development Authority. Two integrated coastal management (ICM) pilot projects started in the mid- to late 1990s were undertaken to test the effectiveness of the process in two tourist beaches north of Mombasa and later Diani. These ICM programs primarily focused on infrastructural development and resource access issues and participants needed to be reminded that that the objectives of the ICM process were to improve natural resource management and protect biodiversity. There was also the problem that government and the larger economic interests were involved in policy and planning but the poor and associated communities were often marginalized because they lacked effective formal organizations and finances to represent them. The financial support for projects prior to 2003 was generally less than US $150 000 and this and the poverty of the institutions and difficulties of establishing financial sustainability limited the programs and their problem solving. Nonetheless, there has been sustained progress and lessons learned concerning interactions with stakeholders, zoning of activities, linkages among groups, and improvements in the environment that should form the basis for further integration and solutions.     

Phosphorus and nitrogen effects on microbial euendolithic communities and their bioerosion rates

Cages and fertilizers were used at Glover's Atoll, Belize to test the relative importance of nitrogen (N) and phosphorus (P) to microbial euendolithic communities (bacteria, algae and fungi) and their bioerosion rates of Strombus gigas shells after 56-days of exposure. By the end of the experiment, the abundance of green algae was higher than cyanobacteria and fungi in N and N+P treatments, although green algae did not increase proportionally with increasing N concentrations, suggesting that green algae were co-limited by P and N. In contrast, cyanobacteria abundance increased with increasing P concentration, suggesting that cyanobacteria were P-limited. Fungi were not significantly affected by the addition of nutrients. Microbioerosion rates in the N and N+P treatments were 2-times greater than rates in the P treatment and 15-times greater than the control treatment. Results demonstrate that increased nutrient concentrations on coral reefs may increase microbioerosion rates, and variations in nutrient ratios can modify microborers community composition.     

Co-management of coral reef fisheries: A critical evaluation of the literature

In many parts of the world, inshore marine resources are being increasingly managed through collaborative arrangements between communities, governments, civil society and other groups. However, co-management of fisheries has had a mixture of successes and failures. Theorists and applied researchers have suggested a series of preconditions or factors thought to improve the chances of successful common-pool resource management. These include common property institutional design principles and their contextual conditions. Using a variety of web-based English keyword searches, published literature on community-based management and co-management of coral reefs was systematically reviewed with the view of determining if and how studies were evaluating these management systems as well as the extent to which critical aspects of common property theory were investigated and tested. Based on a screening of 600 and full evaluation of 157 journal articles, four measures of ecological conditions and five measures of contextual condition improvement were examined or could be evaluated with the data presented in 38 papers, which examined 49 co-management projects. Fewer than half of the 49 studies met the inclusion criteria of the analyses for documenting key design principles or contextual conditions. Additionally, most projects did not systematically report on contextual conditions, common property design principles and measures of success. The analysis demonstrates the large theoretical and empirical gaps in the evaluation of these management systems and begs for a more scientific, critical and multivariate approach.     

Dissolved inorganic carbon sourcing using δ13CDIC from a karst influenced river system

Rivers, representing the primary conduits of dissolved inorganic carbon (DIC) from the continents to the oceans, are important components to the global carbon cycle. To better understand the complex carbon cycling dynamics within two nested, mixed lithology watersheds, two sites were studied along the karst influenced upper Green River in south‐central Kentucky, USA. Weekly samples were collected from June 2013 through May 2014 and analyzed for δ¹³C_DIC. The mixing model IsoSource was employed to better understand source partitioning differences over seasonal time spans and across the two nested basins. In both the lithologically mixed upstream basin (53% carbonate rocks, 47% siliciclastic) and carbonate rock dominated downstream basin (96% carbonate rocks in the drainage area between Greensburg and Munfordville, 78% in the total area upstream from Munfordville), DIC was primarily derived from soil respiration. The proportion of DIC from dissolved carbonate minerals derived from the downstream carbonate rock dominated basin was similar to the upstream basin, due to carbonate mineral dissolution having such a consistent effect on the overall DIC content of the river. Seasonally, soil respiration provided the most DIC from fall to winter. Early spring precipitation, combined with limited seasonal photosynthesis, shifted groundwater to be the primary source of DIC, bringing in a flush of carbonate mineral‐rich water during higher flows. This study provides insight into carbon dynamics across multiple lithologies and the important influence of seasonality using carbon isotope sourcing to determine carbonate mineral dissolution variability and aid in understanding its contribution to global carbon flux quantification. Copyright © 2015 John Wiley & Sons, Ltd.     

Survival estimates for the greater crested tern Thalasseus bergii in southern Africa

The nominate race of the greater crested tern Thalasseus bergii breeds only along the coast of the Benguela region (west coast) of southern Africa, where its population is increasing, in contrast to other species of breeding seabirds in the region which similarly depend on forage fish. Although this population’s trends are well known, its demographic parameters remain obscure. We used multi-event capture–recapture–recovery modelling to provide the first estimates of survival. The survival rate of birds older than two years was 0.93 (0.91–0.95); second-year survival was 0.93 (0.90–0.95) and first-year survival was 0.80 (0.73–0.85). A resighting of a 34-year-old bird is a new longevity record for the species. Population growth rates projected with a Leslie matrix model that included our survival estimates were very similar to estimates from annual counts of the breeding population (7–8% y^?1), suggesting that these survival estimates adequately describe the species’ demography. High survival rates have likely contributed to the species’ recent population increase in the region.     

Differences in livelihoods,socioeconomic characteristics,and knowledge about the sea between fishers and non-fishers living near and far from marine parks on the Kenyan coast

The socioeconomic conditions in nine communities of the Kenyan coast were examined to test the hypotheses that socioeconomic characteristics and knowledge about the sea differ for: (1) fishers compared to non-fishers; and (2) fishers living adjacent to parks compared to fishers living away from parks. Compared to non-fishers, fishers were poorer, had higher occupational diversity, more participation in community decision-making, and higher scores on six dimensions of knowledge about marine resources. Fishers living adjacent parks had lower occupational diversity, higher fortnightly expenditures, greater knowledge of the effects of land-based pollutants and market demands than non-park fishers. These relationships may, however, be a result of urbanization near Kenya's marine parks, rather than the marine parks’ effect on fishers’ knowledge and livelihoods. Consistent with studies from other parts of the world, this study finds that there are aspects of Kenyan fishers’ socioeconomic conditions and knowledge about the sea that characterize them as distinct from non-fishers. Initiatives designed to improve the socioeconomic conditions of fishers or to manage fishery stocks need to understand and account for these differences.     

Top–down and bottom–up regulation of macroalgal community structure on a Kenyan reef

Top–down and bottom–up regulation in the form of grazing by herbivores and nutrient availability are important factors governing macroalgal communities in the coral reef ecosystem. Today, anthropogenic activities, such as over-harvesting of herbivorous fish and sea urchins and increased nutrient loading, are altering the interaction of these two structuring forces. The present study was conducted in Kenya and investigates the relative importance of herbivory and nutrient loading on macroalgal community dynamics, by looking at alterations in macroalgal functional groups, species diversity (H′) and biomass within experimental quadrats. The experiment was conducted in situ for 42 days during the dry season. Cages excluding large herbivorous fish and sea urchins were used in the study and nutrient addition was conducted using coated, slow-release fertilizer (nitrogen and phosphorous) at a site where herbivory is generally low and nutrient levels are relatively high for the region. Nutrient addition increased tissue nutrient content in the algae, and fertilized quadrats had 24% higher species diversity. Herbivore exclusion resulted in a 77% increase in algal biomass, mainly attributable to a >1000% increase in corticated forms. These results are in accordance with similar studies in other regions, but are unique in that they indicate that, even when prevailing nutrient levels are relatively high and herbivore pressure is relatively low, continued anthropogenic disturbance results in further ecological responses and increased reef degradation.     

Transitions toward co-management: The process of marine resource management devolution in three east African countries

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.