Sebastian C. A. Ferse

Global human footprint on the linkage between biodiversity and ecosystem functioning in reef fishes.

A global survey of reef fishes shows that the consequences of biodiversity loss are greater than previously anticipated as ecosystem functioning remained unsaturated with the addition of new species. Additionally, reefs worldwide, particularly those most diverse, are highly vulnerable to human impacts that are widespread and likely to worsen due to ongoing coastal overpopulation.

Bright spots among the world’s coral reefs

Ongoing declines in the structure and function of the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the ‘outliers’—places where ecosystems are substantially better (‘bright spots’) or worse (‘dark spots’) than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We identify 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that have biomass levels more than two standard deviations from expectations. Importantly, bright spots are not simply comprised of remote areas with low fishing pressure; they include localities where human populations and use of ecosystem resources is high, potentially providing insights into how communities have successfully confronted strong drivers of change. Conversely, dark spots are not necessarily the sites with the lowest absolute biomass and even include some remote, uninhabited locations often considered near pristine. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots are characterized by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Alternatively, dark spots are characterized by intensive capture and storage technology and a recent history of environmental shocks. Our results suggest that investments in strengthening fisheries governance, particularly aspects such as participation and property rights, could facilitate innovative conservation actions that help communities defy expectations of global reef degradation.

Allies, not aliens: increasing the role of local communities in marine protected area implementation

Various management approaches have been proposed to address the alarming depletion of marine coastal resources. Prominent among them are community-based management and the establishment of marine protected areas (MPAs). The overall poor performance of MPAs can be traced to a failure to effectively include local communities in the design and implementation of relevant measures. Recent efforts have incorporated aspects of community-based management into a hybrid form of management, which ideally builds upon existing local management practices. A key challenge lies in the development of appropriate frameworks that allow for the successful participation of local communities in management. A review of studies on MPA design and community-based marine resource management and fieldwork observations provides suggestions on how to address current socioeconomic shortcomings in MPA design and implementation, successfully involving local communities in order to provide a better local basis for effective larger MPA networks. A combination of MPA tools as the formal frame and community-based natural resource management as the adaptive core that recognizes local communities as allies, not aliens, is needed to develop successful conservation approaches.

The history of Makassan trepang fishing and trade.

The Malayan term trepang describes a variety of edible holothurians commonly known as sea cucumbers. Although found in temperate and tropical marine waters all over the world, the centre of species diversity and abundance are the shallow coastal waters of Island Southeast Asia. For at least 300 years, trepang has been a highly priced commodity in the Chinese market. Originally, its fishing and trade was a specialized business, centred on the town of Makassar in South Sulawesi (Indonesia). The rise of trepang fishing in the 17th century added valuable export merchandize to the rich shallow seas surrounding the islands of Southeast Asia. This enabled local communities to become part of large trading networks and greatly supported their economic development. In this article, we follow Makassan trepang fishing and trading from its beginning until the industrialization of the fishery and worldwide depletion of sea cucumbers in the 20th century. Thereby, we identify a number of characteristics which trepang fishing shares with the exploitation of other marine resources, including (1) a strong influence of international markets, (2) the role of patron-client relationships which heavily influence the resource selection, and (3) the roving-bandit-syndrome, where fishermen exploit local stocks of valuable resources until they are depleted, and then move to another area. We suggest that understanding the similarities and differences between historical and recent exploitation of marine resources is an important step towards effective management solutions.

Livelihoods of Ornamental Coral Fishermen in South Sulawesi/Indonesia: Implications for Management

Collection of live coral for the marine aquarium trade has increased significantly in recent years, causing concerns over the ecological implications of this activity for the source regions. The Spermonde Archipelago off Southwest Sulawesi is one of the four major ornamental coral collection sites in Indonesia, the country supplying most corals in the trade. Management of the fishery remains ineffective, and overharvesting is widespread. Conservation strategies for marine resources increasingly emphasize the socioeconomic dimensions of resource use, yet little information is available on the livelihoods of fishermen involved in the ornamental fishery. Here, a first analysis of the livelihoods of coral fishermen in the Spermonde Archipelago is presented, along with a discussion of possibilities for future management interventions. The reef fishery of the study area is characterized by a high diversity of target organisms, with none of the fishermen relying exclusively on ornamental corals for income. Moreover, fishermen are organized in a tightly knit web of patron–client relationships, leaving little scope for them to initiate changes in livelihood strategies. The patron–client system emerged as a key institution of the fishery. In order to support sustainable marine resource use, management policies should simultaneously target the fishermen and their patrons as well as the regional coral trade network, broadening the livelihood portfolio of island communities and improving the regulation of the associated trade network.

To cope or to sustain? Eroding long-term sustainability in an Indonesian coral reef fishery

Small-scale fisheries in coral reef areas support the livelihoods of millions of people worldwide. Anthropogenic impacts such as overfishing and climate change increasingly threaten both the reef ecosystem and the livelihood security of the people that depend on the reefs. Adaptive management strategies are needed to adequately deal with these threats, but they require an understanding of the underlying drivers, which often originate and act on multiple levels. Using a social-ecological system approach, the coral reef fishery of the Spermonde Archipelago in South Sulawesi/Indonesia is assessed to identify key drivers and strategic leverage points for management. Under the influence of international markets and technological changes, several export-oriented fisheries have developed in the area that led to distinct subsequent peaks in fishing activity in a pattern of sequential marine resource exploitation. In response to stressors such as seasonality and overfishing of individual locations or species, a number of coping strategies have developed locally. These include extensive borrowing from fishing patrons, diversification of fishing methods, fishing migrations, and the crafting of local institutions to regulate fishing activity. However, the coping strategies hinder, and even decrease, the capacity of the system to adapt to future stressors and undermine the sustainability of the fishery. Potential strategies that target different levels of the fishery system in order to strengthen adaptive management are identified.

'Nested' participation in hierarchical societies? Lessons for social- ecological research and management

In the shift from community-based ecosystem management to co-management by the government and user groups, the participation of local resource users has remained important. In research, participatory approaches aim to enable local communities to contribute to sustainability knowledge. However, the outcomes of participatory practice have been particularly meagre in hierarchical contexts. The article links the difficulties of participatory practice to the hierarchical features of Indonesian society and examines a recently conducted participatory analysis of the social-ecological dynamics surrounding marine resource management in an Indonesian coral archipelago. We discuss the options and limitations encountered in this distinctly hierarchical society and suggest an approach for designing nested participation in this and similarly hierarchical socio-cultural settings. A visual tool is suggested which particularly supports the participation of ecosystem users in the lower ranks of social hierarchies in the search for more sustainable social-ecological futures.

Mapping coral reefs using consumer-grade drones and structure from motion photogrammetry techniques

We propose a novel technique to measure the small-scale three-dimensional features of a shallow-water coral reef using a small drone equipped with a consumer-grade camera, a handheld GPS and structure from motion (SfM) algorithms. We used a GoPro HERO4 with a modified lens mounted on a DJI Phantom 2 drone (maximum total take-off weight <2xa0kg) to perform a 10xa0min flight and collect 306 aerial images with an overlap equal or greater than 90%. We mapped an area of 8380xa0m2, obtaining as output an ortho-rectified aerial photomosaic and a bathymetric digital elevation model (DEM) with a resolution of 0.78 and 1.56xa0cm pixel−1, respectively. Through comparison with airborne LiDAR data for the same area, we verified that the location of the ortho-rectified aerial photomosaic is accurate within ~1.4xa0m. The bathymetric difference between our DEM and the LiDAR dataset is −0.016xa0±xa00.45xa0m (1σ). Our results show that it is possible, in conditions of calm waters, low winds and minimal sun glint, to deploy consumer-grade drones as a relatively low-cost and rapid survey technique to produce multispectral and bathymetric data on shallow-water coral reefs. We discuss the utility of such data to monitor temporal changes in topographic complexity of reefs and associated biological processes.

Local and Regional Impacts of Pollution on Coral Reefs along the Thousand Islands North of the Megacity Jakarta, Indonesia

Worldwide, coral reefs are challenged by multiple stressors due to growing urbanization, industrialization and coastal development. Coral reefs along the Thousand Islands off Jakarta, one of the largest megacities worldwide, have degraded dramatically over recent decades. The shift and decline in coral cover and composition has been extensively studied with a focus on large-scale gradients (i.e. regional drivers), however special focus on local drivers in shaping spatial community composition is still lacking. Here, the spatial impact of anthropogenic stressors on local and regional scales on coral reefs north of Jakarta was investigated. Results indicate that the direct impact of Jakarta is mainly restricted to inshore reefs, separating reefs in Jakarta Bay from reefs along the Thousand Islands further north. A spatial patchwork of differentially degraded reefs is present along the islands as a result of localized anthropogenic effects rather than regional gradients. Pollution is the main anthropogenic stressor, with over 80% of variation in benthic community composition driven by sedimentation rate, NO2, PO4 and Chlorophyll a. Thus, the spatial structure of reefs is directly related to intense anthropogenic pressure from local as well as regional sources. Therefore, improved spatial management that accounts for both local and regional stressors is needed for effective marine conservation.

Differential physiological responses of two congeneric scleractinian corals to mineral accretion and an electric field

Despite increasing popularity of ‘electric’ reefs as a means for reef restoration, there is a distinct lack of quantitative evidence supporting the alleged benefits of this method. This study investigated the effects of an electric field versus an electric field in combination with a cathode on coral growth (skeletal extension) rates, coral survival, zooxanthella densities, chlorophyll a (chl a) concentrations, and chlorophyll fluorescence of Acropora pulchra and A. yongei. Coral transplants were grown for 4xa0months under three treatment conditions: (1) on an iron cathode, (2) on bamboo inside an electric field, or (3) on bamboo in the absence of an electric field. Contrary to predictions, coral growth rates of both species were highest inside the electric field and not on the cathode. Except for chl a concentrations, the cathode had a significant adverse effect on all measured variables for A. yongei but not for A. pulchra. Treatment had no effect on the survival of A. pulchra, while mortality rates of A. yongei were significantly higher in the presence of mineral accretion compared to the electric field and control. A. yongei on the cathode featured low zooxanthella densities, depressed electron transport rates (rETR) and maximum quantum yield (Fv/Fm), and reduced growth. By contrast, treatment had no effect on the fluorescence characteristics of A. pulchra, and zooxanthella densities were highest for corals on the cathode, coincident with high growth rates relative to the control. Overall, the data indicate that the proposed benefits of the mineral accretion technology to meet important objectives of reef rehabilitation with regard to colony growth and survival should be considered with caution.