Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean

This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as ‘stress tolerant’ showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of ‘competitive’ corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for ‘competitive’ corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of ‘stress tolerant’ and ‘generalist’ coral genera.USAi

Protecting Seagrass Through Payments for Ecosystem Services: A Community Guide

Shilland, R., Wanjiru, A., Mohamed, A., Grimsditch, G., & Huxham, M. (2020). Protecting Seagrass Through Payments for Ecosystem Services: A Community Guide. Nairobi, Kenya: United Nations Environnment Program

Opportunities and Challenges for Community-Based Seagrass Conservation

Seagrass meadows are important marine ecosystems, providing a range of services including carbon sequestration, nursery habitats for fish and coastal protection. They are suffering rapid global decline in the face of eutrophication and other pollution, damage caused by fishing activities, tourism and coastal development. Degradation and loss of seagrass meadows negatively impacts their ability to provide ecosystem services, which are often of vital importance to resource-poor communities such as local fishers who depend on seagrass ecosystems for sustenance and income. Community-based management (CBM) presents an opportunity for effective, efficient and socially just conservation of seagrass. Payments for Ecosystem Services (PES) has been used in other ecosystems as a model to support community-based conservation but its application to seagrass meadows is in a very early stage.Community-based PES involving seagrass meadows would involve parties (buyers) making payments to communities or their representatives in exchange for management measures (implementation, restriction or adaptation of certain activities) that can be shown to enhance or ensure the delivery of seagrass ecosystem services. Here, the opportunities and challenges associated with community-based seagrass conservation, particularly PES-based, are discussed; we draw on experience in community-based PES projects in similar settings, but with different ecosystems, such as mangroves, and use carbon as the exemplar service (since a global market exists for carbon trading). Recommendations are made on how community-based seagrass conservation is best facilitated through policy mechanisms and tools

Opportunities and Challenges for Community-Based Seagrass Conservation

Seagrass meadows are important marine ecosystems, providing a range of services including carbon sequestration, nursery habitats for fish and coastal protection. They are suffering rapid global decline in the face of eutrophication and other pollution, damage caused by fishing activities, tourism and coastal development. Degradation and loss of seagrass meadows negatively impacts their ability to provide ecosystem services, which are often of vital importance to resource-poor communities such as local fishers who depend on seagrass ecosystems for sustenance and income. Community-based management (CBM) presents an opportunity for effective, efficient and socially just conservation of seagrass. Payments for Ecosystem Services (PES) has been used in other ecosystems as a model to support community-based conservation but its application to seagrass meadows is in a very early stage.Community-based PES involving seagrass meadows would involve parties (buyers) making payments to communities or their representatives in exchange for management measures (implementation, restriction or adaptation of certain activities) that can be shown to enhance or ensure the delivery of seagrass ecosystem services. Here, the opportunities and challenges associated with community-based seagrass conservation, particularly PES-based, are discussed; we draw on experience in community-based PES projects in similar settings, but with different ecosystems, such as mangroves, and use carbon as the exemplar service (since a global market exists for carbon trading). Recommendations are made on how community-based seagrass conservation is best facilitated through policy mechanisms and tools

A question of standards: adapting carbon and other PES markets to work for community seagrass conservation

Seagrass meadows deliver multiple ecosystem services that are of particular importance to resource-poor coastal communities, yet they are rapidly declining globally. The Payments for Ecosystem Services (PES) approach has been used to fund the protection of other ‘Blue Carbon’ Ecosystems (BCE), yet seagrass has been incorporated in just one PES project worldwide. Some of the ecosystem services delivered by seagrass have the potential for inclusion under a PES framework but multiple challenges currently make this difficult, particularly under community-based management. PES programmes typically focus on carbon as the tradable service, but scientific uncertainties regarding seagrass carbon are likely to remain significant barriers to using carbon as the sole commodity under current carbon trading standards and market conditions. It is recommended here that project developers demonstrate the multiple ecosystem services delivered by seagrass meadows, along with their importance to coastal communities, in the planning and marketing of seagrass PES projects. Moreover, they should consider approaches that incorporate seagrass meadows into other blue carbon certified projects. The capacities of the communities that rely most heavily on seagrass are generally very limited. Consequently, demanding high levels of scientific certainty over carbon stocks and flows will exclude most of these communities. Standards, buyers and policy makers should consider building community capacity in the technical and marketing requirements of voluntary carbon standards. The voluntary carbon market has the flexibility to pioneer certified seagrass carbon, potentially leading to the inclusion of seagrass carbon in formal policy instruments, such as Nationally Determined Contributions (NDCs)

Highly Variable Taxa-specific Coral Bleaching Responses to Thermal Stresses

Complex histories of chronic and acute sea surface temperature (SST) stresses are expected to trigger taxon- and location-specific responses that will ultimately lead to novel coral communities. The 2016 El Niño-Southern Oscillation provided an opportunity to examine large- scale and recent environmental histories on emerging patterns in 226 coral communities distrib- uted across 12 countries from East Africa to Fiji. Six main coral communities were identified that largely varied across a gradient of Acropora to massive Porites dominance. Bleaching intensity was taxon-specific and was associated with complex interactions among the 20 environmental variables that we examined. Coral community structure was better aligned with the historical temperature patterns between 1985 and 2015 than the 2016 extreme temperature event. Addi- tionally, bleaching responses observed during 2016 differed from historical reports during past warm years. Consequently, coral communities present in 2016 are likely to have been reorganized by both long-term community change and acclimation mechanisms. For example, less disturbed sites with cooler baseline temperatures, higher mean historical SST background variability, and infrequent extreme warm temperature stresses were associated with Acropora-dominated communities, while more disturbed sites with lower historical SST background variability and frequent acute warm stress were dominated by stress-resistant massive Porites corals. Overall, the combination of taxon-specific responses, community-level reorganization over time, geographic variation, and multiple environmental stressors suggest complex responses and a diversity of future coral communities that can help contextualize management priorities and activities

Large Geographic Variability in the Resistance of Corals to Thermal Stress

Aim: Predictions for the future of coral reefs are largely based on thermal exposure and poorly account for potential geographic variation in biological sensitivity to ther- mal stress. Without accounting for complex sensitivity responses, simple climate ex- posure models and associated predictions may lead to poor estimates of future coral survival and lead to policies that fail to identify and implement the most appropri- ate interventions. To begin filling this gap, we evaluated a number of attributes of coral taxa and communities that are predicted to influence coral resistance to thermal stress over a large geographic range. Location: Western Indo-Pacific and Central Indo-Pacific Ocean Realms. Major taxa studied: Zooxanthellate Scleractinia – hard corals. Methods: We evaluated the geographic variability of coral resistance to thermal stress as the ratio of thermal exposure and sensitivity in 12 countries during the 2016 global-bleaching event. Thermal exposure was estimated by two metrics: (a) histori- cal excess summer heat (cumulative thermal anomaly, CTA), and (b) a multivariate index of sea-surface temperature (SST), light, and water flow (climate exposure, CE). Sensitivity was estimated for 226 sites using coordinated bleaching observations and underwater surveys of coral communities. We then evaluated coral resistance to ther- mal stress using 48 generalized linear mixed models (GLMMs) to compare the poten- tial influences of geography, historical SST variation, coral cover and coral richness. Results: Geographic faunal provinces and ecoregions were the strongest predic- tors of coral resistance to thermal stress, with sites in the Australian, Indonesian and Fiji-Caroline Islands coral provinces having higher resistance to thermal stress than Africa-India and Japan-Vietnam provinces. Ecoregions also showed strong gradients in resistance with highest resistance to thermal stress in the western Pacific and Coral Triangle and lower resistance in the surrounding ecoregions. A more detailed evaluation of Coral Triangle and non-Coral Triangle sites found higher resistance to thermal stress within the Coral Triangle, associated with c. 2.5 times more recent historical thermal anomalies and more centralized, warmer, and cool-water skew SST distributions, than in non-Coral Triangle sites. Our findings identify the importance of environmental history and geographic context in future predictions of bleaching, and identify some potential drivers of coral resistance to thermal stress. Main conclusions: Simple threshold models of heat stress and coral acclimation are commonly used to predict the future of coral reefs. Here and elsewhere we show that large-scale responses of coral communities to heat stress are geographically variable and associated with differential environmental stresses and histories