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Over 30% of the world’s population lives within 100 km of the oceanic coast. More than three billion people rely on fishing and other ocean-related livelihoods. The ocean is a biodiversity hotspot and moderates the climate, having absorbed around 40% of the world’s total carbon emissions. Oceanscapes provide an essential cultural good, offer recreational opportunities, health benefits, artistic inspiration and an entire cosmology and way of life for indigenous communities. However, anthropogenic pressures have seriously impacted the ocean and threaten its ability to provide human societies with the required climatic and ecosystem conditions for life on earth. The German G7 presidency has proposed a G7 “Ocean Deal” for the sustainable use, protection and effective governance of the ocean and its resources. Several ongoing global ocean governance processes require strong multilateral leadership and close alignment between the G7, in particular in this period of serious international tensions following the Russian invasion of Ukraine. At the One Ocean Summit in February 2022, global leaders have put forth first commitments to make 2022 a decision year for the ocean. Building on the final declaration of the summit and the UK G7 Ocean Decade Navigation Plan, we highlight that a G7 “Ocean Deal” should include provisions for 1) ambitious ocean governance to safeguard ocean health and climate (in the G7’s own waters and through leadership in international settings), 2) improving ocean observation, data infrastructure and knowledge sharing, and 3) financing the transition towards more sustainable interactions with the ocean. Specifically, we recommend that G7 states: 1a. Eliminate national subsidies that contribute to overfishing and push to finalize the related WTO agreement; step up international cooperation, financial & technical assistance to prevent IUU fishing. 1b. Reduce marine debris through a comprehensive global agreement on plastic pollution. 1c. Pause deep sea mining until risks are better understood and a transparent, inclusive and accountable institutional structure is in place that guarantees the effective protection of the marine environment. 1d. Expand marine protected areas in line with the proposed goal of at least 30% by 2030, and accelerate work in the coming months to successfully finalize negotiations for a legally binding instrument to conserve and sustainably use marine biological diversity in areas beyond national jurisdiction (BBNJ). 1e. Fully recognize the importance of the ocean-climate nexus and strengthen the ocean dimension in key climate negotiations. 2a. Adopt a legal framework and binding commitments for a sustained and shared global coordination of ocean observations and infrastructure on marine data, compliant with FAIR and CARE principles. 2b. Ensure long-term, guaranteed funding, clear institutional affiliations, coordinated and integrated data products to enable continuous, comprehensive observations supporting policy monitoring & evaluation 3a. Redesign and scale up ocean finance by increasing funding of early-stage, nature-positive and science-based opportunities, and large-scale investment into zero-carbon, resilient and nature-based coastal blue infrastructure, and by integrating ocean criteria into sustainability finance frameworks (EU Taxonomy, Task Force on Climate-related Financial Disclosures (TCFD), Taskforce for Nature-related Financial Disclosures (TNFD)).

Development of global ocean observing capacity for the biological EOVs is on the cusp of a step-change. Current capacity to automate data collection and processing and to integrate the resulting data streams with complementary data, openly available as FAIR data, is certain to dramatically increase the amount and quality of information and knowledge available to scientists and decision makers into the future. There is little doubt that scientists will continue to expand their understanding of what lives in the ocean, where it lives and how it is changing. However, whether this expanding information stream will inform policy and management or be incorporated into indicators for national reporting is more uncertain. Coordinated data collection including open sharing of data will help produce the consistent evidence-based messages that are valued by managers. The GODS Biology and Ecosystems Panel is working with other global initiatives to assist this coordination by defining and implementing Essential Ocean Variables. The biological EOVs have been defined, are being updated following community feedback, and their implementation is underway. In 2019, the coverage and precision of a global ocean observing system capable of addressing key questions for the next decade will be quantified, and its potential to support the goals of the UN Decade of Ocean Science for Sustainable Development identified. Developing a global ocean observing system for biology and ecosystems requires parallel efforts in improving evidence-based monitoring of progress against international agreements and the open data, reporting and governance structures that would facilitate the uptake of improved information by decision makers.

Recognition of the threats to biodiversity and its importance to society has led to calls for globally coordinated sampling of trends in marine ecosystems. As a step to defining such efforts, we review current methods of collecting and managing marine biodiversity data. A fundamental component of marine biodiversity is knowing what, where, and when species are present. However, monitoring methods are invariably biased in what taxa, ecological guilds, and body sizes they collect. In addition, the data need to be placed, and/or mapped, into an environmental context. Thus a suite of methods will be needed to encompass representative components of biodiversity in an ecosystem. Some sampling methods can damage habitat and kill species, including unnecessary bycatch. Less destructive alternatives are preferable, especially in conservation areas, such as photography, hydrophones, tagging, acoustics, artificial substrata, light-traps, hook and line, and live-traps. Here we highlight examples of operational international sampling programmes and data management infrastructures, notably the Continuous Plankton Recorder, Reef Life Survey, and detection of Harmful Algal Blooms and MarineGEO. Data management infrastructures include the World Register of Marine Species for species nomenclature and attributes, the Ocean Biogeographic Information System for distribution data, Marine Regions for maps, and Global Marine Environmental Datasets for global environmental data. Existing national sampling programmes, such as fishery trawl surveys and intertidal surveys, may provide a global perspective if their data can be integrated to provide useful information. Less utilised and emerging sampling methods, such as artificial substrata, light-traps, microfossils and eDNA also hold promise for sampling the less studied components of biodiversity. All of these initiatives need to develop international standards and protocols, and long-term plans for their governance and support.

The Chagos Archipelago was designated a no-take marine protected area (MPA) in 2010; it covers 550 000km2, with more than 60 000km2 shallow limestone platform and reefs. This has doubled the global cover of such MPAs. It contains 25-50% of the Indian Ocean reef area remaining in excellent condition, as well as the world's largest contiguous undamaged reef area. It has suffered from warming episodes, but after the most severe mortality event of 1998, coral cover was restored after 10years. Coral reef fishes are orders of magnitude more abundant than in other Indian Ocean locations, regardless of whether the latter are fished or protected. Coral diseases are extremely low, and no invasive marine species are known. Genetically, Chagos marine species are part of the Western Indian Ocean, and Chagos serves as a 'stepping-stone' in the ocean. The no-take MPA extends to the 200nm boundary, and. includes 86 unfished seamounts and 243 deep knolls as well as encompassing important pelagic species. On the larger islands, native plants, coconut crabs, bird and turtle colonies were largely destroyed in plantation times, but several smaller islands are in relatively undamaged state. There are now 10 'important bird areas', coconut crab density is high and numbers of green and hawksbill turtles are recovering. Diego Garcia atoll contains a military facility; this atoll contains one Ramsar site and several 'strict nature reserves'. Pollutant monitoring shows it to be the least polluted inhabited atoll in the world. Today, strict environmental regulations are enforced. Shoreline erosion is significant in many places. Its economic cost in the inhabited part of Diego Garcia is very high, but all islands are vulnerable. Chagos is ideally situated for several monitoring programmes, and use is increasingly being made of the archipelago for this purpose. © 2012 John Wiley and Sons, Ltd.

International audience

International audience; Oral presentation about Multi-disciplinary approach for coral reef management in Eparses Islands, SWIO in 12th International Coral Reef Symposium

Measuring recruitment patterns and mortality of corals is important for understanding mechanisms that regulate their populations and mediate species coexistence. However, there is limited data on coral recruitment dynamics in Eastern Africa and much of the WIO. We studied spatial and temporal patterns of coral recruitment and mortality in four lagoonal reefs in Kenya. The objectives of the study were to compare coral recruit densities and juvenile mortality between sites, months, seasons and years. Twelve 1m 2 permanent quadrats were sampled for the variables at each site on a monthly basis from February 2006 to June 2007. Recruit density in the protected Mombasa Marine Park was significantly higher (7.45 recruits/ m2) than the other sites that are not protected. Recruit density was higher in SEM (Southeast Monsoon) than in NEM (Northeast Monsoon) seasons in both years with 2006 having higher recruitment than 2007. A total of 16 genera were recorded with Mombasa Marine Park having the highest number of genera (13) while a non protected site Kanamai had a significantly lower density (3.52 recruits/m2) with a low genera number (8). Other non-protected sites (Nyali and Vipingo) had intermediate recruit densities. Dominating genera were Favia, Porites, Favites, Pocillopora and Pavona in their order of overall abundance. Coral genera exhibited site specific abundance and mortality rates with Pocillopora having high abundance in Nyali (3.46 recruits/m2) and high mortality rate in Vipingo (85%). Benthic cover was dominated by Hard coral, turf algae, sand and rubble in all the sites. There was significant variation in seawater temperature levels with Kanamai recording the highest mean temperature (27.830C), temperature range (12.27) and also recorded the highest maximum temperature (36.230C). These findings suggest that there is spatial and temporal variation in recruit density, genera richness and survival of coral genera. Results also indicate that area protection and sea-water temperature influence recruitment between habitats but benthic substrate characteristics influence recruitment within a habitat. Published

Mombasa Marine Park and Reserve is one of the Marine Protected Areas in Kenya established more than ten years ago. The Park is a no-take-zone, while the Reserve is a zone where regulated extractive uses such as artisanal fishing are allowed. Since the year 2004, ecological monitoring of the MPA has been going on aimed at generating information on the MPA status with a view to improve its management. Four year monitoring data (2004 to 2007) of percentage benthic cover using the Line Intercept Transect (LIT) method reveal relatively high average percentage turf could easily out compete and degrade the hard corals and sea grass beds that are important for MPA ecological and biological health status. The growth of algal turf is triggered by nutrient input mainly from land sources. It is therefore important to identify the nutrient input sources into the MPA so as to address management measures to remedy this ecological threat.

Coral settlement patterns were measured at two sites in the Mombasa Marine National Park for a 2-year period from May 2001 to February 2003. Artificial settlement tiles were deployed for approximately 3-month periods and were collected in Febru - ary, May, August and November of each year. The mean number of coral spat settled on collected tiles varied from 0.75 (± 0.79 s.d.) per tile in August 2001 to a maximum of 16.70 (± 7.53 s.d.) in November 2002, corresponding to mean densities of 8–740 m –2 . The maximum number of spat recorded on a single tile was 38 (November 2002). Although peak settlement rates were recorded in November of each year, settlement was sufficiently variable between months and years to obscure a clear seasonal cycle. Settle - ment was highest at the study site with the best water flow and exchange with the open ocean. Pocilloporids ( Pocillopora spp.) dominated settlement (76%), followed by poritids (19%), then ‘others’. Patterns suggest peak coral recruitment in September– November each year when water temperatures are increasing the fastest prior to reaching their seasonal maxima in March–April, but with substantial recruitment of pocilloporids and poritids throughout the year. Published

Eastern African coral reefs were severely impacted by the El Niño Southern Oscillation of 1997-98, with bleaching and mortality levels varying from

Coral reefs along the entire coast of Kenya suffered widespread bleaching and mortality of corals during the first half of 1998 (Wilkinson, 1998; Obura, 1999; McClanahan et al., 1999). This status report summarises findings relating specifically to coral bleaching, mortality and effects on benthic community structure. In addition, preliminary results from a number of research projects investigating different aspects of the bleaching event are reported here. In shallow waters, on a per-area basis, most of Kenya’s southern fringing reefs have lost between 66% and 80% of their live corals. Coral reefs in deeper water suffered less mortality due to lesser exposure to higher temperatures. Reefs on the northern part of the coast, influenced by cold water currents from Somalia, also suffered less mortality of corals. Coral recruitment appears to be low on Kenyan reefs except for some minor shallow patch reefs. It is likely that alterations in reef ecology due to overfishing (McClanahan & Muthiga, 1988) and consequent rapid growth of fleshy algae may have delaying effects on coral and reef recovery. Effects of the coral mortality on other components of the reef community, such as on algae, invertebrates and fish are only just beginning to be noticed, 1.5 years after the bleaching event. These components are the subject of ongoing research in an integrated study of the Mombasa Marine Park by scientists at the Kenya Marine and Fisheries Research Institute. Published

The 1997-1998 El Nino southern oscillation (ENSO) caused elevated sea temperatures that resulted in global coral bleaching. Coral reefs constitute an important biological resource in terms of their complex biodiversity and are the basis for tropical reef fisheries and marine ecotourism. They represent one of Mozambique's main coastal assets and its coastal communities and growing tourism industry rely mainly on reef-based resources. Mozambican artisanal fisheries are largely centred on reefs and are responsible for about 70% of the total catch, highlighting their importance. Most tourism similarly occurs along the coast where the best infrastructure is established, especially near the coral reefs of Pemba, Mozambique Island, the Bazaruto Archipelago, Inhaca Island and Ponta do Ouro.... Published

Annual peaks in sea temperature occur in the first half of each year, as the sun moves northwards after heating the sea-surface during the southern summer. Long term records in the central Indian Ocean indicate a distinct warming trend (Chagos, Maldives) of almost 1o C over the last 30 to 50 years, leading up to the highest recorded maximum during the El Niño Southern Oscillation in early 1998.

Kenya s coastala population is expected to exceed 2 million people by the year 2000, with an annual growth rate of 3.7%, of which a large proportion is due to migration of people from other parts of Kenya. Increasing economic activity, due to shipping, freight handling and tourism, provides a strong draw for migrant workers, as well as conditions for environmental degradation. Marine resource use is largely unregulated, and the predominant near-shore coral reef activities include subsistence and small-scale commercial fishing and tourism. coastal Published

Increased discharge of terrigenous sediments, due to changing land use practices in the Sabaki River catchment basin, has resulted in concern about the ecological health of coral reefs in the Malindi Marine National Park. A comparison of sediment influences (low, intermediate, high) and time (1980's versos the 1990's) was carried out to determine whether degradation of shallow « 5 meters at low tide) coral communities has resulted from sedimentation. Reef substrate data collected from 284 10m line transects over an eight year period (1985 to 1993) were used to test 6 commonly stated ecological predictions of sediment influence. The predictions are that under increased sedimentation or eutrophication coral reefs should be characterized by 1) increased algal cover, 2) increased soft coral and sponge cover, 3) decreased hard coral cover, 4) decreased coral richness, 5) decreased coral diversity and increased dominance, and 6) either a) decreased mean colony size due to greater sediment clearing efficiency of small corals, or b)increased mean colony size due to lower recruitment success. None of these predictions were unequivocally accepted with the exception of increased soft coral cover. Algal cover remained the same, increasing only in the control reef. Soft coral and sponge cover were higher in high-sediment reefs but only increased over time in the intermediate reef. Coral cover was similar in all reefs except at the intermediate reef, where it increased overtime in direct opposition to the prediction. Coral genera richness, diversity and dominance were predominantly similar overall reefs. Differences in genus abundances between reefs suggest a suite of sediment tolerant genera: Echinopora, Galaxea, Hydnophora, Millepora, Platygra and a suite of 'sediment-intolerant'genera: Acropora, Astreopora, Favia, Favites, Montipora, and Pocillopora. Mean coral colony size increased under higher sediment influence for 'sediment-tolerant' genera and decreased for 'sediment-intolerant' genera. Overall, though there were changes in some of the parameters listed above, no evidence for decreased diversity and hea1th of shallow sediment influenced reefs could be found for Outset of measurements. Evidence for change in the bottom dwelling community in the intermediate reef (Malindi Coral Gardens)was found, with sediment tolerant hard corals gaining in dominance and increases in soft coral cover. The lack of a strong effect is very likely due to the active protection of the Malindi reefs over the last 30years. From an ecological perspective, protection preserves the full suite of natural factors that help maintain reef productivity and diversity. The prevention of fishing has allowed normal herbivore populations to persist, actively preventing the predicted increase in algae. Increasing exploitation of reef resources in the future will necessitate management of other factors that may add further stresses-tourist damage, pollution, and varied extractive uses in the Marine Parks and Reserves reef system. Published

This report presents the findings of Wildlife Conservation International's Coral Reef Conservation Project monitoring program of Kenyan coral reefs and suggest research and management plans for the coral reefs based on the findings. Published

Background High sea surface temperatures resulted in widespread coral bleaching and mortality in Mayotte Island (northern Mozambique channel, Indian Ocean: 12.1°S, 45.1°E) in April–June 2010. Methods Twenty three representative coral genera were sampled quantitatively for size class distributions during the peak of the bleaching event to measure its impact. Results Fifty two percent of coral area was impacted, comprising 19.3% pale, 10.7% bleached, 4.8% partially dead and 17.5% recently dead. Acropora, the dominant genus, was the second most susceptible to bleaching (22%, pale and bleached) and mortality (32%, partially dead and dead), only exceeded by Pocillopora (32% and 47%, respectively). The majority of genera showed intermediate responses, and the least response was shown by Acanthastrea and Leptastrea (6% pale and bleached). A linear increase in bleaching susceptibility was found from small colonies (80 cm, 33% unaffected), across all genera surveyed. Maximum mortality in 2010 was estimated at 32% of coral area or biomass, compared to half that (16%), by colony abundance. Discussion Mayotte reefs have displayed a high level of resilience to bleaching events in 1983, 1998 and the 2010 event reported here, and experienced a further bleaching event in 2016. However, prospects for continued resilience are uncertain as multiple threats are increasing: the rate of warming experienced (0.1 °C per decade) is some two to three times less than projected warming in coming decades, the interval between severe bleaching events has declined from 16 to 6 years, and evidence of chronic mortality from local human impacts is increasing. The study produced four recommendations for reducing bias when monitoring and assessing coral bleaching: coral colony size should be measured, unaffected colonies should be included in counts, quadrats or belt transects should be used and weighting coefficients in the calculation of indices should be used with caution.

Coral reefs are arguably the most threatened marine habitat because of multiple anthropogenic stressors degrading the health and resilience of these systems. In the past 20 years there have been increasing observations of mass coral bleaching and mortality associated with increasing water temperatures in the tropics. Reefs provide ecosystem services worth billions of dollars to people living in tropical coastal areas and are the architects of one of the most beautiful structures found on earth. Conserving these habitats is paramount, and conservation planning must contend with climate change along with local and regional stressors. In this thesis Watamu Marine National Park in Kenya is used as a case study of the current challenges facing the conservation of reefs in a warming world. The Western Indian Ocean suffered dramatic bleaching during 1998, which caused the mortality of 70% of Watamu's corals. Using datasets from the 1980s to present the historical trajectory of Watamu's reef community is presented. The current ecosystem resilience is assessed to suggest how this reef will respond to future climate stress. It appears that Watamu's coral community has remained in an altered state post-1998, which, based on its past thermal stress and current coral community, should be resistant to future bleaching. Watamu's resilience and reef health is compared with other locations in the Indian Ocean, including reefs in Kenya and the Maldives that bleached in 1998 and examples from Mozambique and Sumatra of reefs with little evidence of historical thermal stress. Resilience is a multi-faceted process with different major components and numerous interacting factors, which act synergistically on the reef community. Conservation options and opportunities are discussed for the 6 locations examined, using current resilience models and theory as a framework for identifying priority actions. Local and regional-scale human impacts on shallow marine habitats during the last 50 years has been dramatic, and with global-scale climate change as an additional major threat, the next 50 years will be critical for the future of reefs. The locations visited during this study showed encouraging signs of resilience to past thermal stress, with evidence to suggest that corals are acclimatising and/or adapting to increasing water temperatures. The future of reefs in locations like Watamu is uncertain. Better understanding of reef ecology, appropriate conservation techniques and ultimately greater public concern for reefs is required to ensure that there is a future for these ecosystems in the Indian Ocean.

Stylophora pistillata is a widely used coral "lab-rat'' species with highly variable morphology and a broad biogeographic range (Red Sea to western central Pacific). Here we show, by analysing Cytochorme Oxidase I sequences, from 241 samples across this range, that this taxon in fact comprises four deeply divergent clades corresponding to the Pacific-Western Australia, Chagos-Madagascar-South Africa, Gulf of Aden-Zanzibar-Madagascar, and Red Sea-Persian/Arabian Gulf-Kenya. On the basis of the fossil record of Stylophora, these four clades diverged from one another 51.5-29.6 Mya, i.e., long before the closure of the Tethyan connection between the tropical Indo-West Pacific and Atlantic in the early Miocene (16-24 Mya) and should be recognised as four distinct species. These findings have implications for comparative ecological and/or physiological studies carried out using Stylophora pistillata as a model species, and highlight the fact that phenotypic plasticity, thought to be common in scleractinian corals, can mask significant genetic variation.

With this study we estimated the changes in colour, bleaching and mortality of coral colonies from February to December 2007, using the colour reference card method. The study was developed in the Watamu Marine Park lagoon (Kenya), bridging the local summer when seawater temperatures were highest and coral bleaching risk was at its maximum. Seven coral genera were selected, and their colour recorded using a colour reference card (Coral Watch card). Seven different scenarios of bleaching and mortality were observed, varying among the coral genera and between two species in the genus Pocillopora. Twenty percent of the colonies bleached, of which 50% died. Only 15% of the coral that did not bleach died. Branching genera had a higher bleaching incidence than massive and sub-massive genera. Pocillopora showed the highest bleaching susceptibility, followed by Acropora, and the highest level of mortality. Of the two species of Pocillopora considered in this study, P. eydouxi showed higher bleaching and mortality levels, while P. verrucosa bleached less and experienced only partial mortality. Our results evidenced different patterns of coral bleaching and mortality which were easily and clearly detected with the colour card method during both bleaching and a post-bleaching events.

Seventeen species of Acropora were studied in the Mombasa lagoon in Kenya from 2004-2005 to determine the timing and frequency of spawning, and the level of synchrony within and among different species. Spawning in this genus occurred over an extended 7 month period from October-April, with the majority of marked colonies (77%) releasing gametes between January-March in the northeast monsoon. Individual species were capable of splitspawning over 2-4 lunar months, and the length of spawning varied between species. Spawning occurred over a range of lunar phases, but predominantly in the 2 weeks following the full moon. It is evident that Acropora species in Kenya display a greater degree of spawning asynchrony compared to similar assemblages in other parts of the world. Published