A review of a decade of lessons from one of the world’s largest MPAs: conservation gains and key challenges

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordtribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos Archipelago, interspersed with and surrounded by deep oceanic waters. Islands around the atoll rims serve as nesting grounds for sea birds. Extensive and diverse shallow and mesophotic reef habitats provide essential habitat and feeding grounds for all marine life, and the absence of local human impacts may improve recovery after coral bleaching events. Census data have shown recent increases in the abundance of sea turtles, high numbers of nesting seabirds and high fsh abundance, at least some of which is linked to the lack of recent harvesting. For example, across the archipelago the annual number of green turtle clutches (Chelonia mydas) is~20,500 and increasing and the number of seabirds is ~1 million. Animal tracking studies have shown that some taxa breed and/or forage consistently within the MPA (e.g. some reef fshes, elasmobranchs and seabirds), suggesting the MPA has the potential to provide long-term protection. In contrast, post-nesting green turtles travel up to 4000 km to distant foraging sites, so the protected beaches in the Chagos Archipelago provide a nesting sanctuary for individuals that forage across an ocean basin and several geopolitical borders. Surveys using divers and underwater video systems show high habitat diversity and abundant marine life on all trophic levels. For example, coral cover can be as high as 40–50%. Ecological studies are shedding light on how remote ecosystems function, connect to each other and respond to climate-driven stressors compared to other locations that are more locally impacted. However, important threats to this MPA have been identifed, particularly global heating events, and Illegal, Unreported and Unregulated (IUU) fshing activity, which considerably impact both reef and pelagic fshes.Bertarelli Foundatio

Seasonal radiocarbon and oxygen isotopes in a Galapagos coral: Calibration with climate indices

We present seasonal Δ14C and δ18O measurements from a Galapagos coral sequence that grew during the early 20th century. Our results show that both Δ14C and δ18O values are correlated with sea surface temperature in the Niño 3.4 region and are indicators of El Niño-Southern Oscillation. There is a significant inverse correlation between Δ14C and δ18O values when Δ14C is lagged by ~2 months, indicating that sea surface temperature changes precede upwelling changes at this eastern equatorial location. We find that cold season low- Δ14C values were higher after the Pacific Decadal Oscillation (PDO) changed from a positive to a negative phase. Cold season high-δ18O values were significantly higher after the PDO shift as well. These findings suggest that there are two sources of low-Δ14C waters that upwell at the Galapagos, Subantarctic Mode Water and shallow overturning water from the subpolar North Pacific. © 2014. American Geophysical Union. All Rights Reserved

Remote reef cryptobenthic diversity: integrating autonomous reef monitoring structures and in situ environmental parameters

Coral reef sessile organisms inhabiting cryptic spaces and cavities of the reef matrix perform vital and varied functional roles but are often understudied in comparison to those on exposed surfaces. Here, we assess the composition of cryptobenthic taxa from three remote tropical reef sites (Central Indian Ocean) alongside a suite of&nbsp;in situ&nbsp;environmental parameters to determine if, or how, significant patterns of diversity are shaped by local abiotic factors. To achieve this, we carried out a point-count analysis of autonomous reef monitoring structure (ARMS) plate images and employed&nbsp;in situ&nbsp;instrumentation to recover long-term (12 months) profiles of flow velocity, wave heights, temperature, dissolved oxygen, and salinity, and short-term (3 weeks) profiles of light and pH. We recovered distinct environmental profiles between sampling sites and observed that ocean-facing reefs experienced frequent but short-lived cooling internal wave events and that these were key in shaping&nbsp;in situ&nbsp;temperature variability. By comparing temperature and wave height profiles recovered using&nbsp;in situ&nbsp;loggers with&nbsp;ex situ&nbsp;models, we discovered that global satellite products either failed to recover site-specific profiles or both over- and underestimated actual&nbsp;in situ&nbsp;conditions. We found that site choice and recruitment plate face (top or bottom) significantly impacted the percentage cover of bryozoans, gastropods, soft and calcified tube worms, as well as crustose coralline algae (CCA) and fleshy red, brown, and green encrusting macroalgae on ARMS. We observed significant correlations between the abundance of bryozoans, CCA, and colonial tunicates with lower mean temperature and higher mean dissolved oxygen profiles observed across sites. Red and brown encrusting macroalgae abundance correlated significantly with medium-to-high flow velocities and wave height profiles, as well as higher pH and dissolved oxygen. This study provides the first insight into cryptobenthic communities in the Chagos Archipelago marine-protected area and adds to our limited understanding of tropical reef sessile communities and their associations with environmental parameters in this region. With climate change accelerating the decline of reef ecosystems, integrating analyses of cryptobenthic organisms and&nbsp;in situ&nbsp;physicochemical factors are needed to understand how reef communities, if any, may withstand the impacts of climate change.</p

A review of a decade of lessons from one of the world's largest MPAs: conservation gains and key challenges

Given the recent trend towards establishing very large marine protected areas (MPAs) and the high potential of these to contribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos Archipelago, interspersed with and surrounded by deep oceanic waters. Islands around the atoll rims serve as nesting grounds for sea birds. Extensive and diverse shallow and mesophotic reef habitats provide essential habitat and feeding grounds for all marine life, and the absence of local human impacts may improve recovery after coral bleaching events. Census data have shown recent increases in the abundance of sea turtles, high numbers of nesting seabirds and high fish abundance, at least some of which is linked to the lack of recent harvesting. For example, across the archipelago the annual number of green turtle clutches (Chelonia mydas) is ~ 20,500 and increasing and the number of seabirds is ~ 1 million. Animal tracking studies have shown that some taxa breed and/or forage consistently within the MPA (e.g. some reef fishes, elasmobranchs and seabirds), suggesting the MPA has the potential to provide long-term protection. In contrast, post-nesting green turtles travel up to 4000 km to distant foraging sites, so the protected beaches in the Chagos Archipelago provide a nesting sanctuary for individuals that forage across an ocean basin and several geopolitical borders. Surveys using divers and underwater video systems show high habitat diversity and abundant marine life on all trophic levels. For example, coral cover can be as high as 40–50%. Ecological studies are shedding light on how remote ecosystems function, connect to each other and respond to climate-driven stressors compared to other locations that are more locally impacted. However, important threats to this MPA have been identified, particularly global heating events, and Illegal, Unreported and Unregulated (IUU) fishing activity, which considerably impact both reef and pelagic fishes