Rising Temperature Is a More Important Driver Than Increasing Carbon Dioxide Concentrations in the Trait Responses of Enhalus acoroides Seedlings

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Urban coral reefs: Degradation and resilience of hard coral assemblages in coastal cities of East and Southeast Asia

© 2018 The Author(s) Given predicted increases in urbanization in tropical and subtropical regions, understanding the processes shaping urban coral reefs may be essential for anticipating future conservation challenges. We used a case study approach to identify unifying patterns of urban coral reefs and clarify the effects of urbanization on hard coral assemblages. Data were compiled from 11 cities throughout East and Southeast Asia, with particular focus on Singapore, Jakarta, Hong Kong, and Naha (Okinawa). Our review highlights several key characteristics of urban coral reefs, including “reef compression” (a decline in bathymetric range with increasing turbidity and decreasing water clarity over time and relative to shore), dominance by domed coral growth forms and low reef complexity, variable city-specific inshore-offshore gradients, early declines in coral cover with recent fluctuating periods of acute impacts and rapid recovery, and colonization of urban infrastructure by hard corals. We present hypotheses for urban reef community dynamics and discuss potential of ecological engineering for corals in urban areas

Rehabilitasi Kawasan Pesisir untuk Mitigasi Perubahan Iklim: Peranan mangrove dan penurunan emisi tingkat sub-nasional

Rehabilitasi/restorasi kawasan pesisir yang melibatkan ekosistem mangrove untuk mitigasi perubahan iklim merupakan perjalanan panjang yang penuh risiko. Upaya ini memerlukan tatakelola dan kebijakan yang kuat dan menyeluruh yang melibatkan pemangku kepentingan dari tingkat nasional sampai sub-nasional. Kompleksitas kelembagaan dapat menjadi kendala birokrasi yang menghambat alur informasi dan pendanaan. Rehabilitasi/restorasi kawasan pesisir dan mangrove di dalam maupun di luar kawasan, khususnya yang terkait dengan tambak dan tanah timbul merupakan tantangan baru yang akan dihadapi dalam implementasi program ini. Karena itu perlu disederhanakan dengan mengedepankan akuntabilitas dan kredibilitas pihak yang terkai

Suppressed recovery of functionally important branching Acropora drives coral community composition changes following mass bleaching in Indonesia

Mass coral bleaching events may have disproportionate effects on branching corals, leading to coral community restructuring, reduced biodiversity, and decreased structural complexity. This affects overall reef health and resilience. Functionally important, fast-growing branching Acropora corals were a historically dominant and vital component of Indonesian reefs throughout the twentieth century, yet the genus is also one of the most vulnerable to external stressors. This study used long-term annual reef monitoring data from Indonesia’s Wakatobi Marine National Park (WMNP) to investigate the effects of a mass bleaching event in 2010 on Acropora and other branching corals, evaluate their post-disturbance recovery trajectories, and analyse shifts in coral community composition. Post-bleaching scleractinian coral cover decreased across study sites, with losses in branching corals especially evident. Long-term branching Acropora cover decreased significantly and failed to demonstrate the significant post-disturbance recovery of other branching corals (especially Porites). In areas characterised by relatively high branching Acropora cover (> 15% mean cover) prior to bleaching, long-term coral community composition changes have trended predominately towards branching and massive Porites and branching Montipora. The novelty and key contribution of this study is that results suggest suppressed recovery of Acropora in the WMNP. Contributing factors may include the Allee effect (inhibition of reproduction at low population densities), other forms of inhibited larval recruitment, direct and indirect spatial competition, and changes in the physical reef habitat. These findings have critical implications for this functionally important taxon, future reef conservation efforts, and overall reef health and resilience in the park

High diversity, but low abundance of cryptobenthic fishes on soft sediment habitats in Southeast Asia

Cryptobenthic fishes play a crucial role in marine ecosystems as trophic links between the base of the food chain and higher-level consumers. Infralittoral soft sediments are the largest marine habitat, yet little is known about fish assemblages in these ecosystems. This study investigates the cryptobenthic fish abundance and diversity on soft sediment habitats in the centre of tropical marine biodiversity. We surveyed 20 sites across three regions in Indonesia (Bali, Lembeh Strait) and the Philippines (Dauin) using Underwater Visual Surveys (UVC) and roving diver surveys. We tested the effects of depth (6 m, 16 m), benthic cover and sediment grain size characteristics on fish assemblages. Our results showed a high diversity (112 species), but low abundances (mean: 93 individuals/500 m2 ± SE: 28 ind.). Benthic cover on surveyed sites consisted for 90.1% (±SE: 0.7%) of unconsolidated sediments, which were predominantly poorly sorted (s = 0.975 f), gravelly sand. PERMANOVA analyses showed that fish assemblages and fish diversity was significantly different between regions (p < 0.001) and depth (p = 0.002). Distance based linear Models (DistLM) explained respectively 25% and 33.5% of the variation in fish assemblages and fish diversity. The high cryptobenthic fish diversity found in this study exceeds that of many coral reefs and contradicts the current view of soft sediment fish communities as depauparate ones. Our results provide valuable insights in a poorly studied marine ecosystem and call for more research in these valuable habitats

Time to stop mucking around? Impacts of underwater photography on cryptobenthic fauna found in soft sediment habitats

Scuba diving tourism is a sustainable source of income for many coastal communities, but can have negative environmental impacts if not managed effectively. Diving on soft sediment habitats, typically referred to as ‘muck diving’ is a growing multi-million dollar industry with a strong focus on photographing cryptobenthic fauna. We assessed how the environmental impacts of scuba divers are affected by the activity they are engaged in while diving and the habitat they dive in. To do this, we observed 66 divers on coral reefs and soft sediment habitats in Indonesia and the Philippines. We found diver activity, specifically interacting with and photographing fauna, causes greater environmental disturbances than effects caused by certification level, gender, dive experience or age. Divers touched the substrate more often while diving on soft sediment habitats than on coral reefs, but this did not result in greater environmental damage on soft sediment sites. Dive rs had a higher impact on the substrate and touch animals more frequently when observing or photographing cryptobenthic fauna. When using dSLR-cameras, divers spent up to five times longer interacting with fauna. With the unknown, long-term impacts on cryptobenthic fauna or soft sediment habitats, and the increasing popularity of underwater photography, we argue for the introduction of a muck diving code of conduct

Evaluating sustainable development policies in rural coastal economies

Sustainable development (SD) policies targeting marine economicsectors, designed to alleviate poverty and conserve marine ecosystems,have proliferated in recent years. Many developingcountries are providing poor fishing households with new fishingboats (fishing capital) that can be used further offshore as a meansto improve incomes and relieve fishing pressure on nearshore fishstocks. These kinds of policies are a marine variant of traditionalSD policies focused on agriculture. Here, we evaluate ex anteeconomic and environmental impacts of provisions of fishing andagricultural capital, with and without enforcement of fishingregulations that prohibit the use of larger vessels in nearshorehabitats. Combining methods from development economics, naturalresource economics, and marine ecology, we use a uniquedataset and modeling framework to account for linkages betweenhouseholds, business sectors, markets, and local fish stocks. Weshow that the policies investing capital in local marine fisheries oragricultural sectors achieve income gains for targeted households,but knock-on effects lead to increased harvest of nearshore fish,making them unlikely to achieve conservation objectives in ruralcoastal economies. However, pairing an agriculture stimulus withincreasing enforcement of existing fisheries’ regulations may leadto a win–win situation. While marine-based policies could be animportant tool to achieve two of the United Nations SustainableDevelopment Goals (alleviate poverty and protect vulnerable marineresources), their success is by no means assured and requiresconsideration of land and marine socioeconomic linkages inherentin rural economies