Integrating structure-from-motion photogrammetry with geospatial software as a novel technique for quantifying 3D ecological characteristics of coral reefs

PeerJ, Journal Year: 2015, Volume and Issue: 3, P. e1077 - e1077

Published: July 7, 2015

The structural complexity of coral reefs plays a major role in the biodiversity, productivity, and overall functionality reef ecosystems. Conventional metrics with 2-dimensional properties are inadequate for characterization complexity. A 3-dimensional (3D) approach can better quantify topography, rugosity other characteristics that play an important ecology communities. Structure-from-Motion (SfM) is emerging low-cost photogrammetric method high-resolution 3D topographic reconstruction. This study utilized SfM reconstruction software tools to create textured mesh models at French Frigate Shoals, atoll Northwestern Hawaiian Islands. reconstructed orthophoto digital elevation model were then integrated geospatial order pertaining resulting data provided physical colonies combined live cover accurately characterize as living structure. structure be physiological ecological parameters future research develop reliable ecosystem improve capacity monitor changes health function

Language: Английский

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Gene expression under chronic heat stress in populations of the mustard hill coral (Porites astreoides) from different thermal environments

Molecular Ecology, Journal Year: 2013, Volume and Issue: 22(16), P. 4322 - 4334

Published: July 30, 2013

Abstract Recent evidence suggests that corals can acclimatize or adapt to local stress factors through differential regulation of their gene expression. Profiling expression in from diverse environments elucidate the physiological processes may be responsible for maximizing coral fitness natural habitat and lead a better understanding coral's capacity survive effects global climate change. In an accompanying paper, we show P orites astreoides thermally different reef habitats exhibit distinct responses when exposed 6 weeks chronic temperature common garden experiment. Here, describe profiles obtained same panel 9 previously reported 10 novel candidate response genes identified pilot RNA ‐Seq The strongest change was observed potentially involved calcification, SLC 26, member solute carrier family 26 anion exchangers, which down‐regulated by 92‐fold bleached relative controls. most notable signature divergence between populations constitutive up‐regulation metabolic warmer inshore location, including gluconeogenesis enzymes pyruvate carboxylase phosphoenolpyruvate carboxykinase lipid beta‐oxidation enzyme acyl‐ C o A dehydrogenase. Our observations highlight several molecular pathways were not implicated suggest host management energy budgets might play adaptive role holobiont thermotolerance.

Language: Английский

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Life histories predict coral community disassembly under multiple stressors

Global Change Biology, Journal Year: 2013, Volume and Issue: 19(6), P. 1930 - 1940

Published: March 5, 2013

Abstract Climate change is reshaping biological communities against a background of existing human pressure. Evaluating the impacts multiple stressors on community dynamics can be particularly challenging in species‐rich ecosystems, such as coral reefs. Here, we investigate whether life‐history strategies and cotolerance to different predict responses fishing temperature‐driven bleaching using 20‐year time series assemblages Kenya. We found that initial composition taxa largely determined loss. Prior 1998 event, within no‐take marine reserves were composed three distinct life histories – competitive, stress‐tolerant weedy– exhibited strong declines following with limited subsequent recovery. In contrast, fished reefs had lower cover, fewer genera weedy corals less affected by over long term. Despite these general patterns, evidence for variable their sensitivities bleaching. Overall, have reduced diversity led altered ‘survivor’ species histories. Our findings are consistent expectations climate interacting pressure will result loss critical reef habitat.

Language: Английский

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Coral-the world's most diverse symbiotic ecosystem

Molecular Ecology, Journal Year: 2015, Volume and Issue: 24(21), P. 5330 - 5347

Published: Sept. 28, 2015

Zooxanthellate corals (i.e. those harbouring Symbiodinium) are the main builders of world's shallow-water marine coral reefs. They represent intimate diverse symbioses between animals, single-celled photosynthetic dinoflagellates (Symbiodinium spp.), other microscopic eukaryotes, prokaryotes and viruses. Crabs crustaceans, worms, sponges, bivalves hydrozoans, fishes, sea urchins, octopuses stars itinerant members these 'rainforests sea'. This review focuses on biodiversity scleractinian animals their best studied epi- endosymbionts. In relation to coral-associated species diversity, Symbiodinium internal transcribed spacer region sequence types tally 10(2) -10(3) or up ~15 different operational taxonomic units (OTUs, putative at 97% identity level; this cut-off was chosen based intragenomic diversity observed in monoclonal cultures) (mostly bacterial) total -10(4) OTUs. We analysed all publically accessible 16S rRNA gene data found Gammaproteobacteria were extremely abundant, followed by Alphaproteobacteria. Notably, Archaea poorly represented 'unassigned OTUs' abundant generated high-throughput DNA sequencing studies corals. outline compare model systems that could be used future holobiont. our directions, we recommend a global sampling effort including substantial attention being paid method tissue acquisition, which compartments (mucus, tissue, skeleton) explore, broadening holobiont considered linking with functional investigations.

Language: Английский

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Incorporating adaptive responses into future projections of coral bleaching

Global Change Biology, Journal Year: 2013, Volume and Issue: 20(1), P. 125 - 139

Published: Sept. 14, 2013

Climate warming threatens to increase mass coral bleaching events, and several studies have projected the demise of tropical reefs this century. However, recent evidence indicates corals may be able respond thermal stress though adaptive processes (e.g., genetic adaptation, acclimatization, symbiont shuffling). How these mechanisms might influence warming-induced remains largely unknown. This study compared how different could affect projections. We used latest bias-corrected global sea surface temperature (SST) output from NOAA/GFDL Earth System Model 2 (ESM2M) for preindustrial period through 2100 project trajectories. Initial results showed that, in absence processes, application a climatology NOAA Coral Reef Watch prediction method overpredicts present-day frequency. suggests that already responded adaptively some over industrial period. then modified so threshold either permanently increased response history simulating directional selection) or temporarily 2-10 years event A changes relative preceding 60 reduced frequency events by 20-80% with 'no response' model 2100, depending on emissions scenario. When both types responses were applied, up 14% more reef cells avoided high-frequency 2100. temporary increases thresholds alone only delayed occurrence ca. 10 all but lowest Future research should test rate limit species across latitudes ocean basins determine if much can increasing stress.

Language: Английский

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Endosymbiotic flexibility associates with environmental sensitivity in scleractinian corals

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2012, Volume and Issue: 279(1746), P. 4352 - 4361

Published: Aug. 29, 2012

Flexibility in biological systems is seen as an important driver of macro-ecosystem function and stability. Spatially constrained endosymbiotic settings, however, are less studied, although environmental thresholds symbiotic corals linked to the their dinoflagellate communities. Symbiotic flexibility a hypothesized mechanism that may exploit adapt climate change. This study explores coral– Symbiodinium symbiosis through quantification ITS2 sequence assemblages range coral species genera. Sequence expressed index incorporating phylogenetic divergence relative abundance sequences recovered from host. comparative analysis reveals profound differences for , thereby classifying generalists or specifists. Generalists such Acropora Pocillopora exhibit high intra- inter-species some most environmentally sensitive corals. Conversely, specifists massive Porites colonies low flexibility, harbour taxonomically narrow assemblages, resistant Collectively, these findings challenge paradigm enhances holobiont resilience. underscores need deeper examination extent duration functional benefits associated with diversity under stress.

Language: Английский

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Exploring the Symbiodinium rare biosphere provides evidence for symbiont switching in reef-building corals

The ISME Journal, Journal Year: 2016, Volume and Issue: 10(11), P. 2693 - 2701

Published: April 19, 2016

Abstract Reef-building corals possess a range of acclimatisation and adaptation mechanisms to respond seawater temperature increases. In some corals, thermal tolerance increases through community composition changes their dinoflagellate endosymbionts (Symbiodinium spp.), but this mechanism is believed be limited the Symbiodinium types already present in coral tissue acquired during early life stages. Compelling evidence for symbiont switching, that is, acquisition novel from environment, by adult colonies, currently lacking. Using deep sequencing analysis rDNA internal transcribed spacer 2 (ITS2) PCR amplicons two pocilloporid species, we show consistent with de novo environment following consecutive bleaching events. Most these newly detected symbionts remained rare biosphere (background occurring below 1% relative abundance), one type reached abundance ~33%. Two belong thermally resistant clade D, suggesting switching may have been driven Our results are particularly important given maternal mode transmission study which generally high specificity. These findings will cause paradigm shift our understanding coral-Symbiodinium symbiosis flexibility environmental corals.

Language: Английский

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Shift from coral to macroalgae dominance on a volcanically acidified reef

Nature Climate Change, Journal Year: 2015, Volume and Issue: 5(12), P. 1083 - 1088

Published: Aug. 3, 2015

Language: Английский

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Changing geo‐ecological functions of coral reefs in the Anthropocene

Functional Ecology, Journal Year: 2018, Volume and Issue: 33(6), P. 976 - 988

Published: Nov. 23, 2018

Abstract The ecology of many coral reefs has changed markedly over recent decades in response to various combinations local and global stressors. These ecological changes have important implications for the abundance taxa that regulate production erosion skeletal carbonates, thus geo‐ecological functions provide, including reef framework sediment generation, maintenance habitat complexity growth potential. functional attributes underpin ecosystem goods services provide society. Rapidly changing conditions Anthropocene are likely significantly impact capacity sustain these functions. Although footprint disturbance will be expressed differently across ecoregions habitats, end point may broadly similar: (a) progressively shifting towards net neutral or negative carbonate budget states; (b) becoming structurally flatter; (c) having lower vertical rates. It is also a progressive depth‐homogenisation occur terms processes. defined by an increasing disconnect between processes drive on surface, geological outcome production, is, accumulation underlying structure. Reef structures become increasingly relict senescent features, which reduce generation rates, limit potential accrete vertically at rates can track rising sea levels. In absence pervasive stressors, recovery degraded communities been observed, resulting high net‐positive budgets being regained. However, frequency intensity climate‐driven bleaching events predicted increase next decades. This would spatial disturbances exacerbate magnitude described here, limiting maintain their enforcement effective marine protection benefits geographic isolation favourable environmental (“refugia” sites) offer hope more optimistic futures some locations. A >plain language summary available this article.

Language: Английский

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Standardized short‐term acute heat stress assays resolve historical differences in coral thermotolerance across microhabitat reef sites

Global Change Biology, Journal Year: 2020, Volume and Issue: 26(8), P. 4328 - 4343

Published: June 21, 2020

Abstract Coral bleaching is one of the main drivers reef degradation. Most corals bleach and suffer mortality at just 1–2°C above their maximum monthly mean temperatures, but some species genotypes resist or recover better than others. Here, we conducted a series 18‐hr short‐term acute heat stress assays side‐by‐side with 21‐day long‐term experiment to assess ability both approaches resolve coral thermotolerance differences reflective in situ temperature thresholds. Using suite physiological parameters (photosynthetic efficiency, whitening, chlorophyll , host protein, algal symbiont counts, type association), assessed susceptibility Stylophora pistillata colonies from windward/exposed leeward/protected sites nearshore central Red Sea, which had previously shown differential during natural event. Photosynthetic efficiency was most indicative expected higher thermal tolerance protected site, denoted by an increased retention dark‐adapted quantum yields temperatures. These were resolved using experimental setups, as corroborated positive linear relationship, not observed for other parameters. Notably, per‐colony (genotype) that may have been masked acclimation effects experiment. our newly developed portable system termed Bleaching Automated Stress System (CBASS), thus highlight potential mobile, standardized fine‐scale thermotolerance. Accordingly, such be suitable large‐scale determination complement existing identify resilient genotypes/reefs downstream examination prioritization conservation/restoration. Development framework consistent recommendations National Academy Sciences Reef Restoration Adaptation Program committees new intervention restoration strategies.

Language: Английский

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