Mueller B.,Netherlands Institute for Sea Research |
Mueller B.,University Utrecht |
Van Der Zande R.M.,University Utrecht |
Van Leent P.J.M.,University Utrecht |
And 4 more authors.
Bulletin of Marine Science | Year: 2014
Dissolved organic carbon (DOC) release of three algal and two coral species was determined at three light intensities (0, 30-80, and 200-400 μmol photons m-2 s-1) in ex situ incubations to quantify the effect of light availability on DOC release by reef primary producers. DOC release of three additional algal species was quantified at the highest light intensity only to infer inter-Specific differences in DOC release. For species tested at differentlight intensities, highest net release of DOC occurred under full light (200-400 μmol photons m-2 s-1). DOC released by benthic algae under full light differed (up to 16-Fold) among species, whereas DOC release by scleractinian corals was minimal (Orbicella annularis Ellis and Solander, 1786) or net uptake occurred (Madracis mirabilis Duchassaing and Michelotti, 1860) independent of light availability. DOC concentrations and light intensities were also measured in situ near seven benthic primary producers, sediment, and in the water column at nine sites evenly distributed along the leeward coast of Curaçao. In situ DOC concentrations increased with light availability, although the magnitude of this positive effect differed among species and bottom types tested. In situ DOC concentrations were on average lower in November-December [87 (SD 45) μmol L-1] compared to May-June [186 (SD 136) μmol L-1], which can, at least partly, be explained by the lower light availability in the latter period. Our results suggest that DOC release by Caribbean benthic primary producers varies considerably among species and depends on light availability in reef algae. © 2014 Rosenstiel School of Marine & Atmospheric Science of the University of Miami. Source
News Article | November 11, 2015
Can beauty be quantified? A study revealed that scientists can measure coral reef health through an analysis of the aesthetic quality of reefs or how beautiful they look. Art historians and philosophers from all over the world and from different eras have been looking for ubiquitous and valid criteria that can measure ugliness and beauty. Now, a multidisciplinary team of experts was able to develop a new computational method that can assess what people regard as aesthetically pleasing. Their first application is the assessment of coral reefs. The study, which was issued in the journal[pdf] Peerj, evaluated images of coral reefs and 109 aesthetic features present in the images. These features included relative color, size and location of noticeable objects in the image, as well as color intensity, diversity and texture of the image. Through specifically-designed software, researchers analyzed about 2,000 images of coral reefs and compared them to the customary monitoring procedure known as the National Center for Ecological Analysis and Synthesis (NCEAS) score. The NCEAS score describes the increasing impact of humans on reefs. Researchers then found links between the scores of random images of coral reefs and their corresponding reef ecosystem. Andreas Haas, the study's lead author and a postdoctoral scholar from San Diego State University, said their findings suggest that how people perceive beauty is well-aligned with thriving and healthy ecosystems. Haas explained that the perception of beauty is not entirely subjective, and that it is affected by natural components that show degraded or healthy conditions of an object. He added that measuring the visual features of reef ecosystems is a cost-effective technique that targets their socioeconomic value which is their natural beauty. Sue Sargent, a marine biologist, said previous methods for coral reef health assessment relied on researchers who were highly-trained for observation, but now that a new method has been developed, ordinary citizens could also perform reef monitoring through their computers. It could free up important research funding, she said. "Many animals live in and around coral reefs, so it's crucial that we protect them from further harm," added Sargent. The study is a collaborative effort between SDSU, the Getty Research Institute, and the Scripps Institution of Oceanography, Caribbean Research and Management of Biodiversity (CARMABI), the Université de Paris-Saclay, the College of Charleston, and the University of Amsterdam. Meanwhile, anyone can assess the aesthetic score of images by uploading them on a website created by the researchers.
Bongaerts P.,University of Queensland |
Frade P.R.,CARMABI |
Frade P.R.,University of Vienna |
Ogier J.J.,Netherlands Institute for Sea Research |
And 9 more authors.
BMC Evolutionary Biology | Year: 2013
Background: Scleractinian corals and their algal endosymbionts (genus Symbiodinium) exhibit distinct bathymetric distributions on coral reefs. Yet, few studies have assessed the evolutionary context of these ecological distributions by exploring the genetic diversity of closely related coral species and their associated Symbiodinium over large depth ranges. Here we assess the distribution and genetic diversity of five agariciid coral species (Agaricia humilis, A. agaricites, A. lamarcki, A. grahamae, and Helioseris cucullata) and their algal endosymbionts (Symbiodinium) across a large depth gradient (2-60 m) covering shallow to mesophotic depths on a Caribbean reef. Results: The five agariciid species exhibited distinct depth distributions, and dominant Symbiodinium associations were found to be species-specific, with each of the agariciid species harbouring a distinct ITS2-DGGE profile (except for a shared profile between A. lamarcki and A. grahamae). Only A. lamarcki harboured different Symbiodinium types across its depth distribution (i.e. exhibited symbiont zonation). Phylogenetic analysis (atp6) of the coral hosts demonstrated a division of the Agaricia genus into two major lineages that correspond to their bathymetric distribution ("shallow": A. humilis / A. agaricites and "deep": A. lamarcki / A. grahamae), highlighting the role of depth-related factors in the diversification of these congeneric agariciid species. The divergence between "shallow" and "deep" host species was reflected in the relatedness of the associated Symbiodinium (with A. lamarcki and A. grahamae sharing an identical Symbiodinium profile, and A. humilis and A. agaricites harbouring a related ITS2 sequence in their Symbiodinium profiles), corroborating the notion that brooding corals and their Symbiodinium are engaged in coevolutionary processes. Conclusions: Our findings support the hypothesis that the depth-related environmental gradient on reefs has played an important role in the diversification of the genus Agaricia and their associated Symbiodinium, resulting in a genetic segregation between coral host-symbiont communities at shallow and mesophotic depths. © 2013 Bongaerts et al.; licensee BioMed Central Ltd. Source
Agency: Cordis | Branch: FP7 | Program: CP-IP-SICA | Phase: ENV.2009.2.2.1.5 | Award Amount: 8.58M | Year: 2010
The Future of Reefs in a Changing Environment (FORCE) Project partners a multi-disciplinary team of researchers from Europe and the Caribbean to enhance the scientific basis for managing coral reefs in an era of rapid climate change and unprecedented human pressure on coastal resources. The overall aim is to provide coral reef managers with a toolbox of sustainable management practices that minimise the loss of coral reef health and biodiversity. An ecosystem approach is taken that explicitly links the health of the ecosystem with the livelihoods of dependent communities, and identifies the governance structures needed to implement sustainable development. Project outcomes are reached in four steps. First, a series of experimental, observational and modelling studies are carried out to understand both the ultimate and proximate drivers of reef health and therefore identify the chief causes of reef degradation. Second, the project assembles a toolbox of management measures and extends their scope where new research can significantly improve their efficacy. Examples include the first coral-friendly fisheries policies that balance herbivore extraction against the needs of the ecosystem, the incorporation of coral bleaching into marine reserve design, and creation of livelihood enhancement and diversification strategies to reduce fisheries capacity. Third, focus groups and ecological models are used to determine the efficacy of management tools and the governance constraints to their implementation. This step impacts practical reef management by identifying the tools most suited to solving a particular management problem but also benefits high-level policy-makers by highlighting the governance reform needed to implement such tools effectively. Lastly, the exploitation and dissemination of results benefits from continual engagement with practitioners. The project will play an important and measurable role in helping communities adapt to climate change in the Caribbean.
Mueller B.,Netherlands Institute for Sea Research |
Mueller B.,University Utrecht |
De Goeij J.M.,CARMABI |
De Goeij J.M.,University of Amsterdam |
And 6 more authors.
PLoS ONE | Year: 2014
Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC) as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC) in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean±SD; 13±17 μmol L-1) and 76% (C. delitrix; 10±12 μmol L-1) of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton) despite high bacteria retention efficiency (72±15% and 87±10%). Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461±773 and 354±562 mmol C h-1 respectively. Bacteria removal was 1.8±0.9×1010 and 1.7±0.6×1010 cells h-1, which equals a carbon uptake of 46.0±21.2 and 42.5±14.0 μmol C h-1 respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC) on reefs as a result of the ongoing coral-algal phase shift. © 2014 Mueller et al. Source