1,721,089 research outputs found
Growth measurements from corals in an ocean-based nursery experiment near Sambangan Island, Indonesia, 2003-2004
No full textThis dataset contains growth measurements of corals in ocean-based nurseries. The data derives from coral growth experiments based near Sambangan Island, Indonesia, conducted from October 2003 to March 2004. In this study, the use of cages built from locally available materials in the ocean-based culture of fragments of the coral species Acropora gomezi and Pavona cactus was examined. In a first experiment, fragments were cultured without cages, within concrete frames with bamboo covers of two different mesh sizes, and within control cages at two different depths. In a second experiment, fragments were reared inside concrete frames covered with fishing net, half of which were additionally shaded with bamboo covers. Growth rates were measured every three weeks as linear increases and at the end of the experiments as increases in weight and volume. For size measurements a steel caliper (accuracy 0.1 mm) was used, the weight was measured with an electronic solar letter scale with an accuracy of 0.5 g (MAULtronic S). Volume was measured by suspending the fragments up to the base into a plastic cylinder with a ml scale (Ø 27 mm) which was filled to the rim with sea water or by measuring the water displacement in a larger beaker
Water properties measured in seawater in North Sulawesi, 2006-2007
No full textThis dataset contains measurements and estimates of sea water properties from a PhD project in North Sulawesi. The data were collected from December 2006 to July 2007 in the coral reefs around the islands Bunaken and Gangga and near the city Manado. Secchi depth was estimated by lowering a Secchi disc from a boat. Salinity was measured with a Refractometer. Tidal cycle information was taken from a tide calendar. Wind speed was estimated based on wave development. Underwater visibility was estimated by divers and water temperature was measured with a dive computer (Suunto Favor)
Solomon Islands Local Ecological Knowledge of Marine Fishes 2014-2015
No full textThis submission contains data on local ecological knowledge of marine fishes collected in Roviana Lagoon, Western Province, Solomon Islands, between 2014 and 2015. At four communities (from west to east: Ilangana, Nusa Roviana, Baraulu, and Nusa Hope)—those in the west being closer to the provincial town Munda—eight focus groups were held each, representing four age groups (13-19, 20-35, 36-55 and >55 years) divided by gender. Participants in each age group were selected by each village leadership to participate in the focus groups under the premise of being a "competent marine harvester" for their age group and gender. Participants were asked to free-list all local names of marine species (particularly fishes) known to them, thus allowing each respondent to list as many responses as they wanted. Then, they were instructed to assign the free-listed names into broader categories through pile sorting if possible, which represented local taxonomic groupings, and provide information on the characteristics underlying classification into each of the broader categories. To assess what kind of domains of knowledge respondents drew on in their classification, the descriptors used to characterize categories were assigned to one of five domains: taxonomic (e.g. if respondents used a generic term such as mara [carangids] to describe a group), appearance (i.e. for information on morphology, color or smell), behavior (e.g. schooling), habitat (e.g. deep water, seagrass), or utilitarian characteristics (e.g. bait, gear used to catch a species, or way of preparation). The data comprises two tables
Solomon Islands Local Ecological Knowledge of Marine Fishes 2014-2015, classification of characteristics
No full textThis dataset contains the different characteristics assigned to each species by the respondent groups, and the classification of each characteristic (either taxonomic, appearance, behavioral, habitat or utilitarian)
Solomon Islands Local Ecological Knowledge of Marine Fishes 2014-2015, names and characteristics per group
No full textThis dataset contains all species names listed by respondents in the different focus groups, as well as the characteristics assigned to each species when sorting them into different groups. Samples are in rows, and factors/characteristics in columns. The columns comprise a sample identifier, gender, age and community of the respective focus group, local species names, and up to seven characteristics for each species. Samples are in rows, factors/characteristics in columns
Diverse staghorn coral fauna on the mesophotic reefs of North-East Australia
Full text linkConcern for the future of reef-building corals in conditions of rising sea temperatures combined with recent technological advances has led to a renewed interest in documenting the biodiversity of mesophotic coral ecosystems (MCEs) and their potential to provide lineage continuation for coral taxa. Here, we examine species diversity of staghorn corals (genera Acropora and Isopora) in the mesophotic zone (below 30 m depth) of the Great Barrier Reef and western Coral Sea. Using specimen-based records we found 38 staghorn species in the mesophotic zone, including three species newly recorded for Australia and five species that only occurred below 30 m. Staghorn corals became scarce at depths below 50 m but were found growing in-situ to 73 m depth. Of the 76 staghorn coral species recorded for shallow waters (depth ≤ 30 m) in north-east Australia, 21% extended to mesophotic depths with a further 22% recorded only rarely to 40 m depth. Extending into the mesophotic zone provided shallow water species no significant advantage in terms of their estimated global range-size relative to species restricted to shallow waters (means 86.2 X 106 km^2 and 85.7 X 106 km^2 respectively, p = 0.98). We found four staghorn coral species at mesophotic depths on the Great Barrier Reef that were previously considered rare and endangered on the basis of their limited distribution in central Indonesia and the far western Pacific. Colonies below 40 m depth showed laterally flattened branches, light and fragile skeletal structure and increased spacing between branches and corallites. The morphological changes are discussed in relation to decreased light, water movement and down-welling coarse sediments. Staghorn corals have long been regarded as typical shallow-water genera, but here we demonstrate the significant contribution of this group to the region's mesophotic fauna and the importance of considering MCEs in reef biodiversity estimates and management
Redefining thermal regimes to design reserves for coral reefs in the face of climate change
No full textReef managers cannot fight global warming through mitigation at local scale, but they can use information on thermal patterns to plan for reserve networks that maximize the probability of persistence of their reef system. Here we assess previous methods for the design of reserves for climate change and present a new approach to prioritize areas for conservation that leverages the most desirable properties of previous approaches. The new method moves the science of reserve design for climate change a step forwards by: (1) recognizing the role of seasonal acclimation in increasing the limits of environmental tolerance of corals and ameliorating the bleaching response; (2) using the best proxy for acclimatization currently available; (3) including information from several bleaching events, which frequency is likely to increase in the future; (4) assessing relevant variability at country scales, where most management plans are carried out. We demonstrate the method in Honduras, where a reassessment of the marine spatial plan is in progress
Preserving and using germplasm and dissociated embryonic cells for conserving Caribbean and Pacific coral.
Full text linkCoral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change), not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF) of conspecific eggs using fresh (control) spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05) that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO) at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (∼5 h for one night each spawning cycle). Additionally, cryopreserved F. scutaria embryonic cells had∼50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (-196°C) storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems
A Quantitative Metric to Identify Critical Elements within Seafood Supply Networks
No full textA theoretical basis is required for comparing key features and critical elements in wild fisheries and aquaculture supply chains under a changing climate. Here we develop a new quantitative metric that is analogous to indices used to analyse food-webs and identify key species. The Supply Chain Index (SCI) identifies critical elements as those elements with large throughput rates, as well as greater connectivity. The sum of the scores for a supply chain provides a single metric that roughly captures both the resilience and connectedness of a supply chain. Standardised scores can facilitate cross-comparisons both under current conditions as well as under a changing climate. Identification of key elements along the supply chain may assist in informing adaptation strategies to reduce anticipated future risks posed by climate change. The SCI also provides information on the relative stability of different supply chains based on whether there is a fairly even spread in the individual scores of the top few key elements, compared with a more critical dependence on a few key individual supply chain elements. We use as a case study the Australian southern rock lobster Jasus edwardsii fishery, which is challenged by a number of climate change drivers such as impacts on recruitment and growth due to changes in large-scale and local oceanographic features. The SCI identifies airports, processors and Chinese consumers as the key elements in the lobster supply chain that merit attention to enhance stability and potentially enable growth. We also apply the index to an additional four real-world Australian commercial fishery and two aquaculture industry supply chains to highlight the utility of a systematic method for describing supply chains. Overall, our simple methodological approach to empirically-based supply chain research provides an objective method for comparing the resilience of supply chains and highlighting components that may be critical
Diversity among macroalgae-consuming fishes on coral reefs: a transcontinental comparison
Full text linkDespite high diversity and abundance of nominally herbivorous fishes on coral reefs, recent studies indicate that only a small subset of taxa are capable of removing dominant macroalgae once these become established. This limited functional redundancy highlights the potential vulnerability of coral reefs to disturbance and stresses the need to assess the functional role of individual species of herbivores. However, our knowledge of species-specific patterns in macroalgal consumption is limited geographically, and there is a need to determine the extent to which patterns observed in specific reefs can be generalised at larger spatial scales. In this study, video cameras were used to quantify rates of macroalgae consumption by fishes in two coral reefs located at a similar latitude in opposite sides of Australia: the Keppel Islands in the Great Barrier Reef (eastern coast) and Ningaloo Reef (western coast). The community of nominally herbivorous fish was also characterised in both systems to determine whether potential differences in the species observed feeding on macroalgae were related to spatial dissimilarities in herbivore community composition. The total number of species observed biting on the dominant brown alga Sargassum myriocystum differed dramatically among the two systems, with 23 species feeding in Ningaloo, compared with just 8 in the Keppel Islands. Strong differences were also found in the species composition and total biomass of nominally herbivorous fish, which was an order of magnitude higher in Ningaloo. However, despite such marked differences in the diversity, biomass, and community composition of resident herbivorous fishes, Sargassum consumption was dominated by only four species in both systems, with Naso unicornis and Kyphosus vaigiensis consistently emerging as dominant feeders of macroalgae
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