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Carroll Vinther posted an update 3 weeks, 4 days ago
The healthy status of corals in the isolated atolls of the central South China Sea (SCS) remains unclear. Symbiodiniaceae density (SD) can effectively reflect the thermal tolerance and health of hard corals. Here, the SDs of 238 samples from the Huangyan Atoll (HA) were analyzed. The results revealed significantly intergeneric and geomorphological differences in SD. Intergeneric variation may reflect that corals with high SD have stronger thermal tolerance. Geomorphic analysis showed that the SDs at the outer reef slope were higher than in the lagoon. Hydrodynamics and sea surface temperature were likely the main influencing factors. Most notably, corals in SCS HA had higher SDs than those at neighboring reefs, indicating that their thermal tolerance were strong, which may be related to HA’s local upwelling. These results suggest that the HA has the potential to serve as a refuge for corals, but increasing human disturbance limit its function.In marine settings, anthropogenic disturbances and climate change increase the rate of biological invasions. Predicting still undescribed invasive alien species (IAS) is needed for preparing timely management responses. We tested a strategy for discovering new potential IAS using DNA in a trans-equatorial expedition onboard RV Polarstern. During one-month travel, species inside ballast water experienced oxygen depletion, warming, darkness and ammonium stress. Many organisms died but several phytoplankton and zooplankton survivors resisted and were detected through a robust combination of individual sampling, DNA barcoding and metabarcoding, new in ballast water studies. Ammonium was identified as an important influential factor to explain diversity changes in phytoplankton and zooplankton. Some species reproduced until the end of the travel. These species tolerant to travel stress could be targeted as potential IAS and prioritized for designing control measures. Introducing resistance to travel stress in biosecurity risk analysis would be recommended.The concentrations of Platinum (Pt), Rhodium (Rh) and Palladium (Pd) were evaluated from a highly impacted estuary in Brazil influenced by industrial pole, highway traffic and sewage outfall. The Santos-São Vicente region presents important economic activities derived from a largest harbor of Latin America and an industrial pole surrounded by intensive highway traffic. Values of Rh varied from 0.08 to 1.7 ng g-1 with highest values at stations impacted by domestic waste. Pt ranged from 0.15 to 40.3 ng g-1 with highest concentrations located close to the ferryboat traffic. Pd levels varied from 1.05 to 22.0 ng g-1 with values >5 ng g-1 in 50% of the stations. The spatial distribution of PGEs was not always directly associated with muddy sediments, because high PGE levels found even in sandy sediments. Pollution indexes, including anthropogenic factor (AF), geoaccumulation index (Igeo), Enrichment factor (EF), and Pollution Load Index (PLI) were used for evaluating contaminant potential. Based on EF, Igeo, and PLI, 50% of samples of the sediments from Santos-São Vicente Estuarine System (SSV) were classified with significant to strong PGE contamination. All stations on the Santos Channel (SC), São Vicente Channel (SVC) and Bertioga Channel (BC) had AF higher than 80% in at least one of PGE elements, as showed in station 2A, which presented AF less then 50% for Rh and Pd and 86% for Pt. Despite high anthropogenic enrichment, no correlations among PGE elements were observed in surface sediments. Only two stations presented Pd/Pt, Pt/Rh, and Pd/Rh typical ratios of auto catalyst (st. 14 and Piaçaguera) both located in the vicinity of highways. This could be due to the PGE deposition process in road dust, soil, and water as well as the biogeochemical cycling of PGEs involving organic metallic and inorganic complexes formed in the estuarine and seawaters.We evaluated the resilience of the zooplankton community to the Deepwater Horizon oil spill in the northeast Gulf of Mexico, by assessing abundance, biomass, spatial distribution, species composition, and diversity indices during spring, summer, and winter, May 2010 to August 2014. SEAMAP samples collected between spring and summer 2005-2009 were analyzed as a baseline. Our results did not indicate that there was a long-term impact from the oil spill, but did demonstrate that environmental variability and riverine processes strongly governed zooplankton community dynamics. Zooplankton abundances during the oil spill (spring 2010) were not significantly different from abundances during spring 2011 and 2012. Summer 2010 abundances were the highest observed for the 2005 to 2014 period, due to high river discharge, high chlorophyll, and aggregation in eddies. High densities of the dinoflagellate, Noctiluca, during the oil spill, and the copepod, Centropages velificatus, and larvaceans in all years, suggest that these taxa warrant further investigation. Ecosystem connectivity (zooplankton transport by currents into the oil spill region), high fecundity, relatively short generation times, and refugia in deeper depths are key factors in zooplankton resilience to major perturbations. This study serves as a baseline for assessment of future impacts to this system.The tropical waters of the Northern Arabian Gulf have a long history of maritime resource richness. High levels of biodiversity result from the complex matrix of coastal habitats, coral reefs and sea grass beds that characterise the region. Insight into the ongoing health of such habitats and the broader Kuwait maritime environment can be gauged by the status of indicator species found within these habitats. learn more Here we review information on the occurrence, distribution and threats to key marine habitats and associated indicator species to provide an updated assessment of the state of the Kuwait’s marine biodiversity. Critical evaluation of historic data highlights knowledge gaps needed inform the focus of future monitoring and conservation efforts. This assessment is designed to evaluate performance against environmental policy commitments, while providing a solid foundation for the design of comprehensive marine ecosystem management strategies.