Fine-scale genetic structure in the surface brooding Caribbean octocoral,Antillogorgia elisabethae

Larval dispersal is a critical component of marine species’ life histories because it controls their population dynamics. Dispersal distance can be inferred by the presence and scale of spatial genetic structure (SGS). The larvae of Antillogorgia elisabethae, a surface brooding Caribbean octocoral, have been observed to settle within meters of maternal colonies, although many disperse over greater distances. Using a spatially hierarchical sampling design, A. elisabethae recruits were collected from a site off the coast of Great Abaco, The Bahamas, in June of 2009–2011. Seven microsatellite loci were used to determine whether genetic structure was present among recruits on scales of <1 m to 10s of meters. Multilocus genotypes were autocorrelated within spatial distance classes using Moran’s I coefficient as an estimate of genetic similarity, and Rousset’s genetic distance (â). Genetic structure was present on a scale of <10 m in 2010, but not in the other 2 years, suggesting that larval dispersal was more localized in 2010. Moran’s I coefficients were positive and significant for 0–1, 1–2 and 2–5 m classes in 2010, and the average genetic distance (â) among recruits in the 0–1 m class was significantly lower than the other classes. Autocorrelograms suggested that genetic patch sizes were 7.5 m in 2010, and 20 m in 2009 and 2011. Differences in the SGS of recruits between years might reflect temporal variation in temperature, wind and/or current speeds affecting larval dispersal, or variation in reproduction at the site.     

Harnessing the potential of integrated systematics for conservation of taxonomically complex,megadiverse plant groups

The value of natural history collections for conservation science research is increasingly recognized, despite their well-documented limitations in terms of taxonomic, geographic, and temporal coverage. Specimen-based analyses are particularly important for tropical plant groups for which field observations are scarce and potentially unreliable due to high levels of diversity-amplifying identification challenges. Specimen databases curated by specialists are rich sources of authoritatively identified, georeferenced occurrence data, and such data are urgently needed for large genera. We compared entries in a monographic database for the large Neotropical genus Myrcia in 2007 and 2017. We classified and quantified differences in specimen records over this decade and determined the potential impact of these changes on conservation assessments. We distinguished misidentifications from changes due to taxonomic remodeling and considered the effects of adding specimens and georeferences. We calculated the potential impact of each change on estimates of extent of occurrence (EOO), the most frequently used metric in extinction-risk assessments of tropical plants. We examined whether particular specimen changes were associated with species for which changes in EOO over the decade were large enough to change their conservation category. Corrections to specimens previously misidentified or lacking georeferences were overrepresented in such species, whereas changes associated with taxonomic remodeling (lumping and splitting) were underrepresented. Among species present in both years, transitions to less threatened status outnumbered those to more threatened (8% vs 3%, respectively). Species previously deemed data deficient transitioned to threatened status more often than to not threatened (10% vs 7%, respectively). Conservation scientists risk reaching unreliable conclusions if they use specimen databases that are not actively curated to reflect changing knowledge.     

Correction to: Characterization of a fatty acid-binding protein from the Pacific oyster (Crassostrea gigas): pharmaceutical and toxicological implications

Environmental Science and Pollution Research - A Correction to this paper has been published: https://doi.org/10.1007/s11356-021-13135-x     

Changes in Tundra Pond Limnology: Re-sampling Alaskan Ponds After 40 Years

The arctic tundra ponds at the International Biological Program (IBP) site in Barrow, AK, were studied extensively in the 1970s; however, very little aquatic research has been conducted there for over three decades. Due to the rapid climate changes already occurring in northern Alaska, identifying any changes in the ponds’ structure and function over the past 30–40 years can help identify any potential climate-related impacts. Current research on the IBP ponds has revealed significant changes in the physical, chemical, and biological characteristics of these ponds over time. These changes include increased water temperatures, increased water column nutrient concentrations, the presence of at least one new chironomid species, and increased macrophyte cover. However, we have also observed significant annual variation in many measured variables and caution that this variation must be taken into account when attempting to make statements about longer-term change. The Barrow IBP tundra ponds represent one of the very few locations in the Arctic where long-term data are available on freshwater ecosystem structure and function. Continued monitoring and protection of these invaluable sites is required to help understand the implications of climate change on freshwater ecosystems in the Arctic.     

How Perceived Exposure to Environmental Harm Influences Environmental Behavior in Urban China

Rapid environmental degradation in China makes understanding how perceived exposure to environmental harm influences environmental attitudes and participation in pro-environmental behaviors among the Chinese people crucial. We used a nation-wide survey dataset in urban China to test two hypotheses: experiencing environmental harm directly affects environmental behavior; environmental attitudes mediate the relationship between experiencing environmental harm and environmental behavior. We found respondents who experienced environmental harm had more pro-environmental attitudes. Experiencing environmental harm positively influenced pro-environmental behavior both directly and indirectly through the mediation of pro-environmental attitudes. Among the pro-environmental behaviors, environmental litigation was most strongly related with exposure to environmental harm. Our results suggest that more participation in pro-environmental behaviors may be expected as rapid economic development increases public exposure to environmental harm in urban China.     

Thermoplasticization of High Amylose Starch by Chemical Modification Using Reactive Extrusion

Modified thermoplastic high amylose starch (MTPS) was synthesized by reactive extrusion in the presence of maleic anhydride (MA) as an esterification agent in a twin-screw extruder. The objective of this work was the preparation of reactive thermoplastic starch in the presence of glycerol and with different amounts of maleic anhydride (MA) and free-radical initiator, in order to improve processability and reactivity. The concentration of MA added varied from 2 to 6 wt% (of starch + glycerol), and the free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, also called Luperox 101, varied from 0.1 to 0.5 wt% (of starch + glycerol). Characterization of maleated thermoplastic starch was performed using dynamic light scattering and thermal analysis. Further, proof of chemically modified extrudate was determined by Fourier transform infrared spectroscopy and by soxhlet extraction with acetone. The modified high amylose corn starch (20 or 30% glycerol) could be pelletized and gave pellets that were more transparent than thermoplastic starches not modified with maleic anhydride. There was negligible change in hydrodynamic radius as the percentage of maleic anhydride increased. However, as the percentage of Luperox 101 increased, the hydrodynamic radius decreased. It could be inferred that the molecular weight decreased as the percentage of free-radical initiator increased. Using the maximum temperature in the extrusion process of 165 °C instead of 135 °C caused a decrease in the hydrodynamic radius, due to the high influence of the temperature profile on the molecular weight of the thermoplastic starch. The MTPS samples presented higher melting temperatures compared to TPS samples. The soxhlet studies indicated that the plasticizer, glycerol, was chemically linked to the starch. Using the maximum temperature of 165 °C versus 135 °C in the extrusion temperature profile resulted in more interaction between glycerol and starch.     

Habitat biodiversity as a determinant of fish community structure on coral reefs

Increased habitat diversity is often predicted to promote the diversity of animal communities because a greater variety of habitats increases the opportunities for species to specialize on different resources and coexist. Although positive correlations between the diversities of habitat and associated animals are often observed, the underlying mechanisms are only now starting to emerge, and none have been tested specifically in the marine environment. Scleractinian corals constitute the primary habitat-forming organisms on coral reefs and, as such, play an important role in structuring associated reef fish communities. Using the same field experimental design in two geographic localities differing in regional fish species composition, we tested the effects of coral species richness and composition on the diversity, abundance, and structure of the local fish community. Richness of coral species overall had a positive effect on fish species richness but had no effect on total fish abundance or evenness. At both localities, certain individual coral species supported similar levels of fish diversity and abundance as the high coral richness treatments, suggesting that particular coral species are disproportionately important in promoting high local fish diversity. Furthermore, in both localities, different microhabitats (coral species) supported very different fish communities, indicating that most reef fish species distinguish habitat at the level of coral species. Fish communities colonizing treatments of higher coral species richness represented a combination of those inhabiting the constituent coral species. These findings suggest that mechanisms underlying habitat-animal interaction in the terrestrial environment also apply to marine systems and highlight the importance of coral diversity to local fish diversity. The loss of particular key coral species is likely to have a disproportionate impact on the biodiversity of associated fish communities.     

Biomonitoring approach with mussel Mytilus galloprovincialis (Lmk) and clam Ruditapes philippinarum (Adams and Reeve, 1850) in the Lagoon of Venice

Transplanted Mytilus galloprovincialis and native Ruditapes philippinarum were deployed in 10 sampling stations with different pollution impact within the Lagoon of Venice to evaluate the temporal variations and the suitability of the following cytochemical and histochemical biomarkers just as indicators of environmental stress: lysosomal membrane stability, lipofuscins, neutral lipids and lysosome to cytoplasm volume ratio. The physiological status of the organisms was also investigated by determining the survival in air capability and the reburrowing rate (clams). The biological parameters were assessed in June and October. Furthermore, for a better definition of the environmental aspects of the study sites, heavy metal, PAH and PCB concentrations were also evaluated in the sediments. As a whole, the biological responses examined in both species from all the sampling sites showed significant differences between the two seasonal campaigns, only lysosomal membrane stability exhibited less variability. Pollutants in sediments generally showed low-intermediate contamination levels, few hotspots persisting mostly in the inner areas of the lagoon, the most influenced by the industrial zone. Transplanted mussels were more responsive than native clams and the biological responses of both species varied temporally. The range of the spatial variability was always narrow and reflected only partially the broader variability shown by the chemical content in the sediments. In this sense, biological responses seemed to be particularly influenced by the high temporal and spatial heterogeneity that characterise the Lagoon of Venice, as well as most of the transitional environments.