Opportunistically collected data from aerial surveys reveal spatio-temporal distribution patterns of marine debris in German waters

Environmental Science and Pollution Research - Marine debris is known for its ubiquitousness and harmful effects on marine life. This study is the first analysis to provide information on the...     

Pluri-annual study of the reproduction of two Mediterranean Oscarella species (Porifera, Homoscleromorpha): cycle, sex-ratio, reproductive effort and phenology

This study presents the phenology of two common Mediterranean sponges belonging to the genus Oscarella (Porifera, Homoscleromorpha). Oscarella tuberculata and Oscarella lobularis are two sibling species, dwellers of shallow benthic communities which tend to have distinct ecological behavior, respectively, euryecious and rather stenoecious. The comparative study of their reproductive cycle showed that both Oscarella species have a seasonal reproductive cycle with a successive phase duration differing from one species to another. In both species, there is a continuous oogenesis, with new oocytes appearing in spring, whereas the spermatogenesis generally starts later with the early warming of the sea. The embryonic development and the larval release are restricted to the warmest months of the year. We also observed a shift in the period of gametogenesis and larval emission depending on species and differences in their sensitivity to changes in thermal regime. It appears that an increase in seawater temperature can affect sex determination, with mainly a shift toward males in both species. Their reproductive efforts are variable in time, and can be in some cases influenced by the temperature regime. This is especially the case of O. lobularis which seems to be the most thermosensitive, its phenology responding significantly to changes in thermal regime, whereas O. tuberculata seems to be less sensitive and/or reactive. By detecting phenological changes among sponges, this study demonstrated the relevance of such monitoring to assess the possible biological response to climate change.     

Micropollutants in urban stormwater: occurrence,concentrations, and atmospheric contributions for a wide range of contaminants in three French catchments

This study aimed at: (a) providing information on the occurrence and concentration ranges in urban stormwater for a wide array of pollutants (n?=?77); (b) assessing whether despite the differences between various catchments (land use, climatic conditions, etc.), the trends in terms of contamination level are similar; and (c) analyzing the contribution of total atmospheric fallout (TAF) with respect to sources endogenous to this contamination. The studied contaminants include conventional stormwater contaminants (polycyclic aromatic hydrocarbons (PAHs), Zn, Cu, Pb, etc.), in addition to poorly or undocumented pollutants such as nonylphenol and octylphenol ethoxylates (NPnEO and OPnEO), bisphenol A (BPA), polybrominated diphenyl ethers (PBDEs), a wide variety of pesticides, and various metals of relevance (As, Ti, Sr, V). Sampling and analysis were performed using homogeneous methods on three urban catchments with different land use patterns located in three distinct French towns. For many of these pollutants, the results do not allow highlighting a significant difference in stormwater quality at the scale of the three urban catchments considered. Significant differences were, however, observed for several metals (As, Cr, Cu, Ni, Sr and Zn), PAHs, and PBDEs, though this assessment would need to be confirmed by further experiments. The pollutant distributions between dissolved and particulate phases were found to be similar across the three experimental sites, thus suggesting no site dependence. Lastly, the contributions of TAF to stormwater contamination for micropollutants were quite low. This finding held true not only for PAHs, as previously demonstrated in the literature, but also for a broader range of molecules such as BPA, NPnEO, OPnEO, and PBDEs, whose high local production is correlated with the leaching of urban surfaces, buildings, and vehicles.     

Some Improvements in the Determination of Benzo [α] Pyrene in Air Samples

The earliest measurements of benz[α]pyrene (BαP) in air samples were almost exclusively based on chroma-tography on alumina columns followed by ultraviolet absorption, in spite of the fact that the original discovery and isolation of BαP in coal tar was based on its fluorescence properties. With the increasing use of fluorescence techniques, the vastly increased sensitivity over ultraviolet measurements has become generally apparent. In air sample extracts containing the four polycyclics, benzo[a]pyrene (BαP) benzo[k]-fluoranthene (BkF), benzo[g,h,i]perylene, (BghiP), and BαP, ultraviolet measurements for BαP are particularly, inaccurate. Fluorescence measurements of BαP are much more accurate, but some improvement in accuracy seems desirable. The present work deals with improvement of the fluorescence measurement of BαP. It now is possible to measure BαP in the presence of BkF with greatly increased accuracy. Interferences resulting from the presence of benzo[k]fluoranthene are now much lower.     

Acid–base balance and metabolic response of the sea urchin Paracentrotus lividus to different seawater pH and temperatures

Purpose

In order to better understand if the metabolic responses of echinoids could be related to their acid?Cbase status in an ocean acidification context, we studied the response of an intertidal sea urchin species, Paracentrotus lividus, submitted to low pH at two different temperatures.

Methods

Individuals were submitted to control (8.0) and low pH (7.7 and 7.4) at 10°C and 16°C (19?days). The relation between the coelomic fluid acid?Cbase status, the RNA/DNA ratio of gonads and the individual oxygen uptake were studied.

Results

The coelomic fluid pH decreased with the aquarium seawater, independently of temperature, but this explained only 13% of the pH variation. The coelomic fluid showed though a partial buffer capacity that was not related to skeleton dissolution ([Mg²⁺] and [Ca²⁺] did not differ between pH treatments). There was an interaction between temperature and pH on the oxygen uptake (V _O2) which was increased at pH?7.7 and 7.4 at 10°C in comparison with controls, but not at 16°C, indicating an upregulation of the metabolism at low temperature and pH. However, gonad RNA/DNA ratios did not differ according to pH and temperature treatments, indicating that even if maintenance of physiological activities has an elevated metabolic cost when individuals are exposed to stress, they are not directly affected during short-term exposure. Long-term studies are needed in order to verify if gonad production/growth will be affected by low pH seawaters exposure.