What does the future look like for kelp when facing multiple stressors?

As primary producers and ecosystem engineers, kelp (generally Order Laminariales) are ecologically important, and their decline could have far-reaching consequences. Kelp are valuable in forming habitats for fish and invertebrates and are crucial for adaptation to climate change by creating coastal defenses and in providing key functions, such as carbon sequestration and food provision. Kelp are threatened by multiple stressors, such as climate change, over-harvesting of predators, and pollution. In this opinion paper, we discuss how these stressors may interact to affect kelp, and how this varies under different contexts. We argue that more research that bridges kelp conservation and multiple stressor theory is needed and outline key questions that should be addressed as a priority. For instance, it is important to understand how previous exposure (either to earlier generations or life stages) determines responses to emerging stressors, and how responses in kelp scale up to alter food webs and ecosystem functioning. By increasing the temporal and biological complexity of kelp research in this way, we will improve our understanding allowing better predictions. This research is essential for the effective conservation and potential restoration of kelp in our rapidly changing world.

New methodical approaches for the investigation of weathered epoxy resins used for corrosion protection of steel constructions.

Epoxy resin coatings applied to steel constructions for corrosion protection purposes are often exposed to UV-irradiation and weathering during the construction process. Chemical alteration of the hardened coating might lead to i) the release of potentially harmful substances into the environment and ii) delamination of the polyurethane top layer. However, chemical processes and mechanisms occurring on the surfaces of exposed epoxy resin coatings are not fully understood yet. Herein, we present an innovative approach combining time-of-flight secondary ion mass spectrometry (ToF-SIMS) with inductively coupled plasma mass spectrometry (ICP-MS) and liquid chromatography mass spectrometry (LC-MS) enabling the elucidation of underlying chemical processes and the identification of released organic and inorganic photolytic products. IR-spectroscopy and experiments targeting the acidity/pH-value changes on top of weathered surfaces complement our investigations. It was confirmed that UV-A irradiation leads to photooxidative degradation of the epoxy resin and that inorganic photolytic products are exposed on the weathered surfaces. Polar moieties (hydroxyls, carbonyls, carboxyls, amines) and released metalloids form a hydrophilic surface layer, which hinders adhesion and eventually prevents profound chemical linkage of the polyurethane top layer. Thus, an early delamination of the top layer might occur very likely.

Concentration Effects on the Entropy of Electrochemical Lithium Deposition: Implications for Li(+) Solvation.

The solvation behavior of Li(+) in ethylene carbonate and dimethylcarbonate upon dilution has been investigated by electrochemical microcalorimetry. We measured the heat effects at a Li electrode upon electrochemical Li deposition and dissolution from Li(+) solutions of varying concentration. The exchanged heat is correlated to the entropy of lithium deposition and therefore reveals information about the solvation of Li(+). Lithium deposition from electrolytes with lower concentrations showed less entropy gain than deposition from electrolytes with higher concentrations. This can be fully explained by the entropy of dilution of the Li(+) ions. From our data we further concluded that the inner coordination shell of the Li(+) ions does not significantly change between 0.01 and 1 M Li(+) concentration. The results also suggest that contact ion pairs, which are probably present in the electrolyte, show a similar solvation behavior as regular lithium ions.