Effects of artificial light at night on the feeding behaviour of three marine benthic grazers from the Adriatic Sea are species-specific and mostly short-lived.

Artificial light at night (ALAN) has the potential to change the day-night activity of marine benthic grazers, and can therefore alter the top-down control they exert on macroalgal communities. In laboratory experiments, we investigated the influence of three realistic ALAN regimes on food consumption and feeding rhythmicity in the sea urchins Arbacia lixula and Paracentrotus lividus as well as in the snail Cerithium spp. from the Adriatic Sea. Food consumption was assessed in assays with algal pellets, while feeding rhythms were documented with 24 h time-lapse photography. Both was done in ALAN-acclimated and in non-acclimated animals. We observed temporary and potential long-term changes in the feeding rhythms of Cerithium spp. and Paracentrotus lividus, respectively, but found no lasting influence of ALAN on consumption rates. Effects were weaker when ALAN was applied only part-night, which suggests a possible mitigation measure to reduce the impact of nighttime lighting on coastal ecosystems.

Potassium carbonate (K2CO3) - A cheap, non-toxic and high-density floating solution for microplastic isolation from beach sediments.

Beaches are good indicators for local microplastic distribution and pollution. Multiple methods have been developed for extracting microplastics from sediment through density separation. However, the chemicals applied are often expensive and harmful to the user or the environment. We briefly review the problems associated with the use of these chemicals and present a new floatation medium, potassium carbonate (K2CO3), that has many advantages over other available media. It is non-toxic and cheap, and with a density of 1.54 g/cm3 the K2CO3 solution yielded a mean recovery rate of around 90% for PVC, one of the densest polymers, that cannot be easily extracted with alternative floatation media. We propose that the use of K2CO3 is particularly promising for long term and large-scale monitoring studies, because it allows involving citizen scientists in such studies, leading to an increased public awareness of the plastic problem in the seas.