Behavioral responses of juvenile golden grey mullet Liza aurata to changes in coastal temperatures and consequences for benthic food resources.

Temperature is an important factor for fish. Yet, little is known about temperature effects on the feeding behavior of fish and the subsequent consequences of these behavioral changes on the spatial distribution of resources.We analyzed the differences in the feeding behavior of two size classes of juvenile Liza aurata at two water temperatures (i.e. 10 °C and 20 °C), using laboratory mesocosms. We also examined whether potential temperature-induced changes in feeding behavior of the smaller size of L. aurata would affect the spatial distribution of the microphytobenthos (MPB) biomass, an important resource in coastal systems. Both the number of feeding events and the swimming velocity during feeding were higher at 20°C than at 10°C, independent of the fish size. The time spent feeding did not vary between 10 °C and 20 °C, while the distance covered during feeding was significantly smaller at 20 °C than at 10 °C. Grazing did not affect the mean MPB biomass, but did increase its spatial variance at the smaller scale (i.e. a few centimeters) at 20 °C. A high number of feeding events, a high swimming velocity during feeding and a small distance covered during feeding in 20 °C-acclimated L. aurata most likely represented an adaptation to an increase in metabolism, as well as to the need to reduce the energy costs of feeding at 20°C. Results also indicated that changes in feeding behavior of the 20 °C-acclimated L. aurata were responsible for the increase in small-scale spatial variability in the MPB biomass but not an overall significant effect on theMPBmean.We suggested that the enhanced spatial patchiness due to grazing by fish at 20 °C might yield a local increase in the mean MPB biomass, probably increasing photosynthetic efficiency of cells and algal growth that counterbalance the negative effect of algal removal by fish

Investing in Volunteering: Measuring Social Returns of Volunteer Recruitment, Training and Management

In this paper, we analyse the costs and benefits of the investments that non-profit organizations (NPOs) make for the recruitment, training and management of volunteers. Our main research question is whether we can apply the Social Return on Investment (SROI) to the identification and quantification of social returns in monetary terms. We believe that the “SROI of volunteering” may represent an effective instrument of internal control for NPOs for improving efficiency and sustainability. In order to verify the feasibility and appropriateness of the SROI approach, we present a case-study on the Italian association Dynamo Camp, which works with children with serious illness through the organization of summer camps that offer “recreational therapy.” We believe that the presented methodology has the potential to contribute to the debate about the socio-economic impact organizations create for volunteers and for society at large