A CREDIBILITY, RELEVANCE AND LEGITIMACY FRAMEWORK ANALYSIS OF ENVIRONMENTAL DNA FROM THE POINT OF VIEW OF POTENTIAL END-USERS

As threats to natural resources multiply, the need for effective science-policy interfaces (SPIs) that account for the incorporation of ecological and social issues into decision-making is increasing. A feasible solution to successfully accomplish fast and reliable environmental information is to make use of advanced technologies, such as sampling genetic material shed by organisms into the surrounding environment, also known as environmental DNA (eDNA). While there are many studies on the scientific and technical aspects of eDNA, not much attention has been paid to users’ and decision-makers’ perspectives on eDNA and their implication in aquatic environmental monitoring and assessment. Aiming to verify if the eDNA tool and data generated by its use could make its way into decision- and policy-making, I conducted semi-structured interviews with potential end-users and stakeholders, and reviewed some Acts and Regulations, in order to better understand how eDNA is perceived and accepted. Results were interpreted and discussed using the credibility, relevance and legitimacy (CRELE) framework, as the balance among those criteria is seen as key to effective SPIs. Analysis demonstrated that eDNA is already seen as a relevant tool in inventory-monitoring studies, especially for preliminary assessments and targeted monitoring, but it would be applied as an addition to current techniques and programs, instead of a replacement option. The main challenges for eDNA relate to its resolution, its validity and its users. Although current legislation presents more opportunities than challenges for eDNA incorporation, better reproducibility and repeatability are necessary for strengthening eDNA’s credibility and legitimacy. Hence, through a combination of social perceptions, regulatory information and ecological knowledge, this study enhanced scientists and decision-makers knowledge about the tool, facilitating the identification of relevant points to be addressed towards an improved SPI

Do mud deposition events on sandy beaches affect surf zone ichthyofauna? A southern Brazilian case study

Using fluid mud deposition events which occur regularly at Cassino Beach in south Brazil, we evaluated the influence of such events on the structure of the ichthyofauna inhabiting its shallow surf zone. Wave action was the dominant factor in differentiating between sampling sites, being lower or even absent at the mud-influenced sectors compared to beach area without mud. Samples were collected using a beach seine net at two control locations (A1 and A2), and at three locations influenced by mud deposition (B1, B2, and B3). During the study period (21 Aprile04 August 2009), 15,245 fishes were captured and separated into 26 taxonomic groups, from species to family. Individuals of a total length (TL) up to 50 mm accounted for 65% of the catch, while individuals of TL < 30 mm were the most numerous and more responsible for the total abundance spatial pattern. The area with higher wave action (A2) had the lowest relative species abundance and greatest diversity, whereas the areas with mud-forced lowest wave action (B2 and B3) had the highest species abundance values. Three hypotheses were proposed to explain the higher concentration and capture of juvenile fishes at mud locations. First, longshore currents may be responsible for the displacement of juvenile aggregations toward areas of lower energy. Second, individuals may select habitats with turbid waters, which may provide greater protection from predators and increased food availability. Third, areas under the influence of fluid mud deposition show higher values of viscosity, which may reduce swimming activity and hinder the escape of juvenile fishes from nets, resulting in an increased capture of individuals compared to areas without mud