Assessing the scale and ecological impact of derelict and discarded fishing gear across Thailand via the MARsCI citizen science protocol.

South-East Asia is among the least studied regions for the growing issue of marine debris pollution, despite being a major contributor towards global marine debris. In the present study, we provide the preliminary results from the MARsCI project, a survey protocol designed to utilise citizen science to facilitate data collection on the ecological impact of discarded fishing gear (DFG) in Thailand. Over a three-year period, 103 surveys were carried out across Thailand, resulting in impact assessment of 606 pieces of DFG. Our findings indicate corals are regularly impacted by DFG in Thai waters and that isolated marine habitats may be more severely impacted than near-shore sites. We further identify crabs, muricid snails, and demersal fish to be among the most regularly entangled animals. We discuss our findings in the context of earlier work from Thailand, and conduct a critical review of the protocol itself, identifying improvements for future efforts.

A six-months study on Black Soldier Fly (Hermetia illucens) based diets in zebrafish.

Intensive fish farming relies on the use of feeds based on fish meal and oil as optimal ingredients; however, further development of the aquaculture sector needs new, nutritious and sustainable ingredients. According to the concept of circular economy, insects represent good candidates as aquafeed ingredients since they can be cultured through environmental-friendly, cost-effective farming processes, on by-products/wastes, and many studies have recently been published about their inclusion in fish feed. However, information about the physiological effects of insect-based diets over the whole life cycle of fish is presently missing. At this regard, the present study investigated, for the first time, the effects of Black Soldier Fly based diets (25 and 50% fish meal substitution) administration for a six months period in zebrafish (Danio rerio), from larvae to adults. A multidisciplinary approach, including biometric, biochemical, histological, spectroscopic and molecular analyses was applied. Aside a general reduction in fish growth and lipid steatosis, six-months feeding on Black Soldier Fly based diets did not show major negative effects on zebrafish. Gut histological analysis on intestine samples did not show signs of inflammation and both stress markers and immune response markers did not show significant differences among the experimental groups.