An Overlooked Group of Citizen Scientists in Non-Indigenous Species (NIS) Information: Shell Collectors and Their Contribution to Molluscan NIS Xenodiversity.

This work reports on 60 marine alien mollusks from nine countries across the Mediterranean Sea and the Sea of Marmara collected by two Belgian citizen scientists. Some of their published observations concerning collection dates are compared with the year of first publication for these alien mollusks reported in the literature, which enable us to backdate some of their introductions and set new first Mediterranean records for two species. This underlines the importance of collaboration between volunteers and institutional scientists in tracing variations and changes in the environment and biodiversity. [ABSTRACT FROM AUTHOR]