ISOMED - A Stable ISOtope database of MEDiterranean marine food web components.

Marine food webs shape the ecological dynamics of energy flows and predator-prey relationships. Their study is crucial to understanding human impacts that are monitored within environmental policies, such as the European Marine Strategy Framework Directive. One of the most used methods to assess the structure and functioning of marine food webs relies on the use of carbon and nitrogen stable isotopes (δ13C and δ15N), which are particularly useful for a vast range of taxa whose diet composition may be impractical to evaluate through traditional approaches (i.e., stomach content analysis). However, such data are sparse and have not been consistently collected, making it often difficult to assess the status of marine food webs. Here, we present ISOMED, a georeferenced database of published δ13C and δ15N values and carbon and nitrogen elemental composition of basal sources of organic matter and consumers collected in the Mediterranean Sea. The information reported includes estimates for 4959 records. ISOMED provides a unique tool for investigating trophic interactions and energy flow within Mediterranean food web components.