Analysis on distribution of syngnathid species in confined Mediterranean areas: a literature review

Anthropogenic pressures on marine ecosystems have caused extensive changes and/or degradation of marine habitats. Overexploitation and destructive fishing practices are responsible for biodiversity loss in many coastal ecosystems. Due to their biological and ecological traits, pipefishes and seahorses are particularly sensitive to the effects of anthropogenic activities and habitat changes. Indeed, a decade ago, all syngnathid species were assessed in the IUCN Red List of Threatened Species where most of them have been classified as “Data Deficient”, highlighting the lack of data on distribution, population trends and threats. Aiming enhancement of the current knowledge and implementation of the extinction risk of syngnathids, in this study, we performed a review using published and unpublished sources concerning the distribution data of all syngnathid species in the confined areas of the Mediterranean Sea. Most of the sites were inhabited by low number of syngnathid species. However, the data indicated wider distribution of pipefishes, although seahorses and pipefishes frequently coexisted. The most recorded pipefish species was S. abaster, while concerning seahorses, H. hippocampus resulted more studied than its congener. The present study highlights the necessity to locate and characterize hitherto unknown populations, especially in poorly studied areas, in order to enhance preservation of these sensitive species.