Progress in understanding scyphomedusa outbreaks in the Mediterranean Sea : distribution and phenology

Abstract

Distribution and phenology of Scyphomedusae in the Mediterranean Sea were determined from published data combined with our own observations/monitoring, fishery and regional agency monitorings and from evaluated news reports and citizen science applications. Our results revealed intra- and inter-species variations in phenology across the basins of the Mediterranean Sea. Visual censuses of jellyfish abundance were carried out weekly along three shoreline transects and bi-monthly/monthly along an offshore transect in the Gulf of Trieste, the northern Adriatic Sea (nAd). Visual counting was performed from the shore by walking along the same track of fixed distance in calm weather at the time of the predicted high tide. An observer identified and counted jellyfish along the offshore transect using the same procedure as for coastal transects. Observations differ between transects.