Micro-scale distribution of recently-detached Carybdea marsupialis box jellyfish along the coast of Denia (W. Mediterranean)

Abstract

5th International Jellyfish Bloom Symposium, 30 May to 3 June 2016, Barcelona.-- 1 pageCarybdea marsupialis have been found in high densities (~90 ind m3 juveniles, ~51 ind m3 adults) in shallow waters along the coast of Denia (W. Mediterranean) since summer 2008, varying significantly in abundance from year to year. In order study the role of juvenile stages in population dynamics, we analyzed the seasonal and micro-scale spatial distribution of recently-detached cubomedusae (~0.5 mm DBW). The main objective was to determine whether their distribution was focused or dispersed, as a means of revealing the location of the polyps. We also tested the correlation between environmental variables such as nutrient (P, N, Si), Chl-a and zooplankton abundance. During 2015 we collected samples from 33 points: 11 points along 15km of coastline at 3 distances from the coast (0m, 250m and 500m). Recently-detached C. marsupialis were almost only present at a depth of 0m in the samples collected from May to July. Maximum densities (~5 ind m3) were recorded in June in the centre of the study area. We hypothesized that the polyps would be located where the adults had mated the previous year. However, the distribution of recently-detached individuals did not coincide with the higher 2014 adult densities. This might be ascribed to the advection caused by the currents, which alternate along the coast. Abundance was not directly correlated with either zooplankton, nutrients or Chl-a. The next step would be to model the currents pattern and its effect in the dispersion and survival of juvenilesPeer Reviewe