Life-history trait of the Mediterranean keystone species Patella rustica: growth and microbial bioerosion

The age and shell growth patterns in populations of Patella rustica of the Adriatic Sea were determined by analyzing the inner growth lines visible in shell sections. Marginal increment analysis showed annual periodicity with annual growth line being deposited in May. The growth analysis of 120 individual shells showed that 90.8 % of collected individuals were less than 4 years of age and only two individuals (1.6 %) were older than 6 years. Population structure was described and the generalized von Bertalanffy growth parameters were calculated: asymptotic length (L∞) was 38.22 mm and the growth constant (K) was 0.30 year-1. Growth performance index value of P. rustica (Ø’) was 2.64 and is among the lowest ranges reported for limpet species. Patella rustica shells were degraded to different degrees by microbial bioerosion. Microboring organisms identified were pseudofilamentous and filamentous cyanobacteria Hormathonema paulocellulare, Hyella caespitosa, Mastigocoleus testarum and Leptolyngbya sp. The overall intensity of infestation was relatively low, but increased in severity with shell length. The damage was most often restricted to the oldest parts of the shell, i.e. apex of the shell, posing difficulties in determining the exact position of the first growth line. The present study is first to introduce the use of inner growth lines in Patella rustica shell sections as a reliable method for age determination and it provides the first insight into the growth patterns of this keystone species while taking the interference of microbial shell bioerosion in consideration

An energy budget for the subtidal bivalve Modiolus barbatus (Mollusca) at different temperatures

Clearance rates, respiration rates and food absorption efficiencies of the commercially interesting subtidal bivalve Modiolus barbatus were measured at different temperatures under laboratory conditions and scope for growth calculated. Clearance rates were highest at temperatures from 20°C to 28°C, whereas respiration rate was maximal at 9°C and minimal at 26°C. Highest mean values of absorbed energy occurred at 20°C and 26°C. Scope for growth trend had negative values at 9°C, 15°C and 28°C and positive values at temperatures 20°C and 26°C. The profitable thermal window for M. barbatus to have energy sufficient for growth and reproduction corresponded to <5 months per year. Seawater temperature increases will potentially impact the ecophysiological responses of subtidal M. barbatus causing life history traits to change with important repercussions for subtidal biodiversity in the Mediterranea

Marine Science Communication in Europe – A way forward

The European Marine Board Communications Panel (EMBCP), a pan-European platform for marine science communicators, decided in 2019 to write a policy document, under the auspices and with the support of the European Marine Board (EMB). This document would sketch and analyse the state of the art in the field of marine science communication, aiming to highlight marine science communication as a growing and needed field of activity, and providing recommendations towards its future and developing best practices