Description: Marine optical imaging has become a major assessment tool in science, policy and public understanding of our seas and oceans. Methodology in this field is developing rapidly, including hardware, software and the ways of their application. The aim of the Marine Imaging Workshop (MIW) is to bring together academics, research scientists and engineers, as well as industrial partners to discuss these developments, along with applications, challenges and future directions. The first MIW was held in Southampton, UK in April 2014. The second MIW, held in Kiel, Germany, in 2017 involved more than 100 attendees, who shared the latest developments in marine imaging through a combination of traditional oral and poster presentations, interactive sessions and focused discussion sessions. This article summarises the topics addressed during the workshop, particularly the outcomes of these discussion sessions for future reference and to make the workshop results available to the open public.

Description: Optic technologies and methods/procedures are established across all areas and scales in limnic and marine research in Germany and develop further continuously. The working group “Aquatic Optic Technologies” (AOT) constitutes a common platform for knowledge transfer among scientists and users, provides a synergistic environment for the national developer community and will enhance the international visibility of the German activities in this field. This document summarizes the AOT-procedures and -techniques applied by national research institutions. We expect to initiate a trend towards harmonization across institutes. This will facilitate the establishment of open standards, provide better access to documentation, and render technical assistance for systems integration. The document consists of the parts: Platforms and carrier systems outlines the main application areas and the used technologies. Focus parameters specifies the parameters measured by means of optical methods/techniques and indicates to which extent these parameters have a socio-political dimension. Methods presents the individual optical sensors and their underlying physical methods. Similarities denominates the common space of AOT-techniques and applications. National developments lists projects and developer groups in Germany designing optical hightechnologies for limnic and marine scientific purposes.

Description: Despite considerable progress in the study of predator-prey interactions, our understanding of the role of non-lethal effects in this relationship remains limited. Except of consumption the presence of a predator often causes a behavioural shift in the prey species, called risk effects. They occur immediately by appearance of the predator and can effect the entire prey population. This is the first study dealing with changes in reproduction as a behavioural response to predation in the common periwinkle Littorina littorea. It is a factorial laboratory experiment to analyse the risk effect of the common shore crab Carcinus maenas on the mating success of L. littorea quantified at the number of eggs per female and unit of time. Exposure to water-borne chemical cues from feeding predatory crab caused the snail to decrease their number of eggs significantly about 40%, whereas another crab species (Cancer pagurus), damaged conspecific as well as starving crabs had no effect on the mating success. Furthermore, there was a tendency for decreased feeding activity of the snails when C. maenas were present. These results demonstrate that L. littorea is able to detect risk cues from the widespread predator C. maenas and response with a risk effect in terms of a reduced number of eggs. This shift may be either a direct behavioural answer to increase the chance of survival because the act of copulation enhance visual, tactile and chemical conspicuousness to predators, or a result of diversion of energy or time from reproductive tasks into anti-predator behaviour as escape or refuge seeking. However, it illustrates the potential for chemical cues as a non-lethal interaction between predator and prey, released by actively foraging C.maenas, to have profound effects on gastropod reproduction and by implication on the abundance of the next snail generation.