ReMoBiB: Real time monitoring of bivalve behavior

User group PI: Rob Witbaard, Netherlands Institute for Sea Research, the Netherlands

Hosting infrastructure: HZG/AWI Underwater Node Helgoland, Germany

Main Objectives

The aim of the project is three fold:

First: Establish from in situ experiments the relationship between shell gape (filtration activity) of Arctica islandica, environmental factors (Salinity, Temperature, Chlorophyll, light) and shell growth by collecting a continuous observational series on this gaping behaviour covering at least an entire year.

Second: Another goal is to demonstrate the use of online monitoring of the behaviour of bivalves in environmental studies. This in the context of the effects of extreme conditions like storms.

Third: Develop an online visualisation of real time valve gape activity on the NIOZ and AWI website as means to raise awareness about sea life among the broader public and show that the shells are living creatures reacting to external stimuli.

Since 2008 NIOZ has been working on the development of a valve gape recorder and the equipment has been tested successfully in a stand-alone configuration in different settings. Recently the stand-alone valve gape monitor has been modified by adding a RS232 connection. Now this refit has been done, we want to test the equipment in a real field situation and collect data which are comparable with data from experiments done in northern Norway with the same species (2014-now). From the comparison of these data sets we anticipate to identify which factors control shell gaping behaviour and find its relation with shell growth. From the activity patterns growth season length can be determined. To explain the seasonality, we will focus on the role of temperature, salinity, chlorophyll and light as main factors. All these quantities are standardly measured at the Helgoland node system continuously with a temporal resolution of 1Hz (see and The difference in seasonal succession of these environmental parameters between Norway and Helgoland is a key element for this study and can shed light on geographical differences of the obtained seasonal activity patterns. Later when the experimental shells are recovered the deposited newly formed shell increment(s) can be used in stable isotope, trace elemental and microtextural studies to validate and develop new proxies.

Helgoland lies within the normal habitat range of this species and the German Bight belongs to the most southern area where A. islandica can be found in the eastern Atlantic region. Animals will be collected in the vicinity of Helgoland. Elsewhere in the North Sea the deployment of unprotected structures (such as bottom frames with valve gape monitors like in Norway) is risky because of intense bottom trawling.