Interactions with the BIOFAQS and other EU projects

There are a number of areas in modelling and associated field work where the BIOFAQS and MERAMED projects complement each other:

hydrographic surveys at the common MERAMED/BIOFAQS fish farm in Crete
model development and common model grids for this fish farm
laboratory analyses by the different projects using CHN and stable isotope analyses to determine proportions of food, faecal and natural material in sediment trap contents for the fish farm in Crete

Hydrographic surveys

Deployments of Aanderaa current meters at the fish farm in Crete commenced in July 2001 and continued into 2002, with concurrent meteorological data also being collected. The location of these moorings was adjacent to the location of the biofilter deployed on the cages. Electromagnetic InteroceanTM S4 current meters which are highly accurate and a meteorological station were also deployed for short periods during the 2nd MERAMED cruise at the same location (March 2002). Sediment trap experiments were also undertaken during this period.

During the 1st MERAMED cruise (July 2001), high resolution measurements were taken of the bathymetry and sediment type at the fish farm in Crete using the RoxAnnTM ground master acoustic discrimination system. This survey also included the area around the control biofilter location. Accurate positional information on all the cages surrounding the biofilter was also obtained

Although settling velocities of waste food and faecal material for salmonids are commonly available, little data exist for other species (i.e. Sea Bass/Sea Bream). During the 3rd MERAMED cruise (October 2002) and an additional experiment at a Greek fish farm a number of settling velocity experiments were undertaken. The data from these experiments may again be used for modelling of sediment trap deposition in the MERAMED project and for determining biofilter exposure in the BIOFAQS project. In addition, the 3rd MERAMED cruise collected further hydrography and sediment trap work at the combined MERAMED/BIOFAQS fish farm site in Crete.

Model development

Analysis of hydrographic data was undertaken and determination of residual current and summary statistics. Model grids for the fish farm in Crete containing bathymetry and positional information of fish cages were constructed. These grids are compatible with the models used for modelling of sediment trap deposition in the MERAMED project and also for determining biofilter exposure in the BIOFAQS project.

Laboratory analyses

The MERAMED project has undertaken sediment trap studies to determine the rate of discharge of waste food and faecal material from five MERAMED fish farms. In addition to quantifying the total mass of the trap contents, CHN analyses are being undertaken to determine the proportions of food/faecal material and natural background material in trap contents. The BIOFAQS project has undertaken stable isotope analyses of sediment trap contents at the four BIOFAQS fish farm sites. The fish farm in Crete has been the common site used by both projects and preliminary data from each project have been compared for this site. Collaboration between the different partners in comparing data obtained by different methods towards a common goal is continuing.

Schematic presentation of interactions between Meramed and other EU projects