During an expedition with RV Heincke in October/November 2014 twelve stations in the Norwegian Sognefjord were sampled with the Lightframe On-sight Keyspecies Investigation system (LOKI, Schulz et al. 2010). This optical sampling device allows merging of high quality in-situ image data of individual specimens with ambient environmental parameters on scales of a few centimetres. Investigating raw data for species distribution patterns it became obvious, that epibiont carrying copepods are related to specific water properties in the trough and behind the sill at the entrance of the fjord. Here we give a first peek about small scale relationships between hydrography and interactions of biota, insufficiently detectable with classical net samplings.