Regular papers

Imaging of plankton specimens with the lightframe on-sight keyspecies investigation (LOKI) system

¹ Institute for Marine Resources, Bremerhaven and University of Applied Sciences, Bremerhaven, Germany
² Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
³ Instituto del Mar del Peru, Callao, Peru
⁴ Centre for Computing Technologies - Image Processing, University of Bremen, Germany

^a jan.schulz@imare.de
^b kristina.barz@awi.de
^c payon@imarpe.gob.pe
^d aluedtke@tzi.de
^e oliver.zielinski@imare.de
^f dirk.mengedoht@awi.de
^g hans-juergen.hirche@awi.de

Received: 31 October 2009

Abstract

Zooplankton is a key element in aquatic food webs. Rapid mapping of abundance, combined with information on taxonomic and size composition is necessary to understand ecosystem dynamics. Classical sampling with towed plankton nets does not allow resolving fine scale distributions along hydrographic gradients (e.g. fronts and clines) although such structures determine community assemblages and trophic interactions. Furthermore, sample analysis is labor intensive and time consuming. To overcome these shortcomings, Lightframe On-sight Keyspecies Investigation (LOKI), a new imaging device, was developed for sensing spatial variability of plankton distribution on scales below the 1 m level. Here, we give a brief description of the LOKI system and demonstrate its potential for taxonomic identification using images of various zooplankton taxa collected in the south east Pacific.