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.

No abstract

From March 2002 to until April 2003 we investigated the seasonal nutrient and phytoplankton dynamics in the central Bornholm Basin (Baltic Sea) within the framework of the German GLOBEC Project. We choose a nested approach consisting of vertical fluorescence profiles, phytoplankton counts and nutrient analyses. The Fluoroprobe (MultiProbe, BBE Moldaenke) is capable of distinguishing four algal groups (Cryptophyceae, Cyanophyceae, Chlorophyceae, Bacillariophyceae + Dinophyceae). Winter nutrient concentrations were about 5 lM NO 3 and 0.5 lM PO 4 in the central Basin. The spring phytoplankton bloom was dominated by the diatom Skeletonema sp. and reached a maximum of about 270 lg C/l before the onset of the seasonal stratification. Protozooplankton was dominated by the Mesodinium rubrum (a phototrophic ciliate = Myrionecta rubra) and reached a maximum biomass of about 200-300 lg C/l about 2 weeks after the demise of the diatom spring bloom. During summer, the water column was stratified and a subsurface maximum developed near the thermocline consisting of Bacillariophyceae, Cryptophycea and other phototrophic flagellates. Phytoplankton and protozooplankton biomass was generally low. Nutrient concentrations point towards a nitrogen limitation during this period. The stratification period ended during September and surface nutrient concentrations increased again. Protozooplankton reached a second maximum during September. With the Fluoroprobe small scale structures in the plankton community could be detected like a subsurface Cryptophyceae maximum near the thermocline that however, could not be confirmed by cell counts. The chlorophyll a estimate of the Fluoroprobe was in good agreement with the phytoplankton biomass estimated from counts. We conclude that only by combining modern sensing technology with microscopy, the small-scale dynamics and taxonomic spectrum of the plankton can be fully captured.

-In this short note we give an overview on the development of a new versatile plankton video recording system named LOKI. In addition to the introduction of technical specifications and background information of the device we also demonstrate a possible scientific application in a case study performed in an upwelling area off the Namibian coast.

The inclusion of higher plants in bio-regenerative life support systems has been suggested to contribute to a nutritious menu, increase food acceptability and provide psychological benefits to the crew. In 2017, the EDEN ISS project will deploy a greenhouse module to the Neumayer Station III in Antarctica. This system will be used to advance bio-regenerative life support system technologies and operations. An initial survey was conducted to improve crop selection for the EDEN ISS greenhouse module by further investigating the aspects of food acceptability and psychological benefits of crop cultivation. Former members of the overwintering crews of the three Neumayer stations were asked about their fresh food and vegetable preferences and about further aspects concerning Antarctic plant production. Results confirm the benefits of growing higher plants in isolated and confined environments and offer insight on the importance of crop selection aspects like taste, texture, pungency and colour.