Master-projects on analysis of bycatch data on Appendicularia and Limacina spp. in the Barents Sea.
The Soviet-Russian ichthyoplankton survey covered the southwest the Barents sea (Figure 1) over 35 years (1959-1993). The data have been digitized for the target species, i.e. cod and haddock eggs and larvae and capelin and herring larvae. In addition, copepods were sampled in a co-occuring zooplankon survey. Recently, recorded by-catch of several groups of species in the ichthyoplankton survey have been digitized as well. This includes less well studied species such as Chaetognaths, jellyfish (Hydrozoa) and ctenophores that all are potential predators of fish eggs and larvae. Two less well studied group of species that are present in the data includes Limacina sp. (Limacina retroversa and Limacina helicina) and Appendicularia (Oikopleura labradoriensis and Fritillaria borealis). With semi-quantitative data, including presence/absence and log-scale abundances (1-one individual, 2- tens of indivuduals, 3- hundered og individuals etc.), it is possible to quantify distributions and abundances and how that may be related to climate conditions, such as temperature, the North Atlantic Oscillation (NAO)- index etc. Previously, we have found a positive relationship between occurrence of jellyfish and temperature using the same data. A master-project on this topic will include both a literature review and an analysis of the available data
Figure 1 Overview of the Russian ichthyoplankton data coverage (circles) and spawning grounds of cod (grey ).
If you are interested in pursuing some of these alternatives or have any questions, please contact Øystein Langangen, e-mail: email@example.com