|Toxicity of two marine algal toxins to blue mussel and brine shrimp larvae|
De Rijcke, M. (2012). Toxicity of two marine algal toxins to blue mussel and brine shrimp larvae. MSc Thesis. Universiteit Gent, Faculteit Bio-ingenieurswetenschappen: Gent. 28 pp.
Prorocentrum Ehrenberg, 1834 [WoRMS]; Pseudo-nitzschia H. Peragallo in H. Peragallo & M. Peragallo, 1900 [WoRMS]
Phycotoxins; Domoic acid; Okadaic acid; Phenoloxidase
Overfishing, pollution, introductions of alien species and climate change are making harmful algal blooms (HABs) increase steadily in frequency, intensity and geographical scale over time. Simultaneously aquaculture production continues to grow substantially for which it needs to rely heavily upon a steady supply of high quality larvae. lt is therefore expected that HAB derived toxins may pose challenges to larviculture productions at present or in the near future. This paper embodies one of the first efforts into expanding the existing limited knowledge concerning the possible effects of two HAB toxins on the larvae of key species of the aquaculture industry. To this end, larvae of blue mussel Mytilus edulis and brine shrimp Artemia franciscana were exposed to well-known phycotoxins i.e. domoic acid and okadaic acid. The larval development of M. edulis was carefully monitored along with the survival of A. franciscana nauplii under various toxin concentrations. Additionally larvae were challenged with culture fractions of the toxin producing diatom Pseudo-nitzschia multiseries as well as live cells of P. multiseries and the dinoflagellates Prorocentrum lima. Finally, we investigated a potential influence of toxins and algae on the immune system by recording the phenoloxidase activity. The results of this study indicate that the levels of these marine toxins currently reported for the natural environment do not detrimentally influence the larvae of either aquaculture species. Live algal cells in bloom concentrations were not found to affect M. edulis. A. franciscana however displayed high sensitivity towards the presence of P. lima. Cellular extracts of lab-grown P. multiseries did not affect A. franciscana but hampered the development of M. edulis. However considering the overall quality of the embryos used for this test and the absence of a dose-effect relationship, repetition is required for a proper confirmation. Finally phenoloxidase activity was only found to be affected by domoic acid in A. franciscana. This last observation begs for continued research.