Further promising testing, in small-scale on board trials, shows PrawnFresh tests as highly effective (comparable to meta) against blackspot compared for Banana, Brown Tiger and Grooved Tiger prawns but less effective on Eastern King or Endeavour prawns.
A second round of trials analysed Meta and PrawnFresh across species and fisheries in April-May 2021. The trials concentrated on the differences in species seen in the first round of preservative trials in spring 2020.
The take-home messages are that there are differences in how species take up Prawnfresh and size is a factor:
With relevant species small scale trials indicate short 3 min dip is likely sufficient to capture maximum PrawnFresh efficacy…further confirmatory residual measurements in water and flesh planned.
Reduced dip concentration (0.75ml/L) is sufficient to also capture maximum PrawnFresh efficacy with a caution against reducing the starting concentration.
A more practical approach would be to maintain recommended 1ml/L concentration and include additional dips.
See report for complete results including ‘before and after’ pictures.
Next step plans are to repeat the trials and also test at commercial scale. We are seeking further input from fishers keen to undertake larger scale trials.