2008/793 Prawn industry black spot management: problem size and appropriate research
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2008/793 Prawn industry black spot management: problem size and appropriate research

By Steve Slattery and Richard Musgrove



The wild prawn capture industry is under increasing competition from imported and domestic aquaculture product. One problem facing the industry is the frequent occurrence of black pigment on the head and tail surfaces. This condition is known as black spot and can be prevented by treating the prawns with any of a number of different chemicals such as sodium metabisulphite.

This project aimed to 1) determine the significance of black spot in prawns to producers and processors 2) assess the need for further research on metabisulphite dipping and on the development of a dip meter and 3) assess the need for further research on 4-hexylresorcinol dipping.

A questionnaire was developed for industry members to complete. Interviews were conducted mostly in person or by phone with wild capture prawn industry members in various prawn fisheries around Australia. The results showed that the black spot issues varied with each fishery and that sodium metabisulphite was the chemical of choice for preventing black spot in the wild prawn fishing industry. There were many different ways this chemical was applied but the fishers did not always have the confidence that they were using it effectively.

The planned outcomes and benefits of this project were the identification of issues surrounding metabisulphite and 4-hexylresorcinol use and efficiency in the Australian Prawn fishery, including shelf-life and market perception. The survey identified that fishers are not sure which dip methods were effective for the various prawn fisheries. Research and training would provide them with the latest details on what chemical to use and how to use them. Additionally, easy to use sensor and test methods would ensure that sufficient residue of chemicals are present in the product so that it will be protected while being handled by retailers and consumers.