BUT seastars have 10 testes and the parasite does not usually invade all of them. That means infected male seastars could still produce millions of sperm to fertilise eggs. Therefore, it's unlikely Orchitophrya will have the effect scientists had hoped for. A much more savage parasite is needed for the fight. In the meantime, the search for a solution may be a lot closer to home.
Some scientists believe that disturbed environments are more prone to invasion.
In harbours and ports, dredging to improve shipping channels can destroy native marine communities that are already weakened by pollution. The building of wharves, piers and pylons gives arriving stowaways a vacant home as soon as they jump ship. It will be interesting to see whether the best method to manage northern Pacific seastars in Australian waters may be to reduce pollution and enhance local plants and animals in estuaries. In the future, molecular biology may be harnessed to attack the seastars. Scientists could insert or change a gene in northern Pacific seastars which would castrate them or kill their young.