Anglers – Our Front Line Defence Against Didymo

Recent reports from concerned anglers in Tasmania of algae sightings – suspiciously like didymo – are thankfully not true!

However, the Inland Fisheries Service would like to thank anglers for their vigilance and encourage their continued action in the front line defence against the introduction of this pest alga into Tasmania. Here’s what you can do to help and how to identify didymo.

Although the Australian Government is working to prevent the introduction of didymo at Customs/Quarantine entry points, it’s up to the individual angler to declare all used fishing equipment on entry to the country.

Taking their personal responsibility further, anglers should "check, clean and dry" anything that’s been used in freshwater, as a matter of habit, at least between fishing trips.

The government’s cleaning recommendation for didymo is to scrub and soak all items for a minimum of one minute in a 2% solution of household bleach. As a greater precaution, anglers should use a hot water solution and soak for 30 minutes, and for items that are difficult to clean and dry (like felt-soled boots), you should soak for 45 minutes in water maintained at 45 degrees or higher containing 5% household bleach. Drying gear is also critical because didymo cells can survive in a single drop of water if left untreated.

Anglers are not only the front line defence against didymo as potential carriers of contaminated equipment but they are also the people most likely to discover didymo at a popular fishing location if it is introduced here and does invade our waterways.

The problem is that didymo can be difficult to distinguish from native algae, at least by sight.

The Service recommends that concerned anglers conduct a ‘feel’ test on a sample of the suspect algae. Note that didymo doesn’t feel slimy but rather spongy and scratchy like wet cotton wool. It attaches securely to river stones and doesn’t fall apart or disintegrate when rubbed between your fingers or scrunched and rolled in your hand. Other distinguishing characteristics include didymo’s colour which is beige, brown or white but not green like many native species and it has no identifiable odour.

If you are still concerned that you may have discovered didymo, then please report it immediately to the Service or other authorities including Hydro Tasmania and the Department of Primary Industries, Parks, Water and Environment, which includes Quarantine Tasmania and the Parks and Wildlife Service.  It would help with further investigation if you were able to collect a sample of the suspect material in a jar or bottle containing water and provide this, together with the precise location of the collection, to the relevant authorities as soon as possible.

The Service is very grateful for reports of any suspicious algae sightings and for the high level of concern demonstrated by anglers in general. For further information on didymo visit www.ifs.tas.gov .au and for reporting unusual sightings, phone the Service on 1300 INFISH (After hours on 0408 145768) or Quarantine Tasmania on 6233 3352.