At the end of October the surf suddenly changed from a sparkling clear blue to milky green, almost brown and lacking in lustre or clarity. If the stark colour change wasn’t enough to let us know the Anaulis australis surf algae had bloomed, the accompanying pungent odour certainly was. The algae comes and goes – heavy one day and almost gone the next.
Fortunately it doesn’t tangle fishing gear and isn’t toxic to swimmers. However, it does seem to affect fish moving in and out of the surf zone. The algae lowers dissolved oxygen, which must discourage fish from entering affected areas, but doesn’t altogether prevent them. I have certainly seen quite a number of whiting and flathead caught during severe blooms, and have caught some tailor myself when the surf has been brown with this algae. However, clean water is definitely preferable.
Rarely seen prior to 2001, annual blooms now occur along the entire Australian coastline. They have most often coincided with El Nino events. Nutrient accumulated on the land during dry periods are washed into the estuaries and along the coast during infrequent flood events. Then warm weather and elevated sea temperatures trigger algal growth. The La Nina event should have alleviated this, but it didn’t – at least not much.
In the meantime, greater efforts at reducing nutrient outfall into our estuaries are essential if we are to control this deteriorating situation. While this has been on the agenda of State and Federal Governments for a number of years, they haven’t done much.
Another ‘natural’ event is the large numbers of dead and dying mutton birds being washed on to the beaches between Fraser and Bribie Island. All of the birds I have watched here have frantically been attempting to feed in the surf before eventually landing on the water and washing to shore.
We are told that mutton bird casualties during migration are a natural event, caused by the birds encountering storms en route from the Bering Sea to Tasmania. The strong winds are said to cause exhaustion, but is this the whole story?
When watching the birds feeding, I noticed their efforts were frantic and energetic. They didn’t look exhausted at all; they looked starving.
As the world’s tuna stocks slowly deplete and fewer schools herd baitfish to the surface where seabirds can access them, situations such as this can only become more common. If the shearwater deaths aren’t at least partly as a result of the overfishing of tunas, mackerels, mahi mahi, bonito and the like, I would be very surprised.
Unfortunately for the shearwaters, there haven’t been enough tailor and dart in the surf, either. Recreational catches of tailor and dart have mostly been in ones and twos, with schools seemingly absent. It isn’t a good sign at a time when positive indications of this fishery’s health are desperately wanted.
Flathead continue to be a regular catch and whiting are available in reasonable numbers at times. The occasional jewfish has been taken off Double Island Point and a couple of cobia taken from the beach further south. Bream and tarwhine seem to be scarce, though tarwhine were being taken at this time last year and both species had shown signs of improved numbers earlier in this year.
Reports from Hervey Bay haven’t been glowing in their description of the pelagic season there to date. Hopefully this simply means that a late run of mackerel is still on its way and the tuna nearby. It is increasingly difficult to be optimistic, but should these species not arrive in Laguna Bay this year again after 3 lean seasons, questions are sure to be asked when we know that tailor and other species aren’t here either.Reads: 639