Katherine Gorge in Northern Territory.
Photo: Chris Johnson
September 7, 2001
Whales, The 'Wet' and the Outback
Earlier this week, we drove some 350 kilometers south of Darwin through an ancient, eroded landscape, littered with sparse vegetation and red sandy soils, to a small outback town called Katherine. We had been invited by one of the science staff of Katherine High School, to talk to his students.
In the last year and a half, we have spoken to thousands of school children in a number of countries, but this was the first group we have visited whose lives are not directly tied to the sea, or so they thought.
Even though Katherine is situated far from the ocean, the actions of individuals who live in similar inland areas are still quite capable of having a significant impact on the marine environment and the animals that live there.
The Northern Territory is renowned for its dramatic seasonal changes. Six months out of the year is it incredibly hot and dry. However, October through March are the months the locals nickname 'the wet'. The incredible floods experienced in Katherine and throughout this region, combined with its enormous surrounding river system, means that pollution carried to the ocean can be significant.
For instance, we discussed with the students how a plastic wrapper discarded in the street here, will inevitably find its way into a storm water drain, into the river system and eventually out into the ocean. It may take a little longer to reach its destination than plastic dropped on the ground in a coastal town, but it will get there eventually.
Many students also lived on local farms and had difficulty seeing the connection between their home in the outback and the possible effects of man-made toxicants on whales. Massive water consumption by farmers and agriculturalists, combined with the soaking and subsequent runoff the land receives during the wet season, means that both the runoff and the water that has been used for irrigation is loaded with fertilizers, pesticides and herbicides, all of which inevitably find their way into marine ecosystems.
Before leaving the area, we went to see the spectacular Katherine Gorge, a remote and beautiful place, carved by the Katherine river a mere 25 million years ago, through a base of sandstone material that is some 2.3 billion years old. This geological marvel with its sheer rock faces rising 75 meters above the narrow ravine, displays weathered canyon walls adorned with the aboriginal art of the traditional landowners, the Jawoyn people. Aside from the exquisitely patterned stone floors, and a surrounding landscape that encompasses plateaus and escarpments, Katherine Gorge supports a superb range of wildlife. This is an area of mosses, ferns and gum trees as well as fresh water crocs, long-necked tortoises and the fish made famous by this region, the Barramundi.
The gorge is also an area that illustrates perfectly, the extreme seasonal changes that take place in the Northern Territory. During the dry season, the gorge is a series of tranquil deep pools. During 'the wet', the river doubles its height becoming a thunderous torrent, moving an amount of water equivalent to ten Olympic size swimming pools every second. Downstream it becomes the Daly River before flowing into the Timor Sea, 80 kilometers southwest of Darwin.
This is Genevieve Johnson speaking to you from Northern Australia.
Log by Genevieve Johnson