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REHABILITATING STREAMS
In the 1850's the streams that flowed across the plains of Southland were a lot more sinuous and shaded by trees than they are now.
In the intervening 150 years most of these trees have been removed and the streams straightened. It is impossible for us to say how trout fisheries really were in the old days. Soon after trout were introduced, in the 1860's and onwards there were reports of great catches, both of large and numerous kinds. There is no doubt that the trout made good use of the native fish species that were in the rivers at the time, although larger native fish such as eels and kokopu also ate smaller trout. The comorant, or black shag population no doubt expanded a little as well.
We can only rely on stories told from memories dimmed by time. Even written records of catches can hardly be compared with those of today because the records are incomplete or of a selective kind. Even today's records contain errors or neglect or worse, exaggeration.
What we do know has changed has been the shape of rivers, the places where trout live. It follows that if you change the living quarters of any kind of living thing those individuals have to change or move out. Streams of the last century were much more diverse than they are today. Most are shallower and swifter (on average) than they once were. Making the shops of central Auckland a little darker and a little cooler, or hotter (depending on the outside temperatures) drives away their normal inhabitants. Changes to streams can chase away their inhabitants too. Replacing the cable however is not an easy matter.
The decades of land development in the mid 1900's brought about the greatest changes to streams but as we near the end of the century there are many moves to undo some of these changes. The most obvious of these has been the restoration of flows to the Waiau River, but other events are occurring too. The Fish and Game Council is working with the Regional Council, DoC, Iwi and gravel contractors to recreate wetlands along side rivers. These will provide new habitats for wildlife and fish that like still, deeper waters, such as large trout eels and kokopu.
There has been little in the way of reconstruction of the natural character of small streams however, with most land owners more concerned about drainage than trout. There are opportunities for the power to be restored, for bends to be put back into small streams and for the recreation places for more trout while making better farms. Creative solutions to the conflict between the stream and the landowner are just waiting to be applied.
Maurice Rodway
Southland, New Zealand E-mail: fishgame@southnet.co.nz Article ©1998 Maurice Rodway, All Rights Reserved. |
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