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Figure 8 Lower Parapara River at Site 4, looking upstream. Gorge in LH distance.
Results and Comment
Each site was covered as well as possible using electric fishing equipment, with the lower site (4) also spotlighted. All habitats available were sampled, including riffles, runs, backwaters, pools, and any cascades that could be sampled. The results are summarised in the following table. All the data has been recorded on Freshwater Fisheries Database cards and will be sent to NIWA.
A total of eight fish species and two large invertebrates (koura or freshwater crayfish, Paranephrops planifrons and freshwater shrimps Paratya curvirostris) were recorded during the survey. Only three fish species were detected in the upper river; koaro (Galaxias brevipinnis) and long- and short-finned eels (Anguilla dieffenbachii and A. australis respectively), together with a small population of koura. All these fish species need access to the sea to complete their life cycles, so have negotiated their way through the Parapara River gorge, at an altitude of 180 m, with a rise of 160 m in about 2.3 km from the Glengyle River confluence, or an average gradient of about 7%. In other words, only those species which are well able to climb over cascades and other obstacles are able to colonise upstream of the gorge. The dam itself is yet another impediment to fish movement, but not significantly greater than the gorge.
The three short finned eels were all found adjacent to the swamp area (site 3) in waters draining from the swamp. Short-finned eels normally inhabit still waters such as swamps and lakes, whereas long-finned eels are more common in rivers. Eels are very
Fish & Game New Zealand Nelson Marlborough Region Sports Fish and Game Bird Management ...p7
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