Sound track: listening to fish tales of environmental flows

River impoundment or damming together with flow regulation is implicated in the global decline in ‘health’ of riparian aquatic environments and river biodiversity, but in Australia there is broad variability to this picture depending on how river hydrology has been modified. For the Shoalhaven River in NSW the accumulating water demands from urban use, agriculture and industry for the greater Sydney region combined with increased frequency and duration of drought periods highlight the difficulties of managing low volume flow releases for environmental purposes.

In late April 2013 I had the privilege of accompanying research staff from the NSW Office of Water and NSW Fisheries on a trip down the Shoalhaven River. I have been particularly interested in documenting the novel ways in which river and estuary scientists are using technology to understand the flow requirements of fish as well the more complex problem of how much water a river needs. While recognising that there have been many changes to the river, and that it remains in every sense a dynamic and variable entity, I have been interested to learn how river scientists come to know and understand the inhabitants of the river as well as the river itself.

Our party of six headed off in three canoes, each vessel loaded up with water proof carry bags containing essential supplies and research equipment for the two day journey. On this trip data was being downloaded from ‘listening stations’ anchored at major pools along a 22km stretch of the river below Tallowa dam. The listening stations record sound emitted from acoustic pinger tags inserted in a variety of fish species, including Australian Bass and Estuary Perch. The two day trip is completed by the team a number of times through the year to download data recording when and how fish respond to flow events, both major floods and smaller managed releases of water from the dam.

Why monitor environmental flows? How might we ‘listen’ to fish? What have they got to tell us and how might they help us to ‘listen’ to and understand the river? These are just some of the questions I explored with the research team in a series of interviews logged during the trip. I recorded short discussions at each listening station, longer group interviews at camp and my own observations of the journey as we went along. Experimenting with some of AUSCCER’s own new gear, I also filmed part of the trip on a Go-Pro camera which I wore attached to my safety helmet. Apart from being a useful reminder about what happened, these interviews and film record the practice and vagaries of doing field science and the very human embodied interactions between the research team and the river.

I did get wet feet, it did rain buckets into my dinner and a few times the gear got to be difficult and cumbersome but mucking about in boats for a few days was fascinating more-than-human geography and loads of fun. I am very grateful to the research team and professional river guide, for cooking under the duress of inclement weather and expertly steering our canoe through the rapids.

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