The cost of monitoring pollutants within natural waters is of major concern. Existing and forthcoming bodies of legislation continually drive the demand for spatial and selective monitoring of key pollutants within our environment. Although research and commercial entities continue to drive down the cost of the infrastructure involved in environmental sensing systems (with an aim to increase scalability), the realisation of deploying a number of such systems even now remains out of reach. High cost and maintenance continue to persist as the major limiting factors. The aim of this work is to combine recent advances in robotics with chemical sensing techniques to remove all but the chemo-responsive material from each sensing node, and package the sensing element within a low cost, mobile, biomimetic robotic fish for effective water quality monitoring. Consequently, this approach is believed to radically reduce the systemic cost and maintenance per node and in doing so it will increase the scalability for spatial and selective monitoring of key pollutants within our environment.