The invertebrate communities sampled across the sites contained many families tolerant of low DO concentration, such as isopods and chironomids, while tubificids and oligochaetes indicated sites directly downstream of STWs [3]. The analysis was not as clear in separating out invertebrates influenced by different flow rates, as species within the same family may have varying requirements, but sampling was not always to
species level [25]. In addition, most of the sites had