The use of a Stream Visual Assessment Protocol to determine ecosystem integrity in an urban watershed in Puerto Rico

The growing need to protect stream ecosystems in Puerto Rico requires the development of monitoring procedures that help determine management priorities. Physical habitat assessments have been used to make quick evaluations that are cost efficient and easy conduct, yet they need to be studied further to understand their accuracy at predicting stream health. This study evaluated the efficiency of the Hawaii Stream Visual Assessment Protocol (HSVAP) at determining integrity of streams within the highly urbanized Rio Piedras watershed in Puerto Rico. To validate the protocol we compared results from HSVAP assessments conducted at 16 reaches with water quality and macroinvertebrate data collected at the same sites. Results from linear regressions between the water quality measures and HSVAP scores showed that there was no significant relationships (R2 = 0.48; p = 0.08). This implies that the protocol is not supported by the water quality data. However, results from regressions between macroinvertebrate diversity and the number of families per site showed a significant positive relation with HSVAP scores (R2 = 0.30; p = 0.02; R2 = 0.24; p = 0.05). In addition, a significant negative relation was observed between HSVAP scores and the Family Biotic Index (FBI) (R2 = 0.32; p = 0.02). Comparisons between ratings obtained from the FBI and HSVAP scores suggest that the HSVAP classified sites as having higher quality than the biological metric. Based on these results, it can be concluded that the HSVAP is a good tool for a general assessment of the physical characteristics of a stream, but it needs modifications to accurately assess ecological quality of streams in Puerto Rico.