Monitoring of aquatic biota would be a more direct approach to assessing ecosystem health than measuring physical or chemical properties of water. After all, physico-chemical measurements require considerable interpretation to assess impacts on biological resources and may need to be measured often to establish ranges and average values. Things living in the water integrate conditions over time, so their presence should tell us directly something about water quality, or at least environmental suitability.
Despite the considerable value of biological data, most methods developed for biological monitoring are complex and difficult to implement. Biological monitoring can require, among other things, familiarity with the environment and its inhabitants, intrusive methods of sampling involving collecting and preserving of specimens, and extended efforts processing samples in a laboratory. Yet, simple observations frequently have value, and decisions affecting our environmment quite often are made based upon qualitative observations or scant quantitative ones. Called biological assessments, these usually consist of a reconnaissance survey by a trained biologist. Key here is the training and experience of the biologist that allow him or her to make and interpret observations. With modest effort, students and volunteer community groups should be able to utilize the same methodologies to implement a biological monitoring program. A combination of biological and water quality measurements can be educational and productive to achieving community involvement in protecting watersheds.
Many methods are being utilized by student and volunteer community groups to obtain biological data from aquatic environments (Lathrop and Markowitz, 1995). The Rapid Biological Inventory (RBI) method described here is only one approach and one which should be modified to suit individual situations. The method offers structure to observational techniques widely used in field trips and reconnaissance surveys in aquatic environments. Over the long term, collection of quantitative data -- real numbers -- is always preferable to sdimpling "making observations." Where quantitative methods are not practical, structured observation can be a substantial improvement over random collecting.
The RBI procedure described herein has been developed for shallow aquatic environments (ponds, pools, wetlands,small streams, shallow areas of lakes and estuaries) although it could be adapted for use in other environments (forest, school yard, dunes) as well. In addition to providing valuable data for tracking long-term ecosystem changes, RBI can serve as an early warning system to detect ecosystem stress. Once initial data for key sites are collected and gathered throughout several seasons and years, invaluable baseline data will exist for future comparison. Also, because RBI requires limited training, is visually oriented, and can be conducted by a group, it is adaptable to single educational events involving students at the secondary education level.
RBI relies on four basic elements, which must be learned and understood by its practitioners. These elements are: (1) recording elapsed time spent by observers at a selected survey location (called a station); (2) area estimates (with descriptions) of aquatic environments surveyed at a station; (3) phased observation techniques; and (4) use of abundance categories, rather than counts, for very abundant, cryptic, or small species.
An example of a species listing for a Hawaiian wetland station: Kawainui at Na Pohaku o Hauwahine