Tech Tip

Can Leaf Packs be used in lakes, ponds, marshes or other non-moving bodies of water and be a reliable indicator of water quality? Are aquatic macroinvertebrates the same throughout the world? Is the bioindex calculation accurate outside the US?

These are important questions referring to the Leaf Pack Experiments Stream Ecology Kit, a stream water quality investigation kit developed by LaMotte and Stroud Water Research Center (http://www.stroudcenter.org/lpn/index.htm). The Leaf Pack Kit involves creating an artificial leaf pack (dry leaves in an onion bag), placing it in the stream for three to four weeks and then examining the packs in the classroom, discovering different types of aquatic insects that are used as indicators of stream health. Kristen Travers from Stroud Water Research Center writes about the Leaf Pack method: "developed to use in streams and the typical indicator groups (mayflies, stoneflies, caddis) were also designed for streams. I'd suggest that they try comparing to other habitat (ponds, lakes, marshes). No reason not to try in other habitat but probably shouldn't use as water quality indicator. Some of the animals found in streams such as stoneflies won't typically be found in ponds or marshes so if you compared the two using a typical analysis such as the biotic index, the water quality score might come out bad in the other habitat just because certain animals won't be found there". Dr. Bill Deutsch (Alabama Water Watch), a frequent world wide water quality trainer, believes "most of the bugs would be similar as I once again found out in the streams of the Philippines (Dec. 2003)...bioassessments in Rwanda and Guatemala find the fauna basically similar in Asia, Africa, South and Central America, and North America. There are some exceptions, for example, the dobsonflies are unique to our part of the world, and Africa only has one species of stonefly. The filtering caddisfly, Alabama Water Watch's logo, is found everywhere". To see the logo visit Bill's site: www.alabamawaterwatch.org.