Counting Water Bugs for Rocky Mountain BioBlitz

Tiny bugs called macro-invertebrates help make freshwater ecosystems tick, and as a team of volunteers found out at Lily Lake in Rocky Mountain National Park, they’re diverse, abundant and just plain cool little creatures.

Rachel Harrington, a freshwater ecologist at Colorado State University in Fort Collins, Colorado, led the BioBlitz volunteers in identifying the water bugs that emerged from the lake.  I caught up with Rachel as the inventory was progressing.

Sandra Postel is director of the Global Water Policy Project and lead water expert for National Geographic’s Freshwater Initiative.


  1. LeRoy Poff
    August 29, 2012, 2:05 pm

    Good question.
    Macro-invertebrate is a term applied to an organism that can be seen with the naked eye. Micro-invertebrates require some degree of magnification to see clearly. So, this is not a strict taxonomic category. Nonetheless, most aquatic insects (including benthic ones, the great majority in fresh waters) are considered macro-invertebrates because they are large enough to be seen (e.g., in a dip net sampler). Micro-invertebrates also occur in the benthos, but include many planktonic organisms, such as cladocera (e.g., daphnid species), copepods, rotifers and such. Caddisfly larvae, specifically, are all visible to the naked eye (as are the eggs) so they’re considered macro-invertebrates. Midges (which are quite small) are also generally visible and included among the macro-invertebrates. This characterization is consistent in the international scientific literature.
    Hope this is helpful.
    LeRoy Poff, Professor of Aquatic Biology, Colorado State University

  2. Edward Greenwood
    August 28, 2012, 6:16 pm

    Macro-invertebrates……..? I believe cased caddis are classed as Benthic Micro-invertebrates not Macro… this is even smaller such as Midge pupae for example.

    OR is this integral factor of scientific classification just lost in the UK-US translation of English?