Horaay! Field work time.
In this field work we went to river Winongo in Yogyakarta. Our main goal was water rapid assessment using benthic macroinvertebrates.
Assessment? Yes, it is
As we know in biological and ecological perspectives, functioning biological community is one of the best indicators of a healthy stream. Benthic macroinvertebrates are often used in studies to determine the quality of waters because of their abundance, wide range of sensitivity, well known pollution tolerances, wide range of feeding habits, varied life spans, dependence on the land environment around the stream (watershed and riparian) and may indicate the water quality conditions in the past due to limited mobility. They are large enough to see with the naked eye (macro) and have no backbone (invertebrate). Insects comprise the largest diversity of the these organisms and include mayflies, stoneflies, caddisflies, beetles, midges, crane flies, dragonflies and others. Non-insect members of the benthic macroinvertebrate community are snails, clams, aquatic worms and crayfish.
photograph by me, sample collected from Kali Boyong Yogyakarta
When chemical grab samples are taken, they are really a snapshot of the water at that moment, that can change rapidly, but the macroinvertebrates are living there all the time. Their composition will be affected by either periodic episodes of poor water quality or continuous poor water quality – Diane Oleson, M.S.
Macroinvertebrate studies always interesting and fun! Spent time in the stream, looking under rocks, are the most interesting (as long as river is clean :D)
my student from biological department – UIN Sunan Kalijaga Yogyakarta
