Black Creek

Last week, before we returned home when rain threatened, we also visited the Black Creek to look for lamprey. The Black Creek is a beautiful stream whose lower portions are largely protected wooded areas. In the spring visitors can still see alewife runs returning to spawn. Often times other species follow them, and you may also see large stripped bass resting in small pools and feeding on the alewife.

Sea lamprey have been captured here once before and we initially found conditions which looked favorable to sea lamprey (sandy bottom, clear water, low flow areas, diverse invertebrate community). However, after looking for some time we did not find lamprey of any kind. We did find a dead male blue crab (blue crab are actually common in the Hudson River, even in freshwater areas).

We also found the largest Hellgrammite I have ever run across. These insects are also called dobonsonflies and spend long periods as aquatic larvae (sometimes more than 3 years) feeding on other aquatic animals before emerging to pupate into the adult. The adults live for less than a month and look for a mate before dying. What you cannot see well in the picture are the gills which are all along the abdomen of this larvae. When removed from the water they cling to the abdomen and are difficult to see. This is a very low diversity group (especially in the Northeast) and this animal could be identified to genus on sight, it was a Corydalus spp.

Hellgrammites are indicators of high water quality often. Check your local streams by lifting rocks or kick netting to see if you have any. Be careful, although they rarely do, they are capable of a powerful bite which can hurt.