April 20, 2017

Fish sampling continues at Wreck Pond. Last Week, the Society completed its second sampling event. We caught an additional 11 alewife, bringing our total to 14 for the season. In addition, we caught several other fishes including white perch, common carp, mummichog, Atlantic silverside, and gizzard shad; as well as multiple blue crabs and one painted turtle.

White Perch (Morone Americana)

Painted turtle (Chrysemys picta)

​Gizzard shad (Dorosoma cepedianum) were the most abundant species caught this past sampling event, and thus, I want to take a moment to highlight this lesser known fish:

​Gizzard shad are members of the herring family. They live in freshwater lakes and reservoirs, but can also be found in slow moving rivers and streams and brackish estuaries. In general, they prefer shallow waterbodies with muddy bottoms. Gizzard shad are planktivores, feeding on phytoplankton when young and zooplankton when older. They will also feed on detritus when the zooplankton abundance is low. They are deep bodied fish with distinct rounded snouts and small toothless mouths. Gizzard shad are thus named because they possess a gizzard, an internal organ that is part of their digestive system. The gizzard is essentially a small sack filled with stones or sand (consumed by the gizzard shad) that helps break down the gizzard shad’s food. Gizzard shad typically spawn between May and June during the evening. They have high fecundity i.e. they can produce a lot of offspring. This, coupled with their fast growth rate, means that Gizzard shad can often become a large part of the ecosystem in which they live.