These little shrimps play a huge role in the food chain of our ecosystem breaking down the energy of decaying matter. Not just here in our estuary but all throughout the eastern coastal areas of the country. Most people don’t realize that they are even there because they are very small and transparent which makes them hard to notice. Here are some ways to find them and things to look for on your next trip to help lead you to the fish.
Habitat: Grass shrimp dwell in the areas where fresh water and salt water combine. These areas also typically have an abundance of aquatic vegetation and oyster shell which provides them the cover necessary for survival. They are not intentionally harvested for human consumption and according to animal diversity web their home range stretches from Maine to the Gulf Coast. During the colder months of the year this shrimp will take to the deeper waters for the more consistent water temperatures.
Below are a few underwater pictures provided by Tobin at TroutSupport.com from the shallow water redfish dvd.
Shoal Grass/Sea Grass
Marsh Grass/Gulf Cord Grass
Diet: They are primarily detritivores filling their spot in the food chain and breaking down the plant matter from dead plants but juvenile grass shrimp will also eat zooplankton and algae as well. Research shows that mature grass shrimp will also eat other things such as oligochaetes, polychaetes.
Life Cycle: The life cycle of grass shrimp is fairly short, 6-13 months according to ADW. They will reach full maturity within one and a half to two months and be about 15-18 mm. making them hard to notice when out on the water. They reproduce primarily during the summer with some of the late spring hatchlings starting to reproduce as early as January.
Predation: This little organism is a staple to a lot of different fish ranging from croaker, pin fish, and piggy perch, all of which are prey species as well as the big three. I would start looking for the fish that are eating grass shrimp by looking at the upper bay areas where fresh water is mixing with the saltwater. In an interview with Tobin Strickland of TroutSupport.com, Tobin has noticed the grass flats with grass shrimp will hold trout and reds, and while diminutive in size you can still see them occasionally if there are fish on the flat. “While wading or kayaking a flat, occasionally you’ll notice a little tan, translucent creature hop out of the water in front of you that sort of looks like a water droplet hopping backwards. Trout and red fish will dine on grass shrimp if in high enough abundance. Think of them as the Cheetos in the grass flats, just something they can snack on and sustain until a bigger meal comes along. When they get thick, a fly in a grass shrimp pattern will not be turned away from. Sometimes that is what it takes to get the job done.” Pay particular attention to the bottom makeup and any structure such as grass or shell that might be in the area. There are also areas of marsh on the south shorelines that are natural brackish water marshes that will hold grass shrimp and exhibit a lot of the same characteristics as the upper portions of the estuary. They will also reside on the grass flats of the lower Texas coastal areas so be sure to keep your eyes open for any action. I hope this information helps fill the cooler on your next trip, until the next article, tight lines and smooth drag.
References: Wikipedia, Animal Diversity Web, Barbara J. Welsh (The role of grass shrimp, Palaemonetes pugio, in a Tidal Marsh Ecosystem) Tobin at Troutsupport.com
Wrote by: Jeffrey Keith Daniels
Edited by Jamie Lynn Rasnic
Illustrated by: Tobin Strickland (TroutSupport.com)