Astronomy

By Kristen Travers

April and May showers may bring flowers but for our streams rain can also bring problems. Recent rains have resulted in our streams resembling unappetizing chocolate milk more than the clear clean water that we want to see.

Before many people lived in the Delaware region, most of our area was covered in forests, wetlands and marshes. When it rained most of the rain water would slowly infiltrate (soak) into the ground and into the groundwater. Today our landscape also includes homes, businesses, and shopping centers. Rain water can’t soak through impervious surfaces such as roads, building and parking lots but instead runs over these surfaces picking up contaminants and sediment and quickly flowing into our waterways.

Data on our local streams clearly shows how as stream flow increases during storm events, so does the cloudiness of the water as measured by turbidity – a measure of the relative amount of suspended particles such as sediment.

Bare soil, dirt exposed from poor construction and farming practices, and stream bank erosion caused by excessive flows cause increased turbidity. Muddy water harms aquatic life, smothers habitat, and increases water temperatures. It can also be a health concern to drinking water sources and recreational uses since harmful microbes found in animal and human waste bind to soil particles.

Providing opportunities for rain water to slowly infiltrate into the ground can keep pollutants and sediment out of our waters while reducing flooding

Rainwater and soil are assets that should be kept in place:

  • Soak it Up: Add native shrubs, trees or perennial plants who’s deep root systems help to break-up soil and promote infiltration, while also holding the soil in place.
  • Cover it Up: Cover bare soil with mulch and more importantly plants!
  • Prevent It: Minimize chemical use on lawns and in our houses, don’t mow right up to the creek, and pick up after your pets.

Thank you to the volunteers involved with the Delaware Nature Society Stream Watch, White Clay Wild & Scenic program, and Nature Conservancy Stream Stewards for their dedication to monitoring and improving the health of our waters.

By John Harrod, Manager, DuPont Environmental Education Center

Today while participating in a school field study at the DuPont Environmental Education Center, a student caught a young Amercian eel at a stage known as an elver.

American Eel. Photo by Lesley Bensinger.

A student holds an American eel elver. Photo by Lesley Bensinger.

The American eel hatches in the ocean waters of the Sargasso Sea in the North Atlantic between the West Indies and the Azores. It moves from its birth place to mature in fresh or brackish water and then returns to the sea to spawn. American eels range from Greenland to South America, occurring in all major streams along the coastline.  

American eel by Ellen Edmonson and Hugh Chrisp

American eel adult by Ellen Edmonson and Hugh Chrisp

 Join us at DEEC Tuesdays – Sundays at 2pm for a free netting program to see what you can find in the marsh. For more sightings follow DEEC on Twitter.

By John Harrod, Manager, DuPont Environmental Education Center 

Through this past spring, summer and fall, program participants had the joy of finding a sundry of fish at the DuPont Environmental Education Center. Species included brown bullhead catfish, yellow perch, pumpkinseed, and striped bass. 

One species we did not come across is the Atlantic sturgeon. The Atlantic sturgeon is a prehistoric fish that is listed as an endangered species by the State of Delaware. The Delaware River once supported the largest Atlantic sturgeon fishery along the Atlantic Coast. The population collapsed prior to the turn of the 19th century due to factors including overfishing and poor water quality. 

Atlantic sturgeon. Credit: U.S. Fish and Wildlife Service, Duane Raver.
Prehistoric Atlantic sturgeon. Credit: U.S. Fish and Wildlife Service, Duane Raver.

Things are looking up for this ancient fish.  In the summer of 2009, a small Atlantic sturgeon was caught in a net by Matthew Fisher, Delaware Fisheries Biologist, which had not happened in 5 decades. This provided evidence that Atlantic sturgeon could be spawning in the Delaware Estuary.  One possible spawning location was identified one mile downstream from Wilmington in the Delaware River.

Join us Thursday, February 10, 6:30pm at the DuPont Environmental Education Center for the lecture Atlantic Sturgeon: Historic Problems and Recovery Efforts by Dewayne Fox, Associate Professor of Fisheries Science at Delaware State University.  Learn more about the Atlantic sturgeon’s fascinating life, historic problems and current recovery efforts.  Take home a free copy of Delaware’s Freshwater and Brackish-water Fishes: A Popular Account, by Maynard Raasch.

By John Harrod, Manager, DuPont Environmental Education Center

Over the summer and last weekend at WildFest, Blue Crabs were caught in the DuPont Environmental Education Center’s freshwater tidal pond. Most visitors were surprised to find crabs here since they are usually associated with brackish (slightly salty) and salt water along the Atlantic and Gulf coasts.

An excited summer camper with a Blue Crab. Photo by John Harrod.

  Blue crabs can live in fresh water. To find out the salinity content of our pond, I borrowed a refractometer from the Delaware Nature Society’s technical monitoring program. The pond registered a salinity reading of 0 parts per million (ocean water is 32+ ppm).

Pete Zeigler demonstrating use of a hand refractometer. Photo by John Harrod.

 Growing up to 9 inches, this crustacean is an opportunistic bottom-dwelling predator that feeds on anything it can find including live and dead fish, clams, snails, and detritus (decayed organic matter).

A recent catch at WildFest that could grow up to 9 inches. Photo by Laura Orth.

 This predator is also prey of wildlife including eel, striped bass, other blue crabs and catfish. As its scientific name – Callinectes sapidus – indicates, people enjoy them too. It translates, “beautiful swimmer that is savory.”

 To learn more about DNS technical monitoring program visit here.