Sunday, October 1, 2017

On September 5 and September 20 of 2017, the VLM sent 8 staff from 3 departments, as part of a collaborative effort between the Nature Conservancy and University of Virginia, to help transport and construct functional oyster habitats out of concrete “castles” that are also designed to keep up with sea level rise. This is the third year and fifth round that the VLM provided staff to construct these reefs at multiple sites along the Eastern Shore of Virginia. We have helped build new habitats off of Chincoteague, Oyster, and most recently Nassawadox. 
Getting instructions and some history behind oyster reef construction from Bo Lusk of the Nature Conservancy. 
Short Prong Marsh at Nassowadox, VA 
The VLM has contributed 66 man hours so far this year (with one round to go) to the effort, and has contributed nearly 250 hours over three years. In a typical day, we help construct at least one complete reef that spans 80 feet long and comprised of over 500 thirty pound blocks – that’s over 15,000 pounds of concrete moved and assembled into useful oyster habitats in one day!

Oyster "castles" prior to being alligned

Staff and volunteers arranging the castles
These reefs are constructed of tiered concrete blocks that are designed to be stacked and interlocked vertically into a pyramid-like structure.

Different locations have different castle arrangements, depending on the tides. Above are the desired arrangements for Chincoteague, VA. 
These are the desired arrangements for Oyster, VA. 
When these stacked blocks are oriented in a staggered horizontal line, they create a three dimensional reef that acts as a breakwater to diffuse wave energy, trap sediment also allows plenty of hard surface for oyster spat to settle on preventing their possible burial. The University of Virginia is experimenting with different configurations to assess which height, length, orientation, and style of reef most effectively reduces wave action as well as supplying much needed habitat for oysters.

Full colony of adult oysters at Oyster, VA
Many different fishes and invertebrates live among oyster reefs, such as this striped blenny. 
Though the work is physical – and you will get wet and dirty – you can contribute as much as you are able while making a tangible contribution to our environment. It is very gratifying to see a completed structure assembled on what was once just a bare mud flat that will become home to not only a future oyster reef but countless crabs, shrimp and fishes. 

Sunday, May 28, 2017

Sea grass restoration project


We recently participated in the largest seagrass restoration project in the world run by the Nature Conservancy and Virginia Institute of Marine Science. We were trained to identify and collect the seed bearing structures of eelgrass while snorkeling over thousands of acres of a lush underwater field of grass outside of Oyster, Virginia; to date the project has distributed over 70 million seeds!

Bo (far left) of the Nature Conservancy giving instructions to the volunteers


Britt and Corey snorkeling over the seagrass 

Sea grass Zostera marina


video

Sea grass meadows flourish in wide shallow expanses behind barrier islands and inlets that would ordinarily be mud flats. Once the grass gets established in large enough patches, their extensive root systems provide stability to the sediment, and the grass blades themselves act as a buffer against wave action by absorbing and diffusing wave energy. But most essentially, the grass becomes a complex habitat for a wide variety of invertebrates, crustaceans and larval fishes as well as food for a wide variety of waterfowl. 

Northern pipefish (Sygnathus fuscus) hiding in grass

Lined seahorses are among the many fishes that utilize seagrass to hunt and hide

Juvenile striped burrfish (Chilomycterus schoepfi) are common in sea grass beds

The goal of the project is to restore wide swaths of original sea grass habitats that had been lost over the years due to disease, physical damage by hurricanes and poor water quality. Excess nutrients and sediment run-off  (the two major factors behind almost all of the Bay's problems) cloud the water which prevents adequate sunlight from reaching the plants and may also smother young shoots. In areas with good water clarity, enough depth to keep the grasses submerged throughout the tidal cycles, the grasses can flourish, but they need the head start. That's what the project intends to accomplish. 
Eel grass needs lots of sunlight

The Nature Conservancy trains and leads volunteers to collect and subsequently distribute as many seeds as possible. The first step in the project is where the volunteers (us) come in. Around the last week of May each year, the Nature Conservancy schedules 5 rounds of collecting for approximately 15 volunteers to accompany their staff. Two Carolina skiffs transport volunteers and crew out of the Oyster boat ramp to the grass beds in South Bay where the grass is flourishing. Snorkelers then pluck the seeded grass shoots and fill mesh bags for transport back to the aquaculture facility. For the three days of the five in which the weather held out, enough seeded grass was collected to fill twenty three 40 gallon trash bins! The seeds will subsequently ripen and fall out of suspension in the holding tanks where they are collected and then distributed over potential grass habitats. Hopefully they take root, and sprout into full-sized eel grass.

Getting ready to head out

Actual seeds exposed from the seeded grass structure

Patrycja even found a feisty bay scallop, which have been almost wiped out of the Chesapeake Bay and are slowly returning. 

It's overwhelming how much seagrass (in the mesh bags) was collected in such a short time!


After collecting, the grass was measured and poured into large trough tanks on shore for cultivation. 
Corey, Britt, and Karl on our first day out 

Judging by the expanse of eel grass over which we were snorkeling, the project is obviously working. It's encouraging to imagine larger and larger expanses of eel grasses and the animals this ecosystem supports. As with most conservation projects, it will take time, some luck and a lot of effort. We played our small part this year, but we eagerly look forward to helping out with an increased effort next year and swimming through those beautiful grass beds again.