SAV
Bay Grasses Return to Antipoison Creek
We have submerged aquatic vegetation growing off of both sides of our dock this year on Antipoison Creek for the first time in decades. This observed growth follows reports from the Virginia Institute of Marine Science (VIMS) that the acreage of submerged aquatic vegetation in 2015 Bay-wide significantly increased. Acting as a source of habitat for marine species, such as juvenile blue crabs (which we’ve also seen a lot of this year), it’s nice to see even a little improvement in SAV acreage in our local waters.
Using information from VIMS and the Chesapeake Bay Program, I think this specific grass is Ruppia maritima, commonly known as widgeon grass. While there are several species of submerged aquatic vegetation in the Chesapeake Bay Watershed, widgeon grass and eelgrass are two of the most commonly found species, since they can tolerate a range of salinities. Widgeon grass, according to the Chesapeake Bay Program, typically grows in the slightly brackish to salty waters in the upper, middle and lower reaches of the mainstem of the Bay, but can also be found in freshwater tributaries.
I tried to take underwater photos but the water was too murky today for anything to turn out. However, I’ve included photos of the grasses from above, and a strand of the grass laid out to see what it looks like up close.
Water Quality Improvements in Antipoison Creek
This spring we’ve read reports from the Virginia Institute of Marine Science (VIMS) on the recent resurgence of submerged aquatic vegetation in the Bay; we’ve seen the latest survey from VIMS and the Maryland Department of Natural Resources showing that blue crab populations are higher this year than in several years past; and we’ve seen the University of Maryland (UMCES) report on the overall improving water quality in the Bay watershed. We’ve noticed some of these improvements firsthand in Antipoison Creek, on Virginia’s Northern Neck. Gary Greenwood shares his observations below:
We just spent three days at our place in White Stone. The weather was terrific, but better than that, we saw things in and around the water that we haven’t seen in the 10 years we have been visiting.
Walking out our dock on Antipoison Creek we noticed a lot of underwater grasses growing on both sides. I understand from our neighbor who has lived on the creek for decades that there used to be a lot of underwater grasses in the creek, but it has been gone for a long time.
The grasses must be providing good habitat for young crabs. We have seen lots of skate in the shallows near the grass, and further out we see crab pots set by five different watermen, based on the colors of the buoys. We have always had crabs of course, but seldom a population to support this many pots.
We visited Mike next door at his oyster farm (www.windmilloysters.com). He was too busy getting a shipment of 5,000 oysters out the door, but he did give us some baby oysters so we can start the next generation in the cage under our dock. Mike said he is shipping more than 15,000 oysters a week, which is great for him and his small operation.
In addition to being a good business, Mike’s oyster farm, with a couple of million oysters in the creek and out in Little Bay, is probably one of the reasons the underwater grasses are returning. (See the earlier post about recent water quality in the creek and Little Bay.)
In the evenings I have been reading Kate Livie’s very enjoyable book, Chesapeake Oysters, about the oysters in the Bay and the people who have made a living from them. She does a great job recounting the history of the oyster from the 1600’s to the present. I hope to finish it this weekend.
One of our goals each time we visit is to eat local seafood whenever we can. This weekend we enjoyed roast oysters at Merroir across the river in Topping, and local rockfish from our fishmonger, Blue Water Seafood in Kilmarnock.
The efforts to clean up the Bay certainly need to continue. We plan to continue monitoring the water quality and donating our information and other resources where we think we can make a difference. This weekend has given us a little optimism that the things everyone does to help the Bay can make a difference.
Grasses, Blue Crabs See Comeback
Surveys for both blue crabs and underwater seagrass found increases in population levels and acreage in the Chesapeake Bay this year.
The 2016 joint survey between the Maryland Department of Natural Resources and the Virginia Institute of Marine Science (VIMS) found that there are 35% more blue crabs in the Bay than this time last year. More specifically, the female population reached 194 million individuals, with overall numbers reaching 553 million.
Crab population numbers tend to fluctuate year-to-year, based on a number of factors, such as habitat loss, water temperatures, and harvest levels. The past two years have seen improvements to population numbers, but the blue crab is still considered to be in a state of recovery. Numbers have not reached 800 million, the number of blue crabs found after the first survey in 1988, in many years. With population fluctuation in mind, experts at the Smithsonian Environmental Research Center stated that this year’s good news does not necessarily mean that stricter harvest restrictions in Virginia and Maryland should be lifted. (SERC, 2016).
Crab population levels can be linked to seagrass acreage in the Bay. Seagrass provides habitat and protection for juvenile blue crabs. In past years, seagrass loss has been one predicted cause for blue crab population declines. The most recent survey from VIMS found that Bay seagrass acreage in 2015 was the highest it has been in 30 years. Perhaps these increases correlate to blue crab numbers.
The VIMS survey counted 91,631 acres of seagrass, up 21% from the 2014 survey, and 140% from the first survey in 1984. For more information on growth rates in specific regions (Upper Bay, Mid Bay, Lower Bay), please see the Bay Journal.
Chesapeake Bay environment and water quality blog 