Aerial and Field SAV Observations

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8/27/10 Longs Creek, Back River (MD), planted SAV (with PS about Otter Point Creek)

September 7th, 2010 by Peter Bergstrom · No Comments

On 8/27/10, Mark Lewandowski (Maryland DNR) and I kayaked in Longs Creek, on the north side of the mouth of Back River (MD), which is largely surrounded by Rocky Point Park (see Google map), owned by Baltimore County. For VIMS SAV maps of this creek from recent years, see the creek to the left of Hawk Cove in the lower right of Quad 13, from 2009, 2008, 2007, and 2006.

Like Shallow Creek, on the north side of the mouth of the Patapsco River a few miles to the south (only 3.5 mi/5.6 km as the crow flies–see my recent report on planted SAV in Shallow Creek), it has a small and relatively undeveloped watershed, mainly in parks, and the creek has a narrow mouth that opens on or close to the Bay itself. Unlike Shallow Creek, much of the lower part of the Longs Creek watershed is a golf course with very green fairways, so it probably has much more nutrient runoff than Shallow Creek.  These comparisons are important because these two creeks are the only two sites with long-term SAV growth and spread (for 5-10 years now) among the many small-scale SAV planting projects that we both supervised. Mark supervised the SAV planting here, while I supervised it in Shallow Creek. We plan to write a paper about the small-scale SAV planting we supervised, and why we think it was so successful at these two sites, and not at any of the others.

Groups of students had planted SAV that they grew in their classrooms here. They planted mostly wild celery, but some redhead grass. This was done for several years (probably starting in 1999) but was stopped after 2006 because the planted grasses were doing so well that the creek did not appear to need more planting. Most of the groups planting here were part of DNR’s “Bay Grasses in Classes” program, but some were part of a similar “Grasses for the Masses“program run by the Chesapeake Bay Foundation (CBF), now offered in VA only, but also offered in MD in the past. Several sites along the creek were planted, with substrates that ranged from very mucky at the uppermost planting sites (where some planters sank in to their knees or farther) to fairly rocky at the sites farthest down the creek.

In our visit on 8/27/10 (see map), we found wild celery (Va) at almost all of the spots we checked (see photo taken near the northern planting areas, and another taken where the planted Va has spread to the channel), and redhead grass (Ppf) at a few of them (see photo), although milfoil (Ms) was probably the most abundant species (see photo). There were also a few patches of coontail (Cd, see photo). According to Mark, the creek had only scattered patches of Ms before they started planting here, and both Va and Ppf were planted, so presumably both of those species came from the planted SAV.

I had last visited the creek in 2007 with Mike Lloyd, a student of Maile Neel at the University of Maryland, who was comparing the genetics of paired natural and planted wild celery populations. See description and map from that visit here — scroll down to “Mouth of Back River (Rocky Point)”. (In this 2007 report, I called the creek “Rocky Point Creek” based on the DNR web site about the SAV planting, but since learned that Baltimore County was calling it “Longs Creek” in their watershed maps. It has no official name.)

PS To put the success of the SAV planting here and in Shallow Creek in context with other small-scale planting efforts, on 8/31/10 I returned to a June, 2009 planting site in Otter Point Creek, where we planted about 45 cat litter pans of wild celery and about 15 pans of water stargrass (see photos) that were grown by NOAA staff in their offices. They were planted very shallow (ankle deep at a normal low tide) because it was during the unusually high tides that month, which should have helped their survival in the normally murky waters of Otter Point Creek.  In late September 2009, about 35% of the planted area had some wild celery and about 5% had some water stargrass (see photo1 and photo2 taken at an extra-low tide), which was excellent first-year survival for this sort of project. However, when I returned on 8/31/10 I could only find wild celery covering about 10% of the planted area (see photo). I expect that those few plants probably won’t come back next year.  Otter Point Creek had mapped SAV in 2008 (see VIMS map) but had none mapped in 2009 (see map), so SAV seems to be declining there. The Otter Point Creek site is the only one of all the other sites where I supervised SAV planting (about 20 sites total) that still has any plants surviving, except Shallow Creek.

Tags: SAV Observations · SAV Restoration

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