Aerial and Field SAV Observations

Our seventh grade classes from Calvert County Public Schools have completed their fall SAV monitoring project on Cocktown Creek (Quad #041).  The results were about what we’d expected, plenty of Hydrilla with lesser amounts of Coontail and some small remaining patches of Wild Celery.  The Naiads that were detected early in the season nearly disappered from the creek, with our last observation of this species made on 9/29.

The Hydrilla was rather dense in places, rendering sections of the creek almost impassable to canoes at low tide.  It is evident that these thick stands of SAV are improving water clarity, with secchi readings approaching 1 meter in some locations.  The students enjoyed making observations of small fish and grass shrimp utilizing these areas as habitat.

A photo below illustrates one of the dense patches of Hydrilla on Cocktown Creek.

We’re looking forward to the Spring 2010 season and will report our findings through this forum.

Tom Harten, CHESPAX teacher

Calvert County Public Schools

I made my annual visit to Shallow Creek on Wed. 9/16 to check the survival of the small scale SAV planting that I supervised there in 1999, 2000, and 2001, with an additional planting supervised by DNR staff in 2003.  Shallow Creek is near North Point on the northern edge of the Patapsco River, technically just outside the river mouth in mainstem segment CB3MH, on quad 19 in the VIMS survey (see 2008 SAV map).  We planted wild celery (Va), redhead grass (Ppf), and sago pondweed (Ppc), but only the first two species survived.  We found no redhead grass in the creek before we started planting it there.  For reports from visits in past years, see: my report from 8-26-08, which has links to all of the earlier reports in the 2nd paragraph.

I went with with Jennifer Greiner, US FWS, who helped with the planting in 2000, and Steve Giordano, another fishery biologist at the NOAA Chesapeake Bay Office.  We found more SAV than I have ever seen there.  The whole upper creek and the upper ends of several coves appeared to be solid milfoil, most of it in flower (see photo), and often from shore to channel (see photo).  However, in the lower creek there were extensive mixtures of milfoil with the 2 species we planted that survived (wild celery and redhead, with more redhead visible than in recent years) plus quite a bit of Elodea (Ec), more than I’ve ever seen there before (see photo).  We did not find any sago pondweed on this visit, however.  See overview map of our whole route showing species found; the points where we turned around were usually where the SAV became too dense to paddle easily.  We were hunting just before low tide, starting about 2 hours before and finishing at low tide.

The main planted area next to the main channel, which I called “Area 1″ in my report last year, seemed at least as large and dense as last year, with much more redhead visible (see photo of bed and close-up).  As we saw in past years in Area 1, there was more redhead in the shallows and more wild celery and some milfoil in deeper water, with the bed in Area 1 extending almost to the channel as it did last year.  The shallower plants were much cleaner, presumably because the deeper ones, closer the the channel, were trapping the sediments before they reached the shallows.   See close-up map of Area 1.

There was some wild celery already present on the north side of the “outer cove” in 1999 when we started planting, and the grasses in that area on 9/16 were short enough, and the water clear enough, that I could shoot some underwater video there, online in YouTube here (32 sec).  The wild celery in this area was genetically distinct from that growing in Area 1, so presumably these plants are descended from the ones we found before we did any planting.  The small area we planted  with Va, Ppf and Ppc in the outer cove, Area 2 on the south side of the cove, still had redhead grass (Ppf) mixed with the other species, and redhead is spreading throughout that cove as well as up the creek.  The cove across from the outer cove, labeled Area 3 on the map (where we did no planting), seemed to have a lot more redhead grass than it did last year.  Last year, those 3 areas (1-3) were the only ones in the creek with dense SAV, but this year there were dense beds in several other coves, and a large milfoil bed that appeared to extend from where we turned around to return to the launch point (waypoint 673 on the overview map) to the upper end of the creek.

Two mute swans and a large flock of Canada geese were chowing down on the grasses.  Salinity was fairly high (9-10 ppt, vs. 8 ppt last year).  Secchi depths were better than last year (0.6-0.8 m, vs. 0.3 m last year).  See graph of Secchi depth and salinity by year (usually one visit per year)–this was the best Secchi depth I’d seen there since 2000, but nowhere near the extreme salinity, which was 15 ppt in Sept. 2002 after 2 years of drought, and 2 ppt the next year after a wet year.  It’s amazing that all of the SAV species in this creek have survived salinity swings from 2 to 15 ppt, and such low Secchi depths.   I hope to collect more water quality data here next year, to try to understand better what’s going on.  The CBIBS buoy outside the Patapsco has been back online since 9/14/09 after being shot and then hit by a ship (see the CBIBS web site and click on its icon for data).  Assuming it stays online, we’ll have some more continuous water quality data from outside Shallow Creek.

I know I’ve reported a lot on this one little creek this year, but it’s near my office and I go there for other reasons as well (water quality monitoring and living shoreline projects).  It is interesting to see how its SAV changes over the summer.  See the map of what small patches of SAV we found on 9-1.

Since my last visit two weeks ago on 8-18 (see report), I noticed the following changes:

1. All the SAV we found had very heavy epiphytes and sediment, much heavier than we saw 2 weeks ago, and all of the patches were smaller than what we saw 2 weeks ago.

2. The shallow patches of redhead grass (Ppf) we found in August on the north shore of the creek (waypoints 595 & 596) were gone, apparently smothered by the epiphytes.  This area is labeled “No SAV here” on the map from 9-1.  We did find one patch of Ppf remaining on the north shore next to the downstream side of the Rowe Blvd bridge (waypoint 608), but it had heavy epiphytes; see photo on rake and photo of bed.  Note how shallow the bed is growing in the 2nd photo.  These plants do not look “happy.”

3. We found three small patches of planted SAV (Ppf) along the St. John’s living shoreline, vs. only one on 8-18.  Since these were planted 1 or more years ago, they “count” for the purposes of the SAV survey.  However, given the heavy epiphytes on them (see photo of the shoots from the first patch at waypoint 611), they may not come back next year.

4. We did not find any live dark false mussels, but we did find a branch covered with dead ones on its lower surface only (see photo), in the mouth of Peters Cove.  This branch must have been raised out of the water when the fallen tree to which it is attached shifted; its top side lacks any algae so it may not have been submerged.  We found them only on the underside of branches and rocks before, consistent with their being grazed by ducks (mallards), which cannot reach the underside of branches.  I have seen mallards grazing on barnacles near the surface on a piling; they can’t remove the barnacles, but must be eating plants and animals that grow on the barnacles.  The mussels are much more loosely attached than barnacles (with byssal threads) so I’m pretty sure that mallards can remove them.

The SAV aerial survey has had a bad bout of the summer doldrums due to some really lousy weather as well as uncooperative tide conditions.  Once the tides started getting back to normal in mid-July, the weather became especially troublesome with a lot of hot and hazy atmospheric conditions.  And to top this off August down here in the lower bay was the third wettest month on record!   In addition, we had some really challenging low tides that were more astronomical this time versus the meteorological driven ones back in June.  For parts of August we had unequal low tides, with the morning lows almost a foot higher than both mean low and the afternoon low tide. Since we usually fly in the morning when it is less cloudy, we had to abort several planned missions in the mid-bay as an extra foot of water would mean we would not see the deep edges. However, we did manage to fly the Patuxent, Susquehanna, and Elk rivers and the Flats.  Below are our observations for those areas.  Also, I have included a brief synopsis of what we have heard from other colleagues looking at SAVs this summer.

In general, SAV in the Patuxent is similar to previous years.  It appears widgeongrass has re-appeared in the lower River along the north shore up from Drum Point at the mouth.  That bed is like many widgeongrass beds here one day, gone the next. There are some beds along the upriver side of Broomes Island which have always been dominated by widgeongrass.  It’s not until we get up to Cocktown and Black Swamp creeks near Kings Landing Park that we see freshwater SAV. Tom Harten, who monitors SAV in Cocktown Creek with his high school students, noted an unusual increase in Vallisneria this year in addition to the usual abundance of hydrilla. From this point all the smaller creeks entering the river appear to contain very narrow strips of SAV in the photos. This is similar to what we noted before even when SAV did not occupy the mainstem.  Along the mainstem SAV appears on the many shoals from Fridays Creek in abundances similar to last year.  So SAV in this section of the Patuxent appears to be having another good year.

We were only able to fly 4 of the 7 lines over the Flats but they show the massive bed on the Flats once again this year.  It appears in MODIS when it is not obscured by clouds which was quite frequent this summer
(http://rapidfire.sci.gsfc.nasa.gov/subsets/index.php?subset=AERONET_Wallops). It now pretty much covers the entire region except for the channels.  The flanks of the Flats from Havre de Grace along the eastern margin and south from the Northeast River along the western margin are also thick with SAV.  The Elk River also appears loaded with SAV.  I am not sure there is room for any more!  It is indeed another impressive year in this region of the bay!

While the aerial flights have been limited we have received observations on our blog from people who have visited regions of the Bay, suggesting SAV may be struggling in some areas but doing well in others.  Peter Bergstom reported low abundances of SAV in the Magothy and Severn rivers, as well as Marshy Creek in the Eastern Bay area compared to past years including the lack of flowering in widgeongrass, something we have noted at quite a few locations in the lower bay.  SAV in the Chester, including around Eastern Neck Island, appears dismal according to Terry Willis.  VA DEQ staff report some places in the upper Potomac River are unexpectedly loaded with SAV.  SAV in several of the VA tribs (Mattaponi, Chickahominy) appear to be robust.  Chris Tanner reports that widgeongrass in the St Mary’s may be down this year.  Lee Karrh commented that they have had reports (actually, complaints) of a lot of milfoil in the Baltimore area.  Widgeongrass showed up around Poplar Islands this year according to Chris Guy who shared with us some pretty neat pictures of SAV in this area under some amazing water clarity.

We have not gotten much info for the MD coastal bays except that water clarity has been pretty lousy this year.  A lot of ground observations have been made, but I am still awaiting that information.  Eelgrass in our restoration areas in the VA coastal bays appeared very robust a few weeks ago when we were there
conducting our first bay scallop deployment.

If any of you have anything to add to these observations please add them to our blog or just send them to me and my staff will add them.

September awoke to some really nice, cool weather!  At last!  And let’s hope hurricanes do what Bill and Danny did - stay away!

Diana L. Muller  South River Federation (Quads 030,  031)

We have not seen anything besides the Horned Pond Weed all summer.  I perform water quality monitoring at 19 stations, and I have recorded some of the lowest water clarity and D.O. reading in the past 5 years.

I returned to Marshy Creek off Kent Narrows on 8-29 with a group of 19 teachers, parents, and students from Sudlersville Middle School near Chestertown, MD, led by teacher Barry Conner.  They plan to do SAV surveys in creeks near their school on the Chester River with their “Ecology Corps” (they did one preliminary survey of Radcliffe Creek already).    I suggested that we meet at the Chesapeake Bay Environmental Center (CBEC) since they have quite a few kayaks and canoes that we could use on Marshy Creek, which has fairly healthy SAV beds this year.  I was last there on 7-18 (see report).

As I reported in July, SAV abundance here seems to be down quite a bit from last year.  We found 4 of the 7 species that had been reported there in past years, and no additional ones. The dominant SAV species on this visit was redhead grass (Ppf), with some of its flowers just reaching the surface, followed by widgeongrass (Rm), most of which had flowers and seeds, with much smaller amounts of Eurasian watermilfoil (Ms) and Common waterweed or Elodea (Ec), with more elodea than we found in July.   See the map of what we found. We covered only the southern part of the route we took in July.  The water was about as murky as it was in July (0.55 m Secchi depth) with similar salinity (9 ppt); there were thunderstorms the day before.  There were sea nettles but they were all fairly small.

We were surprised that we did not find any sago pondweed (Ppc), although we did not visit the north side of the creek where we found most of it in July.  We did not expect to find the spring ephemeral species, horned pondweed (Zp), which we were lucky to find in July.  As in July, we could not find any traces of the wild celery that we planted to the left of the launch point on 6/2/08, even with 20 people raking the area where we planted, at lower tide than we had in July.  Thus, it seems likely that none of it survived.

Thanks to the staff at CBEC for making both trips possible.

Greetings!

The CHESPAX staff (Calvert County Public School system’s environmental education) did a pre-school check-up of our SAV study site on Cocktown Creek on 8/26/2009.  The creek is a tributary of the Patuxent River near Huntingtown, MD (Quad #41). 

Nearly all of the expected species were present, including extremely dense beds of Hv, fairly robust growth of Nm and some patchy spots with Cd.  A very real increase in the the patches of Va was noticed, including numerous plants producing flowers.  This species had all but disappeared from the creek over the past decade with the introduction of Hydrilla.

On a non-SAV related note, there seemed to be a great abundance of wild rice along the creek this summer.  Without question there is more than I’ve seen in 18 years of nearly daily spring/fall excursions in the creek.  Has anyone else noticed this along their waterways?

Tom Harten, CHESPAX Teacher

Calvert County Public Schools

Erin Shields, VIMS (Quad 127, 128)

That Najas minor bed in the Chickahominy is back and very thick…bigger than I remember. I went and checked 2 other spots around there where my sites used to be, and the najas is really taking off. They will show up nicely on the photos. Also saw najas and coontail floating mats all over the lower part of the river.

The exclosures we built out there are covered 100% with Val! But no signs of it expanding outside the fencing.

Chris Tanner, SMCM (Quads 079, 080, 089)

We got out to Rosecroft Point, Piney Point and the inside of St. Georges Island today.  The widgeon grass bed at Rosecroft is still there but shows heavy epiphyte loads (probably Polysiphonia) near the outer edge.  I saw only one flowering shoot.  There was no SAV at Piney Point.  Widgeon grass has disappeared from the inside of St. Georges Island near some of the MD DNR eelgrass transplant and seed sites (sites towards the SGI bridge).  The only SAV that I saw there was two short (couple cm tall) shoots of eelgrass.

We serviced the continuous monitoring station at the College pier today, and my student serviced the station on the inside of St. Georges Island on Wednesday.  At both sites the water clarity was good for this time of year:

St. Georges Island (8/19/2009):  Secchi 1.2 m, NTU 3.6 at 0.5 m, 4.0 at 0.5 m from bottom

St. Mary’s College pier (8/21/2009:  Secchi 1.7 m, NTU 1.6 at 0.5 m, 2.1 at 0.5 m from bottom

Water clarity on the inside of St. Georges Island seemed pretty good today (we could see down to bottom with depth being 1 m).  Water clarity was worse today at Piney Point and Rosecroft; however, the wind was from the southeast and waves were stirring up the bottom.

As I reported earlier from a July 21 visit to this creek, SAV abundance in this creek is reduced this year.  We returned to it on August 18 and spent a bit more time looking for SAV, and found more species in a few more places, but the conclusion was the same–much less SAV this year compared to 2008.

The map of what we found on 8/18 shows the following:

1. We found tiny patches of milfoil (Ms) and elodea (Ec) in the mouth of Peters Cove (at waypoint 593), in the same spot where we found both species in September 08 (see report).  All we could find this year were a few tiny shoots almost completely covered with epiphytes, compared to small but dense patches of both species last year.

2. We found a few more and larger patches of redhead grass (Ppf) than we did in July 09 on the north shore of the creek (waypoints 594-596), but they were much smaller and shorter than the Ppf patches on this shore last year, with more epiphytes and no flowers or seeds.

3. We managed to find one clump of Ppf along the St. Johns living shoreline (waypoint 597), between the short fixed pier and the floating pier, in the same are where Mark Lewandowski said that MD DNR supervised Bay Grasses in Classes plantings in previous years.  We could not find any of the other patches of planted Ppf, up the creek from the short pier, that we found off the living shoreline last year (see map from 7-14-08 report).

4. We found a few shoots of a new species for this creek, slender pondweed or Ppu, in the upper end of Peters Cove (waypoint 592).  I’ve found this species in several Magothy creeks and coves, where it was one of the the dominant species in Grays Creek in 2007 (see item 6 in this report), and I’ve found it in small patches in one other Severn creek (Saltworks Creek in June 2006, see report).

We also measured water quality on this trip and found the worst bottom dissolved oxygen (DO) since we started sampling it in 2008, with bottom values from 0.16-0.66 mg/l at 4 of the 5 sampling sites, which are fairly shallow (2-3 m deep).  We’ve seen bottom DO < 1 mg/l here before but never at more than 2 of the 5 sites.  Secchi depths (clarity) were slightly better than last month, however (up to 0.6-0.8 m from 0.5-0.6 m last month).  Salinity was fairly high for August (near 11 ppt, surface and bottom) but we saw no sea nettles.  We found clumps of dead dark false mussel shells on the bottom in Peters Cove, but any live mussels that were present earlier in the summer would have been covered with the abundant bryozoans we saw again this year.

Thanks to those who helped me do the survey (NCBO staff Nick Whittier, John Kuriawa, and Rachel Lipsy, and City of Annapolis staff Jan van Zutphen), and to St. John’s College (and Skip Kovacs) for letting us use their boats and dock.