SAV Meeting (Day One)
Wednesday, February 27, 2008
Virginia Institute of Marine Science
Rt. 1208, Greate Road
P.O. Box 1346
Gloucester Point, VA 23062
10:00 am - 5:00 Dm
Agenda and Presentations are available using the following link:
http://archive.chesapeakebav.net/calendar.cfm?EventDetails=9345&DefaultView=all&R
equestDate=02/06/2008
Attendance
Name
Organization
Email
Lee Karrh (Chair)
MD DNR
lkarrh(fl),dnr. state, md. us
Jessie Jam
VIMS
Campbell®, vims.edu
Erin Shields
VIMS
esheilds®,vims.edu
David Parrish
VIMS
oarrishd® virns.edu
Scott Marion
VIMS
smarion(fl)vims. edu
David Ruble
ODU
drubleffl),odu.edu
Bob Orth
VIMS
ii orth (a), vims, edu
Mark Lewandowski
MD DNR
mlewandowskifaidnr. state.md.us
Peter Bergstrom
NCBO
Peter.bersstrom(fl),noaa. sov
Becky Thur
CRC
thurb(o>,si.edu
Laura Murray
UMCES- HPL
murrav®,hoi.umces.edu
Victoria Hill
ODU
vhillfo),odu.edu
Ken Moore
VIMS
mooreffl), vims, edu
Sarah Hunter
CRC
sarahehunter®comcast.net
Nancy Rybicki
USGS
nrvbicki(fl),usss.sov
Tony Watkinson
VMRC
Tonv.watkinsonfaimrc.virsinia. sov
Jay Woodward
VMRC
Jav. woodward®,mrc.virsinia.sov
Jason E. Gramberg
UMCES- AL
i srambers®, al.umces.edu
Stan Kollar
HA
skollar®,harford. edu
Bob Murphy
ESI
MurDhv®,ecosvstemsolutions.ors
Beth Zinecker
UMD
zinecker®,umd. edu
Evamaria Koch
HPL- UMCES
koch(o),hDl. umce s. edu
Michele Gomez (phone)
USACE
michele. somez®,usace.armv.mil
Krystal Freeman (Staff)
CRC
Freeman.krvstal(o>,eDa.sov
Action Items
•S Krystal will make sure everyone at the meeting is on the SAV workgroup
list serve.
•S Michele Gomez will send the US ACE SAV restoration proposed project
facts sheet to the SAV listserve.
Announcements
~~~ We will work on the SAV strategy document as well as addressing the goal of
planting 1000 acres of SAV by December.
4c;
Date:
Location:
Chesapeake Bay Program
A Watershed Partnership Time.
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~~~ Adjustments need to be made to the SAV list serve. (Krystal)
~~~ Changes to the agenda: Xuyong Li is not able to attend and give his presentation
today and Harris will not be able to attend and present tomorrow.
First Session; Restoration Round-up for '07 and plans for '08
Presentation: Restoration of Submerged Aquatic Vegetation in Mesohaline Chesapeake
Bay (Laura Murray)
Laura presented some of the efforts to overcome challenges faced in trying to develop
effective restoration programs for redhead grass and sago pondweed. These species
produce large amounts of seeds yet seed viability and germination are very low. Can
plant fragments and tubers be used to create satellite colonies until a better understanding
of seed germination is gained for these species? An experiment showed that redhead
grass (P. perfoliatus) fragments in tanks would sink within a week, 50% would root and
begin to produce runners. This experiment conducted in the field yielded the same
results; however there are no local sources for seed plant propagules. Sago Pondweed (S.
pectinata) plant fragments under the same experimental conditions as P. perfoliatus in
the warm green house only 6 out of 50 fragments sank after 6 weeks. During field
observations a large mass of dead S. pectinata had new growth attached. This suggests
that the plant can reproduce from its fragments, outside of the summer season.
Over wintering buds (tubers) are another possible seed independent colonization tool
and for P. perfoliatus. An experiment was conducted to see if the tubers developed
differently after six weeks of cold treatment. The cold treated tubers were fat compared
to the untreated. Both the treated and untreated tubers planted "germinated"/ emerged
however the benefits of cold treatment began to be evident in October. Another
experiment comparing tuber growth to plants with roots in the same sites showed that the
tubers did not grow as well.
Plans for the coming year include more salinity experiments for the fragments and
tubers, planting seeds and tubers side by side in the field, pond, and green house. It still
has not been determined if salinity affects the number of reproductive shoots.
Di scussion/Comments:
1. Improvement to the data can be made by extending the sampling outside of the
bed area. Methods are different closer to shore as opposed to the open water so
be sure there are areas outside of the bed are parallel to the areas inside the bed
that they are being compared to.
2. These species are known to produce seed but seedlings have never been seen.
This is likely because of salinity. One researcher has been able to produce
seedlings but he does it in fresh water and then places the seedlings in higher
salinity later.
Presentation: Summary of MD DNR Activities {Lee Karrh)
Lee's presentation included four major DNR projects: large scale eelgrass
restoration, coupling oyster and SAV restoration, using seeds in mesohaline sites and the
Bay Grasses in Classes program. There are large scale eelgrass restoration projects on
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the Patuxent and Potomac Rivers. Eelgrass plantings in most of the Patuxent River
would germinate and then disappear so efforts were intensified in Jefferson Patterson
Park, the most successful site. That area also saw devastation when clams returned to the
area and fishermen followed destroying the SAV beds with escalator dredges. Another
planting on St. George Island on St. Mary's River (Potomac) had better results. Some of
the beds have been stable and/or expanding since 2004. In monitoring various planting
sites, they have noticed that eelgrass survives better in areas where Rupia is present as
opposed to bare areas.
With a desire to demonstrate the effectiveness of native oysters in improving water
quality while gaining insight into the practicality of multiple habitat restoration, there was
a project that coupled oyster and SAV Restoration in South River, Maryland. Last year
(2007) was a bad year for the oysters because it was a dry and there was 100% Dermo on
the bar, with resulting high mortality.
The first year of a project to test the use of seeds in mesohaline SAV restoration took
place in 2007. The first year included the following activities: site selection, seed
collection, processing and storage, seed dispersal, and seed/seedling monitoring, and
water quality monitoring. They were able to utilize a recently developed protocol for
SAV seed storage and also developed and applied an effective SAV seeding strategy.
There were no seedlings observed at the site during subsequent monitoring surveys which
also recorded extremely poor water quality.
The Bay Grasses in Classes Program is going strong with 150 participating schools
from 15 counties and Baltimore City engaging 4,500 students. 1000 students were able
to attend field experiences. Wild celery, sago pond weed, and redhead grass were planted
by students and in 2008 water stargrass will be added. Plantings will resume in May.
Presentation: Monitoring of Long term Restoration Sites at DoD Facilities (Bob
Murphy)
There was funding granted by the Department of Defense to monitor planting sites in
2007 and additional funding has been secured to continue monitoring into 2008. After
monitoring using pvc quadrats, Mattawoman Creek proves to be an interesting site. The
planted species is not among the species present; however, the area was bare prior to the
planting effort. The species present are well represented; so dense the quadrat can not
reach the floor. Not sure whether to categorize this location as a success or not. That
would depend on whether the current grasses are a result of the initial planting event and
we can't be sure of that. Aberdeen has seen success but we must be careful claiming
credit for it because that seeding area is a natural bed. Success may have little to do with
the seeding event. Even though this is the site of a natural bed the species planted is
different from the natural SAV bed present.
Plantings for 2008: APG Vallisneria, NAB little creek zostera, Patuxent Bloodsworth
zostera, possibly mixed species, (another item). Swan Point is an area that will be
developed and the planners want to include a soft shoreline which it to include SAV.
Great salinity changes occur in this area rapidly. Dense SAV beds have disappeared in a
matter of months.
Presentation: SAV restoration in Virginia's Chesapeake Bay and Coastal Lagoons
(JJ Orth and Ken Moore)
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Bob presented his 2007 work on eel grass, where they established a method to
decrease seed mortality rates during summer storage. They also determined that seedling
establishment was greater when seeds are broadcast in the fall, when seeds are buried,
and when the bottom is sandy. The eel grass restoration project in VA's coastal bays
extended from 1998- 2007 showed that expansion of the restored areas is now being
facilitated by natural seeding from the restored areas. Ken mentioned there was another
experiment comparing seeds and seedpods in restoration of Vallisneria Americana that
indicates seeds work better. The results are available in a C.O.E. Technical Report
(http://el.erdc.usace.army.mil/elpubs/pdf/sav07-3.pdf)
Plans for 2008 include collecting millions of eelgrass seed to Spider Crab Bay, and
continue the re-seeding projects in the James, York, and Rappahannock rivers. They will
also continue with further eelgrass seed testing at VIMS by working on Jarvis seed
experiments and wrapping up the NOAA seed experiment. They would also like to begin
a re-seed experiment to see if it takes several seeding events for a bed to establish.
Discussion/ Comment
1. When collecting the seed there is no stirring process to bring what is on the
bottom to the top. Previously stirring was to improve circulation and with the
improved ventilation system, the stirring was eliminated. The seeds being fragile
is another reason why stirring was eliminated.
2007 Activities Reports
• Orth, R. J., S. R. Marion, and K. A. Moore. 2007. A summary of eelgrass (Zostera
marina) reproductive biology with an emphasis on seed biology and ecology from
the Chesapeake Bay region. SAV Technical Notes Collection (ERDC/TN SAV-
07-1). Vicksburg, MS: U.S. Army Engineer Research and Development Center.
Orth, R. J., and S. R. Marion. 2007. Innovative techniques for large-scale
collection, processing, and storage of eelgrass (.Zostera marina) seeds. SAV
Technical Notes Collection (ERDC/TN SAV-07-2). Vicksburg, MS: U.S. Army
Engineer Research and Development Center
Orth, R., S. Marion, S. Granger and M. Traber. 2007. Restoring eelgrass (.Zostera
marina) from seed: A comparison of planting methods for large scale projects.
SAV Technical Notes Collection (ERDC/TN SAV-07-4). Vicksburg, MS: U.S.
Army Engineer Research and Development Center.
Moore, K. A. and J. C. Jarvis. 2007. Using seeds to propagate and restore
Vallisneria americana Michaux (wild celery) in the Chesapeake Bay. SAV
Technical Notes Collection (ERDC/TN SAV-07-3). Vicksburg, MS: U.S. Army
Engineer Research and Development Center
• Orth, R. J. and S. R. Marion. 2007. Innovative techniques for improving Zostera
marina seedling establishment: Seed encapsulation and machine injected seeds.
Final Report. National Oceanic and Atmospheric Administration. Award Number:
NA05NMF4571250. Dec.
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Orth, R. J., K. A. Moore, S. R. Marion, and B. Anderson. 2007. Eelgrass
Restoration in the Piankatank River, Chesapeake Bay. Final Report. National
Oceanic and Atmospheric Administration. NA03NMF4570462. Aug.
Orth, R., S. Marion, S. Granger and M. Traber. 2007. Restoring eelgrass (Zostera
marina) from seed: A comparison of planting methods for large scale projects.
Final Report. National Oceanic and Atmospheric Administration. Award Number:
NA05NMF4571250. Dec.
Orth, R. J. and S. R. Marion. 2008. Restoration of Eelgrass Communities in
Chesapeake Bay with Seeds: The Emerging Issues. Final Report. National
Oceanic and Atmospheric Administration. Award Number: NA03NMF4570463.
Feb.
Moore, K.A. B.B. Neikirk, B.A. Anderson and J.C. Jarvis. 2007. Water Quality
Conditions and Restoration of Submerged Aquatic Vegetation (SAV) in the Tidal
Freshwater James River 2006. Special Report No. 396 in Applied Marine Science
and Ocean Engineering. Virginia Institute of Marine Science, Gloucester Point,
Va. 77p.
Lunch
Presentation /Discussion: USACE Proposed SAV Restoration Project
(Michelle Gomez)
Michelle presented through the conference line, what she knew of the plans for
aggressive, moderate, and light planting of SAV on a 0 to 30 year time frame. USACE
proposed planting 1700 acres of SAV in 30 years (50acres per year) in St. Mary's. There
is a draft Report going through ITR review and then public review likely in the Fall. The
implementation date is estimated to be FY 2011 but that is highly variable based on the
outcome of the review processes. The original group working on this has changed offices
and it has been turned over to another project manager. This project is likely to take
place as long as funding is attached. This work would likely have to be open for biding
in order to accomplish this task. She would urge that the SAV workgroup be involved in
the public review if not before.
Discussion/ Comments
1. Chris Tanner was mentioned as someone who was consulted or needed to be
consulted.
2. Is there any design to restore the oysters and SAV together? She is not sure.
3. Where are they going to get the seed and who is going to do this work? We are
not sure. In order to do a project of this size would require the entire SAV
workgroup.
4. This project is sponsored by St. Mary's county. She does not know who they
consulted in order to choose the magnitude and scope of this project.
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5. Please send the facts sheet to the entire workgroup via the list serve.
6. Is there enough suitable bottom in St. Mary's to plant 50 acres of SAV per year?
Not sure. Lee Karrh said that he has looked at telemetry and says that there is
plenty of bottom, suitability is unknown.
7. The questions we are asking are likely coming up in the ITR review.
Workgroup Group Discussion: What we've learned & What we want to do (Everyone)
1. In view of the re-colonization of many areas in the upper Bay, we see that some
areas are at a point of recovery and other areas are not. We need to focus on the
areas that are yielding to our restoration efforts. There is not much to show for
the state's investment but this would increase if we focus on the areas that are
close to the point of rebounding.
2. We need to go back to identifying suitable sites. Our tools to identify suitable
sites are not working. Focusing on sites that do persistently well may not give us
the answers we are looking for because we have had sites that are seemingly
identical, one would survive and the other would not. We do not yet have a list of
conditions needed per species. Even if we have unlimited funding, we still don't
know why our planting efforts are failing. Failed efforts expose more of what we
don't know so we may need to focus on the failed sites to set criteria for future
planting sites. Until we can determine what makes a successful planting site
people will want to funding into waste water treatment instead of SAV
restoration.
3. We need to advertise the fact that Bay grasses are cleaning the Bay. People
believe oysters will if they can ever get established but we have examples of how
SAV is cleaning the Bay today. SAV needs a marketing director.
4. Dub tailing with USACE's dredging may be a good idea. There is an RFP by
Schafer for engineering SAV habitat. Dredge spoil usually is not suitable for
SAV habitat due to its composition; however, this could be addressed by
overlaying dredge material with several inches of sand. In doing so, you would
also have to find a way to keep the sand in place. Poplar Island would be a good
case study site for a sand lens since it was built from dredge spoil.
5. Are we as a group doing enough to achieve the tiered approach? We should be
working from one plan, collecting data, and synthesizing it together. The closest
we come to this is the goal of lOOOacres SAV planted by Dec 2008 as stated in
the strategy document.
Presentation: Sun, sand, and waves (Evamaria Koch) (This is the updated presentation
summary)
Evamaria presented on three elements that SAV in the Chesapeake Bay need, sun,
sand, and (not so high) waves. SAV needs lots of light but they can handle pulses of light
caused by turbidity plumes associated with shore erosion.
Sand is also an important element to foster established SAV beds. Photos of
Solomon's Island from 1950 and 1979 show that not only are the SAV missing in the 79
photos but the sand spits are gone as well. This inspired research in SAV sediment
requirements. Experiments in the Maryland Coastal Bays revealed that areas with SAV
have low silt and clay content. 90% of the SAV exist in areas with less than 36% silt and
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clay content but silt and clay substrate overlain with sand is effective habitat for SAV. A
layer of sand of only 2 cm is needed to allow eel grass and widgeon grass to become
established. Shoreline erosion is good for SAV if the shore is sandy, if it is silt and clay,
it can be bad depending on local hydrodynamic conditions.
There is also a critical wave height for SAV. Mid and lower Bay critical wave height
is 0.3m and in the upper Bay it is 0.15 m. Waves have less impact on well established
SAV beds than on seeds. Waves in established beds simply cleared out the dead foliage.
Wave threshold is highly dependent on the substrate. In the sandy substrate of the
Chesapeake Bay the eel grass can't handle much wave action. In Long Island sound with
the gravel substrate, the eel grass can take ocean swells.
Presentation: Florida Bay and St Joseph's Bay (VictoriaHill)
Victoria presented her work on the Florida Bay and St. Jospeh's Bay optical
layers. In Florida Bay particulate matter is not the only thing that absorbs light, CDOM
does also. SAV was not present in areas with a high amount of scattering light. Sea
grass has been lost in the Florida bay area leaving sediment free to suspend, increasing
the turbidity to the point that sea grasses can not survive, reestablish and secure the
substrate once again. TSM was a major attenuating factor in Florida Bay more than algae
and CDOM.
St. Joseph's Bay used to be a shallow clear bay, but the inter-coastal waterway
was opened allowing an influx of sediment loaded water. Her work included using light
spectrum reflected to classify the vegetation observed in aerial photography.
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SAV Meeting (Day two)
Thursday, February 28, 2008
Virginia Institute of Marine Science
Rt. 1208, Greate Road
P.O. Box 1346
Gloucester Point, VA 23062
9:00 am - 3:00 Dm
Agenda and Presentations are available using the following link:
http://archive.chesapeakebav.net/calendar.cfm?EventDetails=9345&DefaultView=all&R
equestDate=02/06/2008
Attendance
Name
Organization
Email
Lee Karrh (Chair)
MDDNR
lkarrh(fl),dnr. state, md.us
Jessie Jams
VIMS
C am ob el l (elm ms.edu
Erin Shields
VIMS
esheildsfo! vims.edu
David Parrish
VIMS
oarrishd® virns.edu
Scott Marion
VIMS
smari on®,vim s. edu
David Ruble
ODU
drubleffl), odu.edu
Bob Orth
VIMS
iiorth®vi rns.edu
Mark Lewandowski
MDDNR
ml ewandowski(fl),dnr. state, md.us
Peter Bergstrom
NCBO
Peter.bersstrom(fl),noaa.sov
Becky Thur
CRC
thurb(o>,si.edu
Victoria Hill
ODU
vhillfo),odu.edu
Ken Moore
VIMS
moore(a>,vim s. edu
Nancy Rybicki
USGS
nrvbicki(fl),usss. now
Jay Woodward
VMRC
Jav. woodward®,mrc.virsinia.sov
Jason E. Gramberg
UMCES- AL
i sramb er«®al. umce s. edu
Stan Kollar
HA
skollar®,harford.edu
Bob Murphy
ESI
Murohv® ecosystem sol utions.ory
Beth Zinecker
UMD
zinecker®,umd.edu
Sarah Hunter
CRC
sarahehunter®, comcast. net
Laura Murray
UMCES- HPL
murrav@,hDl .umces. edu
David Wilcox
VIMS
dwilcoz®vims, edu
Claire Buchanan
ICPRB
cbuchan(o),icDrb. ore
Becky Raves Golden
MDDNR
rsolden(fl),dnr. state, md.us
Katie Busch
MDDNR
kbusch(fl),dnr. state, md.us
Krystal Freeman (Staff)
CRC
Freeman, krystal (a), eoa. sov
Action Items
•S Get links on the bay program site
•S Krystal will find out how the SAV workgroup can connect with the
invasive species response action workgroup about the water lettuce found
in the Potomac.
Date:
Location:
Chesapeake Bay Program
A Watershed Partnership Time.
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¦S Becky will talk to Kevin Sellner about possibly hiring a staffer
specifically for the SAV workgroup during CRC's next grant cycle.
•S Someone should talk to Carl Blankenship about getting the water lettuce
in the Potomac River in the Bay Journal.
•S Workgroup members doing field work should download quads from
VIMS website, and record observations and actions concerning water
lettuce and send to Nancy.
•S Lee and Krystal will update the SAV Strategy Document and circulate it
for further email review by the workgroup.
Announcements
~> Next Meeting will be two days during the first week of October at Horn Point
Day 1 Discussion Re-cap:
The previous workgroup discussion was about how to best coordinate data collection,
funding and publicity by working together to get funding collectively and centralizing
data as part of the grants, engineering SAV sites, and marketing SAV accomplishments.
Workgroup Discussion Continued:
6. Is Seagrass.net a model we would like to follow? For example everyone working
with seeds for restoration purposes should be collecting the same information
across the board; like seagrass.net. They have more freedom because their
funding sources are private organizations. Seagrass.net work on reefs with
volunteers, we work in the Chesapeake and would need divers, getting certified as
a diver is difficult in our organization. We also need someone who will step up to
organizing us as a group. The idea of working together is great but we have to
develop the protocol and keep people on task.
7. The goal of forming this group approach is to document what is actually
occurring at different sites over time. First we need to discriminate the existing
information/successes. The Bay program is supposed to be the organization that
unifies us but the workgroup chair is not paid by the bay program. If we could
have CRC hire an SAV specific staffer during the next grant cycle that could help,
CRC is 2 years into the 5year cycle so it will not be anytime soon.
8. It would be great to have a webpage. VIMS is premier SAV website today.
Instead of creating a page we could have SAV data included in the eyes on the
Bay or the VMRC site. You can't convince funders without a decent website.
Dave's web page serves the role of stating our purpose. SAV is not a charismatic
mega fauna like coral. Circulate more photos like Eva had on her presentation
yesterday. To start we can be sure that all the SAV pages have links on the SAV
bay program web page. As we begin to write pages for the website, we should
start with the strategy document. The main need is to centralize the information.
Our original goal is to educate managers, not just the general public. We must be
careful about relying on people's identification of species when you have a site
where you can input data.
9. Restructure workgroup to form an umbrella organization to gain funding for
restoration efforts, organize data collection, help others understand why SAV
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research is important. CRC could be a great organization to initiate this umbrella
organization because they are a 501c3 organization, and this mission would be
supported by CRC and Kevin Sellner. Becky is to present the idea to Kevin and
find out the appropriateness of hiring someone through CRC to get this moving.
This is the time for structural change since CBP is reorganizing. We will be
working with Tom Parham as he is representing LRSC in the Bay Program's
reorganization efforts.
Presentation: Water Lettuce in Potomac River (Nancy Rybicki)
Nancy presented maps showing the distribution of a new invasive species, water
lettuce, in the fresh tidal Potomac River. Water lettuce is native to Florida and Nancy
identified it in several locations in the Potomac in Fall, 2007. Accompanied by Curtis
Dalpra, ICPRB, they discovered it during a shoreline survey for SAV. The plants had
such a wide distribution that it was impossible to remove them with out a concerted
effort. Nancy contacted National, state, and Bay-wide invasive species programs to find a
partner or an existing program to remove the plants before they spread further, but none
existed. What are the next steps? She provided a short literature review: Water lettuce is
not cold tolerant so the leaves shrivel in the winter but the seeds endure and germinate in
20-25c temp meaning around June. It is possible that the water lettuce came from
someone's pond, was transported on a boat, or, was distributed by waterfowl. There are
several ways to control water lettuce, you can sein it, rake it or chemical control it. The
USGS Nuisance Species site has an 800 hotline, when she called it they added the new
sighting in MD/VA to they distribution website, the existing USGS program doesn't
include action to remove exotics. ICPRB, MDDNR have also written some informational
documents (a poster with a picture of water lettuce asking boaters to call Mark L,
MDNR, if they see water lettuce).
Comments/ Discussion
1. Mark is still waiting for a response to a proposal he wrote to get funding to
remove water chestnut and water lettuce.
2. We could use oil booms and the harvester to gather dense areas of water lettuce
since it is not rooted.
3. We need to let the fishermen and others out on the water know that this species is
bad for fish; they may pull it out while they are out on the water. We need scouts
in June to see if the water lettuce returns before setting off the alarm and rallying
people.
4. Talk to Carl Blankenship about getting this in the Bay Journal.
5. Find out how to get the ball rolling in the Chesapeake Bay when an invasive is
spotted, to stop the spread when it is still containable. Krystal will contact
MAPAIS since they did an invasive species rapid response workshop.
6. In June we need to work in an organized team effort. Designated teams will be
assigned to specific sections of the Potomac, near the previous sitings. Those
teams can download quads from VIMS website, and record observations and
actions concerning water lettuce while they are out in the field and send to Nancy
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or Mark L who will enter the information in arc map and assess the need for
removing plants, if any, for 2008.
7. Richard Kraus (George Mason professor) would likely be a good resource when
dealing with issues on the Potomac.
8. We need to adjust the strategy documents segment on invasive species and
coordinate with MAPAIS.
Presentation: Relating SAV Area to Water Clarity (Becky Golden)
Becky presented on two different approaches used to analyze the relationship
between SAV and Water Clarity. The first approach examined water clarity by
measuring the Secchi depth at 69 mid-channel fixed stations from 2001- 2005. The
second approach used spatially interpolated surface turbidity data from eight segments
ranging from 2003- 2006 and compared the areas with and without SAV. The monthly
dataflow cruises is the source of the turbidity data while the VIMS aerial survey is how
the presence of SAV is determined. Results for the 1st approach showed that as you reach
the Secchi depth goals you also saw an increase in SAV area. This correlation was strong
in the high salinity areas but in the low salinity areas it was only a moderate fit. Results
for the 2nd approach indicates the high salinity and low salinity vegetated areas had lower
turbidity than the un-vegetated areas.
Discussion/ Comments:
1. This turbidity information is extrapolated from the cruising track. Accuracy
would be increased in the turbidity was recorded directly over the SAV beds.
2. The SAV/ turbidity over lay is a 50 meter grid cell, if any portion of the 50m cell
has SAV then the entire 50m cell is identified as vegetated, higher resolution data
would improve accuracy.
3. Suggest increasing water clarity target for SAV planting sites by 10% for
successful sites.
Presentation: Magothy River Index (Peter Bergstrom)
Peter presented the findings of the sixth annual Magothy River Index conducted
by the Magothy River Association. Since 2003 this index has assessed SAV, water
quality, and dissolved oxygen. The over all health status of the river in 2007 was 42% of
the goal, down from its 2004 peak of 65% goal achieved. It is believed that 2004's high
goal attainment was due to the presence and filter feeding of dark false mussels which
died back in 2005. Episodic events such as the mussels seem to have driven changes in
the Magothy aquatic health more than changes in rainfall.
Water clarity is measured by secchi depth for this index. The SAV and water
clarity % goal attained correlated well from 2002 through 2006 but SAV declined more
than the clarity in 2007. This correlation was observed after analyzing water clarity as the
percentage of values above the goal, as opposed to the median values previously used.
Presentation: Exploratory Analysis of CBP water clarity (secchi) data (Claire
Buchanan)
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The method used to calculate the water clarity indicator used in the Chesapeake
Bay Program (CBP) Health and Restoration Assessment (BHRA) reports - i.e., the
frequency (%) of observations above a threshold - makes this indicator sensitive to
changes in the highest water clarity levels. It addresses the question "How often is
underwater light adequate for healthy phytoplankton in open water environments (during
the Spring-Summer season)?" A 23-year downward (degrading) trend of-1.24 cm/year is
evident in the water clarity. The Middle and Lower Bay main stem (CBP segments
CB4MH - CB8PH) are experiencing relatively rapid declines in water clarity. The Upper
Bay main stem (CBP segments CB1TF - CB3MH) and the many large and small
tributaries to the Bay are showing lesser declines.
Secchi depths declines are steepest near the Bay mouth. The higher percentiles
(e.g., 95th%ile3 90th%ile, 75th%ile) of each year's distribution of observed Secchi depths
are declining fastest while declines in the lower percentiles are not statistically
significant. The yearly interquartile range (25th%ile - 75th%ile) and variance around the
mean are compressing. Declines are greatest in the spring, followed by summer, then
autumn. Secchi depths greater than 2.0 m were common in 1980s and are now
uncommon.
The expected consequences of this water clarity decline in the middle and lower
Bay mainstem are: higher frequencies of algal blooms and algal crashes (busts), higher
frequency of HABs, higher pheophytin and DOC concentrations (indicators of algal
stress), unstable and sometimes inadequate phytoplankton food for grazers, and higher
(but also highly variable) chlorophyll cell content in phytoplankton cells.
Obvious factors such as total suspended solids and chlorophyll a that affect
Secchi depth do not appear to be the explanatory causes. The relative amounts of volatile
(typically organic) and fixed (typically inorganic) suspended solids are not changing.
One can see the expected decline in the frequency of above-threshold Secchi depths as
flow increases; however there is a distinct difference in the patterns of the 1984 - 1995
period and the 1996 - 2007 period. Therefore, flow-related changes are probably not
causing the observed 20+ year decline. Factors that are not well monitored, such as
photopigments other than chlorophyll a, biotic and abiotic particles < 0.45 microns, and
dissolved organic compounds, need to be further investigated.
Strategy Document Discussion:
The workgroup reviewed the SAV strategy document and made revisions to each
strategy. The revisions discussed will be made to doc and the strategy document will be
circulated for further email review.
Next SAV Meeting
Reserve the first week of October for the next two day meeting at Horn Point.
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