[CT Birds] State of the Birds Report

[wingsct at juno.com]

Ron,
You've certainly given a very interesting historical perspective on salt marshes
in CT.  I think seawalls have also contributed to declines in salt marshes,
especially in heavily developed towns and cities such as Stamford and
Greenwich, where salt marshes are almost non-existent.

You also mention sudden vegetation die-off.  Are you referring to eelgrass?
Parts of Cape Cod Bay have been experiencing unexplained die-off's in 
recent years as have parts of the CT coast.  Could this be a cyclical 
phenomenon as what occurred globally in the 1930's?  

Meredith Sampson
Old Greenwich



-- ORCHIDS <bulbophyllum at charter.net> wrote:
I have read the Audubon report State of the Birds and the recent New  
London Day article and offer these points of clarification.  Chris  
Elphick cites an estimate of ‘salt marsh’ loss in New England on the  
order of 80%, estimates prepared by Bertness and others.  First, there  
is no way to use historic maps and charts and differentiate between  
salt marsh, brackish marsh and fresh-tidal marsh.  Connecticut  
estimates for tidal marsh loss based upon two estimated acreage in   
the 1800’s is on the order of 30% (http://camel2.conncoll.edu/ccrec/greennet/arbo/publications/34/FRAME.HTM 
).  The most accurate historic maps for CT are the “Coast & Geodetic  
Charts” of the 1880 series.  The older charts lack the accuracy of  
this series and should never be used to estimate tidal wetland acreage.

The 1880 series cannot be used to derive an absolute historic acreage  
for the emphasis was mapping shore areas and so for many large tidal  
rivers (e.g., Hammonassett, East River), the mapping does not extend  
to the head of the tide.  DEP did develop estimates of wetland losses  
in individual towns by comparing the same extent of mapped wetlands in  
the 1880’s to the same area of wetlands mapped in the mid-1990’s.   
Stamford’s losses are on the order of 90% but the losses for the lower  
Connecticut River (a DEP/USFWS project resulted in the designation of  
these wetlands as  “Wetlands of International Importance” under the  
Ramsar Convention in 1994) are less than 5%.

The report calls for the protection of tidal wetlands and to actively  
prevent their degradation.  Not sure what the basis of this  
recommendation is for the passage of the tidal wetlands act of 1969  
stopped wetland losses from new activities.  The loss rate prior to  
1969 was estimated at 70 acres/year and the current permitted losses  
are 0.25 acres/year or less.  The Tidal Wetland Acts does not permit  
new activities that could cause wetland degradation (e.g.,  
installation of new tide gates, undersized culverts) but the tidal  
wetlands act (TWA) had no provision to reverse the degradation caused  
by pre-1969 structures such as tide gates.  The failure of the TWA to  
foresee the need for restoration was corrected by the Coastal  
Management Act of 1980 which established a state policy that  
encourages the restoration of degraded tidal wetlands (and also other  
coastal resources such as beaches, dunes, intertidal flats).  This  
policy became the foundation or driver for the state’s tidal marsh  
restoration (nearly 30 years old) originally spearheaded by the  
Coastal Management Program.  It is estimated that over 80 tidal flow/ 
restoration projects have been implemented, resetting over 1800 acres  
of tidal marshes on a trajectory to becoming a self-maintaining  
ecosystem.  It is not clear what the Audubon report is calling for  
with regards to tidal wetlands.

The Audubon report describes (the non-native) grasslands of  
Connecticut as the most threatened environment.  The most threatened  
environment in Connecticut are tidal wetlands and the chief threat is  
global warming.  The expansive tidal marshes we know today formed 3000  
years ago when sea level rise slowed to a rate of 1 mm/yr.  Today  
ocean sea level is rising at 3 mm/yr.  We know that nearly all low  
marsh west of New Haven has been gradually (over several decades)  
converting to mudflat and this process began by at least the late  
1880’s.  The rebound of northern New England from deglaciation has  
caused southern New England to warp downward and thus increase the  
relative sea level rise.  The rates of sea level rise are highest in  
western LIS and lowest in eastern LIS.

Presently there appears to be unprecedented changes in marsh  
vegetation, at rates that have not been observed by wetland scientists  
in the last 50 years.  Chris refers to Black Grass as an important  
high marsh indicator.  This non-native grass is fleeing the high marsh  
and is invading the terrestrial forests of the coast and the former  
Kentucky bluegrass lawns at Hammonassett.  The stone dust trail at  
Great Meadows in Stratford is now the habitat for Black Grass.   
Spartina patens appears to be disappearing from the high marsh and is  
being colonized by Spartina alterniflora.  On Cape Cod, the seaward  
edge of high marsh (several meters wide) is now barren.  This same  
trend has been observed at Hammonassett.  All of these changes are not  
unexpected given the estimated sea level rise rates of the 1990’s at  
11 mm/yr!  If I had to make a forecast, I would predict that we are  
witnessing the loss of high marsh and in several years low marsh will  
be the dominant habitat in CT marshes.

I wonder too what the impact of the recent sudden vegetation dieback  
along tidal creeks of marshes from East Lyme to the Housatonic River  
have had on marsh sparrows (http://wetland.neers.org/).   The  
Connecticut Agricultural Experimentation Station is attempting to  
determine if the cause of dieback is a pathogen.  This emerging  
wetland issue is not mentioned in the Audubon report.

Finally, Audubon recommends the creation of marsh islands.  Had  
Audubon reviewed state policies and practices it would know that such  
an action cannot be permitted by the Corps of Engineers or DEP.   
First, to create marsh islands, one must destroy existing healthy  
intertidal or subtidal habitat thus creating unacceptable adverse  
impacts.  Marsh islands are ephemeral features for they are created in  
areas that nature wants to sustain as ‘deep’ water habitat.  From the  
day of their creation, marsh islands are eroded by wave energy until  
they become submerged features returning once again to subtidal habitat.

Ron Rozsa, Phytosociologist, Ashford, CT
_______________________________________________
This list is provided by the Connecticut Ornithological Association (COA) for the discussion of birds and birding in Connecticut.  
For subscription information visit http://lists.ctbirding.org/mailman/listinfo/ctbirds_lists.ctbirding.org
_____________________________________________________________
Free comparison of top car rental companies. Click Here!
http://thirdpartyoffers.juno.com/TGL2121/fc/Ioyw6i3nMUoD4qAwT7G3yTvbhYWOIrREJgVHsxkhcuC7NdpiQU2vRC/