The Hackensack
Meadowlands District is a 32-square mile area covering portions
of 14 municipalities in northeastern New Jersey. Of the
21,000 acres which comprise the District, approximately
17,000 were originally wetlands and waters, and comprised
a diverse array of wetland cover types, including tidal
marsh, hardwood forest, and Atlantic white-cedar swamp.
From the beginning of European colonization up until the
present, the District’s wetlands have been logged, diked,
drained, farmed, filled, and contaminated, with the result
that half of the wetlands and waters have been lost to fill
and/or degradation. Today, the District’s landscape is surrounded
by urban development, and its once diverse plant communities
have been succeeded by what is essentially a monoculture
of invasive Phragmites australis, better known as
common reed.
In spite
of a history of abusive land-use practices, however, there
has been a remarkable renaissance of fish and wildlife use
in the District. The passage of the Clean Water Act in 1972
along with aggressive local enforcement by the New Jersey
Meadowlands Commission resulted in dramatic increases in
water quality, air quality, and surface land quality in
the last 30 years. The result: the number of species of
both migratory and resident birds which use the Meadowlands
has more than tripled during this time, and the numbers
of fish and invertebrate species have shown similar increases.
Crackdowns on illegal dumping, as well as ongoing clean
closure of some of the District’s landfills, are reducing
the volume of leachate which enters the Hackensack River
and adjacent wetlands. In addition, the Meadowlands Environmental
Research Institute (MERI) has intensively begun to study
the myriad environmental problems which still face this
urban wetlands ecosystem.
What is
it that makes the Meadowlands so significant? First, despite
loss of about half of its original wetland and open water
areas, the Meadowlands is still a large system, comprising
about 8,500 acres of wetlands and open water. Second, it
is located within the Atlantic flyway, a significant coastal
pathway for migratory birds, for which the Meadowlands represents
a significant resource. Finally, because it is surrounded
by intense urban development, the Meadowlands is an important
island of wetlands in a landscape that has lost most of
its coastal wetlands. The only other large estuarine wetland
in the New York metropolitan area is the Jamaica Bay National
Wildlife Refuge; consequently, the Meadowlands becomes especially
important for its ability to provide food and resting habitat
for hundreds of migratory bird species, as well as breeding
habitat for more than 60 resident bird species. Additionally,
a variety of estuarine fish species such as blueback herring
depend on the Meadowlands for nursery habitat as juvenile
fish make their way to coastal waters.
Apart from
the obvious human pressures on this ecosystem, however,
there are serious ecological problems facing the Meadowlands.
Aerial photographs from over a period of 30 years show that
some marshes which were not filled or altered have lost
half of their open water. The cause of this loss appears
to be from sediment accretion and overgrowth resulting from
colonization by invasive forms of Phragmites australis.
This variant of P. australis is probably a recently
identified non-native genotype, dubbed haplotype M, which
seems to be responsible for the aggressive colonization
of northeastern marshes and concomitant displacement of
other plant and animal species from those systems. This
variant is highly aggressive, forming dense root mats and
clonal populations of stems which remain standing for several
years after dying. Ecosystem fragmentation promotes the
spread of Phragmites; the plant reproduces through
rhizomes and seed germination and is able to tolerate fairly
high levels of salinity (in the range of 15 ppt). While
type M Phragmites can provide benefits to the urban
environment, such as sediment stabilization and toxicant
immobilization, it changes marsh dynamics dramatically.
Over time this monoculture is much less likely to support
larval fishes and causes loss of open water/marsh complexes,
rendering less habitat available to wading birds, waterfowl,
shorebirds and other species. Consequently, the choice of
what to do to save the Meadowlands’ remaining marshes will
need to balance a variety of considerations.
The Meadowlands
is likely to experience considerable change over the upcoming
decades as hazardous waste sites are remediated, brownfields
are redeveloped, and the estuary’s watershed responds to
development pressures. As resilient as the Meadowlands has
shown itself to be, it is now in an urban landscape setting
which places enormous stress on the ecosystem. One thing
seems certain: if the Meadowlands is not managed, it is
likely to experience an overall decline in wetland quality
and estuarine life support. Ongoing research, such as the
studies being performed by MERI, can help fill the information
gap that currently exists on urban ecosystems, and hopefully,
allow for better informed decisions.