Rivers and streams
Cascade Brook salt marsh restoration in Scarborough Marsh
|Cascade Brook salt marsh restoration.
Scarborough Marsh Wildlife Management Area, Maine's largest salt
marsh (3,100 acres), has the greatest diversity of water-dependent
birds statewide. However, barriers to tidal flow, undersized culverts,
upland development, invasive plants, fill material and drainage ditches
limit the Marsh's full biological potential.
Al 100-acre section of Scarborough Marsh became the focus of an ambitious
restoration effort coordinated amongst federal, state and local conservation
partners. In 1996, a 500-year flood destroyed the road crossing at
the Old Blue Point Road, dumping large quantities of spoil material
on two acres of downstream marsh, smothering native salt marsh vegetation
and filling a tidal creek. In addition, 45 large piles of peat (ranging
in size from one to 100 cubic yards) were ripped out of the marsh during
the flood, floated downstream and came to rest on the surface of the
marsh. Non-native Phragmites began aggressively invading the newly
disturbed areas, threatening the natural resource values of the Cascade
Brook salt marsh.
The Cascade Brook restoration porject, completed in early 2004, involved:
- lowering the water control structure to increase tidal flow,
- partially removing the underwater berm,
- removing 5,000 cubic yards of spoil material on the surface of
the marsh and in the intertidal creek,
- removing all of the peat piles,
- controlling the spread of Phragmites, and
- pre-restoration monitoring and five years of post-restoration monitoring
Our Gulf of Maine Coastal Program office, along with partners at
Natural Resources Conservation Service, Maine Department of Inland
Fisheries and Wildlife, Friends of Scarborough Marsh and several environmental
consulting firms -- provided uncounted hours of technical support needed
to design the restoration work, plan the monitoring protocols, obtain
permits, fundraise, conduct community outreach and coordinate partner
Weskeag Marsh restoration projects
|Weskeag Marsh culvert installation.
Weskeag Marsh is one of the largest marshes in mid-coast Maine (1,000 acres)
and ranks as one of the most productive shorebird roosting and feeding sites
in the Muscongos Bay region. Four phases of salt marsh restoration work focusing
on ditch plugging, and a fifth phase involving the removal of an undersized
culvert, have been completed at Weskeag, with active involvement of our Gulf
of Maine Coastal Program office, Natural Resources Conservation Service,
Maine Department of Inland Fisheries and Wildlife, Ducks Unlimited, USFWS
Partners for Fish and Wildlife Program and several environmental consulting
firms. Restoration work involving plugging mad-made ditches to prevent excessive
drainage and permit the re-establishment of permanent pool habitat on the
marsh surface. Restoring salt marsh water levels helps attract many native
species -- aquatic plants, invertebrates, fish, shorebirds, wading birds
and waterfowl -- that depend on permanent pools of water on the high marsh.
Replacement of the undersized culvert at Buttermilk Lane was funded by Maine
Department of Transportation, with technical support from our Gulf of Maine
Coastal Program staff and other partners.
Phragmites control and monitoring in Scarborough Marsh
|Biologists assessing non-native phragmites.
A non-native form of Phragmites is aggressively invading Scarborough
Marsh, Maine's largest and most well-known salt marsh. Scarborough
Marsh still retains a natural assemblage of salt marsh vegetation,
pools and creeks, and it has recently been documented as the marsh
with the greatest waterbird biodiversity statewide. However, Phragmites
has the potential to eliminate native salt marsh vegetation, creating
a monoculture of tall reeds that destroys salt marsh habitat values
for many native fish and wildlife.
Phragmites first appeared in Scarborough Marsh about 25 or 30 years
ago. Since then, it has aggressively
invaded the Marsh, converting some areas into pure, dense stands of
Phragmites up to 18 feet tall. Phragmites has expanded into previously
pristine sections of the Marsh, and all partners involved in Scarborough
Marsh restoration activiites recognize that Phragmites has the potential
to overtake the Marsh. Some of the restoration activities Gulf of
Maine Coastal Program and our conservation partners have already completed
have halted the spread of Phragmites in a few sections of Scarborough
Marsh, but parnters have now embarked on a Marshwide program to identify
and then control the spread of Phragmites. For more information on
Phragmites, read our five-page fact sheet, "Phragmites:
Questions and Answers."
Rivers and streams
Somes-Ripple-Long Pond watershed fish passage restoration
|Somes Sound dam and fishway.
Four degraded fishways located at low-head mill dams no longer provided
effective passage for diadromous (searun) fish in the Somes-Ripple-Long
Pond watershed on Mt. Desert Island, Maine, adjacent to Acadia National
Park. Without effective fish passage at the dams, annual native fish
runs (alewife, blueback herring, American eel, sea lamprey) have declined
dramatically. Without the fish, valued local traditions associated with
the harvest of searun fish have also been lost. In 2006, the deteriorated
fishways located at the first and third dams in the watershed were repaired.
Work continues to monitor and evaluate fish runs at the two restored
fishways, and to implement restoration projects at the two remaining
degraded fishways. Once all four fishways are restored, conservation
partners will have restored searun fish access to 1,032 surface acres
of lake habitat and one mile of riverine habitat throughout the watershed.
Bringing searun fish back has added benefits of attracting birds and
other wildlife, increasing the biological vitality of the entire watershed.
Throughout this restoration project, Gulf of Maine Coastal Program
has provided key strategic advice to local,
state and federal partners, helped plan the restoration
project, provided advice in developing the wayside
exhibit, and directed substantial funds from
several nationally competitive grants to the
project. GOMCP will continue working with partners
from Somes-Meynell Wildlife Sanctuary, Maine
Department of Marine Resources, USFWS Fish Passage
Engineers, NOAA and other locally-based supporters.
Highland Lake fishway restoration
|Highland Lake fishway after it was restored.
In 1936, a dam built at the outlet of 640-acre Highland Lake in the
Presumpscot River watershed cut off native sea-run
alewives, as well as some American eel and sea
lamprey from their historic spawning and nursery
habitat. More than 50 years later, in 1988, Maine
Department of Marine Resources constructed a
concrete denil fishway at the dam to allow adult alewives
to pass upstream to spawn in Highland Lake, and
to allow adult and juvenile alewives to move
downstream to the Gulf of Maine. When the new
fishway was installed, alewife populations rebounded.
However, after only eight years of operation,
the old Highland Lake Dam breached in a massive flood, destroying the
fishway and overwidening the downstream channel of Mill Brook in the
process. Unfortunately, a new dam and fishway constructed in 2000 did
not effectively pass alewives.
In 2006, after several years of planning and fundraising, the existing
fish ladder was renovated, the Mill Brook stream
channel was restored, and post-restoration monitoring
is now ongoing. Gulf of Maine Coastal Program
has been actively engaged in many aspects of
this restoration project – coordinating with
partners (Maine Department of Marine Resources,
USFWS Fish Passage Engineers, town officials,
environmental consulting firms, building contractors,
and nearby residents), planning, designing, fundraising,
conducting outreach, and monitoring, With fish passage restored from
the ocean to Highland Lake, fisheries biologists expect that Highland
Lake can now produce an estimated 150,000 adult and 1,000,000 juvenile
alewives annually – all part of exciting, collaborative and multi-pronged
efforts to bring the Presumpscot River watershed back to life after centuries
of abuse dating back to the Industrial Revolution.
St. Croix River alewife interaction study
In sections of downeast Maine, there has been a widely held, but scientifically
unsubstantiated belief that alewife restoration interferes with a well-established
and recreationally/economically significant non-native bass fishery.
Unfortunately, the controversy has led to management decisions that have
caused precipitous declines in alewife populations (see the next slide
for an example), and has threatened to de-rail alewife restoration elsewhere
in Maine. To resolve the controversy, Maine Rivers, a non-government
conservation group, took the lead in hiring a fisheries scientist to
conduct an objective review of existing scientific literature and carry
out original research designed to fill knowledge gaps. The work, completed
in 2006, is detailed in two reports that are both available on this website:
Together, these reports replace unsubstantiated claims with credible
scientific information and provide documented evidence that native searun
alewife do not outcompete non-native bass. This information should contribute
to reasoned decision-making for future restoration and management decision-making
in the St. Croix River watershed and beyond.
Gulf of Maine Coastal Program provided funding through the National
Fish and Wildlife Foundation -USFWS Maine Habitat Restoration Partnership,
as well as technical and biological support through our participation
on a Scientific Advisory Committee. The Advisory Committee oversaw the
design, implementation and distribution of the studies. The Committee
included Maine Rivers, NOAA, Fisheries and Oceans-Canada, New Brunswick
Department of Natural Resources, Maine Department of Marine Resources,
Maine Department of Inland Fisheries and Wildlife, St. Croix Waterway
Commission, Trout Unlimited, and Maine Atlantic Salmon Commission.
St. Croix River and Milltown Dam monitoring
|Milltown dam fishway trap.
Fisheries biologists estimate that the St. Croix watershed on the Maine-Canada
border may have once suported 14-38 million alewives and similar-looking
blueback herring. However, in the 19th and early 20th century, when dams,
water pollution and overfishing overwhelmed the river, the alewife population
plummeted. With installation of fishways and water pollution controls
in the 1970s and 1980s, the population of alewives began to rebound --
up to two milion adult alewives by the early 1990s. However, based on
unsubstantiated fears of negative interactions between native alewives
and non-native bass, the Maine Legislature (over the objection of the
Canadian government, the St. Croix International Waterway Commission,
Maine Department of Marine Resources, Trout Unlimited, Maine Rivers and others)
mandated closure of the federally-funded Milltown Dam fishway at Woodland.
In a few short years, the alewife run declined to a shadow of its former
abundance. Only 900 fish returned in 2002, and today, a tiny remnant
populations is being maintained with a small-scale trap and truck operation,
managed by the Canadians.
The St. Croix International Waterway Commission, under agreement with
Maine Department of Marine Resources and Canada's Department of Fisheries
and Oceans, operates the Milltown Dam fishway and research trap on the
St. Croix River during the spring alewife run. Gulf of Maine Coastal
Program has provided funding from 2004 - 2007 to collect, analyze and
submit data on the St. Croix River alewive population. The data clearly
documents the precipitous decline in the alewife population, and will
be essential in taking future steps to restore alewives in the St. Croix