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The
Three Rivers Watershed
Like 3 long fingers reaching into the
sea, the combined Three Rivers watershed
is 72.4 kilometres in length and drains
an area of 357 square kilometres on
the eastern shore of Prince Edward Island.
Placid and pastoral, the river network
slips quietly through a landscape of
mixed woodlands, farmlands, sand spits,
beaches and shale outcroppings into
Cardigan Bay. From north to south, the
waterways of the Three Rivers watershed
include:
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Tour the Cardigan Fish
Hatchery and Water Science
Centre
Learn about the rearing
and stocking of salmonids
– Atlantic salmon,
rainbow trout, speckled
trout, brook trout and
Arctic char – at
the Cardigan Fish Hatchery,
located on the Cardigan
River just west of the
village of Cardigan. Since
1937, the Hatchery has
been a focal point for
visitors who tour the
facility’s egg incubation
areas, rearing tanks and
ponds. Fish raised at
the Hatchery are used
to stock the area’s
Three Rivers. Aquaculture
research and education
is carried out by Atlantic
Veterinary College, in
association with the University
of Prince Edward Island.
Since 2000, the Cardigan
Water Science Centre,
operated by the Southeast
Environmental Association,
has offered guided tours
and public education programs.
The Centre also operates
a public fishing pond
stocked with rainbow and
speckled trout.
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Cardigan River, draining
an area of 105 square kilometres, with
5.4 kilometres of fresh water and 13.6
kilometres of tidal estuary.
•
Brudenell River, draining
an area of 55 square kilometres from
its headwaters north of New Perth to
its estuary mouth at Georgetown. The
river is fresh for 9.4 kilometres and
tidal for 11 kilometres.
•
Montague/Valleyfield River,
draining an area of 197 square kilometres.
The waterway flows from the Valleyfield
headwaters in the Caledonia Hills, 1
of only 2 significant hill-lands in
Prince Edward Island. The watershed’s
most southerly river is fresh water
for 20 kilometres, and tidal for 13
kilometres.
Drowned Forests of the Deep
Could people have once walked to Prince
Edward Island from the mainland? The
presence of “drowned forests”
off the eastern coast of the island,
along with a trail of ancient tools
and stone implements that have washed
up on its beaches, suggests that dry
land once existed where ocean swells
now rise.
Underwater
Evidence: Along the coastline
of the Three Rivers area, between Panmure
Island and Boughton Island, there are
7 known sites of submerged forests,
lands that disappeared below the sea
thousands of years ago when sea levels
rose due to post-glacial flooding. In
eastern Prince Edward Island, sea-floor
imaging and core sample drilling have
revealed evidence of ancient white pine
forests, buried valleys and drowned
rivers. Remains of pre-contact human
habitation, including scrapers, bifaces
(stone artifacts flaked on both faces)
and celts (polished stone axes), have
been found at Launching Pond, and a
spear point has been recovered from
Panmure Island.
The study of drowned forests is carried
out by marine geologists, who use core
sampling techniques, underwater acoustic
profiling, carbon-dating, and tree ring
analysis to gather evidence about ancient
landscapes and civilizations. On Canada’s
east coast, seabed changes caused by
ocean turbulence add to the challenge
of finding, mapping and analyzing significant
underwater sites.
The
Precarious Piping Plover
When the entire provincial population
of a nesting bird species can be counted
in double digits, it comes as no surprise
that conservationists are concerned.
On the beaches of Prince Edward Island,
naturalists are struggling to protect
the habitat of the fragile, sensitive
Piping Plover from disturbance by swimmers,
boaters, cottagers and dog-walkers.
The timorous, sandy-coloured, sparrow-sized
shorebird that skitters along the shoreline
has the misfortune of preferring sand
flats, coastal sand dunes and coastal
inlets - the very habitat that attracts
thousands of beach-goers every summer.
Its nest, which is usually nothing more
than a shallow depression in the sand,
is highly vulnerable to disturbance.
Stormy weather, high tides, predatory
birds, horses, dogs, all-terrain vehicles,
and humans can easily injure young chicks,
or cause them to be abandoned. Studies
show that Plover chicks that fail to
achieve 60% of their adult weight by
12 days of age are unlikely to survive.
Island Distribution:
The entire North American population
of Piping Plovers amounts to just under
6,000 birds; in 2000, Canada’s
Maritime provinces had a total Plover
count of 428 birds, with Prince Edward
Island contributing 87 birds, or about
20% of the total. Plover nesting sites
are scattered around the Island, with
significant concentrations in Prince
Edward Island National Park on the north
shore, and on Canavoy Beach, St. Peters
Lake Run, Savage Harbour West, and St.
Peter’s Harbour Beach on the northeastern
shore. In the Three Rivers watershed,
Plovers are known to have nested at
Launching Point as recently as 1984.
Partners in Protection: Several
layers of legislation and a number of
conservation groups are involved in
ensuring the Plover’s survival.
The National Parks Act, the provincial
Wildlife Conservation Act, Environment
Protection Act, and Natural Areas Protection
Act can all be brought to bear on the
protection of Plover habitat. The Canavoy
Beach area, with a total Plover population
in 1999 of 21 birds, is in the process
of being designated as an international
“Important Bird Area “ (IBA),
with an accompanying conservation plan.
The Canadian Wildlife Service operates
a Piping Plover Recovery Plan for Atlantic
Canada, designed to prevent the further
decline of the Atlantic Piping Plover
population, to increase the population
to the historically-abundant level of
670, and to protect a minimum of 65%
of nesting plovers in Atlantic Canada.
In Prince Edward Island, the Natural
History Society of Prince Edward Island
and the Island Nature Trust have been
involved in Plover monitoring and protection
programs. Since 1992, the Island Nature
Trust has operated a Piping Plover Guardian
Program with the help of local volunteers,
and has developed the Prince Edward
Island Piping Plover Atlas to identify
nesting locations that may be affected
by beach activities. Ultimately, a variety
of protection measures will be required
to preserve and expand the Island’s
Plover population, including:
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Fencing of Plover nesting sites
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Explanatory signage
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Education through media campaigns, public
meetings, field visits, school presentations
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Identification and designation of provincial
Natural Areas or Wildlife Management
Areas
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Restriction of motorized vehicle use
on beaches
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Suspension of breakwater maintenance
during the nesting season
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Contact and education of landowners,
developers, resort and vacation property
operators and tourists
Focusing on Fish Kill Prevention
When more than 2500 fish were killed
by silt and pesticide run-off in the
Valleyfield River during a torrential
downpour in 1999, the Montague-based
Southeast Environmental Association
formulated a response. Using the financial
penalty assessed to the offending landowner
as funding for its project, the Association
measured the scope of the fish kill,
monitored rebound levels (by comparing
fish counts to the nearby Montague River),
and participated in the installation
of erosion-preventing check dams at
the location where the run-off occurred—all
in preparation for re-stocking of the
fish reared at the Cardigan Fish Hatchery.
The Valleyfield “fish kill,”
which also proved deadly to amphibian
species in the river, is one of several
pollution incidents in Prince Edward
Island in recent years. The frequent
use of high quantities of pesticides
(as many as 12 applications in a 4-month
growing season), the planting of crops
close to the edges of streams, and the
tendency of the Island’s sandy
soil to wash away during heavy rains,
have resulted in fish kills and river
degradation across the province.
Some of the blame has been placed on
the use of the insecticide azinphos-methyl,
which appears to suffocate fish by interfering
with the function of their gills. The
chemical has now been banned from areas
that border water or that could act
as conduits to water.
While the deadly effects of silt and
pesticide contamination are quickly
apparent, conservationists and biologists
are also concerned about the lingering,
sub-lethal consequences of fish kill
incidents. Impaired reproduction and
the accumulation of toxic residues,
especially in shellfish, may also be
part of the negative outcome.
The use of pesticides in an economy
that depends on effective control of
pests, such as the Colorado potato beetle
and potato blight, remains a controversial
and challenging issue. In an effort
to reduce soil erosion, protect waterways,
and lessen their dependence on pesticides,
some Prince Edward Island farmers have
adopted sustainable agricultural practices,
including:
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The planting of trees and shrubs between
fields and waterways as “filter
strips” that anchor soil, provide
shade to water and increase the volume
of leaf litter.
•
The use of terracing, strip cropping,
fall mulching and 3-year rotation to
encourage soil enrichment.
 Homebodies
of the Harbour
Floppy and flabby, with upturned noses
and endearing, pup-like faces, the harbour
seals that populate Cardigan Bay, and
the Three Rivers that drain into it,
are popular targets of visiting wildlife-watchers.
While the seals’ appetite for
fish may be less popular with the area’s
commercial fishermen, the sight of a
roly-poly baby seal snuggled onto the
belly of a doting, nursing mother rarely
fails to find appeal.
Harbour seals, found on the coasts of
the Atlantic, Pacific and Arctic Oceans,
in Hudson Bay and some inland freshwater
lakes and rivers, tend to stay within
20 kilometres of shore. They thrive
in the bays, inlets and tidal pools
of estuarine environments, where they
“haul out” to breed, give
birth and rest on rocks, beaches, reefs
and piers. Some territorial movement
of harbour seals does take place; recent
tagging studies have demonstrated that
a few juvenile seals migrate up to 1500
kilometres along the coast.
At an average adult weight of 80 –
100 kilograms, harbour seals are the
smallest seals in the Maritimes. They
are brown, tan or grey in colour, with
white mottling. Their heads are much
smaller than those of grey seals, and
their nostrils form a more distinctive
“V” shape.
Female harbour seals give birth to only
1 pup per season. Pups shed their white
fetal coat before birth, emerging with
the short, stiff coat of the adult.
Baby seals are able to swim within a
few hours of birth, but are easy prey
to sharks.
Harbour seals are opportunistic feeders,
consuming 2-3 kilograms a day of herring,
squid, flounder, alewife, hake, smelt,
capelin, shrimp and cod. Equipped with
several oxygen-conserving adaptations,
the seals can dive to a depth of several
hundred metres and remain submerged
for up to 40 minutes. In water, their
hind flippers provide excellent propulsion,
and their foreflippers are efficient
rudders. But on land, where the seals
spend up to half their time, their rotund
bodies make movement slow and laborious.
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