Burrard Inlet Environmental Indicators Report - the BIEAP and ...

Burrard Inlet Environmental Indicators Report February 2008
Part 2 – Links Between Human Activities and Burrard Inlet Status
Before discussing the indicators in detail, it is useful to look at the types of human activities
that affect the state of Burrard Inlet, in terms of availability of wildlife habitat, introduced
invasive species, and sources of contaminants and their effects on birds, fish and mammals in
the Inlet. This information adds context about historic and current activities and illustrates the
interconnectedness of the ecosystem.
Habitat and shoreline change over time
Stanley Park Seawalk
The 190 km of shoreline and 11,300 hectares of water
and seabed of Burrard Inlet are biologically diverse
ecosystems that provide habitat for many species of
fish and shellfish. Changes to these habitats can have
significant consequences, and can occur as a result of
natural processes as well as human activities. The
Burrard Environmental Review Committee (BERC), a
BIEAP subcommittee of agencies with project
environmental review mandates, began reviewing
project proposals in Burrard Inlet in 1991. BERC
objectives are to ensure that projects are designed and
located to minimize or avoid significant habitat impacts
and to promote habitat development.
Significant changes in Burrard Inlet have taken place
since the start of European settlement, and have resulted
in substantial declines in some habitat types (e.g., salt
marsh and tidal flats). However, the BERC project review
process helps ensure that further human-induced habitat
changes over time are neutral or positive.
Invasive marine species
Invasive species have massive potential for
ecological and economic impacts on existing
species and habitat. Most invasive marine
species found in Burrard Inlet were accidentally
introduced through ship ballast water, pleasure
boat traffic and ocean currents (e.g., Manila and
varnish clams), although some (Japanese oyster)
were intentionally imported to increase shellfish
production.
Introduced species pose a risk to the environment
by taking over habitat used by native species.
Two categories of invasive marine species can be
considered: those that were introduced decades
ago and are now well established (making it
difficult to eliminate them) and those that have
been recently introduced (where a program to
eliminate them may still be successful).
Currently the risks from invasive marine plants
are considered relatively low; however, the
status of these organisms should be reviewed
periodically. The Vancouver Port Authority is
reducing the risk of ongoing introduction of
invasive marine species by requiring exchange
of ship ballast water at mid-ocean to prevent
introduction of Asian Pacific species to the
west coast.
Recent introductions and threats
English cord grass (Spartina anglica), identified
at Roberts Bank and Boundary Bay in Delta in
2003, but not yet in Burrard Inlet; this plant has
an aggressive growth pattern and high potential
for damage.
Salt marsh cord grass (Spartina patens), found at
the western boundary of Maplewood
Conservation Area; has spread to Port Moody
Arm and possibly to other areas.
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