Post Point Lagoon is one of only seven remaining pocket estuaries in Bellingham Bay. The ecological importance of estuarine habitat and its scarcity locally is widely recognized. Pocket estuaries provide important habitat features including eelgrass beds, saltwater marsh with pickleweed (PDF) overhanging terrestrial vegetation, large woody debris, and the connection to other productive nearshore habitats.
Post Point Lagoon provides current and potential habitat for three
species listed under the federal Endangered Species Act (Chinook salmon,
bull trout, steelhead), and for the recently de-listed Bald Eagle. It is
designated as Critical Habitat for Chinook salmon and bull trout by NOAA
Fisheries and the U.S. Fish and Wildlife Service. The lagoon is also home to
the only Great Blue Heron colony within the City of Bellingham. The Great
Blue Heron is recognized as a Priority Species by the Washington Department
of Fish and Wildlife. Herons typically forage within three miles of their
nesting site and are known to prefer foraging in the eelgrass habitat of
protected embayments, such as the Post Point Lagoon. Juvenile and fledging
herons are often observed experimenting with foraging techniques in the
lagoon’s protected environment.
Post Point Lagoon has been the focus of restoration efforts since 2004. In 2007, the City increased capacity of the alternate outfall for the Post Point Pollution Control Plant to allow proper plant operation during high flows. Replacing the outfall pipe impacted a healthy, well-established bed of marine eelgrass. To mitigate the impact, some of the eelgrass was transplanted to the Post Point Lagoon.
In 2008, restoration work was completed to improve the shoreline riparian
corridor, upper intertidal salt marsh, and intertidal mud flat. This project
benefited eelgrass beds by combining to form a complex interacting mosaic of
marine habitats that provide critical rearing and refuge functions for
migrating juvenile fish and wildlife. Elements of this project include:
placing large woody debris within and around the lagoon; removing fill from
the shoreline, increasing shoreline length by 18% and saltmarsh area by 70%;
re-establishing a native marine riparian buffer along the shoreline;
protecting native vegetation and habitat elements by restricting access to
sections of the upland, shoreline and intertidal zones; and installing
educational signs.
Before and after restoration: Photos on left from 2005, photos on right from
2010.
The City of Bellingham monitored fecal coliform bacteria levels in the
Post Point Lagoon during 2000-2001, 2005, and on a monthly basis since 2008.
Post Point Lagoon Monitoring Project, 2005 (PDF)
Fecal coliform bacteria are used as an indicator of bacterial levels in
surface waters because they are easily quantified. Sources of fecal
contamination to surface waters include domestic and wild animal feces,
human feces, on-site septic system leaks, and stormwater runoff. Although
they are generally not harmful themselves, fecal coliform bacteria indicate
the possible presence of pathogenic bacteria, viruses, and protozoans that
also live in human and animal digestive systems. In addition to the possible
human health risk associated with the presence of elevated levels of fecal
bacteria, they can also cause cloudy water, unpleasant odors, and increased
oxygen demand.
Washington State bacteria level criteria are based on the anticipated level
of recreational use and shellfish harvest and are measured as a geometric
mean value of all samples. The geometric mean measure of fecal coliform
determined to be safe for the harvest of shellfish as well as for primary
recreational activities (i.e. swimming) in marine waters is 14 colonies (cfu)/100
ml (WAC 173-201A-210).
Late summer and early fall peaks in fecal coliform bacteria levels, such as
those seen in 2000 and 2005, are likely associated with rainfall events
following dry periods. These wet weather events flush fecal coliform
bacteria into stormwater systems and streams. The magnitude of these peak
levels has been greatly reduced since monitoring began in 2008. Overall
bacteria levels have also been lower.
The reduction in bacteria levels could be considered an early success for
the restoration of the Post Point Lagoon. Native plants and partial fencing
installed in 2004, as well as a dog exclusion fence installed in 2008 have
helped to reduce the amount of fecal coliform bacteria inputs in the
nearshore vicinity. The use of dog waste bags and disposal bins by
conscientious dog owners has also been key to reducing fecal coliform
inputs.
