BURT LAKE SHORELINE SURVEY 2009: SUMMARY
During the summer of 2009, the Tip of the Mitt Watershed Council
conducted a comprehensive shoreline survey on Burt Lake to document
conditions that have the potential to impact water quality. Funding for this project
was provided by the Burt Lake Preservation Association (BLPA). This survey
was performed because shoreline property is the first and most important line of
defense for protecting the lake ecosystem. Of all the land in the Burt Lake
watershed, shoreline properties have the greatest potential to impact water
quality. Therefore, Watershed Council staff traveled all 35 miles of Burt Lake’s
shoreline in kayak to survey the following parameters that pose a threat to the
lake’s health:
1. Nutrient pollution. Nutrients are necessary to sustain a healthy aquatic
ecosystem, but excess nutrients as well as other contaminants associated
with nutrient pollution, such as bacteria and pharmaceuticals from septic
systems, automotive fluids and metals in stormwater runoff, and chemicals
in lawn-care products, can degrade the lake’s water quality. Cladophora
algae occurring on the shoreline was noted because it is a reliable
biological indicator of nutrient pollution. Furthermore, select shoreline
areas that lacked habitat for Cladophora algae (i.e., sandy areas) were
surveyed a second time using a Septic Leachate Detector, which helps
identify areas where malfunctioning septic systems are contaminating
shallow groundwater.
2. Greenbelt health. Greenbelts are the vegetated areas along the shoreline.
A greenbelt consisting of a variety of native woody and herbaceous plant
species provides habitat for near-shore aquatic life, as well as birds,
turtles, and amphibians. Deep-rooted plants help to control erosion while
stabilizing the shoreline and providing protection against wave action and
ice. The canopy of the greenbelt provides shade to near-shore areas,
which is particularly important for lakes with cold-water fisheries. In
addition, greenbelts provide a mechanism to reduce overland surface
runoff and absorb pollutants carried by the flow during rainstorms and
snowmelt. Thus, greenbelts provide many benefits to the lake ecosystem,
but these benefits are lost when shoreline vegetation is removed
3. Shoreline alterations. Shoreline development often includes the
installation of seawalls, rip-rap, or other structures to stabilize the
shoreline, but these structures have negative impacts on the lake
ecosystem. These impacts stem primarily from the loss of natural
vegetation and the many benefits associated with this vegetation, such as
the loss of habitat and food sources for aquatic and terrestrial life in
nearshore areas
4. Shoreline erosion. Erosion commonly occurs in nearshore areas followed
by greenbelt removal, but is also caused by other factors such as
recreational access. Eroding shorelines results in sediments washing into
and impacting the lake ecosystem. Sediments clog fish and insect gills,
smother spawning beds and habitat in nearshore areas, and increase
water temperatures. Furthermore, nutrients adhere to sediment particles
and lead to nutrient pollution.
The 2009 survey examined these stressors at all 1123 properties on
Burt Lake and found that shoreline property management is undoubtedly
impacting the lake ecosystem and water quality. Some sign of nutrient pollution
was noted at over half of shoreline properties; 36% had greenbelts in poor
condition; 46% had altered shorelines; and erosion was present at 6%. Relative
to other lakes in Northern Michigan, Burt Lake had a high percentage of
shoreline properties with signs of nutrient pollution and a moderate number of
properties with poor greenbelts and altered shorelines. Properties with strong
signs of nutrient pollution and those with poor greenbelts were scattered
throughout the lake, but also concentrated in certain locations.
On a positive note, there was noted improvement in greenbelt health since
the last shore survey performed in 2001. There was a 23% increase in the
number of properties with greenbelts that rated in the good or excellent
categories while those in the poor condition decreased by 20%. This is fantastic
news for Burt Lake because greenbelts are critical for maintaining a healthy,
diverse aquatic ecosystem.
In spite of problems in nearshore areas exposed during this survey, data
collected by Watershed Council staff and BLPA volunteers show that the water
quality of Burt Lake remains high. Great progress has been achieved during the
last decade through the joint efforts of BLPA and Tip of the Mitt Watershed
Council to “restore the shore” by improving greenbelt health. However, the Burt
Lake ecosystem will only benefit from further improvements in shoreline property
management. Each and every shoreline property owner can help protect and
improve the lake ecosystem by doing simple things like properly maintaining
septic systems, eliminating or reducing fertilizer use, properly managing
stormwater, improving greenbelts, controlling erosion, and encouraging
shorelines to revert to a more natural state.