Download - Crooked Lake 2011
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Alteredwatershedconditions
clearcutting changes
in
runoff/infiltration;
lake
Additionof
nutrients
Fertilizers(nonpointsource) lawns
treatmentplants
EffectsareoftenrapidExperimentalLakesArea
t pp ngpo nt w enoxygenatbottomoflakeisusedupinsummer)
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Eutrophication Indicator3
TotalPhosphorus
No P added
Eutrophica e
Nutrientinputs;primarilyphosphorus(P)causealgaetobloom
eutrophication
http://www.dfo-mpo.gc.ca/regions/CENTRAL/pub/ela-rle/ela-rle_e.htm
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Eutrophication Indicator1
aterc ar ty
Affectslightpenetration
Secchi disk
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Eutrophication Indicator2
Chlorophylla
Chloro h ll a is a i ment in al ae
and plants
amount of phytoplankton blooming
y op an on anpond weeds limited
near the surface ofthe lake where li htpenetrates
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Ploadingversusmeandepth
P P PP
Phosphorusloading
and
depth
interact
to
determine
trophic
stateinmostlakes
SHALLOWLAKES
MORE
LIKELY
TO
BE
GREEN
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Other De th Effects
Kalff
wo a es ave e same amoun o p y op an on n esurface, the shallow lake is more likely to have all oxygenused up in the bottom (hypolimnion) than a deep lake
Negatively affects fish
Increases nutrient and toxin release from sediments
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H olimnetic
NH4(ammonium)
onlypresentwithout
ratesofdecayofbloom
andplants
s arsen c; ox c;releasedwithlowoxygen
Ironand
Manganese
(Mn) releasedwithlowoxygen
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(eutrophication;lack
of
oxygenandhighdecayin
hypolimnion)
Nitrate,nitrite,
ammon a, o a
(nitrogenisasecondary
blooms)
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H indicatorofacidit
lower[
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assessment Plantcovera e
Recreational
assessment
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Phytoplankton(algae)
Macrophytes ondweeds
Zooplankton
(small
animals
in
open
Macroinvertebrates(biggeranimalsin
Fish Invasivespecies
Local climate change air and water temp.
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Eutrophic EutrophicALTERNATE STABLE STATES in small MESO AND EUTROPHIC LAKES
High P, High Algae en eP in macrophytes
light penetration light penetration
PP P P PGrass carp
Low water clarityAlgal blooms (sometimes
High water clarityFew algal blooms
BenthicLow ond weeds and
BenthicHi h ond weeds
filamentous algae Higher growth of filamentous algae on
pond weeds
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Cancausewatertobecome
turbid Favorsexcessivealgal
ooms,o eno nu sance
ortoxicspecies
Microcystis
u sances neu rop c
lakes
blooms
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Summary Report
CrookedLakethisyearhadmoresignsof
eutro hication moreTPandchloro h lla,
lowertransparency
(hypolimnion)duetohighammoniumandTP
Potablewaterqualityfactorsstable;
biologicalconditionnotassessed
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Summary Homeownerconcerns
Ifalakeiseutrophic youcangroweitherlotsofpondweeds,orlotsofalgae
Grasscarp
addition
will
almost
certainly
reduce
pondweeds,butwillalsolikelyincreasealgal
blooms,includingtoxicblooms
Nutrientreduction
is
onl
ermanent
strate
to
remediatelakes;dredgingtomakelakedeeper
mayalsohelp
Localizedsolutions
within
lake
weed
removal,
macrophyte mats,bubblerscheaper;ongoing
costs;notawholelakesolution