Crooked Lake 2011

8/3/2019 Crooked Lake 2011

1/15

Alteredwatershedconditions

clearcutting changes

in

runoff/infiltration;

lake

Additionof

nutrients

Fertilizers(nonpointsource) lawns

treatmentplants

EffectsareoftenrapidExperimentalLakesArea

t pp ngpo nt w enoxygenatbottomoflakeisusedupinsummer)


2/15

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


3/15


aterc ar ty

Affectslightpenetration

Secchi disk


4/15


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


5/15

Ploadingversusmeandepth

P P PP

Phosphorusloading

and

depth

interact

to

determine

trophic

stateinmostlakes

SHALLOWLAKES

MORE

LIKELY

TO

BE

GREEN


6/15

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


7/15

H olimnetic

NH4(ammonium)

onlypresentwithout

ratesofdecayofbloom

andplants

s arsen c; ox c;releasedwithlowoxygen

Ironand

Manganese

(Mn) releasedwithlowoxygen


8/15

(eutrophication;lack

of

oxygenandhighdecayin

hypolimnion)

Nitrate,nitrite,

ammon a, o a

(nitrogenisasecondary

blooms)


9/15

H indicatorofacidit

lower[


10/15

assessment Plantcovera e

Recreational

assessment


11/15

Phytoplankton(algae)

Macrophytes ondweeds

Zooplankton

(small

animals

in

open

Macroinvertebrates(biggeranimalsin

Fish Invasivespecies

Local climate change air and water temp.


12/15

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


13/15

Cancausewatertobecome

turbid Favorsexcessivealgal

ooms,o eno nu sance

ortoxicspecies

Microcystis

u sances neu rop c

lakes

blooms


14/15

Summary Report

CrookedLakethisyearhadmoresignsof

eutro hication moreTPandchloro h lla,

lowertransparency

(hypolimnion)duetohighammoniumandTP

Potablewaterqualityfactorsstable;

biologicalconditionnotassessed


15/15

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

Crooked Lake 2011

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Transcript of Crooked Lake 2011