Eutrophic Diagram
2
Est ua ri ne Eut r oph i ca t i on: Nut ri ent S ou r ce s and E ff ect s i n Estua ri e s Eutrophication is a process in which the addition of nutrients to water bodies stimulates algal growth. Under natural condit ions, this is usually a slow process that results in healthy and productive ecosystems. In recent decades, however, a variety of human activities has greatly accelerated nutrient inputs to estuarine systems , causing excessive growth of algae and leading to degraded environmental conditions . Eutrophication Diagram ix A t m o s p h e r i c n i t r o g e n f r o m a u t o m o b i l e a n d p o w e r p l a n t e m i s s i o n s . N i t r o g e n a n d p h o s p h o r u s i s t r a n s p o r t e d t o t h e e s t u a r y , w h e r e i t s p u r s o v e r g r o w t h o f a l g a e , c a u s i n g n u m e r o u s p r o b l e m s . N i t r o g e n a n d p h o s p h o r u s f r o m f e r t i l i z e r s a p p l i e d t o c r o p s a n d f r o m f a r m a n i m a l s . N i t r o g e n a n d p h o s p h o r u s f r o m u r b a n r u n o f f . N i t r o g e n a n d p h o s p h o r u s f r o m w a s t e w a t e r t r e a t m e n t p l a n t s . E p i p h y t e s ( a t y p e o f a l g a e ) e n c r u s t l e a f b l a d e , d r a m a t i c a l l y r e d u c i n g l i g h t a v a i l a b l e t o t h e p l a n t . T h i c k b l o o m s o f a l g a e o r o v e r a b u n d a n c e o f m a c r o a l g a e p r e v e n t s u n l i g h t f r o m p e n e t r a t i n g t h e w a t e r c o l u m n . D e e p e r S A V g e n e r a l l y d i e s o f f f i r s t a s l i g h t i s d i m i n i s h e d . B a c t e r i a u s e o x y g e n t o d e c o m p o s e a l g a l m a t e r i a l . A l g a e d i e o f f a n d s e t t l e t o t h e b o t t o m . L i g h t e r f r e s h w a t e r D e n s e r s e a w a t e r i n h i b i t s m i x i n g w i t h u p p e r o x y g e n r i c h l a y e r . O x y g e n f r o m w a v e a c t i o n a n d p h o t o s y n t h e s i s m i x e s w i t h u p p e r f r e s h e r w a t e r l a y e r . I n c r e a s e s o c c u r i n t h e d u r a t i o n , f r e q u e n c y , a n d s p a t i a l e x t e n t o f n u i s a n c e / t o x i c b l o o m s . S h e l l f i s h b e c o m e c o n t a m i n a t e d w i t h a l g a l t o x i n s . I m m o b i l e s h e l l f i s h d i e o f f . S o m e t i m e s f i s h k i l l s o c c u r , b u t m o r e l i k e l y , f i s h a v o i d a r e a . S u b m e r g e d A q u a t i c V e g e t a t i o n ( S A V ) D e c l i n e D e p l e t e d D i s s o l v e d O x y g e n N u i s a n c e / T o x i c A l g a l B l o o m s T h i c k b l o o m s o f a l g a e o r o v e r a b u n d a n c e o f m a c r o a l g a e g e n e r a t e t o o m u c h o r g a n i c m a t t e r . C o n s e q u e n c e s L e s s h a b i t a t i s a v a i l a b l e f o r f i s h a n d s h e l l f i s h . I m p a c t s o n c o m m e r c i a l a n d r e c r e a t i o n a l f i s h e r i e s . • I m p a c t s t o t o u r i s m . C o n s e q u e n c e s L e s s h a b i t a t i s a v a i l a b l e f o r f i s h a n d s h e l l f i s h . L o w e r c o m m e r c i a l a n d r e c r e a t i o n a l f i s h y i e l d s . I m p a c t s t o t o u r i s m . • H u m a n h e a l t h e n d a n g e r e d b y e x p o s u r e t o t o x i n s . • C l o s u r e o f s h e l l f i s h b e d s t o h a r v e s t . I m p a c t s o n c o m m e r c i a l a n d r e c r e a t i o n a l f i s h e r i e s . I m p a c t s t o t o u r i s m . C o n s e q u e n c e s T y p e s o f s o u r c e s a r e d i v e r s e a n d l e v e l s o f n u t r i e n t s g e n e r a t e d v a r y g r e a t l y d e p e n d i n g o n a n u m b e r o f f a c t o r s . H o w e v e r , p o p u l a t i o n i s t h e c o m m o n f a c t o r t h a t c r e a t e s d e m a n d f o r t h e p r o d u c t s a n d s e r v i c e s t h a t a f f e c t t h e l e v e l o f n u t r i e n t p o l l u t i o n e m a n a t i n g f r o m t h e s e s o u r c e s . S o m e t o x i c b l o o m s c a u s e f i s h k i l l s . W i n d b l o w s t o x i n s s h o r e w a r d , w h e r e t h e y m a y c a u s e h u m a n r e s p i r a t o r y p r o b l e m s .
Transcript of Eutrophic Diagram
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Estu a rine Eutro p h ic a tion: Nutri e nt So urc es a n d Eff e c ts in Estu a ri esEutrophication is a process in which the addition of nutrients to water bodies stimulates algal growth. Under natural conditions, this is usually a slowprocess that results in healthy and productive ecosystems. In recent decades, however, a variety of human activities has greatly acceleratednutrient inputs to estuarine systems, causing excessive growth of algae and leading to degraded environmental conditions.
Eutrophication Diagram
ix
Atmosphericnitrogenfrom
automobileandpower
plantemissions.
Nitrogenandphosphorusis
transportedtotheestuary,
whereitspursovergrowthofalgae,
causingnumerousproblems.
Nitrogenand
phosphorusfrom
fertilizersappliedto
cropsandfrom
farmanimals.
Nitrogenand
phosphorus
fromurban
runoff.
Nitrogen
and
phospho
rus
fromwaste
watertre
atment
plants.
Epiphytes(atypeof
algae)encrustleafblade,
dramaticallyreducinglight
availabletotheplant.
Thickbloomsofalgaeor
overabundanceofmacroalgae
preventsunlightfrom
penetratingthewatercolumn.
DeeperSAV
generallydies
offfirstasligh
t
isdiminished.
Bacteriauseoxygento
decomposealgalmaterial.
Algaedieoffandsettle
tothebottom.
Lighterfreshwater
Denserseawater
inhibitsmixingwith
upperoxygen-richlayer.
Oxygenfromwaveaction
andphotosynthesismixeswith
upperfresherwaterlayer.
Increases
occurintheduration,frequency,
andspatia
lextentofnuisance/toxicblooms.
Shellfish
become
contaminated
withalgal
toxins.
Immobile
shellfishdieoff.
Sometimesfishkills
occur,butmorelikely,
fishavoidarea.
SubmergedAquaticVegetation(SAV)Decline
DepletedDissolve
dOxygen
Nuisance/ToxicAlgalBlooms
Thickbloomsofalgaeor
overabundanceof
macroalgaegeneratetoo
muchorganicmatter.
C o n s e q u e n c e s
•
Lesshabitatisavailableforfishandshellfish.
•
Impactsoncommercialandrecreationalfisheries.
•
Impactstotourism.
C o n s e q u
e n c e s
•
Lesshabitatisavailable
forfishandshellfish.
•
Lowercommercialandrecreationalfishyields.
•
Impactstotourism.
•
Huma
nhealthendangeredbyexposuretotoxins.
•
Closureofshellfishbedstoharvest.
•
Impac
tsoncommercialandrecreationalfisheries.
•
Impac
tstotourism.
C o n s e q u e n c e s
Types
ofsources
are
diverse
and
levels
of
nutrientsgeneratedvarygreatlydependingona
number
offactors.However,populationisthe
commo
n
factorthatcreates
demand
forthe
productsand
servicesthataffectthelevelof
nutrientpollutionemanatingfrom
thesesources.
Sometoxic
bloomscau
se
fishkills.
Windblowstoxinsshoreward,
wheretheymaycausehuman
respiratoryproblems.
