1312.pdf

A BS TRA C T

S U ZAN N E P . T H OMP S O N . Spa t i a l a nd Te mp o r a l P a t t e r n s o f

De n

i

t r

i

f

i

c a t

i

o n

i

n a N at u r a l a nd

i

n a Re s t o r e d Sal t Ma r sh .

(

U n d e r T h e D

i

r e c t

i

o n of Dr . H AN S W. P A E R L

)

Ma r sh c r e a t i o n f o r mi t

i

_gat

i

o n o f wet l a nd l o s s ha s c ome

i

nt o i n c r e a s i n_g u s e , b u t l i t t l e r e s e a r c h ha s e x am

i

n ed

n ut r i e nt c_y c l i n _g o r o t h e r cr

i

t

i

ca l we t l a nd hab

i

t a t f u n c t

i

o n s

i

n c o n st r u ct e d m a r s he s . T h i s st ud y c o m p a r e s sp a t

i

a l a n d

t em

_p

o r a l _p a t t e r n s o f n

i

t r o_ge n c _y c l

i

n _g v

i

a t he n

i

t r

i

f

i

c a t

i

o n

-d e n

i

t r

i

f

i

c a t

i

o n

_p

a t h wa

_y

i

n a n a t u r a l a nd

i

n a r e st o r e

d

s a l t

ma r sh . Se d i me n t a r y de n i t r i f i c a t i o n r a t e s w e r e ap p r o x

i

mat e l y

4 4 t

i

me s _gr e a t e r

i

n a n at u r a l ma r s h r e l a t

i

v e t o a n ad

_j

ac e nt

t r a n s

_p

l a n t e d ma r s h _, w h i l e n

i

t r i f

i

c a t

i

o n r at e s _{w e r e} s

_i

m

i

l a r

a t b o t h s

i

t e s . Th e d

i

f f er e n c e

i

n d e n

i

t r

i

f

i

c a t

i

o n r a t e s

i

s

a t t r

i b

ut e

d

t o o x

_{y g}

e n

i

n

h i b i

t

i

o n a t

l

ow t

i d

e a n

d

t

i

d a

l

f l u s h

i

n

_g

o f _po r e w a t e r n u t r

i

e n t s

i

n t he co a r s e s e d

i

me n t s o

f

t he r e s t o r e d ma r s h . D e ni t r i f i ca t i o n wa s

p

o s i t

i

v e l y

c o r r e l at ed w

i

t h n

i

t r

i

f

i

c at

i

o n t hr o u_{g h}o u t t he

_y

e a r

i

n t he

n at u r a l ma r s h w

i

t h a s e a so n al f a l l

_p

e a k

i

n d e n

i

t r

i

f

i

c at

i

o n

co r r e s_p o nd

i

n_g t o a ma x

i

mum

i

n

_p

o r ewa t e r a mmo n

i

u m

c o n c e nt r at

i

o n . A w e a

k

c o r r e

l

a t

i

o n e x

i

st ed

b

e t we e n t

h

e t wo

p

r o c e s s e s

i

n t h e r e st o r ed ma r sh _{w h} e r e n

i

t r

i f i

c a t

i

o n r at e s

e x c e e d e d d e n i t r i f i c a t i o n _{b y} a f ac t o r o f 2 0 . T r a n s p l a n t ed

ma r s h d e n

i

t r

i

f i c a t

i

o n r a t e s e x h

i

b

i

t e d a n e a r _{l y} s_p r

i

n _g

_p

e a k

co r r e s_p o nd i n_g t o e _l e v a t e d _po r ewa t e r amm o n

i

a c o n c e n t r at

i

o n s .

E n ha n c ed de n i t r i f i c a t i o n ac t i v

i

t _y wa s de t ec t e d

i

n s e d

i

me n t

ad

_j

ac e n t t o Uc a _p u _g

i

l a t o r

b

u r r ows a n d

i

n se d

i

me n t a s s o c

i

a t e d

w i t h t h e r o o t - _{r h i z ome s}

y st em o f S_p a r t i n a a l t e r n i f l o r a i n t h e

r e s t o r e d ma r s h o n _{l y} . T he s e r e s u l t s de mo n st r a t e f u n c t

i

o n a l

d

i

f f e r e n c e s i n n i t r o _ge n d

_y

n am

i

c s o f a _y o u n_g r es t o r ed ma r sh

T AB L E OF C ON T ENT S

Pa _ge

AC K N OWL E D G EME N T S v

i

L I S T O F F I G URE S v

i i

I . I N T R O D U C T I O N 1

I I . B A C K G R O U N D I N F O R M A T I O N 1 0

A s s o c i a t e d N i t r o _ge n T r a n s f o r ma t

i

o n s 1 0

N

i

t r

i

f

i

c a t

i

on - _{D e n}

_i

_{t r}

_i

_{f i c at}

_i

_{o n Co u}

p

l

i

n

_g

1 0

N i t r i f i c a t

i

on 1 2

D

i

s s

i

m

i

l a t o r

_y

N

i

t r a t e Re du ct

i

o n t o Am mo n

i

a . . . . 1 4

T e_{m p}o r a l a n d _{S p} at

i

a l Pa t t e r n s o f De n

i

t r

i

f

i

c a t

i

o n . . 1 6

Se a so n a

l

C

_y

c

l

e s 1 6

D

i

u r n a l a nd T

i

da l _{C y} c l es 1 8

F a u n a l B

i

o t u r ba t

i

o n 1 8

Ve _ge t a t i o n Ef f e ct s 2 0

I I I . M E T H O D S 2 4

Re v

i

e w o f De n

i

t r

i

f

i

c a t

i

o n Te c

h

n

_{i q}

u e s 2 4

S t u d

_y

S

i

t e 3 5

Mat e r

i

a l s a nd Me t h o d s 3 5

W ho l e Co r e s 3 5

S l u r r

i

e s 3 9

G r ee n ho u s e E x _p e r

i

m e nt s 4 0

N

i

t r

i f i

c at

i

o n 4

1

P o r ewa t e r N u t r i e n t s 4 3

Red o x 4 3

S t at i s t

i

c a l An a l y s

i

s _{4 4}

I V . R E S ULT S A N D D I S C U S S I ON 4 5

Se a so n a l P a t t e r n s 4 5

D

i

u r n a l a n d T

i

d a l C

_y

c l e s 6 1

Hab

i

t a t F e a t u r e s 7 3

V . C O N CL U SI O N S 8 0

A CK NOW L ED GEME N T S

I wo u l d l i k e t o t ha n k Dr . H a n s W. P a e r l f o r h i s s up po r t

a n d _gu

i

d a n c e du r

i

n _{g m y} s t u_{d y} a t t h e I n s t

i

t u t e o f Ma r

i

n e

Sc

i

e n c es . T ha n k s a l so t o c on u ni t t e e m e mbe r s Go r d o n T hay e r

a n d F r e d P f ae nd e r . I am v e r

y

g

r a t ef u l t o Ca r o l

y

n Cu r r

i

n ,

Mal i a G o a n d C l ar i t a L u n d f o r f i e l d _, t e ch ni ca l a nd mo r al

a s s

i

st a nc e .

I e s _pe c

i

al l

_y

w

i

s h t o t ha n k Gabr

i

e l e On o r at o f o r h

i

s

h e_{l p} w

i

t h a l l t h e l o o s e e n ds o f f a m

i

_{l y} l

i

f e .

S u

_p

_po r t f o r t h

i

s _pr o

_j

e c t w as

_p

r o v

i

de d _{b y} N OA A _, N at

i

o n a l

Ma r

i

n e F

i

sh e r

i

e s Se r v

i

c e Co as t a l Oc e a n s P r o

_g

r am

₍

Gr a n t No .

R- _{E H P} - ₁

)

ad m i n i s t e r e d t hr o u _{g h} t he U n

i

v e r s

i

t y o f N o r t h

Ca r o l

i

n a Se a Gr a n t Co l l e _ge P r o

_g

r a m .

L I S T OF F I G U RE _S

P a_g e

1 . N

i

t r og e n t r a n s f o r m a t

i

o n s

i

n sa l t ma r s

h

s e

d i

me nt s . . . . 8

2 . C om p a r i s o n o f d e n

i

t r

i

f i c at

i

o n r a t e s me a s u r ed

i

n s a l t ma r s h s ed

i

me n t s w

i

t h d i f f e r e n t t e c hn i

_q

u e s 2 5

3 . D e n

i

t r

i

f

i

c a t

i

o n s a t u r at

i

o n k

i

n et

i

c t r

i

a l s

i

n n at u r a l

ma r s h s ed

i

m e n t s _{3 0}

4 . L

i

n ewe a v e r - B u r k e p l o t s o f d e n

i

t r

i

f

i

c a t

i

o n sa t u r at

i

o n

k

i

n e t

i

c t r

i

a l s 3 1

5 . T

i

me s e r

i

e s t r

i

a l f or

d

e n

i

t r

i

f

i

c at

i

o n

i

n n at u r a l

ma r s

h

s ed

i

me nt s 3 3

6 . Com

p

a r

i

s o n o

f

amb

i

e nt a n d ame n de

d

d

e n

i

t r

i

f

i

c at

i

o n

r a t e s 3 4

7 . M_a

p

o f P or t ma r s h n a t u r a l a nd r e s t o r e d ma r s h s

i

t e s . . 3 6

8 . P l a n o f t r e at me n t

p

l o t s

i

n t he r es t o r e d ma r sh 3 7

9 . An n u a l

p

a t t e r n o f de n

i

t r

i

f

i

c a t

i

o n a n d po r ewa t e r N H ^

" *"

i n n a t u r a l m a r sh s e d

i

me n t s 4 6

1 0 . Tot a l mo nt h l

y

r a

i

nf a l l n

i

t r o

g

e n co l

l

e c t e d a t t h e

I n s t

i

t u t e o f Ma r

i

n e Sc

i

e n c e s _, Mo r e h e a d C

i

_{t y} 4 8

1 1 . An n u a l pa t t e r n s o f de n

i

t r

i

f i c at i o n a nd po r ewa t e r N H_^

"_*"

i

n t h e

_p

l a n t ed c o nt r o l a n

d

_p

e a t t r e at me nt s

o

f

t h e r e s t o r e d m a r s h 5 0

1 1 . An n u a

l

p

a t t e r n s o f d en

i

t r

i

f

i

c at

i

o n a n

d

p

o r e wat e r N H_^

" ^

i

n t he

_p

e a t +N a n d n ew

_p

e at t r e at me n t s o f

t

h

e r e st o r e d ma r s

h

5 1

1

2

. N

i

t r

i f i

c at

i

o n a n

d

d

e n

i

t r

i f i

c at

i

o n r at e s

i

n n at u r a

l

a nd

p

l a nt e d co n t r o l t r e a t me nt of t h e r e s t o r ed ma r s

h

5 3

1 2 . N

i

t r

i

f

i

c at

i

o n a nd de n

i

t r

i

f

i

c a t

i

o n r a t e s

i

n

p

e at a nd _p e at +N t r e a t me n t s o _{f t h}e r e s t o r e d ma r s h 5 4

1 3 . Ar r h e n

i

u s p l ot s f o r n

i

t r

i

f

i

c a t

i

o n r a t e s

i

n n at u r a l

1 4 . R e gr e s s i o n a na l y s i s o f n

i

t r i f i c a t i o n a nd de n

i

t r

i

f

i

ca t

i

o n r at e s

i

n n a t ur a l a n d r e st o r ed

ma r s h s e

d i

me nt s 5 7

1 5 . Po r ewa t e r N H ^

" *"

i

n n at u r a l a nd r e s t o r ed ma r sh

s e d i m e n t s _{6 0}

1 6 . E f f e c t o f t i da l ex

p

o s u r e o n d e n i t r i f i c a t

i

o n r a t e s me a s ur e_{d w}

_i

_{t h t h}e w ho l e co r e a nd s l u r r _y t e c hn

i q

u e s

i

n n at u r _a l a n d r e s t o r e d ma r s _{h p l a n t e d} co n t r o l

sed i me n t s 63

1 7 . E f f e c t o f wa t e r c o v e r a

g

e a nd l

i

g ht l e v e l o n

de n

i

t r

i

f

i

c a t

i

o n r at e s m e as u r e d

i

n

_g

r e e nho u s e s a nd

y

a nd mu d d

y

s ed

i

me n t s 6 4

1 8 . Red o x

p r o f

i

l e s o f n a t u r a l a nd r e s t o r e d ma r s_h

_p

_l a nt e

d

c o nt r o l s e d

i

me nt s 6 6

1 9 . R edo x p r o f i l e s o f

g

r e e nh o u s e mu d d y a nd s a nd y

sed

i

m e nt s

i

_n t

h

e mo r n

i

n

_g

a nd m

i

d d a

_y

6 7

2 0 . D

i

u r n a l p a t t e r ns o f d e n

i

t r

i

f

i

c a t

i

o n r a t e s

i

n

gr e e nho us e t r

i

a l s o f s a n_{d y} a nd mu_{d d y} se d

i

me n t s 6 9

2 1 . D

i

u r n a

l

a n

d

t

i

d a l

p

at t e r n s o

f

de n

i

t r

i

f

i

c a t

i

o n r at e s

i

n n at u r a l ma r sh s u r

f

a c e s e

d i

me nt s 7 1

2 2 . D

i

u r n a l a nd t

i

d a l

p

a t t e r n s o

f

d e n

i

t r

i

f

i

c a t

i

o n r at e s

i

n r e st o r ed ma r s h s u r f ac e s e d

i

m e n t s 7 2

2 3 . D e n

i

t r

i

f

i

c a t

i

o n a nd n

i

t r

i

f

i

c a t

i

o n r at e s

i

n r e s t o r e d

ma r s h s e d

i

me nt s w

i

t h a nd w

i

t ho u t Uc a bu r r o ws 7 4

2 4 . D e n

i

t r

i

f

i

c at

i

o n r a t e s

i

n s e d

i

me n t s w

i

t h Uc a b u r r ows , S_p ar t

i

n a r o o t s a nd s e d

i

me n t w

i

t ho u t t he s e f e a t u r e s . 7 5

2 5 . D

i

u r n al a nd t

i

da l

p

at t e r n s o f

d

e n

i

t r

i f i

c at

i

o n r at e s

i

n sed

i

me nt a s s oc

i

a t e d w

i

t h S

_p

ar t

i

n a r o o t s 7 8

2 6 . Mo de l o f n

i

t r o

g

e n t r a n s f o r ma t

i

o n s

i

n n at u r a l a n

d

r e st o r ed m a r s h s e d

i

me nt s 8 4

I N T RODU CT I ON

W e t l a nd r e s t o r a t i o n i s r e c e i v i n_g

i

n c r e a s i n _g a t t e n t i o n

a s a me a n s t o mi t

i

_g a t e ha b

i

t a t l o s s . I n t h e U n

i

t ed S t a t es _,

a n es t

i

mat ed 3 0 t o 5 0

_p

e r c e n t of t he o r

i

_g

i

n a

l

we t l a n

d

s had

b e e n l o s t _{b y} t he 1 95 0 '

s _, mo s t _{l y} dr a

i

n ed f o r a _gr

i

cu l t u r e _, a nd

a n o t he r 1 0 % of co as t a l wet l a nd s we r e l o st f r om t h e 1 9 5 0 ' s t o

t

h

e m

i

d 1 9 7 0 '

s

(

M

i

t s ch a nd Go s s e l

i

nk 1 9 8 6 , Ma d s e n 1 9 8 6

)

.

Co a s t a l ma r s he s _, a s w e l l a s o t he r wet l a nd s _, we r e

h

i

s t o r i c a _{l l y} v

i

e w ed a s wa s t e l a nd s s

i

n c e t h e r e wa s _l

_i

t t l e t o

e x_{p l} o

i

t f r om t he o f t e _n f o r b

i

d d

i

n _g t e r r a

i

n . Co n s e q u e n t l y _,

c o a s t a l s a l t ma r s he s ha v e bee n e x t e n s i v e l

_y

d r a

i

n e d a nd

f

i

l l e

d

f o r v a r

i

o u s

_p

u r

_p

o se s

i

n c l ud

i

n

_g

mo s

_q

u

i

t o c o nt r o l ,

dr e d

_g

e s

_p

o

i

l d e

_p

o s

i

t

i

o n _, a nd d e v e l o

_p

me nt . A

d

d

i

t

i

o n a

l

l

y

,

c o a s t a l ma r s he s

h

a v e be e n l o s t t o o

_p

e n wa t e r t

h

r o u

_{g h}

_p

o r t

a nd ma r

i

n a d e v e l o

_p

me n t

₍

T h e Co n s _{e r v a} t

i

o n F o u n

d

a t

i

o n 1 9 8 8

₎

.

T h r o u

_g

h t he s t ud y o f s a l t m a r s h e c o s

_y

s t e _{m f u n c t}

_i

_{o n} ,

e co l o_g

i

c a l v a l u e s o f t he s e w e t l a nd s ha v e b e c o me a

_{p p}

a r e nt .

Fr om a u t

i

l

i

t a r

i

a n s t a n d

_p

o

i

n t , t h e mo st v

i

t a l f u n c t

i

o n o

f

sa l t m a r s he s

i

s

_p

r o v

i

d

i

n

_g

n u r s e r

_y

_g

r o u n

d

s

f

o r

j

u v e n

i l

e

f i

s h .

An es t

i

mat ed 6 0- _{9 0 % o f a l l c o mme r c}

_i

_a

l l y

i

m

p

o r t a nt s

_p

e c

i

e s

a r e d e_p e nd e n t o n t he m a r s h- e s _t u a r

i

n e s

_y

s t e m

₍

T he

s a l t ma r s

h

c o r

d

_gr a s s , S

p

a r t

i

n a a l t e r n

i f l

o r a

p

r o v

i

de s t r o

p

h

i

c

s u_{p p} or t f or i m_p o r t a n t sh e l l a n d f

i

n f i sh e r

i

e s

₍

e . g . Pe t e r s o n

a nd H o w a r t h 1 98 7

₎

. T he se co as t a l we t l a n d s a r e a l so a

c r

i

t i c a l hab i t a t f o r b

i

r d s t hat n e s t a n d f e e d t he r e .

Ma r s he s a r e d

_y

n am

i

c s

i

t es o f n ut r i e n t t r a n s f o r mat

i

o n ,

f u n c t i o n i n_g i n some c as e s a s a b u f f e r o r f i l t e r f o r

t e r r es t r

i

a l r u n of f

i

n t o e s t u a r

i

e s . I n t e r t

i

d a l ma r s he s a r e

i

nh e r e n t l

y

v a l u ab l e f o r t he s t ud

_y

o f ada_{p t} at

i

o n t o t he

c o n t i n u a _{l l y} ch a n_g

i

n _{g p h y} s

i

c a l ex t r eme s o f t h

i

s h ab

i

t a t .

P

_{h y}

s

i

c a l l

_y

, ma r s he s h e l p p r o t e ct sho r e l

i

n e s f r om e r o s

i

o n b y

d

i

s s

i

_pat

i

n_g w a v e e n er _{g y} a nd mo d

i

f

_{y i}

n

_g

s e _d

_i

me n t t r a n s

_p

o r t .

As t he s e v a l u es of sa l t ma r sh e c o s

_y

s _t ems ha v e be co me

r ec o _gn

i

zed , s u

p p

o r t f o r t h e

p

r ot e c t

i

o n o f d

i

m

i

n

i

s h

i

n

g

wet l a nd r e s o u r c e s h a s

i

n c r e a se d . Howe v e r

, t he c o n t

i

n u e d

p

o

_p

u l a t

i

o n _gr ow t h

i

n c o as t a l a r e a s h as l e d t o

i

n c r e a s e d

de v e l o

_p

me n t w i t h t he r e s u l t t hat sa l t m a r s he s ha v e be e n

de st r o_ye d t hr o u _{g h} d

i

r ec t f

i

l l

i

n _g a n d dr e _{d g i} n _g o r d

i

s t u r b e d

t

h

r o u_{g h}

h

_{y d}r o l o

_{g i}

c a l c h a n_ge s

i

n t h e wa t e r s hed

₍

Zed l e r 1 9 8 8

₎

.

Und e r f ed e r a l l a w , wet l a nd hab

i

t a t s a r e

p

r ot e c t ed u n

d

e r

Se c t

i

o n 4 0 4 o f t he C l e a n Wa t e r Act . I m p l eme n t at

i

o n o

f

t

h i

s

a ct ha s b e e n h

_{i g}

h l

_y

v a r

i

a b l e s u c

h

t ha t w e t

l

a n

d

l o ss

h

a s

c o n t

i

n u e

d

a t a n a l a r m

i

n

_g

r at e .

W

i

t

h

r e

_g

a r d t o t

h

e

_p

a s t Bu s

h

ad m

i

n

i

s t r a t

i

o n ' _{s s t at e}

d

p o l

i

c

_y

o f "

n o ne t l o s s "

o f w et l an d s _, ma r sh cr e at

i

o n a nd

r e st or at

i

o n h a s b e e n v

i

ewe d b

_y

ma n a

_g

e r s a n

d

d

e v e

l

o

_p

e r s a s a n

c o a s t a l zo n e s . T he t e r m '

m

i

t

i

_gat

i

o n '

ha s e v o l v e d f r om t he

c o n c e_{p t} o f

_p

r e v e n t

i

n

_g

or m

i

n

i

m

i

z

i

n

_g

i

m

_p

a c t s o n t he

e n v i r o nme n t t o me a n "

po s t f a c t o a ct

i

o n s t ake n t o r e st o r e o r

c om

_p

e ns a t e f o r t h e u n a v o

i

da b l e

i

m

_p

a c t s o

f

a n a c t

i

v

i

t

_y

o n

wet l a nd s "

₍

R ac e a nd Ch r

i

st

i

e 1 9 8 2

)

. Me t ho d s o f m

i

t

i

ga t

i

o n

i n c l u de _p r e - a_{p p l i} c a t i o n , r e st o r a t i o n a nd e n h a nc e me n t , ma r s h

c r e a t

i

o n a nd m i t _{i g} a t

i

o n b a nk

i

n_g

₍

T ha _ye r e t a l . 1 9 8 6

)

. On l y a

f ew s t a t es ha v e de v e

l

o_p e d a s

_p

ec

i

f

i

c

_p

o l

i

c

_y

of we t

l

a n d

m

i

t

i

_g a t

i

o n . I n s t e ad _, m o st s t a t e s

i

m

p

l e me n t w e t l a n d

r e

_g

u

l

at

i

o n s t

h

r o u

_g

h a

_p

e r m

i

t t

i

n

_g

_p r oc e s s o n a c a s e-

_{b y}

- _{c a s e}

b as

i

s . Ma r sh c o n st r uc t i o n ma

y

be r e gu i r e d a s a c o n d

i

t

i

o n o f

p e r m i t a _{p p} r o v a l . T he p e r m i t t

i

n g p r o c e s s a l l ows c o n s i d e r a b l e

l a t i t ud e i n i n t e r _pr e t a t

i

o n o f we t l a n d r e_gu l a t

i

o n s a n d

t h e r e f o r e n e

_g

ot

i

at

i

o n b e t we e n de ve l o_pe r s a nd ma n a

_g

e r s h as

co n s i d e r ab l e i n_pu t t o e me r _g

i

n _g we t l a nd m

i

t _{i g}a t

i

o n _po l i c

_y

.

Cr

i

t

i

c s o

f

we t l a n

d

m

i

t

_{i g}

at

i

o n c o nt e n

d

t ha t t

h

e r e

i

s n o t

a s u f f

i

c

i

e n t s c

i

e n t

i

f

i

c ba s

i

s f o r t he t r e a t me n t o f we t

l

a n

d

s

a s r e n ewa b l e r e so u r c e s

₍

R a c e a nd C h r i st

i

e 1 9 8 2 , C a

i

r n es

1 9 8 8 _, Mo

_y

a nd L e v

i

n 1 9 9 1

₎

. Re s e a r c

h

o n ma n

y

a s

p

e c t s of t he

e c o l o

_{g i}

c a l

f

u nc t

i

o n o f n at u r a l m a r s he s

i

s

l i

m

i

t e d . T he

v a r

i

a

b i

l

i

_{t y} w

i

t h

i

n a n d b et we e n n a t u r a l a s we l l as

t r a n s

_{p l}

a n t e d ma r sh e s mak e s c om

_p

a r

i

s_{o n} d

_i

_{f f}

i

c u l t a n d

_p

r e s e nt s

p

r ob

l

ems

f

o r t

h

e d e v e l o

_p

me n t o

f

r e

_g

u

l

at o r

_y

s t a n

d

a r

d

s

_f

o r

e s t ab l

i

sh

i

n

_g

a n d mo n

i

t o r

i

n

_g

ha b

i

t at r e

_p

l a c eme nt . I n t h

i

s

r e s

_p

ec t _, t he r o u t

i

n e u s e o f we t l a nd m

i

t

_{i g}

a t

i

o n

i

n t he

Be c a u s e t he t e ch n o l o _{g y} of t r a n s_{p l} a nt i n _g s al t ma r she s

de v e l o _p ed a s a me a n s o f s ho r e l

i

n e s t ab i l i z a t

i

o n _,

i

n

i

t

i

a l

r e s e a r ch o n m i t _{i g}a t e d s a l t ma r s he s f o c u s e d o n t _h e su c c e s s o f

S

_p

a r t

i

n a a l t e r n

i

f l o r a s t a nd s o n t he U . S . E a st a n d Gu l f

C o as t s . Ma ny p l a n t e d m a r s he s h a v e a t t a i ne d r a t e s o f pr

i

m a r y

p r o du ct i v i t _y c o _{m p} a r a b l e t o co n t r o l n a t u r a l ma r sh e s i n a f e w

t o 1 0 _y e a r s t i me

₍

Sen e c a e t a l . 1 9 7 6

, B r o ome et a l . 1 9 8 8

)

.

T he s e r es e a r c he r s f o u n d t h a t su c c e s s f u _l r e v e _ge t a t

i

o n

i

s

a f f e c t ed b

_y

s u c h f a ct o r s a s e l e v a t

i

o n _, s l o _pe _, wa v e e x _p o s u r e _,

s o

i

l c hem

i

st r _y a nd _{p h y} s

i

c a l n ut r i e nt s u

_p

_{p l}

_y

_, s a l

i

n

i

t

_y

a nd

a v a

i

l a b

i

l

i

_{t y} o f _{p l} a nt _p r o_p a _gu l e s .

On _{l y} a f ew s t u d

i

e s ha v e co _{m p}a r e d

i

n f a u n a l c o mmu n

i

t

i

e s

i

n a r t

i

f

i

c

i

a l a n

d

n at u r a l ma r sh e s

(

Cam ma n 1 9 7 6 , Sa c co e t a l .

1 9 8 7 , Sa c c o 1 9 8 9 , Moy a nd L e v

i

n 1 9 9 1

)

. D

i

f f e r e n c e s

i

n

b

i

o ma s s a nd d

i

v e r s

_i

_{t y} b e t we e n a r t i f

i

c i a l a nd n at u r a l ma r s he s

s e e me d u n r e l a t e d t o ma r s h a _ge

₍

Sac c o 1 9 8 9

₎

. Ma r sh e l e v at

i

o n

(

Sa c c o 1 9 8 9

₎

, s e d

i

me n t s

i

z e a n d o r

g

a n

i

c c o nt e nt

(

Mo

y

a nd

Le v i n 1 9 9 1

₎

ha v e be e n i de n t i f i ed a s f a ct o r s r e s_po n s

i

b l e f o r

i

n f a u n a l c o mmu n

i

t

_y

d

i

f f e r e n c e s b u t t h e c om

_p

l e x

i

t

_y

a nd

v a r

i

ab

i

l

i

t

_y

o f t

h

e s e s

_y

s t e ms s u

_{g g}

e s t t h a t c o mmu n

i

t

_y

st r uc t u r e

i

s de_p e nde n t o n ma n

_y

_,

i

n t e r r e l at e d v a r

i

a b

l

e s a n

d

i

s d

i

f f

i

c u l t t o

_p

r e d

i

c t .

L

i

kew

i

s e _, l

i

_{t t l} e r e s e a r c

h

ha s a d d r e s s e d n ut r

i

e nt

c _y c l i n _g

i

n co n s_t r u ct e d ma r s _he s . C om p a r i so n s o f s e d i me n t

p

o o l s o f n

i

t r o _gen a n d o r _ga n

i

c c a r bo n r e v e al e d t hat

p

r ed i c t e _d r e co v e r _y t

i

me s

(

t o n at u r a l ma r s

h

l e v e l s

)

v a r

_{y i}

n

_g

f r om 2 t o _g r e a t e r t ha n 3 0 _y e a r s

₍

L i nd a u a nd H o s s i _{n e r} 1 9 8 1 _,

C r a f t e t a l . 1 9 8 8 _, L a n g i s e t a l . 1 9 9 1 _, C r a f t e t a l . 1 9 9 1

)

.

Cr af t e t a l .

(

1 9 8 8

)

d

i

st

i

n

g

u

i

s he d bet we e n ma c r o o r

g

a n

i

c

p

o o l s

o

f

n u t r

i

e n t s t hat a_{p p}r o x

i

ma t e d n a t u r a l ma r s h l e v e l s w

i

t h

i

n

1 5 t o 3 0 _y e a r s a nd s o i l n u t r i e n t _p o o l s t h a t w e r e mu c h s l o we r

t o de v e l o_p . La n g i s e t a l

(

19 9 1

)

f o u n d t ha t a l t ho u g h t he

s

_p

ec

i

f

i

c r a t e s o f n

i

t r o_ge n m

i

ne r a l

i

zat

i

o n we r e s

i

m

i

l a r

i

n a

n a t u r a l a n d co n st r u c t e d ma r sh _, t ot a l m

i

n e r a l

i

z at

i

o n wa s

t w

i

c e a s h

i

_{g h} i n t h e n a t u r a l ma r sh . N i t r o ge n f

i

x at

i

o n r at e s

we r e l owe r

i

n su r f a c e s e d

i

me n t s b u t h

_{i g}

h e r

i

n t h e

r h

i

z o s_{p h}e r e of a c o n s t r u c t ed ma r s h c o _{m p} a r e d t o a n at u r a l

ma r sh

i

n Sa n D

i

e

_g

o B a_y

₍

L a n _g

i

s e t al . 1 9 9 1

)

. I n c o n t r a s t _,

C u r r

i

n

₍

i n _pr e_p .

)

f o u nd h i g he r n i t r o ge n f

i

x a t i o n r a t e s

i

n

r e st o r e d ma r sh su r f a c e s e d

i

me nt c o_{m p} a r e d t o a n a d

_j

a ce n t

n a t u r a l ma r s

_h

i

n N o r t h Ca r o l

i

n a . Ot he r n

i

t r o

g

e n

t r a n s f o r ma t

i

o n s _,

i

n c

l

u d

i

n _g n

i

t r

i f i

c at

i

o n , d

i

s s

i

m

i

l a t o r

y

n

i

t r a t e r e d uc t i o n t o ammo n i u m a nd d e n i t r i f i c a t i o n , ha v e n o t

p r e v

i

o u s l

_y

b e e n me as u r ed

i

n c o n st r u ct ed s a l t m a r sh e s .

Co n s

i d

e r a b l e _{r e} s e a r c

_h

h a s f o c u s ed o n n ut r

i

e nt c

_y

c _l

_i

n

_g

i

n n a t u r a

l

s a

l

t m a r s h s

_y

st e m s . N

i

t r o

g

e n

i

s o

f

p

a r t

i

c u l a r

i

n t e r e s t b ec a u s e su

_p

_{p l}

i

e s o f t h

i

s n ut r

i

e nt h a v e c o n s

i

st e nt l

_y

b e e n f o u n d t o l

i

m

i

t

_p

r

i

ma r

_y

_p

r od u c t

i

o n o

f

s a l t ma r s h

v e _ge t at

i

o n

₍

Me n de l s s o hn 1 9 7 9 , B u r e s ch e t a l 1 9 8 0 , S ma r t a n d

Bu r k o 1 9 8 0

₎

. N

i

t r o

g

e n bud

g

e t s

h

a v e

b

e e n d e v e l o

p

ed f o r

o f n i t r o_g e n be t wee n ma r sh e s a nd a d

_j

a ce n t e s t u a r i e s

₍

e -

g

-Ha i n e s e t a l . 1 9 7 7 _, S t e v e n s e n e t a l

. 1 9 7 7 , Wo o d we l l et a l .

1 979 , J o r d a n a nd Co r r e l l 1 9 9 1

)

. A r ev i e w o f t he s e s t u d

i

e s

s _ho ws t ha t t he n e t e xc h a n_ge o f d

i

f f e r e n t f o r ms of n

i

t r o_ge n

o f t e n v a r

i

e d s e as o n a _{l l y} a nd t h e o v e r a l l so u r c e

_/

s

i

n

k

r o l e o f

ma r s he s f o r ni t r o_ge n wa s o f t e n ma r sh - s_p e c i f i c . N i x o n

(

1 9 8 0

)

c o n c l u d e d t ha t , i n ge n e r a l , ma r sh e s e xp o r t ed o r ga n

i

c

n

i

t r o_ge n a nd NH ^

"_*"

a n d

i

_{m p} o r t ed N 0 2

~

a n d N0 ₃ ~

. A r e c e nt

t

h

e o r _y

₍

D ame et a l .

i

n p r e s s

)

_, su g ge s t s t ha t ma r s h n u t r

i

e nt

e x c _ha n_g e

i

s

_p

r ed

i

c t a b l e a l o n _g a

_g

e o h

_y

d r a u l

i

c co n t

i

n u um o f

ma r s h l o c at

i

o n w

i

t h

i

n t he e s t u a r

i

n e s

_y

st em a nd ma r sh

g

e o l o

_{g i}

c a

_g

e . I n t h

i

s s c h eme

(

s u

p p

o r t e d b

y

da t a f r o m t h e

N o r t h I n l e t ma r s h - e s t u a r i ne s

_y

s t e m

i

n So ut h Ca r o

l i

n a

₎

,

mat u r e ma r s he s

i

m p or t _pa r t

i

c u l a t e a nd d

i

s s o l v ed n u t r

i

e n t s _,

i

nt e r me d i a t e a_ge ma r sh e s t a k e u _{p p}a r t

i

c ul at e s a n d r e l e a se

d i

s s o l v ed n ut r

i

e n t s , w

h i

l e mat u r e ma r s he s e x

p

o r t b ot h f o r ms

o f n ut r

i

e nt s . Ma r s h - e st u a r

i

n e e x ch a ng e s o f n

i

t r o

g

e n a r e

t h o u

_g

h t t o b e sma l l c om

_p

a r e d t o bo t h e st u a r

i

n e

_p

h

_y

t o _{p l} a n k t o n

r e

_q

u

i

r eme nt s a n

d

s e as o n a

l

v e

_g

e t a t

i

o n r e

_q

u

i

r eme nt s w

i

t

h i

n

s al t m a r s h e s

₍

Wo o d we l l e t a l . 1 9 7 9

, N

i

x o n 1 9

8

0

)

.

N

i

t r o _ge n r e c _y c l

i

n

_g

_p

r o ce s s e s w

_i

t h

_i

n m a r s he s ma

_y

be mo r e

r e l e v a n t t o o v e r a l l ma r sh _p r odu ct i v

i

t _y t h a n n

i

t r o_ge n

e x c _ha n

_g

e _,

_p

a r t

i

c u l a r _{l y}

i

n

_p

r o t e c t e d s

i

t e s o r w he r e

g

r o u nd wat e r a n

d

o r r

i

v e r

i

n e

i

n

_p

ut s o f n

i

t r o

_g

e n a r e

r e l a t

i

v el

_y

sma l

l

. Sev e r a

l

r e s e a r c

h

e r s

h

a v e s u

g g

e st e

d

t

h

at

s_y st ems _, wh i l e _{y o u n g} ma r ah e s ma_y "

l e a k "

n i t r o_ge n t o t h e

a m b i e n t e n v i r on me n t

₍

Od u m 19 6 9 , Wo od we l l 1 9 7 9 , A zn i b . Ab d .

Az

i

z a n d Ne _{d w}e _{l l 1 9 8 6 , M}o r r

i

s a nd Bo w de n 1 9 8 6

₎

. I n t h

i

s

r e

_g

a r d , n i t r o ge n cy c l i n g o r r e - _c

y c _l

_i

n_g

i

s a v a l u ab l e

c r

i

t e r i a f o r e v a l u a t

i

n _g a nd mo n

i

t o r

i

n _g c o n s t r u c t ed ma r s _he s .

N i t r o _ge n c _y c l i n_g i s a co _{m p l} ex o f mo s t _{l y} m i c r ob i a _{l l y}

-me d

i

at e d n

i

t r o _ge n t r a n s f o r m a t

i

o n s su b

_j

e c t t o

i

nh

i

b

i

t o r _y a n d

co_{m p}e t

i

t

i

v e r e _gu l at

i

o n

₍

F

i

_gu r e 1

₎

. I n sa l t ma r s he s _,

s e a so n a l , t

i

da l a n d d

i

u r n a l c

y

c l e s

i

m

p

o s e a c o nt

i

n u a l l

y

d y n am

i

c r e _gu l a t

i

o n o f m

i

c r o b i a l _p r o c e s s e s . Ma r s h ma c r op h y t e s

a n d f a u n a a r e d

i

r e ct _{l y} l

i

nk e d t o t h e n i t r o _ge n c_y c _l e a nd a l s o

ma

_y

i

n d i r e c _{t l y} r e _gu l at e N t r a n s f o r ma t

i

o n s t hr o u_{g h ,} f o r

e x a_{m p}

l

e _, o x _y

_g

e n at ed r h

i

z o s

_p

he r e s o r bu r r ow s t r u c t u r e s .

P e r h a_p s b e c a u s e o f t h

i

s

i

nh er e n t v ar

i

ab

i

l

i

_{t y} , o n l y a

f

ew r e se a r c

h

e r s ha v e

d

ev e

l

o

_p

e

d

n

i

t r o

_g

e n bu

d g

et s t h a t

i

n c l ud e s

i

mu l t a n e o u s me a s u r e d r at e s o

f

s e v e r a l m

i

c r ob

i

a l l

_y

me d

i

at e d N t r a n s f o r ma t

i

o n s

i

n sa l t ma r s he s

₍

K a_{p l} a n e t a l .

1 9 7 9 , Va l

i

e l a a nd T e al 1 9 7 9 , D e l u a ne a nd Pa t r i c k 1 9 8 0 , A zn

i

b

. A b d . A z

i

z a n d Ne

d

we l l 1 9 8 6

)

. I n t

h

e s e s

y

st ems t h e

l a r

_g

e s t N t r a n s f o r ma t

i

o n s w e r e m

i

n e r a l

i

z at

i

o n a n d u

_p

t a ke b

_y

v e

_g

e t a t

i

o n ; t h e t wo

_p

r o c e s se s a c c o u n t

i

n _g f o r 8 2 t o 9 6 % o

f

o v e r a l l N c _y c l

i

n _g

₍

A zn i b . Ab d . A z

i

z a nd N e d we l l 1 9 8 6 _,

De l u a ne a n d P a t r

i

c k 1 9 8 0

)

. N i t r oge n f

i

x a t

i

o n a nd

d e n

i

t r

i f i

c at

i

o n w e r e r o u

_{g h}

l

_y

ba l a nc ed a nd o n t

h

e s ame o r

d

e r

o

f

ma

_g

n

i

t u de a s n et ma r s h- e st u ar

i

n e n

i

t r o

_g

e n ex c h a n

_g

e a n d

I N P U T

A

t

m

o s

_p

h

e n c

T

e r r e s

t

r

ia

l

G

r o u n

d w

a

t

e r

R

iv e r

in e

t

^

F

_{i g}

u r e 1 . N

i

t r o

g

e n t r a n s

f

o r mat

i

o n s

i

n s a

l

t ma r s

h

s e

d i

me n t s

D e ni t r i f i c at i o n wa s a_{p p} r o x i ma t e _{l y} e_q u a l t o o r s l i

_g

ht l

_y

gr e a t e r t h a n n i t r i f

i

c a t i o n i n t wo s t ud i e s w h e n bo t h

p

r o c e s s e s we r e me a su r ed

₍

Ka _p

l

a n e t a l . 1 9 7 9 _, A zn

i

b . A b

d

.

A z

i

z a n d N e d we l l 1 9 8 6

₎

.

I n r e st o r e d ma r s he s

, t he pa r t i t i o ni n g a nd ba l a n c e

amo n _g t he c o m_po n e n t s o f n i t r o_ge n c_y c l i n _g ma_y be _q ui t e

d

i

f f e r e n t t ha n t h e _pa t t e r n _p r ev

i

o u s l y s u _g

_g

e s t e d . A l t

h

o u g h

s

_p

e c

i

f

i

c r at e s o f m i n e r a l

i

z a t

i

o n a r e s

i

m

i

l a r

i

n c o ns t r u c t ed

a n d n a t u r a l m a r sh e s _, o n a n a r e a l b a s

i

s _, m

i

n e r a l

i

z a t

i

o n

i

s

l owe r

i

n co n s t r u c t e d mar sh e s d ue t o l owe r l e v e l s o f

pa r t

i

cu l a t e o r _g a n

i

c ma t t e r

₍

Cr af t et a l . 1 9 8 8 _, L a n

g i

s e t a l .

1 9 9 1

₎

. Co n s e q u e n t l y , t he ba l a n c e a mo n

g

ot he r N

t r a ns f o r mat

i

o n s ma _y h a v e a co n s

i

d e r ab l e

i

m

_p

a c t o n m a r s

h

p

r i mar _y

_p

r o duc t i v i t _y .

T h e

_p

r es e nt wo r k f oc u s e s o n a c o m

_p

a r

i

s o n o

f

de n

i

t r

i

f

i

c a t

i

o n

i

n a n at u r a l a nd r e s t o r ed s a l t ma r s

h

.

D e n

i

t r

i

f i c a t i o n r e _p r e s e n t s a b i o l o _{g i} c a l l

_y

me d

i

a t e d l o s s of N

t o t h e a t mo s

_p

he r e t h a t , i n t h e a b s e n c e o f a nt h r opo

g

e n

i

c N

i

n

_p

u t , c a n o n l y b e o f f s e t b

y

n

i

t r o

g

e n f

i

x at

i

o n . I n t h

i

s

st ud

_y

, t h e a c e t

y

l e n e b l oc k t e c hn

i q

u e was ad a

p

t e d t o me a s u r e

de n

i

t r

i

f

i

c at

i

o n

i

n t he sa l t ma r s

h

ha b

i

t at a nd a n e

f

f o r t wa s

mad e t o a s s e s s t h e c o m_{p l} e x o f

i

nt e r a ct

i

n

_g

v a r

i

ab l e s

r e

_g

u l a t

i

n

_g

de n

i

t r

i

f

i

c at

i

o n t h r o u

_g

h s e a so n a l , d

i

u r n a

l

a nd

t

i

d a l c

_y

c

l

es . I n ad d

i

t

i

o n _, t he

i

m p ac t o

f

s a l t ma r sh

v e

_g

e t a t

i

o n a nd f a u n a o n de n

i

t r

i

f

i

c a t

i

o n r a t e s wa s

BA CKGROU N D I N FO R MA T I O N

As de_p

i

c t e d

i

n F

i

_gu r e 1 , de n

i

t r

i

f

i

c at

i

o n

i

s o n e o f ma ny

i

n t e r ac t i n _g n i t r o

_g

en t r a ns f o r ma t

i

o n s ch a r a c t e r

i

z

i

n _g t h e

n

i

t r o _ge n c _y c l e . C o n se

qu e n t _{l y} ,

i

t

i

s d i f f

i

c u l t t o st u d y

d e n

i

t r

i

_f

i

c at

i

o n w

i

t h o ut c o n s i de r

i

n _g o t he r n

i

t r o

_g

e n

t r a n s f o r ma t

i

o n s t o w h i c h t h i s

_p

r o c es s i s l

i

n k ed . T h e

f o l l ow

i

n_g r e v

i

e_w o f de n i t r i f i c at i o n r es e _{a r} c h i n c o a st a l

ma r

i

n e s

_y

st ems

i

n c l ud e s

i

n f o r ma t

i

o n o n t h e c l os e _{l y} r e l at e d

p

a t h wa_y o f n

i

t r

i

f

i

c a t

i

o n a nd a l t e r n at e

_p

at h wa

_y

s o f N 0 ₃~

r ed u c t

i

o n .

A s so c

i

a t e d N

i

t r o

_g

e n Tr _{a n} s f o r ma t

i

o n s

N

i

t r

i

f

i

c a t

i

o n- D e _n

_i

t r

i

f

i

c a t

i

o n Co u_{p l}

i

n _g

D e n

i

t r

i

f

i

c a t

i

o n c a n be _{n i t r a t e} - _{l i m}

_i

_{t e d}

_i

_{n r edu c e d}

s ed

i

me n t s w he r e N 0 3

~

i

nf l u x

i

s l ow a nd N H ^

"_*"

i

s t he

p

r edom

i

n a n t f o r m o f n

i

t r o_ge n . S t ud

i

e s

i

n e st u a r

i

n e a n d

i

n t e r t

i

da l s e d

i

me nt s ha v e sh own t ha t

_p

o t e n t

i

a l r at es o f

d e n

i

t r

i

_f

i

c at

i

o n

₍

n

i

t r at e en r

i

c he

d

₎

f

a r e x c _{e e}d _{u n a}me nd e d

r a t e s

(

Va nRaa l t e a nd Pa t r

i q

u

i

n 1 9 7 9 , Ka s

p

a r 1 9 8 3

)

. So u r c e s

o f n

i

t r a t e t o t he s e d

i

me nt

i

n c l u

d

e d

i f

f u s

i

o n f r om o v e r l

_{y i}

n

_g

wa t e r , n

i

t r

i

f

i

c at

i

o n w

i

t

h i

n t

h

e se

d i

m e n t a n

d

,

p

a r t

i

c u

l

a r

l y

i

n i nt e r t

i

d a l s _ys _{t e m}s _{, g r o u n}dw at e r a nd _p r e c

i

_p

i

t at

i

o n .

Be c a u s e n

i

t r

i

f

i

ca t

i

o n o c c u r s _{o n}

l

_{y u n}

_d

e r a e r o

b i

c c o n

d i

t

i

o n s

s e d i me n t r a t e s o f de n i t r i f i c a t

i

o n a r e _pr e d i c t ed a t t he

i

nt e r f a c e o f t h e s e t w o zo n es . S t ud

i

e s

i

n e st u a r

i

n e a nd

ma r

i

ne s_y st ems ha v e s u

_{p p}

o r t e d t h

i

s

_p

r ed

i

c t

i

o n

₍

So r e n s e n

1 9 7 8 , Ka spa r 1 9 8 2

)

. Mo d e l i n g o f a 2

- _{l a}

y e r s _y st em

i

n w h

i

c h

n

i

t r

i

f

i

c a t

i

o n o c c u r s

i

n t he s u r f ac e , a e r at e d s t r at a a nd

de n i t r i f i c a t i o n o c cu r s i n d ee_p e r a n ae r ob i c s e d i me n t s h a s

s u c c es s f u _{l l y} ma t c _hed ex _pe r

i

me nt a l dat a

i

n some s t u d

i

e s

(

Va n de r

b

o r _{g h t} a nd B

i

l l e n 1 9 7 5 , P at r

i

c k a nd Red d y 1 9 7 6

)

.

Howe v e r _, t

h i

s s

i

m

_p

l e mo de l

_i

s n ot a

_{p p l i}

c a

b l

e t o v e _ge t a t e d o r

b

i

o t ur b at ed s e d

i

me n t w h e r e o x _{y g}e n _gr ad

i

e nt s a r e d yn am

i

c o n

s

_p

a t

i

a l a n d t em p or a l s c a l e s . I n ad d

i

t

i

o n

, de n

i

t r

i

f

i

c a t

i

o n

ha s b e e n f o u n d t o o c c u r

i

n r e du c e d m

i

c r o z o n e s w

i

t h

i

n t h e

s u r f ac e a e r ob

i

c l a_y e r

₍

J or _ge n s e n e t a l . 1 9 7 7

)

.

I nd

i

r e ct e v

i

d e nc e o f c o u_{p l} e d s e d

i

me nt a r

_y

n

i

t r

i

f

i

c at

i

o n

-de n

i

t r

i

f

i

c a t

i

o n c ome s f r o m ob s e r v a t

i

o n s t h a t ma x

i

ma l r at e s

o f bo t h _p r o c e s s e s o f t e n o c c u r a t t he sa me d e _{p t h}

(

Ma c f a r l a n e

a nd H e r be r t 1 9 8 4

₎

a n d f r o m da t a demo n s t r a t

i

n

_g

a _p o s

i

t

i

v e

c o r r e l a t

i

o n

i

n t h e ma _gn i t ude o f bot h _p r o c e s se s

(

K em

_p

e t a l .

1 9 9 0

₎

. N t r a c e r s t u d

i

e s ha v e

p

r o v

i

de d d

i

r e ct e v

i

d e n c e o f

c o u

_{p l i}

n

_g

i

n e st u a r

i

n e s e

d i

m e nt s

(

N

i

s

h i

o _, e t a

l

. 1 9 8 3 _,

J e n

k i

n s a n

d

Ke m

_p

1 9 8 4

₎

. J e n k

i

n s an

d

Ke m

p

(

1 9 8 4

)

f

o u nd t

h

a t

t h e t i g ht n e s s o f c o u_{p l}

i

n_g v a r

i

e d se as o n a l l

_y

. I n t he s

p

r

i

n

g

9 9 % of t he d e n

i

t r

i

f

i

e d n

i

t r at e o r

i

_g

i

n at e

d

f r om n

i

t r

i

f

i

c a t

i

o n

w h

i

l e a l mo st n o c o u_{p l}

i

n _g w a s d e t e c t e d

i

n t h e su mme r w h e n

n

i

t r

i

f

i

c a t

i

o n r at es we r e

i

nh

i

b

i

t e d b y l ow o x

_{y g}

e n . N

i

s h

i

o e t

a l .

(

1 9 8 3

)

f o u n d t h at co u

p

l

i

n

g

w a s t

i g

h t e r

i

n s a n d

y

N0 ₃ ~

ge n e r a t ed f r om n i t r

i

f

i

c a t

i

o n s u _{p p l y}

i

n _g 7 0 %

d e n

i

t r

i

f i c at i o n

₎

v s . a mu d d y s

i

t e h a v

i

n g r e l a t

i

v e l y h

i

g h

wa t e r c o l i imn ni t r at e

₍

6- _{9 %}

)

.

Few r e s e a r c he r s ha v e me a s u r e d n i t r

i

f

i

c a t

i

o n a nd

de n

i

t r

i

f

i

c a t

i

o n co nt em

_p

or a n e o u s l

_y

i

n s a l t ma r s he s

(

Ka_{p l} a n e t

al . 19 79 _, Az n i b . Ab d . A z i z a nd N e d we l l 1 9 8 6

)

. I n b ot h

s t ud

i

e s n

i

t r

i

f

i

c at

i

o n was c o _{m p} a r a b l e t o o r e x ce e

d

e d

d e n

i

t r

i

f

i

c at

i

o n ,

i

n d

i

c at

i

n g t h a t t h e co up l

i

n g o f t h es e

p r o c e s s e s ma_y b e

i

m po r t a n t

i

n t h

i

s hab

i

t a t . S t e ep o x

y

ge n

gr ad

i

e nt s be t we e n t he o x _{y g}e n at e d r o o t s o f S

_p

a r t

i

n a

al t e r n

i

f l o r a a nd r e du c e d s ed

i

men t s _p r o v

i d

e

i

d e a

l

s

i

t e s

f

o r

t he c l o s e s

_p

a t

i

a l o r

i

e n t a t

i

o n o

f

n

i

t r

i

f

i

c at

i

o n a n

d

de n i t r i f i c at i o n . Th e a bu n da nt f

i

d d l e r c r ab

(

U c a sp p .

)

b u r r ow s a l so _pr o v

i

de s u c h _gr ad

i

e n t s as we l l as e x c r et e d N H_^

t hat c o u l d a u_{g m}e n t n

i

t r

i

f

i

c a t

i

o n . A t e m p o r a l s e p a r at

i

o n o f

b o t h _p r o c e s s e s

i

s a l so _po s s

i

b l e b e c a u s e o f t he d

_y

n am

i

c

n at u r e o f v e r t

i

c al s ed

i

me n t o x

_{y g}

e n co n c e n t r at

i

o n s f r om t

i d

a

l

a nd d

i

u r n a

l

c_y c l e s . T he st r o n

g

po s s

i

b

i

l

i

t y t

h

at t

h

e se

t r a n s f o r ma t

i

o n s a r e c l o s e l y l i n ke d

i

n s a l t ma r s h s_y st e ms

wa r r a nt s

i

n v e s t

i g

at

i

o n . Fu r t he r mo r e _, u n de r s t a n d

i

n

g

t h e

f

ac t o r s r e _g u l a t

i

n

_g

n

i

t r

i

f

i

c a t

i

o n ma

_y

b e

i

m

_p

o r t a nt

i

n a n

a s s e s sme n t o f n i t r o

_g

en l o s s v

i

a de n

i

t r

i

f i c a t i o n f r om s a l t

ma r s

h

s

_y

st ems .

N

i

t r

i

f

i

c at

i

o n

I n c o a s t a l ma r

i

n e s_y s t ems n

i

t r

i f i

ca t

i

o n

i

s l

i

m

i

t e d _{b y}

b

o t

h

o x

_{y g}

e n a n

d

n

i

t r o

_g

e n o u s s u

b

s

t

r at e s .

T h

e

h

a

l f

f r om Ki n= 5 5- _{1 0 0uM} N H 4

" '"

i

n t wo . ud

i

e s

(

Ha n s e n 1 9 8 0 _, He l d e r

e t a l . 1 9 8 3 a s r e f e r e n c ed

i

n Hen r

i

k s e n a n d Ke m p 1 9 8 8

)

.

L

i

_{g h} t

i

n h

i

b

i

t

i

o n o f n

i

t r

i

f

i

c a t

i

o n de t e ct ed

i

n t h e su r f a c e ₂

-3mm o f e st u a r

i

n e s e d

i

me nt wa s a_{p p} a r e n _{t l y} du e t o c _{om p et}

_i

_t

_i

_{o n}

w

i

t h

_p

ho t os

_y

n t he t

i

c o r _ga n

i

sms f o r N H ^

" ^

(

He n r

i

k s en a n d Ke _{m p}

19 88

₎

. R ed o x

po t e n t i a l i s u s ed a s a me a s u r e o f e l e c t r o n

f l o w a nd c a n t he r e f o r e

i

n d

i

c at e t he l o c a t

i

o n o f

_p

a r t

i

cu l a r

r e do x r e a c t

i

o n s

i

n t he s e d

i

me n t . I n e st u a r

i

n e se d

i

me nt s ,

n

i

t r

i

f

i

c a t

i

o n o n _{l y} o c c u r r e d a t r e do x _p o t e n t

i

a l s

_g

r e at e r t ha n

2 0 0 o r 2 5 0 m V

₍

J e n k

i

n s a nd K e_{m p} 1 9 8 4 , B

i

l l e n 1 9 7 5

r e s

_p

ec t

i

v e _{l y}

₎

.

Se a s o n a l _p at t e r n s o f s e d

i

me n t a r

_y

n

i

t r

i

f

i

ca t

i

o n

i

n

e st u a r

i

n e s

_y

st ems

_p

r o v

i

de e v

i

d e nc e f o r t em

p

e r at u r e

r e_gu l a t

i

o n o f t h

i

s _p r o c e s s . I n t

h

e l abo r at o r

y

_,

n

i

t r i f

i

c a t

i

o n ha s b e e n s _ho w n t o be t e_{m p} e r a t u r e r e_g u

l

at e d .

I n _pu r e cu l t u r e n

i

t r

i

f

i

e r s e x h

i

b

i

t e d a n o

_p

t

i

mum at 2 5- _{3 5}° _C ,

w

i

t h a

_g

r owt h r a n _ge b e t we e n 3- _{4 5}° _C

.

(

F o c h t a nd Ve r s t r at e

1 9 7 7

₎

. N

i

t r

i

f

i

c a t

i

o n r e s e a r c h

i

n e s t u a r

i

n e s ed

i

me nt s sh ow

t wo

b

a s

i

c s e a so n a l

_p

a t t e r n s . I n s e v e r a l s t u d

i

e s

,

n

i

t r

i f i

c a t

i

o n wa s

_p

o s

i

t

i

v e l

y

c o r r e l at e d w

i

t h t em

_p

e r at u r e

t hr o u

_g

ho u t t h e

_y

e a r

₍

Se

i

t z

i

n

_g

e r e t a l . 1 9 8 3 , Ma c F a r l a n e a nd

He r b er t 1 9 8 4

₎

. A s e c o nd t r e n d showe d a s e a so n a l s u mme r

de c l i n e a t t r

i

b ut ed t o l o w o x _{y g}e n _pe n e t r a t

i

o n a nd

i

n c r e a s ed

c om

_p

et

i

t

i

o n f o r N H_^ "_*^

(

H a n s e n e t al . 1 9 8 1

, J e n k i n s a nd K em

p

1

9

8 4

₎

.

H_^ S ha s be e n sh o w n t o

i

n h

i b i

t n

i

t r

i

f

i

c a t

i

o n at

r e f e r e n c e d i n H en r i k s e n a nd K e_{m p} 1 9 8 8

₎

_, a l t h o u _{g h}

n

i

t r

i

f

i

c a t

i

o n wa s o n l

y

i

n h

i

b

i

t e d at c o n c e n t r at

i

o n s o f 4 0 uM

i

n a no t he r s t u_{d y} o f e s t u a r i n e s e d i me nt s

₍

Y o s h i da 1 9 6 7 , a s

r e f e r e n c e d

i

n He n r

i

k s e n a nd Kem

_p

1 9 8 8

₎

.

D

i

s s

i

m

i

l a t o r _y N i t r a t e R edu c t i o n t o A mmo n

i

a

R at e s o f d i s s i m i l a t o r _y n i t r a t e r e du c t i o n t o am mo n

i

a

(

DN_R

₎

_ha v e b e e n d e t e r m

i

ne d f o r s e v e r a l sa l t ma r s he s . As

o _p

_p

o s e d t o de n

i

t r

i

f

i

c at

i

o n _{, N}

i

s c o n s e r v ed

i

n t he s

_y

s t em

t hr o u_{g h} t h

i

s

_p

a t h wa _y . Ne d we l l

(

1 9 8 2

)

f o u n d t ha t D NR

c om

_p

r

i

s e d f r om 1 t o 2 0 % o f t o t a l n

i

t r at e r e d uc t

i

o n

i

n s a l t

ma r s h s e d

i

me n t s w he n N 0 3

~

wa s ad ded t o a _{f l} o_w- _{t hr o u}

g h

s _y st em . I n t h

i

s s t u d

y

, D NR wa s h

i

g h es t

(

n e a r 2 0 % o f t ot a

l

r edu c t

i

o n

₎

w he n ad de d N 0₃ ~ w a s be l ow 4 5 0uM a nd r a

_{p i}

d l

_y

f e

l

l

o f f t o a b o ut 3 % a t co n c e n t r at

i

o n s h

i

_{g h} e r t ha n t h

i

s .

De n

i

t r

i

f

i

c a t

i

o n sh o we d a n

i

n v e r s e

_p

a t t e r n , sh

i

f t

i

n g f r om 7 8 %

t o 9 6 % o f t o t a l r edu ct

i

o n a t a nd a bo v e 4 5 0uM ad de d N 0 3

~

.

S l a t e r a n d Ca_po n e

₍

1 9 8 9

₎

f o u nd t ha t D NR c o m

_p

r

i

s ed t

h

e

g

r e a t e s t

_p

o r t

i

o n

₍

5 1 %

₎

o f N O_g" r e du c t

i

o n

₍

c o_{m p} a r e d t o 3 8

%

d e n

i

t r

i

f

i

c a t

i

o n

₎

i

n a Ne w Y o r k s a l t ma r sh . S

i

m

i l

a r l

y

_, u

p t o

5 0 % of ad d ed -'■^

NO j

"

a d de d t o sa l t m a r sh s e d

i

me nt s

i

n

L o u

i

s

i

a n a wa s r e

d

u c e_d t o a_{m m}o n

i

a

₍

S m

i

t h e t a l . 1 9 8 5

)

.

Ka s

_p

a r

₍

1 9 8 3

₎

d e t e r m

i

n e

d

t ha t de n

i

t r

i

f

i

c a t

i

o n com

p

r

i

s e d

be t wee n 7 0 a nd 9 5 % o f t o t a

l

n

i

t r at e r e du c t

i

o n

i

n a Ne w

Ze a l a nd ma r s h r e _ga r d l e s s o f s e d

i

me n t _{t y p}e a nd de_{p t h} . He

c o n c l u d e d t ha t o n l

_y

a sma l l

_p

o r t i o n o f N O

j

"

g

e t s t o r e du c ed

a r e a s w

h

e r e a i nmo n

i

a

_p

r o

d

u ct

i

o n

i

s

f

a v o r e

d

.

t h e se _p at h wa _y s c o_{m p} r

i

s e d f r om 3 0 t o 8 0 % a nd 7 t o 5 2 %,

r e s _pe ct

i

v e l y _, o f o v e r a l l n

i

t r at e r ed u ct i o n ,

(

Ko

i

ke a nd

Ha t t o r

i

1 9 7 8 , So r e n s e n 1 9 7 8a , r e s

p

ec t

i

v e l

y

)

.

De n

i

t r

i

f

i

c a t

i

o n r a t e s _ge n e r a l l

_y

de c r e a s e d w

i

t h d e

_p

t h , w h

i

l e

DNR e

i

t he r

i

n c r e a s e d o r r ema

i

n ed s t ab l e w

i

t h de _{p t h}

(

Ma c f a r l a n e a nd He r b e r t 1 9 8 4 , 1 9 8 5 , S o r e n s e n 1978a ,

Jo r _ge n s e n

1

9 8 9

₎

. T he

i

n s

i

t u n

i

t r a t e c o n c e nt r at

i

o n a nd t he

o r _ga n

i

c c a r b o n :N 0 3

~

r at

i

o a _{p p}e a r s t o r e

_g

u l at e w h

i

c

_h

_p

_{a t}

_h

_wa

_y

o f n

i

t r a t e r ed u c t

i

o n w

i

l l

_p

r e d om

i

n a t e a t a

_p

a r t

i

c_{u l a r} s

i

t e .

At _{h i g h} o r _g a n i c c a r bo n l ev e l s r e l a t

i

v e t o N0

3

~

e l e c t r o n

a c c e_{p t} o r s _, e l e ct r o n f l o w

i

s ma x

i

m

i

z e d b

y

c o _{m p l} e t e r ed u c t

i

o n

t o N H

^ '*'

. A T P

y i e l d

i

s ma x i m i z e d f r om t he

i

n c o m

p

l e t e

r ed u ct i o n t o _g as _{e o u} s _p r odu c_t s w

h

e n e x c es s n

i

t r at e

i

s

a v a

i

l ab l e f o r e l ec t r o n d

i

s_po s a l . H

i

g he r l e v e l s o f o r

_g

a n

i

c

c a r b o n a n d l o w n

i

t r a t e h a v e be e n s hown t o f a v o r DN R

(

Ma c f a r l a n e a nd H e r be r t 1 9 8 4 , 1 9 8 5 , Ko

i

ke a nd Hat t o r

i

1 9 7 8

)

w h

i

l e h i g he r n i t r a t e l ev e l s f a v o r t he d e n

i

t r

i

f

i

c at

i

o n

p

a t h wa_y

₍

Ma c _{f a r l a n} e _{a n}d He r b e r t 1 9 85 , Co l e 1 9 8 8

)

. I n

c o n t r a s t _, J o r

_g

e n s e n

₍

1 9 8 5

₎

f o u n d t h e K_^ f o r d e n

i

t r

i

f

i

c at

i

o n

(

5- _{1 0 uM N O}

3

"

)

wa s _l owe r t h a n t h a t f o r D N R

₍

1 0 0- _{5 0 0 u M}

₎

;

v a l u e s t h a t m a _y r e f l e ct t h e s

i

ze , a s we l l a s t h e a c t

i

v

i

t

y

,

o f t h e D NR c o mmu n

i

t

_y

.

W h

i

l e t he _da t a d o n o t

p

r o v i d e a co n s

i

s _t e nt

p

a t t e r n of

t h e r e l a t

i

v e

i

m

p

o r t a n c e o f D NR a nd de n

i

t r

i

f

i

c a t

i

o n

i

n s a

l

t

ma r s

h

e s , o n e w o u

l d

p

r e

d i

ct t

h

at

d

e n

i

t r

i

f

i

c a t

i

o n

i

s t he

p

r edo m

i

n a nt _p a t h w a

_y

f o r n

i

t r a t e r e du ct

i

o n at t

h

e s u r

f

a c e a n

d

n i t r i f i c a t i o n - de n i t r i f i c a t i o n _p r oc e s s e s _pr e d om i n a t e . I n

c o nt r a s t _, t he f e r me n t a t i v e

_p

at h wa

_y

o f D N R c o u l d b e

i

m

p

or t a nt

i

n

d

e e

_p

e r

_{h i g}

h l

_y

r e du c e d z o ne s _, wh e r e o r

_g

a n

i

c c a r

b

o n

i

s

p l e n t

i

f u l . A l t ho u g h D NR w as n ot a s se s s e d

i

n t h e c u r r e n t

st u_{d y} , i t c o u l d be a n

i

m p or t a n t a l t e r n at e p at h wa y o f n i t r at e

r e d u c t i o n i n t _h e s e s e d i me n t s .

T e_{m p}o r a l a nd _{S p} a t

i

a l P a t t e r n s o f De n i t r

i

f

i

c a t

i

o n

Fr om t h e ab o v e

d i

s cu s s

i

o n _,

i

t

i

s e v

i d

e n t t ha t o t h e r

n

i

t r o_ge n t r a n s f o r mat i o n s c a n d

i

r ec t _{l y} o r c o m_p et

i

t

i

v e l

_y

r e _gu l a t e t h e ma_gn i t ud e o f de n i t r

i

f i c a t

i

o n

i

n s al t ma r s he s .

A l l N t r a n s f o r ma t i o ns a r e s u b

_j

e c t t o r e _gu l a t

i

o n _{b y}

h

ab

i

t a t

-s _pe c

i f i

c

_p

a r a m et e r s t h at ar e o f

_p

a r t

i

cu l ar

i

m

_p

o r t a n c e

i

n t h e

d

_y

n am

i

c

i

n t e r t

i

da l hab

i

t at o f t he sa l t ma r s

h

. T h e o v e r l a

y

o

f

s e as o n a

l

_, d

i

u r n al a nd t

i

d a l c

_y

c

l

es

i

m

_p

o se s a co m

_{p l}

e x

c o n t r o l o f de n

i

t r

i

f

i

c at

i

o n t h at

h

a s

b

e e n l

i

t t l e st u d

i

e

d

i

n

s a l t ma r sh e s . I n ad d

i

t

i

o n _, r e s

i

d e nt v e g e t at

i

o n a n d

ma c r of a u n a ma

_y

a l so af f e ct de n i t r

i

f i c at

i

o n

i

n s a

l

t ma r s

h

e s .

Se a s o n a l c

_y

c l e s

Se a s o n al

_p

a t t e r n s o f d e n

i

t r

i

f

i

c at

i

o n

i

n sa l t ma r s he s

a

_{p p}

e a r t o

b

e r e

_g

u l at e d b

_y

t em

_p

e r at u r e

i

n a d d

i

t

i

o n t o t h e

N 0 ₃~ a n

d

o r

_g

a n

i

c c a r

b

o n su

b

s t r a t e s . Ka

p l

a n et a

l

.

(

1

9 7 7

)

f o u nd a

_p

o s

i

t

i

v e c o r r e

l

at

i

o n o f

d

e n

i

t r

i f i

c at

i

o n w

i

t

h

t e m

_p

e r a t u r e a n d

i

de n t

i f i

e

d

b

o t

h

wa r m- a n

d

c o l

d

- a

d

a

_p

t e

d

d

e n

i

t r

i

f

y i

n

_g

_p

o

_p

u

l

at

i

o n s

i

n s al t m a r sh s e

d i

me nt s . S h e r r a n d

Pa

_y

n e

₍

1 9 7 8

₎

de t e c t e d s e a so n a l

_{l y}

h

_{i g h}

r at e s o

f

d

e n

i

t r

i f i

ca t

i

o n a s s o c

i

a t e

d

w

i

t h t

h

e r o o t - _r

_{h i}

_{z ome s}