Lesson
s Learned
from
a Decade of Hypoxia Forecasts in
Chesapeake Bay
Jeremy Testa, Blake Clark, W
illiam Den
nison,
Caroline Do
novan, Alexand
er Fish
er, W
enfeiN
i, Matthew
Parker, Do
nald Scavia, Suzanne
Spitzer,
Anthon
y Waldrop
, Vanessa Vargas, Gregory Ziegler
A Multi‐Institu
tional Effo
rtJeremy Testa, Blake Clark, W
illiam Den
nison, Caroline Do
novan,
Alexande
r Fish
er, W
enfeiN
i, Suzann
e Spitzer, Vanessa Vargas
University
of M
arylan
d Center fo
r Enviro
nmental Scien
ce
Matthew
Parker
University
of M
arylan
d Extension
Anthon
y Waldrop
University
of M
arylan
d Co
llege
Park
Gregory Ziegler
Wye Resea
rch an
d Education Center
Donald Scavia
Graha
m Sustainab
ility In
stitu
te, U
niversity
of M
ichiga
n
Marylan
d DNR, USEPA
Che
sape
ake Ba
y Prog
ram
USG
S, NOAA
, man
y pa
st fo
recasters
An Overview
•The Hy
poxia Prob
lem
•Ch
esapeake Bay Hypoxia and
a Scien
ce History
•Forecasting Hy
poxia –Why? Can it be
don
e?•What is the
Impact of H
ypoxia Forecastin
g•Looking Ah
ead
Luo et al. 2011
Ecolog
ical Forecastin
g: Increasin
gly
Common
and
It Gets B
etter w
ith Age
Coastal hypoxia is a global
phen
omen
on, has worsene
d in m
any
coastal ecosystem
s in recent decades
(Dia
z &
Ros
enbe
rg 2
008)
•Rec
ent (
2008
) sur
vey
iden
tifie
d >
400
repo
rted
syst
ems
with
hyp
oxia
du
e to
eut
roph
icat
ion;
exp
ande
d to
mor
e re
gion
s co
verin
g ~
250,
000
km2 .
•Hyp
oxia
dis
tribu
tion
linke
d w
ith w
ater
shed
regi
ons
havi
ng la
rge
hum
an
“foot
prin
t” (i.
e., i
nten
se h
uman
act
ivity
and
influ
ence
).
Hyp
oxia
R
epor
tsH
isto
ry
’20
’40
’60
’80
‘00
Cumulative Hypoxia Reports
Hypo
xia Influ
enced by M
any Factors,
Has M
any Negative Im
pacts
•Biological, che
mical, and
physic
al processes all relevant
•Hy
poxia im
pacts B
OTH
biogeoche
mistry and
food
web
Chesapeake Bay Hypoxia
•Ch
ronic season
al hypoxia in
Che
sape
ake Bay
•Hy
poxia linked to eutroph
ication originating from
watershed
inpu
ts•
Season
al hypoxia largely confined
to deep water chann
el in
Che
sape
ake Bay (red
, yellow)
Severity of hypoxia accom
panied
by
increased scientific interest
Why fo
recast hypoxia?
•Oxygen is a keystone
molecule for life
•Hy
poxia integrates th
e respon
se to
a variety of p
oint
and no
npoint so
urce nutrie
nt inpu
ts, as w
ell as p
hysic
al
forces –test of kno
wledge
•Co
nsiderable m
anagem
ent e
fforts b
eing
made to
redu
ce eutroph
ication that leads to hypo
xia
•Legacy of scientific re
search AND Bay mon
itorin
g has
allowed
for reasonable pred
ictive mod
els
Forecast M
odels
Three mod
els h
ave be
en used to fo
recast su
mmer hypoxia and
ano
xia in Che
sape
ake Bay
July Average Hypoxia
O2< 2 mg/L
Early
Sum
mer
O2< 0.2 mg/L
Late Sum
mer
O2< 0.2 mg/L
•All m
odels forecast h
ypoxia and
or a
noxia based on
winter‐sprin
g nu
trient inpu
ts•
http://ia
n.um
ces.ed
u/ecoche
ck/forecast/chesapeake‐bay/201
7/•
Anoxia m
odels a
re re
gressio
n based, hypoxia m
odel is a m
odified
oxygen sag mod
el•
Each fall, fo
recast is evaluated
with
a Sum
mer Review
How Have the Forecasts P
erform
ed?
•All m
odels h
ave routinely
forecast low‐oxygen
volumes with
success
•There has b
een a slight
tend
ency fo
r over‐prediction
of ano
xic volumes
overpred
ictio
n unde
rprediction
Summer W
ind Direction (and
speed)
Affects H
ypoxia Forecastin
g Success
Strong
Sum
mer Storm
s
Increased Med
ia Interest in
Hypoxia
and Forecasting
Forecasting
Begins
Lesson
s Learned
•Hy
poxia forecasting in Che
sape
ake Bay has b
een a
success, but th
ere is room
for improvem
ent
•Hy
poxia forecast ra
ised pu
blic awaren
ess for
Chesapeake Bay hypoxia issues
•The forecasts h
elpe
d commun
icate the complex
ecology of th
e Bay in a dynam
ic and
widely
accessible fo
rmat
•Forecast m
odels o
nly de
velope
d after d
ecades of
research and
especially, m
onito
ring –we ne
ed to
maintain mon
itorin
g efforts!
2017
•Forecasts c
alled for a
bove
average cond
ition
s
•Initial estim
ates indicate
lower th
an average volum
es
•Early
August m
aps reveal a
deep
water intrusion of
relatively oxygen
ated
water
•Why?
2017
Pattern Con
sistent with
Season
‐and
Region‐Specific Tren
ds
Testa, M
urph
y, Brady & Kem
p, in
prep
Testaet al. (201
7)
CB5.2 (ju
st north of P
otom
ac)
CB6.1 (Rapp. m
outh)
Thank You