Transcript Document

Understanding Patterns of Fishery Production in
Coastal Marine Ecosystems Impacted by Hypoxia
Edward J. Chesney1, Donald M. Baltz2 and Theodore S. Switzer3
1 Louisiana Universities Marine Consortium
2Department of Oceanography and Coastal Sciences, Louisiana State Univ.
3Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research
Institute
Eutrophic systems are among the most
productive marine systems for fishery
production
All ecosystems do not respond to eutrophication
in the same ways because of differences in the
characteristics of the systems.
All species of nekton are not affected to the
same degree by environmental impacts in spite
of strong overlap in the habitats they occupy.
In terms of ecosystem function what combination of
factors dictates vulnerability to eutrophication?
• How do those factors compare among large
eutrophic marine systems
A comparison of Large Marine Ecosystems Impacted by Nutrients
Basin
Morphology
Latitude
Basin
Surface
Temperature
o
C
Surface
Salinity
Range
Stratification
Pattern
Mediterranean
--N. Adriatic
Chesapeake Bay
Seto Inland Sea
Baltic Sea
Black Sea
Neuse R. Estuary
Mobile Bay
Delaware Bay
Dutch Wadden Sea
Long Is. Sound
Gulf of Mexico
--La, Ms, Tx Shelf
Mostly enclosed sea1
Semi-enclosed gulf1
Semi-enclosed bay
Semi-open sea1
Mostly enclosed sea1
Mostly enclosed sea1
River estuary
Mostly enclosed bay
Open bay
Semi-open bay
Semi-enclosed bay
Semi-open gulf1
Open shelf
-45oN
38oN
34oN
57oN
43oN
35oN
30oN
39oN
53 oN
41oN
-29oN
-6-277
2-2811
10-27
0-17
4-20
5-30
10-34
2-28
---12-32
-26-387,8
11-2011
28-32
2-1312
12-18
0-12
0-32
10-30
---15-35
-Moderate, seasonal
Strong, seasonal
Moderate, seasonal
Strong, semi-permanent
Strong, permanent
Moderate, seasonal
Moderate, seasonal
Weak, seasonal
Weak, seasonal
Strong, seasonal
-Strong, seasonal
Basin
Principal
Watershed
Mean
Depth
(103 km2)
(m)
Annual
Freshwater
Input
9
P
Loading
N
Loading
-1
mmol m-2 y
Tidal
Range
(cm)
Primary
Production
(g C m-2 y-1)
---2-3
8-9
-15-45
-130-21020
32-106
50-12022
40020
21823
13520
12025
-19424
30724
48020
30020
32
30021
mmol m-2 y
Suboxic*
area
(103 km2)
Basin to
Suboxic
Area
-139:1
6:1
10:1
5:1
25:1
-2.5:1
--7:1
290:1
6:1
-1
3
(10 m )
Mediterranean
--N. Adriatic
Chesapeake Bay
Seto Inland Sea
Baltic Sea
Black Sea
Neuse R. Estuary
Mobile Bay
Delaware Bay
Dutch Wadden Sea
Long Is. Sound
Gulf of Mexico
--La, Ms, Tx Shelf
-709
166
25
1,729
2,405
16
115.5
34.8
18520
41
2,901
1502
3022
6.5
3710
55
1,191
3.6
3.0
6.4
3.9
20
2,1642
3519
48
125
7017
670
30025
-7124
18
23.6
38
-4020
-1020
--21824
19324
24020
7020
-143020
-21020
--260524
163224
55020
104020
-1.0
1-26
2.23
8415
20
-0.4
0
0
0.2-0.4
580
--
--
10-205
Basin
Surface
Area
(103 km2)
2,5102
1397
12
2213
413
423
-1
2
1.5
3
1,813
12619
Annual
Fishery
Yield
(103 mt)
-10014
27514
83013,+
622++
80016
-8
3
-18
-769**
Major
Fisheries
-Sardine
Menhaden
Anchovy, oyster
Herring, sprat, cod
Sprat, whiting
Crabs, oysters
Menhaden, shrimp
Crabs
Flatfish
-Menhaden, shrimp
Watershed
to Basin
Area
Basin
Volume
(103 km3)
0.6:11
0.5:1
14.4:1
1.2:11
4.2:11
5.7:11
-115:1
17.5:1
120:1
13.7:1
1.6:1
--
3771
357
0.075
1.06
38
605
-.003
12.7
5.920
.06
3923
4.4
System
Residence
Time
(months)
long
moderate
64
1518
26220
very long
2
short
weeks
0.520
<3620
long
wks.-mo.
Rotated Factor Loadings for Large Marine Systems
Variable
Mean Depth
Primary Production
Basin Area
Basin Morphology
Annual Flow
Stratification
North Latitude
Turnover Time
Percent SubOxic
Factor 1
0.90
-0.71
0.63
0.53
0.06
0.39
-0.00
0.45
-0.12
Factor 2
0.14
-0.24
0.63
0.01
0.95
0.77
0.07
0.43
0.22
Factor 3
0.02
-0.11
0.41
0.46
0.11
0.04
0.97
0.63
-0.27
Factor 4
-0.21
-0.30
-0.03
0.65
0.06
0.27
-0.19
0.16
0.92
Eigenvalue
Variance Exp %
Cumulative %
2.37
26.3
26.3
2.20
24.5
50.8
1.82
20.3
71.1
1.53
17.1
88.2
Large marine systems impacted by nutrients
High Latitude
Slow Turn
Green
Yellow
Red
Factor 4
Low or no % suboxic (open)
Moderate
High % suboxic (mostly enclosed)
Black Sea
Factor 3
Wadden Sea
N.Adriatic
Low Latitude
Fast Turn
LIS
Seto
Chesapeake
nGOM
Mobile
Deep
Low PP
Large
Closed
Baltic
Delaware
Factor 1
Shallow
High PP
Small
Open
High Flow
Strong perm.
Stratification
Large
Factor 2
Low Flow
Weak&seasonal
Stratification
Small
What species of nekton are most likely to be severely
impacted by hypoxia?
• Those species with life histories and habitat
requirements that chronically affected or have
multiple stages of their life history affected increase
risks.
• Refuges from hypoxia reduce risks at the population
level.
Evaluated 52 species of nekton for their potential risks
associated with the formation of hypoxia based on their life
history characteristics
• Principal adult habitat
– Estuary, inshore (0-5m), nearshore (5-25m), offshore (25-200m)
•
•
•
•
Principal nursery habitat
Spawning season
Spawning location
Foraging habits
– Benthos, piscivorous, omnivorous
• Water column distribution
– Demersal, epi-demersal, pelagic, nektonic
• Other habitat characteristics
– Reef associated, marsh associated
Unraveling the Effects of Hypoxia
• In response to
hypoxia, nekton
may move:
– Vertically
– Alongshore
– Inshore/offshore
•
•
•
•
Estuary
Inshore (0-5m)
Nearshore (5-25m)
Offshore (25-200m)
PCA of life history characteristics of 52 species of nekton
(nGOM)
Variable
Factor 1
Factor 2
Factor 3
Principal Nursery Habitat
0.86174
0.09371
-0.12820
Principal Adult Habitat
0.71291
-0.50409
-0.10680
Foraging Habits
0.68231
-0.02719
0.35962
Spawning Habitat
0.54615
-0.71573
-0.10960
Spawning Season
0.15489
0.87953
-0.15766
Water Column Distribution
-0.00666
-0.05685
0.93495
Eigenvalues
2.0386989
1.5526919
1.0681789
% Variance explained
33.98
25.88
17.80
Cumulative % variance
explained
33.98
59.86
77.66
Demersal
Water Column
Distribution
Summer
Estuary
Pelagic
Spawning
Season &
Habitat
Offshore
Principal Adult & Nursery
Habitat
Estuary
Winter
Offshore
BA=bay anchovy, GM=gulf menhaden, Ca=sand seatrout, AC=Atlantic croaker, HC=hardhead catfish, S=spot, AB=Atlantic bumper, AT=Atlantic
threadfin, FF=fringed flounder, SP=silver perch, C=cutlassfish, LP=least puffer, H=hogchoker, AM=Atlantic moonfish, SK=southern kingfish,
LS=lined sole, SF=southern flounder, BT=blackcheek tonguefish, SS=spotted seatrout, SD=star drum, GB=gulf butterfish, SM=Spanish
mackerel, Cn=silver seatrout, WS=white shrimp, BS=brown shrimp, BC=blue crab, RS=red snapper, Rc=cobia, KM=king mackerel, RD=red
drum, Cf=Atlantic spadefish, BW = bay whiff, Sg=shoal flounder, AS=Atlantic stingray, Da= southern stingray, CR=cownose ray, P=pinfish,
SA=striped anchovy, Al=shortfin anchovy, MS=mantis shrimp, Lb= brief squid, Mm=stone crab, Sc=longspined porgy, IL=inshore lizardfish,
Ps=shortwing searobin, Pa=harvestfish, BR=blue runner.
Coastal species of the nGOM with high risks of being
affected by hypoxia
Species
Water Column
Distribution
Principal Adult
Habit
Foraging Habits
Principal Nursery
Habitat
Spawning Location
Spawning Season
Atlantic Stingray, Dasyatis sabini
Demersal
Inshore/Estuary
Benthos
Inshore/Estuary
Inshore/Estuary
summer
Bc. Tonguefish Symphurus plagiusa
Demersal
Nearshore-Estuary
Small Benthos
Nearshore-Estuary
Nearshore-Estuary
Summer
Blue Crab, Callinectes sapidus
Demersal
Nearshore-Estuary
Omnivorous
Nearshore-Estuary
Nearshore/Inshore
Spring-Fall
Fringed Flounder, Etropus crossotus
Demersal
Nearshore-Estuary
Benthic Copepods
Estuary
Nearshore
summer
Hogchoker, Trinectes maculatus
Demersal
Nearshore-Estuary
small Benthos
Nearshore-Estuary
Estuary
summer
Lined Sole, Achirus lineatus
Demersal
Nearshore/Inshore
Small Benthos
Inshore/Estuary
Nearshore
Summer
Mantis shrimp, Squilla empusa
Demersal
Offshore/Nearshore
Benthos
Nearshore-Estuary
Offshore-Nearshore
winter-summer
rock sea bass, Centropristis philadelphica
Demersal
Offshore/Nearshore
Nekton/Benthos
Nearshore/Inshore
Offshore/Nearshore
Summer
Shoal Flounder, Syacium gunteri
Demersal
Inshore-Offshore
Small Benthos
Nearshore
Nearshore/Estuary
summer
Silver Perch, Bairdiella chysura
Demersal
Nearshore-Estuary
Small Benthos
Inshore/Estuary
Nearshore-Estuary
summer
southern stingray, Dasyatis americana
Demersal
Nearshore-Estuary
Decapods/Nekton
Inshore/Estuary
Inshore/Estuary
summer
Star Drum, Stellifer lanceolatus
Demersal
Offshore/Nearshore
Small Benthos
Nearshore-Estuary
Offshore/Nearshore
summer
stone crab, Menippe mercenaria
Demersal
Nearshore-Estuary
Benthos
Inshore-Estuary
Inshore-Estuary
summer
MS=mantis shrimp
SD=star drum
BC=blue crab
Da= southern stingray
Demersal
AS=Atlantic stingray
H=hogchoker
BT=blackcheek
tonguefish
LS=lined sole
Mm=stone crab
Sg=shoal flounder
Water
Column
Distribution
SP=silver perch
Summer
Estuary
Pelagic
Spawning
Season &
Habitat
Offshore
Principal Adult & Nursery
Habitat
Estuary
Winter
Offshore
BA=bay anchovy, GM=gulf menhaden, Ca=sand seatrout, AC=Atlantic croaker, HC=hardhead catfish, S=spot, AB=Atlantic bumper, AT=Atlantic
threadfin, FF=fringed flounder, SP=silver perch, C=cutlassfish, LP=least puffer, H=hogchoker, AM=Atlantic moonfish, SK=southern kingfish,
LS=lined sole, SF=southern flounder, BT=blackcheek tonguefish, SS=spotted seatrout, SD=star drum, GB=gulf butterfish, SM=Spanish
mackerel, Cn=silver seatrout, WS=white shrimp, BS=brown shrimp, BC=blue crab, RS=red snapper, Rc=cobia, KM=king mackerel, RD=red
drum, Cf=Atlantic spadefish, BW = bay whiff, Sg=shoal flounder, AS=Atlantic stingray, Da= southern stingray, CR=cownose ray, P=pinfish,
SA=striped anchovy, Al=shortfin anchovy, MS=mantis shrimp, Lb= brief squid, Mm=stone crab, Sc=longspined porgy, IL=inshore lizardfish,
Ps=shortwing searobin, Pa=harvestfish, BR=blue runner.
Coastal species of the nGOM with economic or ecological
significance & moderate risks of being affected by hypoxia
Species
Water Column
Distribution
Principal Adult
Habit
Foraging Habits
Principal Nursery
Habitat
Spawning Location
Spawning Season
Atlantic Croaker, Micropogonias undulatus
Demersal
Offshore/Nearshore
Benthos
Inshore/Estuary
Offshore
fall/winter
Brown Shrimp, Farfontepenaeus aztecus
Demersal
Offshore/Nearshore
Small Benthos
Estuary
Offshore
winter/spring
Gulf Butterfish, Peprilus burti
Epi-demersal
Offshore
Omnivorous
Nearshore
Offshore/Nearshore
winter
longspined porgy, Stenostomus caprinus
Epi-demersal
Offshore/Nearshore
Benthos
Nearshore/Inshore
Offshore
winter
Sand Seatrout, Cynoscion arenarius
Demersal
Offshore/Nearshore
Piscivororous
Inshore/Estuary
Offshore
spring/summer
Red Drum, Sciaenops ocellatus
Epi-Demersal
Inshore-Offshore
Nekton
Estuary
Inshore/Estuary
fall
Red snapper, Lutjanus campechanus
Epi-demersal
Offshore
Benthos/Nekton
Offshore/Nearshore
Offshore
summer
Silver Seatrout, Cynoscion nothus
Demersal
Nearshore-Estuary
Piscivorous/Nekton
Offshore/Nearshore
Offshore/Nearshore
summer
Southern Flounder, Paralichthys lethostigma
Demersal
Nearshore-Estuary
Piscivorous/Nekton
Freshwater/Estuary
Offshore
Winter/Spring
Southern Kingfish, Menticirrhus americanus
Demersal
Offshore/Nearshore
Small Benthos
Nearshore-Inshore
Offshore
Summer
White Shrimp, Litopenaeus setiferus
Demersal
Offshore/Nearshore
Small Benthos
Estuary
Offshore/Nearshore
Spring/ summer
Coastal species of the nGOM with economic or ecological
significance & lower risks of being affected by hypoxia
Species
Water Column
Distribution
Principal Adult
Habit
Foraging Habits
Principal Nursery
Habitat
Spawning Location
Spawning Season
Atlantic Bumper, Chloroscombrus chrysurus
Pelagic
Nearshore
Zooplankton
Estuary
Nearshore
summer
Atlantic Spadefish, Chaetodipterus faber
Nektonic
Nearshore/Inshore
Plankton/Benthos
Inshore/Estuary
Nearshore/Inshore
summer
Atlantic Threadfin, Polydactylus octonemus
Nektonic
Offshore/Nearshore
Shrimp/Crustacea
Nearshore-Estuary
Offshore
winter/spring
Bay Anchovy, Anchoa mitchilli
Pelagic
Inshore/Estuary
Zooplantivorous
Estuary
Inshore/Estuary
summer
blue runner, Caranx crysos
Pelagic
Offshore/Nearshore
Sm nekton/Zooplankton
Offshore/Nearshore
Offshore
winter-summer
Cobia, Rachycentron canadum
Nektonic
Offshore
Nekton
Offshore/Nearshore
Offshore
summer
Gulf Menhaden, Brevoortia patronus
Pelagic
Nearshore/Inshore
Planktivorous
Estuary/freshwater
Offshore/Nearshore
winter/spring
King Mackerel, Scomberomorus cavalla
Pelagic
Offshore
Piscivorous
Offshore/Nearshore
Offshore
summer
shortfin anchovy, Anchoa lyolepis
Pelagic
Estuary
Zooplankton
Estuary
Estuary
summer
Spanish Mackerel, Scomberomorus maculatus
Pelagic
Offshore/Nearshore
Piscivorous
Nearshore/Inshore
Offshore/Nearshore
summer
Spotted Seatrout, Cynoscion nebulosus
Nektonic
Nearshore-Estuary
Piscivorous
Estuary
Inshore/Estuary
summer
Squid, Lolliguncula brevis
Nektonic
Neashore/Inshore
Zooplankton/Sm nekton
Inshore/Estuary
Nearshore/Inshore
spring/summer
striped anchovy, Anchoa hepsetus
Pelagic
Inshore
Zooplankton
Inshore/Estuary
Inshore
spring/summer
How can we fine tune these risks assessments?
• Directed studies of species at risks
• Additional analyses based upon fisheries
data
• Modeling
Suitability analyses based upon fisheries
independent data
SEAMAP Data
Mississippi
Louisiana
Texas
Subdivided coastal zone
WLA
ETX
WTX
• Five alongshore zones:
CLA
Hypoxia
WTX , ETX, WLA, CLA, ELA/MS
• Intensity of hypoxia determined by areal extent (Rabalais et al.):
– Low (0 – 9,500 km2)
– Moderate (9,500 – 16,000 km2)
– Severe (16,000 + km2)
Habitat Suitability – Star Drum
0.7
0.3
Availability
Use
Suitability
0.6
0.5
1.0
1.0
0.2
0.4
0.3
0.5
0.1
0.0
0.0
0
20
40
60
0.0
80 100 120 140
0.0
12
16
20
24
28
32
Temperature (° C)
Depth (m)
0.6
0.4
0.5
1.0
1.0
0.3
0.4
0.3
0.2
0.5
0.5
0.2
0.1
0.1
0.0
0.0
16
20
24
28
32
Salinity (psu)
36
40
0.0
0.0
0
2
4
6
8
10
Dissolved Oxygen (mg / L)
Standardized Suitability
0.2
Relative Frequency
0.5
0.1
Inshore (0 - 5 m)
6
Star Drum
4
Low Hypoxia
Moderate Hypoxia
Severe Hypoxia
Summer
2
0
2
4
Fall
Source: FishBase (US FWS)
• Similar patterns in
summer/fall
• Abundances highest in
inshore WLA waters
CPUE (Individuals / 1000 m2)
6
Nearshore (5 - 25 m)
6
4
Summer
2
0
2
4
Fall
6
Offshore (25 - 200 m)
6
4
Summer
2
• Some differences with
respect to intensity of
hypoxia
0
2
4
Fall
6
WTX
ETX
WLA
Alongshore Zone
CLA
ELA/MS
Inshore (0 - 5 m)
3
2
Low Hypoxia
Moderate Hypoxia
Severe Hypoxia
Summer
1
Rock Sea Bass
0
1
2
Fall
CPUE (Individuals / 1000 m2)
3
Nearshore (5 - 25 m)
3
2
Summer
Source: FishBase (D. Flescher)
1
0
1
2
• Abundances in nearshore
CLA decrease with
increasing hypoxia
Fall
3
Offshore (25 - 200 m)
3
2
Summer
1
0
1
2
Fall
3
WTX
ETX
WLA
Alongshore Zone
CLA
ELA/MS
• Abundances in adjacent
zones increase with intensity
of hypoxia (dependent on
season)
De Leiva Moreno et al 2000
• Advocated calculating the ratio of pelagics to
demersals as an indicator of system condition in
eutrophied coastal systems.
Figure 4 from De Leiva Moreno et al 2000
How does the nGOM look in term of this proposed index?
The Pelagic to demersal ratio for the nGOM is ~3.8
2.5e+6
5.0e+5
Mu
lle
t
Sn
ap
pe
rs
Tu
na
s
Ma
ck
er
els
Gr
ou
pe
Am
rs
be
rja
ck
s
Fl
ou
nd
er
er
s
Oy
st
Cr
ab
s
0.0
Me
nh
ad
en
Sh
rim
ps
Metric Tons
Composite catch by species for TX, LA and MS for 2000-2004
How does this compare to troubled coastal Seas
Impacted by Eutrophication?
P/D<1.0=Oligotrophic
P/D>10=Eutrophic
Pelagic to Demersal Ratio 1950-2004 for the Fertile Crescent
nGOM
Pelagic to Demersal Ratio-1950-2004 for the Fertile Crescent nGOM
1.2e+6
12
P/D ratio
Pelagics
Demersals
10
8.0e+5
8
6.0e+5
6
4.0e+5
4
2.0e+5
2
0.0
0
1950
1960
1970
1980
1990
Year
Data Source: NOAA Fisheries Statistics
2000
Pelagic to Demersal Ratio
Catch (metric Tons)
1.0e+6
Conclusions
• A simple risk assessment framework might be a useful tool for
evaluating relative risks from hypoxia.
• Simple metrics to index the condition of the ecosystem may not be
adequate because no two ecosystems (nor their fauna) are likely to
respond exactly the same to nutrient inputs because of variations
among the characteristics of ecosystems.
Acknowledgements
• Funding provided by NOAA Coastal Ocean
Program
• Data:
–
–
–
–
National Marine Fisheries Service
Louisiana Department of Wildlife and Fisheries
Mississippi Department of Marine Resources
Texas Parks and Wildlife