Download Influence of Hypoxia on the Distribution, Behavior, and Foraging of

Influence of hypoxia on the distribution, behavior, and
foraging of zooplankton and planktivorous fish in central
Lake Erie: Field observations & future directions
Hank Vanderploeg, GLERL
Stuart Ludsin, GLERL
Steve Pothoven, GLERL
Tomas Höök, CILER Univ. of Michigan
James Roberts, Univ. of Michigan
Steve Ruberg, GLERL
Joann Cavaletto, GLERL
James Liebig, GLERL
Gregory Lang, GLERL
Stephen Brandt, GLERL
Hypoxia is an old problem in freshwater—Results for
Cyclops bicuspidatus (Einsle 1965)
This species is very tolerant of low oxygen (~ 0.1mg/L)
Original Lake Erie
Fish-Centric Hypotheses
1. Hypoxia will disrupt vertical migration behavior
– Reduce time spent on bottom
2. Hypoxia will influence horizontal movement
– Fish will move into oxygenated, shallow nearshore zones
3. Hypoxia will reduce availability of prey, both ZP & benthic
macroinvertebrate prey
– ZP use hypoxia as a refuge from predation
– Hypoxia reduces benthic prey abundance
4. Fish consumption & condition will decline
Playing chess with death—a zooplankton-centric view
Scene from Bergman’s “The Seventh Seal”
Death normally comes in two
forms: predation and starvation
• Zooplankton vertical migration is strategy to
minimize overlap with visually preying
invertebrate and vertebrate (fish) predators—
conspicuous or unprotected (spineless)
zooplankton move to lower light levels
• Move into upper favorable (temperature and
food) areas at night.
• Predator abundance is assessed by
kairomones.
• When many predators, the zooplankter (prey)
must play chess to avoid overlap.
The Great Lakes have both visual invertebrate & and
vertebrate predators—Lake Michigan example
Playing chess with death—the piscine players
Scene from Bergman’s “The Seventh Seal”
Dominant planktivores of Lake Erie and their Vanderploeg &
Scavia (1979) selectivity coefficients (W´) pre-hypoxia
Emerald Shiner August 2005
Emerald shiner:
Epilimnetic planktivore
1.00
W'
0.75
Night
0.50
Day
0.25
Si
Bo
sm
in
id
ae
di
da
e
Cy
clo
po
id
Da
ph
ni
da
Ca e
la
no
Ch
id
yd
or
id
ae
Le
pt
od
By
or
th
a
ot
re
Ch
ph
es
iro
m
om
id
ae
0.00
Rainbow Smelt August 2005
1.00
W'
0.75
Night
0.50
Rainbow Smelt:
Planktivore-benthivore
Day
0.25
di
da
Cy
e
clo
po
id
a
Da
ph
ni
da
e
Ca
la
no
id
Ch
a
yd
or
id
ae
Le
pt
od
By
or
th
a
ot
re
Ch
ph
es
iro
m
om
id
ae
Si
Bo
sm
in
id
ae
0.00
Prey size
USGS-NAS
Hypoxia, another form of death, alters the
game—some hypotheses:
• Differential tolerance of zooplankton to
hypoxia allows some species to enter the
hypoxic zone to escape predators—the
refuge
• Others will be forced out and trapped in
lighted areas above—the hypoxia-light
trap.
Lake Erie
Some results before and after major hypoxia will give us
some insights
43
Diel Station B
42.5
12
42
41.5
43
-83.5
August
-82.5
-81.5
-80.5
-79.5
42.5
9
6
3
42
41.5
-83.5
September
-82.5
-81.5
-80.5
-79.5
0
Dissolved
Oxygen
(mg/l)
General Methods—What we did
Introduction to Study Systems & General Methods
• Zooplankton
• Temperature
• Dissolved oxygen
• Light levels
• Chlorophyll a
Fish
Biomass
• Trawling (fish species & samples for diet & ration work)
• Zooplankton net and pump sampling (zooplankton)
• Ponar sampling (benthic macroinvertebrates)
Lake Erie Field Program (IFYLE 2005)
EPA-GLNPO
R/V Lake Guardian (180’)
Source: Don Coles
NOAA-GLERL
R/V Laurentian (80’)
Diel Station B
Transect B
Diel (24-hr)
Transect (day-night)
Water Column Pumping Method
shooting for pumping 1 cubic meter of water
0
5
10
15
20
0
Sept. 2005
2
4
6
o
Water Temp ( C)
1 min. ea.
depth
DO (mg/L)
Depth (m)
8
10
12
14
1 min. ea.
depth
16
5 min.ea.
18
20
22
24
2 min. ea.
depth
25
Lake Erie
Ho 2: Hypoxia will alter horizontal distribution of abundance
– Fish will move into oxygenated, shallow nearshore zones
43
42.5
August
42
41.5
-83.5
43
42.5
Transect B
-82.5
-81.5
-80.5
-79.5
September
9
6
42
41.5
-83.5
43
42.5
12
3
-82.5
-81.5
-80.5
-79.5
0
October
42
41.5
-83.5
-82.5
-81.5
-80.5
-79.5
Dissolved
Oxygen
(mg/l)
Lake Erie
Ho 2: Hypoxia will alter horizontal distribution of abundance
(August – Pre-Hypoxia)
0
0
Day
30
Night
22
10
10
14
20
20
Depth (m)
0
Temp
(º C)
41.7
41.8
41.9
42
42.1
0
41.7
41.8
41.9
42
42.1
12
9
10
10
6
6
20
20
0
0
41.7
41.8
41.9
42
42.1
10
3
41.7
41.8
41.9
42
42.1
0
-30
-50
10
-70
20
41.8
41.9
42
42.1
Fish
(dB)
-90
20
41.7
DO
(mg/l)
41.7
41.8
41.9
42
42.1
-110
Latitude (degrees)Ludsin, Vanderploeg & Ruberg, unpub
Lake Erie
Ho 2: Hypoxia will alter horizontal distribution of abundance
(September – Peak Hypoxia)
30
0
0
Day
Night
10
22
10
Depth (m)
14
20
20
0
0
41.7
41.8
41.9
42
42.1
6
41.7
41.8
41.9
42
42.1
12
9
10
10
6
20
20
0
0
41.7
41.8
41.9
42
42.1
10
41.7
41.8
41.9
42
42.1
0
-30
-50
-70
41.8
41.9
42
42.1
Fish
(dB)
-90
20
41.7
DO
(mg/l)
3
10
20
Temp
(º C)
41.7
41.8
41.9
42
42.1
-110
Latitude (degrees)Ludsin, Vanderploeg & Ruberg, unpub
Lake Erie
Ho 2: Hypoxia will alter horizontal distribution of abundance
– Reject: Fish move into oxygenated waters, but offshore
(October – Post Hypoxia)
0
0
Day
10
30
Night
22
10
14
20
Depth (m)
0
20
41.7
41.8
41.9
42
42.1
0
6
41.7
41.8
41.9
42
42.1
12
9
10
10
6
20
20
0
0
41.7
41.8
41.9
42
10
42.1
41.7
41.8
41.9
42
42.1
0
-30
-50
-70
20
41.6
41.7
41.8
41.9
DO
(mg/l)
3
10
20
Temp
(º C)
Fish
(dB)
-90
41.6
41.7
41.8
41.9
-110
Latitude (degrees)Ludsin, Vanderploeg & Ruberg, unpub
Playing chess with death—Insights from pre-hypoxia
(control) & hypoxia distributions and prey selection
Scene from Bergman’s “The Seventh Seal”
Diel B, Aug 17, 01:00 EDT
PAR
0
100
200
300
400
500
0
Fish biomass
(relative)
Depth (m)
5
Zoomass (10 ug/L)
Chl (ug/L)
10
DO (mg/L)
15
Temp ('C)
20
PAR (uE/m2/s)
25
0
5
10
15
Chl, DO, Zoop, Temp
20
25
Diel B, Aug 17, 13:00 EDT
PAR
0
200
400
600
800
1000
1200
0
Fish biomass
(relative)
Depth (m)
5
Zoomass (10 ug/L)
Chl (ug/L)
10
DO (mg/L)
15
Temp ('C)
20
PAR (uE/m2/s)
25
0
5
10
15
Chl, DO, Zoop, Temp
20
25
Lake Erie B 8-17-05 DIEL 02:00
Copepods mg . m-3
0
10
20
30
40
Cladocerans mg . m-3
0
100
200
Predatory Cladocerans mg . m-3
0
10
20
0
4
Diacyclops
Mesocyclops
Tropocyclops
Diaptomids
Epischura
nauplii
Bosmina
Eubosmina
Daphnia mendotae
D. longiremis
Leptodora
Bythotrephes
Cercopagis
EPI
depth
8
12
META
16
20
HYPO
4.8 mg/L DO
24
4.8 mg/L DO
4.8 mg/L DO
30
Lake Erie B 8-17-05 DIEL
Cladocerans mg . m-3
Copepods mg . m-3
0
50
100
0
20
40
14:00
Predatory Cladocerans mg. m-3
0
1
0
4
Diacyclops
Mesocyclops
Tropocyclops
Diaptomids
Epischura
nauplii
depth
8
Bosmina
Eubosmina
Daphnia mendotae
D. longiremis
D. retrocurva
Leptodora
Bythotrephes
EPI
12
META
16
20
HYPO
4.8 mg/L DO
24
4.8 mg/L DO
4.8 mg/L DO
2
Diel B, Sept 18, 03:00 EDT
PAR
0
100
200
300
400
500
0
Fish biomass
(relative)
Depth (m)
5
Zoomass (10 ug/L)
Chl (ug/L)
10
DO (mg/L)
15
Temp ('C)
20
PAR (uE/m2/s)
25
0
5
10
15
20
Chl, DO, Zooplankton, Temp
25
Diel B, Sept 17, 15:00 EDT
0
100
200
PAR
300
400
500
0
Fish biomass
(relative)
Depth (m)
5
Zomass (10 ug/L)
Chl (ug/L)
10
DO (mg/L)
15
Temp ('C)
20
PAR (uE/m2/s)
25
0
5
10
15
20
Chl, DO, Zooplankton, Temp
25
Lake Erie B 9-18-05 DIEL 02:00
.
-3
.
Copepods mg m
0
100
200
Cladocerns mg m
0
20
40
60
-3
80
.
Predatory Cladocerans mg m
0
1
2
0
depth
4
Diacyclops
Mesocyclops
Tropocyclops
Diaptomids
Epischura
nauplii
Bosmina
Eubosmina
Daphnia mendotae
D. longiremis
D. retrocurva
Diaphanasoma
8
upper epi
12
lower epi
Leptodora
16
meta
20
hypo
1.2 mg/L DO
24
1.2 mg/L DO
1.2 mg/L DO
-3
3
Lake Erie B 9-17-05 DIEL 14:00
.
-3
.
Copepods mg m
0
20
40
60
80
-3
Cladocerans mg m
0
20
40
.
0.0
0.5
0
4
Diacyclops
Mesocyclops
Tropocyclops
Diaptomids
Epischura
nauplii
depth
8
Bosmina
Eubosmina
Daphnia mendotae
D. longiremis
D. retrocurva
Diaphanasoma
Leptodora
upper epi
lower epi
12
16
meta
20
hypo
1.2 mg/L DO
24
1.2 mg/L DO
-3
Predatory Cladocerans mg m
1.2 mg/L DO
1.0
Selectivity coefficient of Vanderploeg & Scavia (W´) for
Emerald shiner and Rainbow Smelt in August 2005
Emerald Shiner August 2005
Emerald shiner:
Epilimnetic planktivore
1.00
W'
0.75
Night
0.50
Day
0.25
Si
Bo
sm
in
id
ae
di
da
e
Cy
clo
po
id
Da
ph
ni
da
Ca e
la
no
Ch
id
yd
or
id
ae
Le
pt
od
By
or
th
a
ot
re
Ch
ph
es
iro
m
om
id
ae
0.00
Rainbow Smelt August 2005
1.00
W'
0.75
Night
0.50
Rainbow Smelt:
Planktivore-benthivore
Day
0.25
di
da
Cy
e
clo
po
id
a
Da
ph
ni
da
e
Ca
la
no
id
Ch
a
yd
or
id
ae
Le
pt
od
By
or
th
a
ot
re
Ch
ph
es
iro
m
om
id
ae
Si
Bo
sm
in
id
ae
0.00
Prey size
USGS-NAS
Selectivity coefficient of Vanderploeg & Scavia (W´) for emerald
shiner and rainbow smelt in September 2005
Emerald Shiner September 2005
Emerald shiner:
1.00
Epilimnetic planktivore
W'
0.75
Night
0.50
Day
0.25
di
da
e
Cy
clo
po
id
Da
ph
ni
da
Ca e
la
no
Ch
id
yd
or
id
ae
Le
pt
od
By
or
th
a
ot
re
Ch
ph
es
iro
m
om
id
ae
Bo
sm
Si
in
id
ae
0.00
Rainbow Smelt September 2005
1.00
Night
0.50
Day
0.25
po
id
a
Da
ph
ni
da
e
Ca
la
no
id
Ch
a
yd
or
id
ae
Le
pt
od
By
or
th
a
ot
re
Ch
ph
es
iro
m
om
id
ae
di
da
e
Cy
clo
Si
in
id
ae
0.00
Bo
sm
W'
0.75
Rainbow smelt:
Planktivore-benthivore
Prey size
USGS-NAS
What’s going on down there?
Present status:
Heavy emphasis in IFYLE Hypoxia study on upper
food web (fish and location of fish food)
We do know, however:
• Mesozooplankton and microzooplankton
distribution relative to hypoxia response is
species specific
• Microzooplankton grazing dominates during the
summer
• Bacteria-based food web becomes important in
hypoxic zone
What’s going on down there?
For the development of a conceptual
framework we’d like to know:
• What is the minimum oxygen concentration a
zooplankter (species by species) is willing to
enter yet survive under various predation risk
scenarios?
• How does feeding and behavior vary with
oxygen concentration?
• What is the joint distribution of meso-and
microzooplankton around hypoxic zones
• How is production and predation risk affected?
We know something about Daphnia foraging in
hypoxic areas but nothing for copepods, the
dominants in the Great Lakes, or for visual
invertebrate predators
From Heisey & Porter (1977)
Some possible lab approaches to define spatial
rules of food web assembly (“indirect effects”)
• Observe location of position of zooplankton in
laboratory water columns with gradients of light,
temperature, kairomones of potential predators
& oxygen
• Directly observe behavior and foraging in
hypoxic water columns.
• Observe effect of hypoxia on visual predation
(both invertebrate & vertebrate)—have predators
watch TV
Inside the lab
Outside the lab: keeping the
predator in focus