linking fish productivity to deep-sea coral and sponges in ......linking fish productivity to...
TRANSCRIPT
Linking fish productivity to deep-sea coral
and sponges in Alaska
Chris Rooper1, Christina Conrath1, Jerry Hoff1,
Brian Knoth1, Jennifer Boldt2
1Alaska Fisheries Science Center, NMFS 2Fisheries and Oceans Canada, PBS
December 10, 2014
Overall questions: Are there more rockfish where coral
and sponge are present?
Does coral or sponge presence
increase rockfish growth or
condition?
How much fishery production do we
lose with every kg of invertebrates
removed?
Studies
Aleutian Juvenile POP study 2003, 2004, 2007, 2008
Zhemchug Ridges study 2008
Snakehead Bank study 2009
Modeling-habitat studies 2003-2012
FMP – Production study 2012-2014
Background map of world
Nanaimo
Seattle
Gulf of Alaska
Eastern
Bering Sea
Trawl survey data (Gulf of Alaska) CPUE = s(location)+s(depth)+s(slope)+s(coral/sponge)
Juvenile POP Dusky rockfish Northern rockfish
Adult POP
Shortspine
thornyhead
Shortraker
rockfish
Other Analyses on Alaska trawl survey data
• Aleutian Islands – Multiple species (Heifetz et al. 2002, Malecha et al. 2005) – Juvenile POP (Rooper and Boldt 2005, Laman et al. in
review) – Adult POP (Laman et al. in review)
• Gulf of Alaska – Multiple species (Rooper and Martin 2012, Krieger and
Wing 2002, Malecha et al. 2005) – Shortspine thornyhead (Rooper et al. 2010)
• Eastern Bering Sea – (Malecha et al. 2005, Sigler et al. in review)
Background map of world
Nanaimo
Seattle
Islands of Four
Mountains
2003, 2004,
2007, 2008
SIN
SIS
Juvenile POP study - Aleutians
Nursery Habitat Study
Collected data: Sidescan and multibeam sonar maps
Temperature
Zooplankton abundance
Juvenile Pacific ocean perch
Abundance
Diet
Energetics
Habitat use
Bare sand with hydroid cover
Bare sand with boulders/cobble
Bedrock and boulders with
sponge and coral
Bedrock with sponge and coral
Bare sand with sea whips
Bare sand
Juvenile POP observed by substrate type
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
SIN IOFS SIS
Cb
Kb
Sb
Sc
Ss
Islands of Four Mountains
Kk
Association with structure
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
SIN IOFS SIS
Fracti
on
No association
< 1 m
< 1 Body length
POP association by structure type
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
SIN IOFS SIS
Per
cen
tag
e o
bse
rved
no association
sponge
longline tangle
crevice
coral
cobble sponge
cobble coral
boulder sponge
boulder coral
Background map of world
Seattle
Zhemchug
Ridges
Acoustic Assessment – Zhemchug Ridges
0
200
400
600
800
1000
1200
1400
Ridge Flats
Den
sity
(no.*
ha-1
)
Adult rockfish
Juvenile Rockfish
Dusky Rockfish
Juvenile POP observed by substrate type
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
SIN IOFS SIS
Cb
Kb
Sb
Sc
Ss
Islands of Four Mountains
Zhemchug Ridges
Kk
Acoustic
Data
(b)
(a) 0.5 km
100 m
100 m
50 m
50 m
Day
Night
Water column Sv
Daytime
Nightime
0
1000
2000
3000
4000
5000
6000
7000
Daytime Nighttime
Den
sity
(no.*
ha-1
)
Adult rockfish
Juvenile Rockfish
Dusky Rockfish
Video Observations
Size and Species Composition of Rockfish on the Seafloor
Daytime
Nighttime
Num
ber
of
fish
Zhemchug
Ridges – 2014
Background map of world
Snakehead Bank
Acoustic Assessment – Snakehead Bank
Snakehead Bank habitats
Rockfish SA height off bottom (to 10m) by pass
Pass 2 - Day
Pass 3 - Night
Pass 4 - Day
Pass 5 - Night
Pass 6 - Day
Pass 7 - Day
Pass 8 - Night
Pass 1 - Night
Average = 1.4 m Average = 1.8 m
Height off bottom – Observed in imagery
Sponge
Coral
Invertebrates combined
All camera studies lumped together
Same types of habitats
95% reduction
91% reduction
Trawl survey data
Adult rockfish – DSCRTP Alaska Study Central GOA
Yes – For most shelf and shelf break species*
– Trawl survey data
– Underwater image data
*Association differs with species
– Schooling semi-pelagic adults (POP, Northern RF, Dusky RF)
– Juveniles and small RF (POP, Harlequin, Sharpchin)
– Large Demersals (Yelloweye RF, Rougheye RF, Blackspotted RF)
– No association (Shortspine thornyhead, Shortraker RF)
• Overall suggests (given the same substrate type) more
coral = more juvenile POP
Are there more rockfish where sponge
and coral are present?
Overall questions: Are there more rockfish where coral
and sponge are present?
Does coral or sponge presence
increase rockfish growth or
condition?
How much fishery production do we
lose with every kg of invertebrates
removed?
Background map of world
Nanaimo
Seattle
Islands of Four
Mountains
2003, 2004,
2007, 2008
SIN
SIS
Juvenile POP study - Aleutians
Size classes
0
10
20
30
40
50
60
<100
10
0-1
20
12
0-1
30
13
0-1
40
14
0-1
50
15
0-1
60
16
0-1
70
17
0-1
80
18
0-1
90
19
0-2
00
20
0-2
10
21
0-2
20
22
0-2
30
23
0-2
40
24
0-2
50
Forklength (mm)
Fre
qu
en
cy
SIN
SIS
Condition
-0.02
0
0.02
0.04
0.06 SIN
SIS L-W residuals
*
*
Energy Content (cal/g dry wt)
Juvenile POP growth
Invertebrate Biomass
Sponge
Coral
Diet
Other
Larvaceans
Euphausiids
Lg. Copepods
0
0.2
0.4
0.6
0.8
1
Nu
meri
cal p
rop
ort
ion
0
0.2
0.4
0.6
0.8
1
SIN SIS
Weig
ht
pro
po
rtio
n
SIN SIS SIN SIN
Zooplankton Biomass
0.0
0.4
0.8
1.2
1.6
SIN SIS
Bio
mass (
ml/m
3)
Temperature
150
100
50
150
100
50
150
100
50
150
100
50
402SIN_9
3 5 7 9 11
402SIN_11
3 5 7 9 11
402SIS_16
3 5 7 9 11
402SIS_17
3 5 7 9 11
De
pth
SIN
SIS
Adult rockfish – DSCRTP Alaska Study Central GOA
Boulder
Also measuring
- Fecundity
- Growth potential
Maybe:
- Condition was higher where sponge density was higher
for juveniles
- Growth didn’t vary significantly
• Higher zooplankton biomass = higher condition
• Higher temperature = higher condition
Local feeding condition dominates
Does coral or sponge presence increase
rockfish growth or condition?
Overall questions: Are there more rockfish where coral
and sponge are present?
Does coral or sponge presence
increase rockfish growth or
condition?
How much fishery production do we
lose with every kg of invertebrates
removed?
Juvenile POP nursery
habitat = untrawlable habitat
at depths from 85-240 m
Total nursery area = 20,334 km2
Mean recruitment = 52,235,000
Age 2 Recruits = 257/ha
Depth distribution
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 100 200 300 400
Depth (m)
Cu
mu
lati
ve %
CP
UE
240 m
85 m
DSCRTP Modeling
Studies
Coral CPUE
Sponge CPUE
Combined nursery average
= 1.08 kg/ha
How much fishery production
for a kg of coral and sponge?
POP recruits = roughly 257/ha
- 1.08 kg sponge and coral/ha
- Remove all the sponge and coral
- 233/ha (roughly 8% drop)
- Increase sponge and coral by 1 kg/ha
- 521/ha (roughly 100% increase)
Summary: 1) Are there more rockfish where coral and sponge are present?
Yes, but juveniles and adults use the habitat differently as do
different species
2) Does coral or sponge presence increase rockfish growth or condition?
No for growth, possibly for condition, but feeding conditions
(local) seem more important
3) How much fishery production do we lose with every kg of invertebrates
removed?
Lost 24 recruits/ha by removal all
Gained 264 recruits/ha by adding 1 kg
Probably close to having the answer to #1
Probably soon have the answer to #2
Far away from seriously answering #3
Collaborators
• POP Diet & Energetics • Ron Heintz - ABL • Kerim Aydin - REFM • Mary Auburn-Cook – Inverte Inc • Dave Beauchamp – UW SAFS • Jon Hill • Sonia Batten
• Video and Acoustics • Gary McMurrin – RACE RSST • Scott McEntire - MACE • Kresimir Williams – MACE • Bill Flerx - RSST • Bob Lauth – RACE GF • Patrick Ressler – MACE • Taina Honkalehto – MACE • Mark Zimmermann – RACE GF • Chris Wilson – MACE • Tom Weber – UNH • Bob Stone – ABL • John Olson - AKR
• Data and Analysis • Michael Martin – RACE GF • Mark Wilkins – RACE GF • F/V Gladiator, • F/V Ocean Explorer • F/V Vesteraalen • F/V Epic Explorer • R/V Oscar Dyson • GOA and AI Survey Scientists
• Funding Sources • North Pacific Research Board • NMFS Essential Fish Habitat Program • NMFS Industry Cooperative Program • AFSC - Resource Assessment and Conservation Engineering Division • DSCRTP