Linking fish productivity to deep-sea coral and sponges in ......Linking fish productivity to...

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