Resilience of Soft-Sediment Communities after Geoduck Harvest in - - PowerPoint PPT Presentation

▶
resilience of soft sediment communities after geoduck
SMART_READER_LITE
LIVE PREVIEW

Resilience of Soft-Sediment Communities after Geoduck Harvest in - - PowerPoint PPT Presentation

Mar 22, 2023 25 likes •438 views

Resilience of Soft-Sediment Communities after Geoduck Harvest in Samish Bay, Washington Micah Horwith, Department of Biology, University of Washington Fisk Bar Fisk Bar = Eelgrass = Bare = Channel Timeline 1 - Pre-harvest Geoduck crop

slide-1
SLIDE 1

Resilience of Soft-Sediment Communities after Geoduck Harvest in Samish Bay, Washington

Micah Horwith, Department of Biology, University of Washington

slide-2
SLIDE 2

Fisk Bar

slide-3
SLIDE 3

= Eelgrass = Channel = Bare

Fisk Bar

slide-4
SLIDE 4

Timeline

1 - Pre-harvest

Summer 2002 Geoduck crop planted Eelgrass colonizes Fisk Bar farm Geoduck crop harvested May 2008 ???

slide-5
SLIDE 5

Timeline

1 - Pre-harvest 2 - Post-harvest

slide-6
SLIDE 6

Geoduck harvest

May 2008

slide-7
SLIDE 7

7

Tube installation

June 2008

slide-8
SLIDE 8

Net installation

July 2008

slide-9
SLIDE 9

How does geoduck farming affect eelgrass?

slide-10
SLIDE 10

How does geoduck farming affect eelgrass?

1 - Reduced size

slide-11
SLIDE 11

How does geoduck farming affect eelgrass?

1 - Reduced size

4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

Mean sheath length (cm ± SE) 5 10 15 20 25 Unfarmed Farmed

Harvest Mean sheath length (cm ± SE)

slide-12
SLIDE 12

4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

Mean sheath length (cm ± SE) 5 10 15 20 25 Unfarmed Farmed

How does geoduck farming affect eelgrass?

1 - Reduced size April 2008 Unfarmed Farmed Harvest

slide-13
SLIDE 13

4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

Mean sheath length (cm ± SE) 5 10 15 20 25 Unfarmed Farmed

How does geoduck farming affect eelgrass?

1 - Reduced size April 2008 April 2009 Unfarmed Farmed Harvest

slide-14
SLIDE 14

How does geoduck farming affect eelgrass?

1 - Reduced size 2 - Reduced reproductive activity

slide-15
SLIDE 15

How does geoduck farming affect eelgrass?

1 - Reduced size 2 - Reduced reproductive activity April 2008 Unfarmed Farmed Frequency of # of branches

slide-16
SLIDE 16

Frequency of # of branches

How does geoduck farming affect eelgrass?

1 - Reduced size 2 - Reduced reproductive activity April 2009 April 2008 Unfarmed Farmed

slide-17
SLIDE 17

How does geoduck farming affect eelgrass?

1 - Reduced size 2 - Reduced reproductive activity 3 - Decline and loss

slide-18
SLIDE 18

How does geoduck farming affect eelgrass?

1 - Reduced size 2 - Reduced reproductive activity 3 - Decline and loss

4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

Mean shoot density (per m^2) 100 200 300 400 500 Unfarmed Farmed

Harvest Mean eelgrass density (shoots m-2 ± SE)

slide-19
SLIDE 19

How does geoduck farming affect sediment?

slide-20
SLIDE 20

How does geoduck farming affect sediment?

1 - Reduced sediment organic content

slide-21
SLIDE 21

4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

Mean sediment organic content (% ± SE) 0.0 0.5 1.0 1.5 2.0 2.5 Unfarmed Farmed

How does geoduck farming affect sediment?

1 - Reduced sediment organic content Harvest Mean sediment

  • rganic content

(% ± SE)

slide-22
SLIDE 22

How does geoduck farming affect sediment?

1 - Reduced sediment organic content 2 - Elevation loss and recovery

slide-23
SLIDE 23

How does geoduck farming affect sediment?

1 - Reduced sediment organic content 2 - Elevation loss and recovery

6/4/08 6/25/08 7/29/08 11/12/08 4/26/09

Mean Point !Elevation (cm ± SE)

  • 2
  • 1

1 2 Unfarmed Farmed

Mean Point ∆Elevation (cm ± SE)

slide-24
SLIDE 24

Does geoduck farming have ‘spillover’ effects?

slide-25
SLIDE 25

Does geoduck farming have ‘spillover’ effects?

1 - Reduced eelgrass size near farm

slide-26
SLIDE 26

Does geoduck farming have ‘spillover’ effects?

1 - Reduced eelgrass size near farm 4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

20 40 60 80 10 12 14 16 18 Distance from farm (m) Mean sheath length (cm) Rsquared = 0.132 F1,23 = 3.484 p =0.075

slide-27
SLIDE 27

Does geoduck farming have ‘spillover’ effects?

1 - Reduced eelgrass size near farm 2 - Increased eelgrass density near farm

slide-28
SLIDE 28

Does geoduck farming have ‘spillover’ effects?

1 - Reduced eelgrass size near farm 2 - Increased eelgrass density near farm 4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

20 40 60 80 100 200 300 400 500 Distance from farm (m) Shoots per m^2 Rsquared = 0.23 F1,23 = 6.882 p = 0.015

slide-29
SLIDE 29

Does geoduck farming have ‘spillover’ effects?

1 - Reduced eelgrass size near farm 2 - Increased eelgrass density near farm 3 - Possible increased sediment organic content, reduced standing biomass near farm

slide-30
SLIDE 30

Does geoduck farming have ‘spillover’ effects?

1 - Reduced eelgrass size near farm 2 - Increased eelgrass density near farm 3 - Possible increased sediment organic content, reduced standing biomass near farm 4/9/08 6/30/08 7/29/08 11/12/08 4/26/09 7/18/09 11/4/09 4/30/10

20 40 60 80 0.1 0.2 0.3 0.4 Distance from farm (m) Dry eelgrass biomass (g per m^2)

Sediment organic content Standing biomass

slide-31
SLIDE 31

How do predator-exclosure tubes affect eelgrass?

slide-32
SLIDE 32

How do predator-exclosure tubes affect eelgrass?

1 - Reduced eelgrass seedling success

slide-33
SLIDE 33

5/22/09 5/28/09 6/23/09 8/18/09

Proportion of surviving seedlings 0.0 0.2 0.4 0.6 0.8 1.0 Tubes No Tubes

How do predator-exclosure tubes affect eelgrass?

1 - Reduced eelgrass seedling success Proportion of surviving seedlings

slide-34
SLIDE 34

How do predator-exclosure tubes affect eelgrass?

1 - Reduced eelgrass seedling success 2 - No effect on sediment organic content

slide-35
SLIDE 35

!Sediment organic content (% ± SE)

  • 1.5
  • 1.0
  • 0.5

0.0 0.5 1.0 1.5 Tubes No Tubes

How do predator-exclosure tubes affect eelgrass?

1 - Reduced eelgrass seedling success 2 - No effect on sediment organic content ∆Sediment organic content (% ± SE)

slide-36
SLIDE 36

How do predator-exclosure tubes affect eelgrass?

1 - Reduced eelgrass seedling success 2 - No effect on sediment organic content 3 - No effect on sediment stability

slide-37
SLIDE 37

How do predator-exclosure tubes affect eelgrass?

1 - Reduced eelgrass seedling success 2 - No effect on sediment organic content 3 - No effect on sediment stability

Cumulative !Elevation (cm ± SE)

  • 40
  • 20

20 40 Tubes No Tubes

Cumulative ∆Elevation (cm ± SE)

slide-38
SLIDE 38

Geoduck farming effects to date

slide-39
SLIDE 39

Geoduck farming effects to date

Within farm

  • Loss of eelgrass
  • Reduced size and reproductive activity prior to loss
  • Reduced sediment organic content
  • Short-term loss of elevation
slide-40
SLIDE 40

Geoduck farming effects to date

Within farm

  • Loss of eelgrass
  • Reduced size and reproductive activity prior to loss
  • Reduced sediment organic content
  • Short-term loss of elevation

Spillover

  • Reduced eelgrass size
  • Increased eelgrass density
  • Possible increase in sediment
  • rganic content and decrease in

standing biomass

slide-41
SLIDE 41

Support

Julianna Chen Katie Cochrane Audrey Djunaedi Giorgio Guerra Caleb Hecker Kelsey Hinton Isaac Horwith Henry Howes Sarah Jubinski Ailene Kane Satprit Kaur Max Maliska Claire Miccio Gia Nguyen Julie Nicol

  • Dr. Fernanda Oyarzun

Emily Palm Adam Parast Sascha Troiano Chaochung Tsai Chaowei Tsai

  • Dr. Ursula

Valdez Brady Walkinshaw Kyle Wataya Inness Wragg Sylvia Yang

  • Dr. Jae-Won

Yoo

Field Assistance Guidance

  • Dr. Janneke Hille Ris Lambers
  • Dr. Jennifer Ruesink