Photo: CINMS
Photo: J. Maassen
Could spatial management of sea
urchins increase fishery profits?
Sarah Teck, Nick Shears, Sarah Rathbone, Steve Gaines
Department of Ecology, Evolution, and Marine Biology,
University of California Santa Barbara
Background
Santa Barbara
San Miguel
• red sea urchin fishery:
– California
~11.2 million lbs.
~$6.1 million
– N. Channel Islands
~66%
– Port of Santa Barbara
~52%
– 90% western end
Santa Rosa Santa Cruz
Anacapa
Image: www.incabrain.com
Background
• seasonal variability in gonad quality influences price
($0.39/lb vs >$1.00/lb)
• fishermen race to harvest year-round vs. waiting for
optimal quality
(how much more $ would they make, if they waited?)
• delaying harvest through spatial property rights,
TURF’s (Territorial Use Rights in Fisheries) 
fishermen’s profits
(also would save time, no need to survey area to fish
during suboptimal conditions, just wait for optimal quality)
Background
• with fished species need to wait for
individuals and population growth
with urchins also need to wait for
seasonal gonad quality
• first, we need to understand more detailed
ecological information on temporal and spatial
variability of gonad quality
Background
• with fished species need to wait for
individuals and population growth
with urchins also need to wait for
seasonal gonad quality
• first, we need to understand more detailed
ecological information on temporal and spatial
variability of gonad quality
Channel Island field sampling
Santa Barbara
San Miguel
Santa Rosa Santa Cruz
Anacapa
Red urchin gonad
variability over space
Santa Barbara
San Miguel
0.12
(GSI)
index
gonad: somatic
index
gonad:somatic
Santa Rosa Santa Cruz
0.1
Anacapa
0.08
0.06
0.04
0.02
0
San Miguel
Island
Santa Rosa
Island
Santa Cruz
Island
Anacapa
Island
Mainland
Santa Barbara
Island
Santa Barbara Port sampling
Red urchin gonad variability over time
0.2
(GSI)
index
somatic
gonad:
index
somatic
gonad:
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
Oct
9-Sep
‘08
Dec 18-Dec
Feb
‘09
Mar
May
28-Mar
Jul
6-Jul Aug
Oct
14-Oct
Red urchin gonad variability over time
0.2
(GSI)
index
somatic
gonad:
index
somatic
gonad:
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
Oct
9-Sep
‘08
Dec 18-Dec
Feb
‘09
Mar
May
28-Mar
Jul
6-Jul Aug
Oct
14-Oct
Red urchin gonad variability over time
0.2
(GSI)
index
somatic
gonad:
index
somatic
gonad:
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
Oct
9-Sep
‘08
Dec 18-Dec
Feb
‘09
Mar
May
28-Mar
Jul
6-Jul Aug
Oct
14-Oct
Red urchin gonad variability over time
0.2
(GSI)
index
somatic
gonad:
index
somatic
gonad:
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
Oct
9-Sep
‘08
Dec 18-Dec
Feb
‘09
Mar
May
28-Mar
Jul
6-Jul Aug
Oct
14-Oct
Red urchin gonad variability over time
0.2
(GSI)
index
somatic
gonad:
index
somatic
gonad:
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
Oct
9-Sep
‘08
Dec 18-Dec
Feb
‘09
Mar
May
28-Mar
Jul
6-Jul Aug
Oct
14-Oct
a)
a)
Red urchin landings 1985-2005
Red urchin landings 1985-2005
Red urchin landings 1985-2005
% Landings
%<1
Landings
Purple urchin abundance 2007
Purple urchin abundance 2007
b)
b)
Purpleurchin
urchinabundance
abundance
2007
Purple
2007
Purple urchin abundance 2007
34.6 <1
1-5
34.6
1-5
6-10
6-10
11-20
11-20
20-30
34.4
20-30
34.4
34.2
34.2
34
34
-120.6
-120.6
-120.6
-120.6
33.8
Figure
Spatial distribution
urchin landings
from
-119.2
-119.4
-119.8of red-119.6
-120
-120.2
-120.4 4. (a)
-120
-120.2
-120.4
33.8
1985
to
2005
in
the
CINMS
(landings
are
assigned
to
10
x
10
Figure
4.
(a)
Spatial
distribution
of
red
urchin
landings
from
-119.2
-119.4
-119.6
-119.8
-120
-120.2
-120.4
-120
-120.2
-120.4
nautical
mile blocks
as reported
to CA are
Dept.
of Fishto
and
1985 to 2005
in the CINMS
(landings
assigned
10 x 10
purple sea urchin
• purples compete with reds for kelp
• not commercially harvested (smaller)
• form persistent urchin barrens
(mostly in the east)
• long-term monitoring sites
deforested by purples ~33% of the
time—mostly in the east
• manipulate ecology of a
managed area to increase
profits
kelp restoration
19 1
85 9 85
0
Reserve(n=2)
(n=2)
Reserve
Fished(n=5)
(n=5)
Fished
500
0
20
07
1
20 20
07 07
2
20
05
10003
20 20
05 05
4
20
03
5
20 20
03 03
1500
20
01
6
20 20
01 01
2000
19
99
Redurchins
urchins
red
19 19
99 99
0
19
97
10
20
07
20
05
20
03
20
01
10
19
99
2000
19
97
Fished (n=5)
19
95
19
93
20
07
20
05
20
03
20
01
19
99
kelp Kelp
19
91
purple urchins
urchins
Purple
19
97
14
19
89
30
19
87
19
85
60
19 1
97 9 9
7
Reserve (n=2)
19
95
Fished (n=5)
19
95
Reserve (n=2)
19 19
95 95
0
Density (m-2)
2
19
93
19
91
4
19
93
19
91
19
89
19
87
19
85
6
19 1
93 9 9
3
7
19
89
70
19 1
91 9 9
1
25008
19
87
19
85
-2
Density (m )
Density (m-2)
12
19 1
89 9 8
9
Density (m )
Density (m-2)
Density (m-2)
80
19 19
87 87
-2
-2
Density (m-2)
(gm-2)
Biomass
Biomass (g m )
2500
Reserve (n=2)
Long-term (1985-2007)
Variation in Kelp and Urchin
8
1500
1000
Fished (n=5)
500
50
40
20
0
Red urchin biomass
NPS—KFM data (eastern SCI and Anacapa Island)
19 1
85 9 85
0
Reserve(n=2)
(n=2)
Reserve
Fished(n=5)
(n=5)
Fished
500
0
20
07
1
20 20
07 07
2
20
05
10003
20 20
05 05
4
20
03
5
20 20
03 03
1500
20
01
6
20 20
01 01
2000
19
99
Redurchins
urchins
red
19 19
99 99
0
19
97
10
20
07
20
05
20
03
20
01
10
19
99
2000
19
97
Fished (n=5)
19
95
19
93
20
07
20
05
20
03
20
01
19
99
kelp Kelp
19
91
purple urchins
urchins
Purple
19
97
14
19
89
30
19
87
19
85
60
19 1
97 9 9
7
Reserve (n=2)
19
95
Fished (n=5)
19
95
Reserve (n=2)
19 19
95 95
0
Density (m-2)
2
19
93
19
91
4
19
93
19
91
19
89
19
87
19
85
6
19 1
93 9 9
3
7
19
89
70
19 1
91 9 9
1
25008
19
87
19
85
-2
Density (m )
Density (m-2)
12
19 1
89 9 8
9
Density (m )
Density (m-2)
Density (m-2)
80
19 19
87 87
-2
-2
Density (m-2)
(gm-2)
Biomass
Biomass (g m )
2500
Reserve (n=2)
Long-term (1985-2007)
Variation in Kelp and Urchin
8
1500
1000
Fished (n=5)
500
50
40
20
0
Red urchin biomass
NPS—KFM data (eastern SCI and Anacapa Island)
2500
Reserve (n=2)
14
Reserve (n=2)
Density (m-2)
12
Long-term (1985-2007)
Variation in Kelp and Urchin
Fished (n=5)
kelp Kelp
Fished (n=5)
2000
-2
Density (m )
10
Reserve (n=2)
Density (m-2)
70
Density (m-2)
20
07
20
05
500
60
50
40
30
0
19
99
20
01
20
03
20
05
20
07
19 19
99 99
20 20
01 01
20 20
03 03
20 20
05 05
20 20
07 07
Redurchins
urchins
red
2000
5
1500
4
10003
20
07
20
05
20
03
20
01
19
99
19
97
19
95
• Reproductive output is ~4
times higher in kelp
forests versus urchin
barrens
2
500
1
19 1
93 9 9
3
19 1
91 9 9
1
19 1
89 9 8
9
19 19
87 87
0
0
19 1
85 9 85
Density (m-2)
-2
Density (m )
6
19
93
19
91
19
89
19
97
19 1
97 9 9
7
Fished(n=5)
(n=5)
Fished
19
95
Reserve(n=2)
(n=2)
Reserve
7
19 19
95 95
19
91
19
89
19
93
Red urchin biomass
19
87
19
85
25008
19
87
19
85
20
0
-2
20
03
purple urchins
urchins
Purple
Fished (n=5)
10
(gm-2)
Biomass
Biomass (g m )
• Red urchins have
persistently higher
biomass inside of the
reserves.
1000
20
01
19
91
19
89
80
19
87
19
85
0
19
99
2
19
97
4
1500
19
95
6
19
93
Density (m-2)
8
NPS—KFM data (eastern SCI and Anacapa Island)
Proposed restoration sites
Proposed restoration sites
ecological restoration & economic revitalization