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Young-of-the-Year Survey in RI Coastal Ponds
John Lake – Marine Biologist
RIDFW-Marine Fisheries Section
3 Ft. Wetherill Road
Jamestown, RI 02835
[email protected]
Purpose of Survey
To monitor juvenile fish populations
in Rhode Island coastal ponds and
estuaries, for the purpose of
forecasting recruitment in relation to
the spawning stock biomass of
winter flounder and other
recreationally important species.
Survey Facts
 Survey began in 1992
 Data has been collected on 98 fish species
 Over 500,000 fish have been collected since
surveys inception
 Being expanded this year
Winter Flounder Reproduction
 Males and females reach maturity at 3 years of age
 Adults believed to show spawning site affinity, subpopulations of winter flounder exist in RI waters
 Spawning occurs in estuaries from January – May
 Eggs clump together and rest on bottom (<1mm)
 Usually hatch 15 – 18 days after being released
 When the larvae are 1/3 of an inch they have
completely metamorphosed
Recruitment and Predation
 Spawning and settlement in near shore demersal
habitats makes eggs, larvae, and juveniles sensitive
to disturbances
 Egg, larval, and juvenile growth and survival are
inversely related to increasing water temperature
 Predation rates increase with increasing temperature
 Increase in Sand Shrimp (Crangon septimspinosa)
predation is thought to have a large impact on egg
mortality when water temperatures are elevated
Juvenile winter flounder and sand shrimp
Winter Flounder in the Coastal Ponds
 Ponds are a breeding ground/nursery with repeat
spawners returning annually
 Juveniles believed to be relatively stationary with
affinity to sites near spawning locations
 Prefer sandy-silt bottom texture
 Larval and juvenile stages feed on the eggs and
larval stages of various invertebrates
 Juveniles use eelgrass and other submerged aquatic
vegetation (SAV) habitats as a refuge from predation
Map of Sampling Locations
Sampling Procedure
 Beach Seine is set and hauled in a semicircle at each
station
 Water quality data is collected at each station
(Temperature, Salinity, Dissolved Oxygen, Secci
Depth)
 Finfish species are identified, counted, and measured
Physical Parameters
40
30
Salinity
20
Temperature
10
Dissolved Oxygen
0
19
93
19
95
19
97
19
99
20
01
20
03
20
05
20
07
20
09
Temp (deg C)
Sal (ppt) DO (mg/l)
Average Physical Parameters from Coastal Pond
Survey
Year
Average Water Temperatures from Coastal Pond Survey
by Month 1993 -2010
30
Temp deg C
25
20
15
10
5
0
May
Jun
Jul
Aug
Sep
Oct
Target Species







Alewife
Black Sea Bass
Bluefish
Menhaden
Scup
Tautog
Winter Flounder
Tautog Tautoga onitis
Year
0
Year
2010
2010
2006
2005
2004
2009
1
0
2008
5
4
3
2
2009
7
6
2007
Tautog
2008
Year
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
Year
2003
Year
2002
Scup
2001
0.1
1997
Bluefish
2000
0.2
1996
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
Alewife
1999
0.3
1998
0.5
1997
0
1995
0.5
1995
1
1996
2
1994
1.5
CPUE (fish/haul)
2.5
1994
4
3.5
3
2.5
2
1.5
1
0.5
0
CPUE (fish/haul)
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
CPUE (fish/haul)
3
1995
0.4
CPUE (fish/haul)
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
CPUE (fish/haul)
3.5
1994
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
CPUE (fish/haul)
Recreationally Important Finfish Species Abundance
Indices in Coastal Ponds
Black Sea Bass
2.5
1.5
2
1
0.5
0
Year
Menhaden
700
600
500
400
300
200
100
0
Coastal Pond Winter Flounder Length Frequencies
June 2010 Winter Flounder Length Frequency
May 2010 Winter Flounder Length Frequency
16.5
17.6
15.4
14.3
13.2
12.1
17.6
Length (cm)
15.4
14.3
13.2
12.1
11
9.9
8.8
7.7
6.6
5.5
4.4
0
17.6
16.5
15.4
14.3
13.2
11
12.1
9.9
8.8
7.7
0
6.6
0
5.5
5
3.3
10
5
4.4
11
15
2.2
10
20
1.1
15
3.3
16.5
25
2.2
17.6
20
Frequency
30
1.1
9.9
August 2010 Winter Flounder Length Frequency
25
0
Length (cm)
October 2010 Winter Flounder Length Frequency
September 2010 Winter Flounder Length Frequency
3.5
3
5
Frequency
4
3
2
1
2.5
2
1.5
1
Length (cm)
15.4
14.3
13.2
12.1
11
9.9
8.8
6.6
5.5
4.4
3.3
2.2
1.1
18
17
16
15
14
13
12
11
10
9
7
6
5
4
3
2
1
0
8
Length (cm)
0
0.5
0
0
7.7
Frequency
8.8
Length (cm)
July 2010 Winter Flounder Length Frequency
Frequency
16.5
Length (cm)
7.7
6.6
0
17.6
16.5
15.4
14.3
13.2
11
12.1
9.9
8.8
7.7
6.6
5.5
4.4
3.3
2.2
1.1
0
0
5.5
2
4.4
4
1.1
6
3.3
Frequency
Frequency
8
14
12
10
8
6
4
2
0
2.2
10
2010 Winter Flounder Frequency from Coastal Pond Survey
2010 Winter Flounder Frequency by Pond
250
Frequency
200
150
CP
100
NR
50
PJ
0
QP
M
ay
ne
u
J
ly
Ju
st
u
g
Au
Month
em
t
p
Se
r
be
er
b
o
ct
O
WP
Coastal Pond Winter Flounder Abundance Indices (fish/haul)
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
40
35
30
25
20
15
10
5
0
1994
CPUE (fish/haul)
Average CPUE of Winter Flounder from Coastal Pond
Survey
Year
CPUE of Winter Flounder from Coastal Pond Survey
by Pond
50
CP
40
NR
30
PJ
20
QP
10
WP
Year
20
10
20
08
20
06
20
04
20
02
20
00
19
98
19
96
0
19
94
CPUE (fish/haul)
60
Comparison of CPS Winter Flounder
Abundance Indices to other surveys
60
50
40
30
20
10
0
Coastal Pond
Survey
Narragansett
Bay Survey
Year
20
09
20
07
20
05
20
03
RIDFW Spring
Trawl
20
01
19
99
CPUE (fish / haul)
CPUE of Winter Flounder from Trawl and Seine
Surveys
URIGSO Trawl
Point Judith Pond Adult and Juvenile Indices
CPUE of Winter Flounder from RIDFW Fyke Net
and Seine Survey in Point Judith Pond
CPUE (fish/haul)
50.00
40.00
30.00
Fyke
20.00
CPS
10.00
0.00
1999
2001
2003
2005
2007
2009
Year
• Point Judith Pond was closed to harvest and
possession of Winter Flounder on April 8, 2011
Funded by Rhode Island Division of Fish and Wildlife,
USFW Federal Aid to Sport Fish Restoration
Grant No: F-61-R-17
Assessment of Recreationally Important Finfish
Stocks in Rhode Island Coastal Ponds