common prey items along the texas coast: a fly fishing perspective mark r. fisher science director...
Post on 16-Dec-2015
218 Views
Preview:
TRANSCRIPT
Common Prey Items Along the Texas Coast: A Fly Fishing Perspective
Mark R. Fisher
Science Director
Rockport Marine Lab
TPWD Resource Monitoring Program Overview
• Initiated in 1975.
• Stratified random sampling.
• Standardized methods.
• Gill nets (780/year).
• Bay trawls (1,680/year).
• Gulf trawls (960/year).
• Bag seines (2,160/year).
• Oyster dredges (1,200/year).
• Total—6,780/year.
Sample Locations, 1975-2007All Gears Combined
n=175,306
360 fish species324 invertebrate species
Diet of Legal-Sized Red Drum and Spotted Seatrout
• Opportunistic predators.
• Diet reflects habitat, feeding mode, prey availability and prey size.
• Trout consume shrimp and fish.
• Reds consume crabs, shrimp and fish.
Don’t put your finger in there!
Upper Plate Lower Plate
Prey Items Can Be Highly Seasonal!
• Spawning occurs in Fall (croaker), Spring (silversides), Winter (mullet), or year-round (blue crab, killifish).
• Rapid growth rates for some (shrimp ~ 1 mm/day); juveniles are typically the only edible size.
• Different life stages utilize different habitats—juveniles typically inhabit shorelines, subadults and adults in open water.
• Our bays are not food-limited!
Corpus Christi Bay Monthly Mean Water Temperatures
0
5
10
15
20
25
30
35
°C
Gulf menhaden(Brevoortia patronus)
Monthly Abundance and Size of Menhaden from Coastal Bend Shorelines
0
200
400
600
800
1000
1200
1400
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Ca
tch
pe
r h
ec
tare
0
10
20
30
40
50
60
70
80
90
100
Me
an
le
ng
th,
mm
Catch per hectare Mean length
Late Fall/Early Winter Gulf spawners, 115 mm by age 1, 5 years max age
World’s Largest Menhaden?
2.9 pounds, 18.7 inches!
Bay anchovy(Anchoa mitchelli)
Striped anchovy(Anchoa hepsetus)
Dusky anchovy(Anchoa lyolepis)
Maximum size – 90 mmStriped anchovy – 150 mmBay anchovy – 100 mm
Distribution of Anchovies in the Coastal Bend
Dusky anchovy schools along Padre Island
Scaled sardine(Harengula jaguana)
Size range—90-125 mm
Spanish sardine(Sardinella aurita)
Size range—125-200 mm
Distribution of Sardines in the Coastal Bend
Distribution of Sardines by Salinity Zone
0%
10%
20%
30%
40%
50%
60%
0 5 10 15 20 25 30 35 40 45
Salinity, ‰
Mullet, striped and white(Mugil cephalus and M. curema)
World’s Largest Mullet?
30 inches, 7 pounds!
Killifish and Sheepshead minnow(Fundulus sp. and Cyprinodon variegatus)
30-40 mm50-75 mm
50-75 mm
Distribution of Cyprinodonts in the Coastal Bend
Killifish and Sheepshead minnowHabitat
Proof!
Inland silverside(Menidia beryllina)
Distribution of Silversides in the Coastal Bend
Pinfish and Atlantic croaker(Lagodon rhomboides and Micropogonias undulatus)
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Nov
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Oct
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Dec
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Jan
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Feb
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Mar
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Apr
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
May
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Jun
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Jul
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Aug
0
50
100
150
200
250
300
350
400
10 20 30 40 50 60 70 80 90 100 110 120130140150
Sep
MonthlyBay Trawl
AtlanticCroakerLengths
Length class, mm Length class, mm
GobiesFamily Gobiidae
Shrimp eel(Ophichthus gomesi)
150-600 mm length
Brown, Pink, and White Shrimp
Brown
Pink
White
Browns are brown to olive green.Pinks are grayish to red-brown.Whites are bluish white.
Browns, White, and Pink Shrimp Life History Overview
• Offshore spawning• Eggs hatch within 24 hours• Postlarvae migrate into bays• Fast growth, ~ 1 mm/day• Migrate to deeper water as
they get larger• Brown—fall spawners• White—spring spawners• Pink—spring spawners.• Browns & pinks burrow
during the day
Brown Shrimp Distribution and Abundance
Brown Shrimp Distribution and Abundance
Coastwide Monthly Brown Shrimp CPUEBay Trawls
0
50
100
150
200
250
300
350
400
Cat
ch p
er h
our
Grass Shrimp(Palaemonetes sp.)
20-40 mm total length
Distribution of Grass Shrimp in the Coastal Bend
Other Shrimp Species
Sargassum Shrimp
Shrimp Flies
Crabs
Atlantic brief squid(Lolliguncula brevis)
Longfin squid(Loligo pealei)
Arrow squid(Loligo pleii)
Squid Mantle Lengths
0
0.05
0.1
0.15
0.2
0.25
0.3
Fre
q
20 40 60 80 100 120 140 160 180
Length, mm
Brief Arrow Longfin
Distribution of Squid in the Coastal Bend
Distribution of Squid by Salinity Zone
0%
10%
20%
30%
40%
50%
60%
70%
0 5 10 15 20 25 30 35 40 45
Salinity, ‰
Brief Arrow Longfin
Good Fly Selections—Flats, Grassy Shorelines, Creeks
Good Fly Selections—Jetty and Surf
Want to Know More?
Common Bait Species Within Texas Bays
• Pinfish• Bay anchovy• Inland silverside• Gulf menhaden• Mullet• Sheepshead minnow• Killifish• Atlantic croaker
• Grass shrimp• White and brown
shrimp• Blue crab• Atlantic brief squid
Common Bait Species Along Texas Gulf Beaches
• Mullet• Striped anchovy• Dusky anchovy• Scaled sardine• Spanish sardine• Bay anchovy• Rough silverside
• Seabob• White and brown
shrimp• Blue crab• Sargassum shrimp• Sargassum crab
Common Bait Species in Redfish Bay, South Bay and B&R Flats
• Pinfish• Sheepshead minnow• Inland silverside• Killifish• Mullet• Bay anchovy• Atlantic croaker• Gobies
• Grass shrimp• White, pink, and
brown shrimp• Blue crab• Mud crabs
top related