3. Appearance
Striped bass are quick powerful
fish with silvery sides and white
belly. They have seven or eight
black stripes along the sides.
Stripes are absent on young fish
of less than six inches
4. Habitat
In Florida, striped bass are found
primarily in the St. Johns River
and its tributaries, and a few
panhandle rivers. Striped bass
need long stretches of flowing
water to reproduce successfully.
These conditions are rare in
Florida.
5. Behavior
Stripers do not tolerate water
temperatures over 75˚F for long.
During Florida summers, striped
bass become less active and must
find cool water to survive.
Striped bass populations depend
on annual stockings from FWC
and federal hatcheries.
8. Life history tales
Fish photographs by D. Flescher, downloaded from www.fishbase.org
Fish illustrations from: Lippson, A. J. and
R. L. Moran. 1974. Manual for
identification of early developmental
stages of fishes of the Potomac River
Estuary. Prepared for MD DNR Power
Plant Siting Program. PPSP-MP-13. 282
pp.
Larvae
http://www.dnr.state.md.us/fisheries/juvindex/index.html
Juveniles
Adults
Eggs
http://www.mdsg.umd.edu/MarineNotes/Sep-Oct98/
12. To understand how physical conditions affect
striped bass in the St. John’s River, we need
to:
determine how physical conditions
change in the St. John’s River
identify how striped bass respond
to physical conditions
13. Physical conditions affect all life stages
Water temperature, salinity, dissolved oxygen
concentrations, and currents influence:
survival (heat shock, winter mortality)
growth rates
location, movement, migration
16. Striped bass and water temperature:
lethal limits and optimal ranges
Juveniles Adults
Stress/Mortality
Optimal
o
C
o
C
Optimal
Stress/Mortality
Setzler-Hamilton and Hall 1991
22. Salinity measures the amount of salts
dissolved in water. An estuary can
exhibit a change in salinity throughout
its length as fresh water entering from
the tributaries mixes with seawater
from the ocean.
Striped bass are migratory fish which
spend most of their life in bays and the
ocean, but travel up tidal freshwater
rivers in the spring to spawn.
25. Dissolved Oxygen (DO) is one of the
most important indicators of water
quality. It is essential for the survival
of fish and other aquatic organisms.
The DO test tells how much oxygen is
dissolved in the water.
26. Factors that effect the amount of dissolved
oxygen in the water
Water Temperature:
Colder water holds more oxygen.
Warmer water holds less oxygen.
Salinity:
Fresher water holds more oxygen.
Saltier water holds less oxygen,
too many bacteria or algae in the water may reduce oxygen
levels.
The DO test tells how much oxygen is
dissolved in the water.
27. Striped bass and dissolved oxygen concentrations:
lethal limits
Juveniles Adults
Stress
Mortality
Preferred
Setzler-Hamilton and Hall 1991
30. Helpful Links
Water Quality St. John’s River
http://www.lake.wateratlas.usf.edu/river/waterquality.asp?
wbodyid=1025&wbodyatlas=river
St. John’s River Operational Forecast System: Get current data at specific parts
of the St.John’s using Nowcast
http://tidesandcurrents.noaa.gov/ofs/sjofs/sjofs.html
31. Summary
Physical conditions affect all life
stages of striped bass
Understanding changes to striped
bass habitat is important for fisheries
management
Habitat quality is determined by a suite
of physical conditions
Notas do Editor
Spawning takes place when temps are 11-24 degrees C, peaks from 14-19 degrees C. Fecundity for striped bass is dependent upon weight; a 5 lb female may spawn up to 25, 000 eggs while a 12 lb female can spawn up to 1, 250, 000 eggs Larval stage approximately 30 days depending on temperature and food
During periods of high abundance, fish spawned in Chesapeake Bay can contribute up to 90% of East Coast stocks.
