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The South Carolina Striped Bass:A Unique Story
The
striped bass, sometimes known as the “Rock”, “Rockfish” or “Striper”
has a long and interesting history in South Carolina.
It is the “state game fish” and the “state fish.”
The scientific name of the striped bass is Morone
saxatilis and it is typically catalogued as an anadromous fish.
Anadromous means that it spends the greater part of its life in the ocean
and travels to freshwater streams to spawn. Over the past century, fish biologists have reported that
striped bass populations have steadily declined.
This decline is primarily due to pollution, siltation, construction of
power dams and overfishing. Striped Bass are found along the Atlantic Coast from
the St. Lawrence River in Quebec and ends in the St. John’s River in Florida.
North of Cape Hatteras, the Striped Bass is an anadromous fish.
It is one of the most popular saltwater sport fish along the eastern
seaboard. In
the spring, the Striped Bass enters freshwater, traveling up rivers to spawn.
When spawned, fertilized eggs must have a volume and flow of water that
insures at least 48 hours flotation. If
they sink, the eggs die. Once
hatched the fry begin their journey down river and enter saltwater as
fingerlings, juvenile fish. In
South Carolina, the striped bass tend to spend the greater part of its life in
freshwater streams. Once it was believed that the Santee-Cooper population of
Striped Bass had become landlocked because of the construction of two dams that
impounded Lake Moultrie and Lake Marion. More
recently, fish biologists have come to believe that the Striped Bass in South
Carolina were “functionally” landlocked or “riverene” long before the
dams were built. This means that they have become residents of the river
naturally. This is supported by the
current research. Therefore, the
Santee-Cooper Striped Bass population is entirely a freshwater population
(Campbell, Striped White & Hybrid Bass
in South Carolina). Striped
Bass have a tendency to travel in small schools during the first two years of
life. They have enormous appetites and feed on shad, menhaden, herring and
minnows. Spawning grounds for
Striped Bass are typically in streams and rivers with moderate to fast current
flowing over a rock or sand bottom. In
South Carolina, the spawning period ranges from April 1 to May 15.
During this time, the males typically migrate to the spawning grounds
first and wait until the larger females arrive.
Spawning is governed by water temperature and it starts when the water is
around 58-60 degrees F. Spawning of
Striped Bass involves several small males surrounding one large female as she
lays her eggs freely into the running water. No spawning “bed” or “nest”
is created by Striped Bass. The
males jockey for position creating much splashing which is known as a “rock
fights.” The males brush against
the female to stimulate spawning. After
the eggs are laid, milt from the males then fertilizes the eggs.
Studies have shown that greater than 80 percent of the eggs are usually
fertilized. The eggs at the time of
fertilization are very small and nonadhesive and settle to the bottom.
After a short time, the eggs swell to about four times the original size
and possess a tiny oil globule. This
change makes the egg approximately the same density of the surrounding water.
The eggs become somewhat buoyant and are easily carried by the water
currents. The hatching time varies
from 65 hours at 60 degrees F to 36 hours at 70 degrees F. According to Bulak (1988), if a striped bass spawned at
70 degrees F in a low rainfall year, approximately 36 miles of flowing water is
necessary for the eggs to hatch. But
if a striper spawned at the same temperature during a high rainfall period,
about 72 miles of flowing water from the spawning area is required.
A flow velocity in the river of approximately one-foot per second is
required to keep the eggs afloat. If the egg sinks to the bottom, its chances of
hatching are reduced because the sediments reduce oxygen exchange between the
egg and the surrounding water. The
flow rates of the water are basically controlled by the upstream flows from
dams. Egg mortality is high, especially in water temperatures above
70 F, but many eggs are laid to increase survival. Less than one percent of the
eggs will survive the fist two months. Bulak
(1988), stated that “In most years, the prime spawning grounds are in the
upper Congaree, between the city of Columbia and the Eastman Kodak plant.
But in years of low water, such as 1985 and 1986, striped bass do not
migrate as far upstream to spawn. This
points out once again, the impact river flow can have on spawning migration (p.
44).” Depending
in the size of the female, one female can lay from 14,000 (3 pounder)-3,000,000
eggs (10 pounder). A thirty-pound
female is capable of producing as many as five million eggs.
In a fast moving current, the eggs hatch out at a considerable distance
downstream from the spawning place. At the time of hatching, the tiny
transparent fish, less than ¼ inch long emerges with a heavy yolk sac attached.
It derives nourishment from this sac.
The fry at this stage is at the mercy of the water currents. Within four to five days, the yolk sac is absorbed and the
fry begins to swim and feed on small crustaceans (Scruggs, 1954). Male
Striped Bass usually reach sexual maturity at two years.
They are generally less than 12 inches long.
About 25% of the females reach maturity at four years of age when they
are about 17 inches in length. Nearly
all of the females are mature at five years of age when they reach a weight of
six pounds or a length of twenty-three inches.
Age studies have shown that the Striped Bass grow slowly during the first
two years. The rate of growth of females is faster then that of the
male. The average length of a
striper is 20-36 inches, while the average weight is 3-10 pounds.
Striped Bass attain a maximum weight of 60 pounds in freshwater and 125
pounds in saltwater, but fish over 55 pounds are rare (Bayless, 1982). In
South Carolina, the majority of the spawning occurs in the Wateree and Congaree
Rivers, which are tributary streams of Santee-Cooper. Results of a 1983 study indicated that the Congaree River is
a major spawning area while additional studies in 1987, now show that the
majority of striped bass egg production comes from the Wateree River.
In 1973, the SC Wildlife and Marine Resources Department, now known as
the SC Department of Natural Resources, reported that there are five main rivers
which support populations of Striped Bass: the Cooper, Santee, Congaree, Wateree,
and Saluda above Lake Murray. Excellent
reservoir fisheries exist in Lakes Marion, Moultrie, Murray and Wateree.
Smaller populations are found in Lakes Hartwell, Thurmond, Secession and
Greenwood. Biologist believe that a
slow moving current in a short stretch of river or a faster current in a longer
river may provide the necessary time for eggs to develop and hatch.
They believe that of all the state’s rivers, which empty into
reservoirs, only the Congaree and Wateree provide the correct ratio of length
and flow necessary for reproduction. It should be noted that most striper populations in
reservoirs are maintained solely by stocking.
This stocking benefits other game fish such as largemouth bass and
crappie. The striper seeks out fish
such as gizzard shad for its main food supply, thus eliminating fish that would
compete with wanted game fish (Davis, 1973). In the early 1960’s, SCDNR fishery biologists
provided the key to propagating Striped Bass artificially by experimenting with
various hormones to speed up spawning. The
pioneering efforts by Dr. Robert E. Stevens put Striped Bass hatcheries on a
reliable production basis. This
technique plus the documentation that Striped Bass in the Santee-Cooper River
system was “landlocked”, opened a new era of Striped Bass culturing and
fishing. It enabled the expansion
of Striped Bass into land-locked reservoirs (Bayless, 1982).
These techniques have allowed the stocking of Striped Bass in many
reservoirs in the United States. Since
the1970’s, many anglers throughout the United States now enjoy Striped Bass
fishing. Freshwater striped bass
fisheries are now in almost every state because of what was discovered in the
Santee-Cooper System (Bulak, 1988). In
More information about striper production at state hatcheries may be found in
the Hatchery Section of this guide. In
recent years, the low rate of hatching survival of striper eggs in
Santee-Cooper, indicate that something is affecting the ability of stripers to
successfully reproduce and maintain their populations.
In hopes of speeding up the recovery of Santee-Cooper striped bass
populations, the daily creel limits in 1989 were reduced from 10 stripers to
five in lakes Marion and Moultrie and the rivers nearby.
Therefore, the law prohibits keeping more than five striped bass or any
striped bass less than 18 inches long in the following waters:
Lake Marion, Lake Moultrie, Diversion Canal, Rediversion canal, Tailrace
Canal, Santee River, Congaree River, Wateree River, Lower Saluda River, Broad
River northward to the lock and dam of the Columbia Canal, Cooper River (no
length limit) and Wando (no length limit) (South
Carolina Wildlife Roundtable, M-A, 1990).
In 1993, it was discovered that heavy fishing was creating the reduction
of striper populations in the Santee-Cooper lakes.
The striped bass are caught so fast and in such large numbers that few of
the fish live long enough to reproduce. DNR
studies have shown that 80% of the Lake Marion and Moultrie female stripers are
caught before they reach spawning size. This
reduction of egg-laying females and other factors has caused the drastic decline
in the striper population in the two reservoirs (Bulak, Wethey, and White III,
1995). It was stated by DNR
fisheries biologists that we have now have to stock more than two million
hatchery-reared fish into the lakes each year to meet the demands of fishermen.
This may suggest that the 18 inch minimum size limit needs to be changed,
or lower the daily creel limit to ease the fishing pressure (South
Carolina Wildlife Roundtable, M-J, 1993). Miller
White, District Fisheries Biologist for DNR, is now tagging striped bass in the
Santee-Cooper lakes to get a better understanding of the factors influencing
striper populations. He feels that
the tagging study can produce valuable information about striper management.
Fishermen are asked to report the tagged stripers they catch.
For this study. DNR will even pay $20 for each tag reported (South Carolina Wildlife Roundtable, J-A, 1997).
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