Looking into the future the Pelican feeding its young from a self-induced wound in its own breast (as depicted, mysteriously, on the state flag of Louisiana) is accepted as an appropriate symbol of both self-sacrifice and rebirth. Through his selfless efforts, man is raised from the slavery of ignorance to the condition of freedom conferred by wisdom. Given the current state of affairs in Louisiana, one hopes that the understanding of the Pelican as a symbol shall point the way towards a new consciousness of ourselves as a whole, and lead us to face our futures with strength, grace, wisdom and faith, to learn from our mistakes and carry our successes and zest for living to future generations.

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Food and Habitat of Gar Fish in the Tide Water of Southeastern Louisiana

A Thesis Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Master of Science in Game Management in the School of Forestry

By Victor William Lambou
B.S., Louisiana State University, 1951
August 1952

Acknowledgement

For this study, the author wishes to express his appreciation and gratitude to those without whose help it would have been impossible. To Professors Bryant A. Bateman and Leslie L. Glasgow, of the Louisiana State University School of Forestry, for their direction and guidance, he is deeply indebted. He is grateful to Mr. Louis Lambou for the generous use of his camp during study period. The use of the facilities of Mr. Morris Gladys’s camp at Howze Beach and the companionship of his son, Junior, on many collecting trips is appreciated. He thanks Mr. Merlin Remmens of Johnny Lynch’s Sporting Goods Store for the use of the bass contest data. The encouragement of Miss Lorraine Granier was helpful. Special thanks is given to the writer’s mother, Mrs. Regina Lambou, for her encouragement and help which made this manuscript possible.

Abstract

A study was made to determine the nature and importance of predation by gars in brackish water. The study area, known as the Howze Beach Section, is in St. Tammany Parish, Louisiana, along the northeastern shore of Lake Pontchartrain. The food of gars was determined by the examination of the stomachs of 54 alligator gars (Lepisosteus spatula), the stomachs of 42 spotted gars (Lepisosteus productus) and one longnose gar (Lepisosteus platostomus). To determine the competition for food between gars and yellow bass (Morone interupta) and largemouth black bass (Micropterus salmoides), 273 yellow bass stomachs, and 93 largemouth bass stomachs were examined. The most important food species in the area are as follows:

1. alligator gar-blue crabs (Callinectes sapidus);
2. spotted gar-blue crabs and fish;
3. yellow bass-white shrimp and blue crabs;
4. largemouth black bass-blue crabs and shrimp.

Introduction

Fishing, in the United States, is one of our largest and most popular sports. Carhart (1947) estimated that there were twenty-four million hunting and fishing licenses sold in 1947. Fishing success, however, has steadily declined in inland waters since 1900 (Bennett, 1947:276). In order to alleviate this downward trend there is a great need for research. Swingle (1950:5) states:

1. “The interrelationship between species, between groups of species and between groups within species, and the dynamics of their relationship in fish population must be understood if fisheries biologists are to manage effectively fisheries resources.”

The relationships of gars (Lepisosteus spp.) to other fishes and their dynamics in fish populations are very poorly understood. Gars are usually considered to be predatory fish. As pointed out by Lagler (1942:116), it is important to determine the nature and the extent of their predation and their effects on fish populations. Lagler (1944:217) states:

1. “If the predaceous fish are non-game kind (such as gar and bowfin) their benefits seem more remote than if they were game fish but may still exist.”

Bennett (1947:281) believes that the loss of natural predators in bodies of water often leads to a decline in fishing resulting from overpopulation and stunting. In order to determine the importance of their predation, the food habits of gars must be known. Very little information has been recorded on the food habits of these fish (Lagler, Obrecht and Horry, 1942:118).

Jordan (1905) states that alligator gars (Lepisosteus spatula) are scavengers and compete with sharks for garbage at the wharves in Pensacola, Florida. Viosca (as reported by Weed, 1923:9) thinks that they are almost strictly a scavenger, will never seize a bait which is moving, and do not take a quiet bait unless it has a strong odor. Large numbers of alligator gars are reported (Wolf, 1951) to gather in Pass Manchao, in southeastern Louisiana, to feed on the refuse from commercial fish houses. However, Gowanloch (1940:20) reports:

1. “It was found, contrary to popular opinion, that gars (all four species) are scavengers; they are not so but are alert, stealthy, efficient killers of living fish and crabs and other useful aquatic life.”
2. He further reports (Gowanloch:1940:359) that gars subsist chiefly on game and food fish, and when in brackish or salt water, on considerable quantities of blue crab (Callineotes sopidus).

Weed (1923:10) believes that gars are scavengers when garbage is present, but in other places eat whatever is available. Bonham (1940:357) found that only three out of 21 alligator gars, examined in Texas, contained food. He explained that this was probably due to the long period of time the fish were present in the nets, and the possibility that some food was lost by regurgitation (a common occurrence with the species, according to commercial netters). The food of these Texas gars consisted of plankton, an eel, a buffalo fish, and a freshwater drum.

Raney (1942:50) believes that gars might be important predators of ducks and other water birds. He found remains of large birds in four out of six alligator gars taken in a Texas coastal lake. O’Neil (1949:114) lists gars as a predator of muskrats in Louisiana, but states that little scientific data has been collected substantiating it as such.

According to Lagler (1942:122) this taxonomic separation of the spotted gar (Lepisosteus productus) from the shortnose gar (Lepisosteus platostomus) by Hubbs, in 1939, leaves a doubt as to which species were used in food habits studies previous to this date. Lagler, Obrecht and Horry report (1942:122) that the gars studied by Parker (1939), from Reelfoot Lake, Tennessee, were spotted gars. Parker found that 27 of 40 fish eaten by 15 gars were game species (sunfish, 16; largemouth bass, 1; bullhead, 1) Five fish were foreign species; two were Esox sp. and six were undetermined species. Bonham (1940:361) found that grayfish and gizzard shad were the most important food of 26 spotted gars from Texas. Small sunfish and minnows were next in importance, and freshwater shrimp was a common item of the diet. Lagler, Obrecht and Horry (1942:124) found that the most important food of this gar, based on 27 specimens, was forage fish. Game fish were second in importance. Crustacea and insects were of only minor importance.

A review of the literature shows that the longnose gar (Lepisosteus osseus) is essentially piscivorus. Poarse (1918) found that the food of ten longnose gars, in Wisconsin, consisted of 86.8 percent fish, by volume, and 11.2 percent insects. Trembly (1929) reported that fish (mainly game species) made up almost 100 percent of the diet of 100 gars from Lake Champlain, New York. Bonham (1940:361) stated that small sunfish were the most important food of 191 longnose gars taken in lakes and streams of Texas. Lagler and Hubbs (1940:239) reported fish (especially game fish) were consumed most frequently in Michigan, while Frisby (1942) found that forage and game fish were the principal items of food of 26 longnose gars in Ohio.

Lagler (1942:120) reports that game fish and their forage organisms were the principal foods of 132 shortnose gars examined in Indiana. He believes that this gar is less piscivorous than the spotted gar or the longnose gar.

The Sub-delta Marshes of Louisiana consist of approximately 2,940,000 acres (O’Neil, 1949:20). Much of this is interlaced with numerous ponds, bayous, and canals. This is primarily a brackish water habitat. Gars are very numerous and fishermen often complain that they are eating all the game fish and consequently are ruining the fishing. In order to determine the true nature and importance of predation by gars, in this type of habitat, a food habit study was initiated by the writer. Other species besides gars were studied to determine the competition between them.

The area known as the Howze Beach Section was chosen for this study. It is believed that this area is typical of the brackish water, ponds, bayous, and canals of the Gulf Coast. Even though the ponds and canals of the Howze Beach Section were created by man and do not resemble the natural waterways in shape, biologically, they are the same.

DESCRIPTION OF THE AREA

Location

The study area, known as the Howze Beach Section, is located in St. Tammany Parish, along the northeastern shore of Lake Pontchartrain. St. Tammany Parish is situated in southeastern Louisiana and is bounded on the south by Lake Pontchartrain and on the east by the Pearl River.

The Howze Beach Section consists of a strip of land approximately two and one-half miles deep and four miles long, extending along the shore of Lake Pontchartrain. It is bounded by Highway 11 on the west, State Highway Number Two on the east, and pine woods on the north.

History

At one time Howze Beach was agricultural land. A system of canals was used to drain the land. Agriculture proved unprofitable and was abandoned, and the levees, which at one time prevented water from reentering from Lake Pontchartrain, have broken down and the area is flooded.

Topography

Howze Beach consists of a system of ponds and canals. The ponds vary in depth from a few inches to approximately five feet, but the majority are two or three feet deep. The canals are, for the most part, approximately six to eight feet deep. Areas of marsh are scattered throughout the area. The spoil banks, thrown up when the canals were dug, are several feet above water level in some places.

Hydrography

O‘Neil (1949) lists the area as Sub-delta Marsh which is subject to daily tidal movements. Penfound and Hathaway (1938:46) believe that the development of canals has brought about increased and abnormal fluctuation in water levels and salinity. This is probably true on the study area. Because of the system of canals, changes of water levels are often very rapid and extreme. ‘Neil (1949:2) gives eighteen inches as the variation between mean low and mean high tides of the Gulf Coastal regions, but says that water levels are more influenced by wind directions than by sun and moon positions. In the Lake Pontchartrain area, easterly winds bring in high water while westerly winds blow it out. Water level measurements were taken by the writer. A permanent mark was established on June 26, 1952, and all subsequent readings were taken in relation to it. Since the lowest reading was minus 30, while the highest was plus 13, there was a variation of 43 inches. However, this does not represent the maximum variation. Equatorial storm tides (O’Neil, 1949:2), ranging from two feet to four feet above mean tide level, generally occur two to three times annually, somewhere along the Louisiana coast. Such tides raise the water level considerably in the study section.

The fluctuation in salinity in the area is considerable. O’Neil (1949) describes the Howze Beach Area as a “brackish three-cornered grass marsh.” O‘Neil (1949:88) states that all “three-cornered grass marshes” on the Gulf Coast show an annual range in salinity from 2 percent to 50 percent seawater. (Salinities are commonly expressed in three different ways: percent seawater, percent salt, and parts per million. In this report, salinities are expressed as they were expressed by the author quoted. Seawater is often considered as having 3.5 percent salt content). Penfound and Hathaway (1938) found that Scirpus olneyi tolerated from 0.55 to 1.68 percent salt. O’Neil (1949:88), however, believed that the salinity of the marsh may be increased two to five percent above that of open water, due to evaporation of surface water during dry seasons. Therefore, the salinity range of the marsh proper does not necessarily correspond with the salinity range of open water. All of the “three-cornered marshes” (‘Neil, 1949:84) are adjacent to large bodies of water which act as mixing bowls for fresh and salt water. Lake Pontchartrain is such a mixing bowl. The salinity of water at Howze Beach is controlled primarily by the salinity of Lake Pontchartrain and to a lesser degree by rainfall. There is practically no drainage of fresh water into the study area. However, rain falling on the surface affects salinity somewhat. The salinity of Lake Pontchartrain is varied by the amount of fresh water poured into it by its effluents and by salt water from the Gulf of Mexico. Salinity in Lake Pontchartrain, before the opening of the spillway (Owen and Walter, 1950), in 1950, was found to be 2.0 percent. This determination was made at New Orleans Airport, on the south shore of the lake. Several water samples were taken in the study area and analyzed. Salinities ranged from 0.16 percent to 0.51 percent salt. It is probable that, in the course of the average year, the salinity of the water in the area ranges from almost zero to two percent salt, with the maximum exceeded for short periods during equatorial storm tides.

Weather

The region has an essentially semi-tropical and coastal climate due to its proximity to surrounding water. Temperature is approximately 69° Fahrenheit, with extreme lows ranging from 20° to 25° Fahrenheit and extreme highs from 100° to 102° Fahrenheit. The annual rainfall is approximately 60 inches and the average annual growing season for vegetation is approximately 300 days (weather information from O’Neil, 1944:2).

Vegetation

The vegetation of the area can be divided into two main classes: land and aquatic vegetation. The marsh is termed a “brackish three-cornered grass” type. This is dominated primarily by the climax species; cordgrass (Spartina patens). Coco (Scirpus robustus) and three-cornered grass (Scirpus olneyi) occupy areas that were probably barren and inundated by salt water. Patches of black rush (Juncus roemerianus) are present. Occasional specimens of saw grass (Oladium jamaicensis) are found at the northern part of the area, where the water is freshest. Narrow leaf cattail (Typha angustifolia) grown along the canal banks and edges of some of the canals and ponds. Roseau (Phragmites communis) is common on high ground and in small stands throughout the area. Bull tongue (Sagittaria lancifolia) and pickerelweed (Pontederia cordata) are seen occasionally along some of the canals and ponds.

The species of plants present on the spoils banks are numerous and varied. However, they are typical upland herbaceous and woody plants. Numerous aquatic species are present in the area. The most important of these are: coontail (Ceratophyllum domersum), southern naiad (Najas guadalupenas), wigeongrass (Ruppia martma), wild celery (Vallisneria spiralis), dwarf spice-rush (Eleocharis parvula), white waterlily (Castalia adorata), and alligator grass (Alternanthera philoxeroides). Coon-tail, southern naiad and wigeongrass are common in the ponds throughout the area. They are sometimes found in separate stands but are usually in a combination of the three.

Spike rushes, mostly dwarf spike rush, is very numerous in the shallow areas of ponds and on mud flats. It is present in the area where there is not much current and occurs in dense growths, appearing like grassy tuft when the shallow areas are exposed by low tides.

Animal Life

The area is very rich in its animal fauna. A complete list of the animal life was not possible in this study; therefore, only the most important or numerous species will be listed. For convenience, these can be divided into five general groups: amphibians, reptiles, birds, mammals, and aquatic animals.

Amphibians

The pig frog (Rana grylio) and tree frog (Hyla oinerea) are plentiful, especially among the cattails and waterlilies. Sportsmen occasionally hunt pig frogs at night with spot lights.

Reptiles

Water snakes (Natrix ssp.) and water moccasins (Agkristodon pisciverous) are numerous throughout the area. Alligators (Alligator mississippiensis) are present but are not very numerous.

Birds

The bird life is both abundant and varied. Table 3 lists those commonly encountered. Ducks and coots (Fulica americana) are important game species. Immense numbers of coots usually winter on the ponds. The most common ducks encountered are the mallard (Anas platythynchos), pintail (Anas acuta), gadwall (Anas strepera), mottled duck (Anas fulvigula), blue-winged teal (Anas discolor), green-winged teal (Anas carolinensis) and lesser scaup (Aythya affinis).

Table 3. Birds Commonly Encountered in the Study Area

Mammals

The most abundant mammals on the area are the muskrat (Ondetra zebethisa), marsh raccoon (Procyon lotor), mink (Mustela vison), and swamp rabbit (Sylvilagus aquaticus). Swamp rabbits are sometimes hunted by sportsmen, and often illegally spotted with a light at night.

Aquatic Animals

The aquatic fauna is very rich. It consists of both fresh and saltwater forms. Table 4 lists those commonly encountered; other species are present but are not numerous. All of the freshwater forms are year-round residents, but the blue crab is the only saltwater form, which occurs year-round.

The blue crab, although considered a saltwater species, will enter completely fresh water. The female, however, must return to saltwater to lay her eggs (Brown, 1950:447). The water is too fresh for this purpose at Howze Beach. Immense numbers of crabs of all sizes are present in the area. Small crabs, less than one and one-half inches long, are especially numerous and, at night, the water will often appear to be alive with them.

Large numbers of freshwater shrimp (Paleomoonetes exilipes) are present, especially along the aquatic vegetation. During summer and fall, white shrimp appear in abundance. Their appearance is erratic, however. One day an area may be swarming with them, and yet, on the next day, almost completely void of them. Large quantities are caught by fishermen using cast nets. Speckled trout (Cynosoion nebulosus), redfish (Soiaenops ocellata) and croakers (Macropogon undulates) often come into the area and fair catches of these species are sometimes made. Many other saltwater forms appear, but their occurrence is erratic and often rare.

From an angling standpoint, the freshwater forms are the most important. Most angling is done for three species: largemouth bass (Micropterus animoides), yellow bass (Morona interrupta), and red-eared sunfish (Lopomis microlophus). It is the belief of the writer that most of the man-hours of fishing in the area are spent for yellow bass. The fish is excellent eating, is very game, and is readily caught during all seasons of the year. Even though the limit, in Louisiana, is twenty-five, anglers often pay no attention to this restriction. On many occasions, the writer has witnessed fishermen with many times that number. Saltwater shrimp, both dead and alive, and living freshwater shrimp, are the principal baits used in catching them. Sometimes, however, they are caught on small, artificial lures. Most of the fish are from six to nine inches in total length. They reproduce themselves in large numbers and withstand heavy fishing pressure. However, they prefer deep water (canals) and do not range very far into the ponds.

Largemouth bass are very plentiful in the study area, in both ponds and canals. They are fished with both artificial lures and live bait. Large catches are made with artificial bait during the fall and winter months. Many fishermen angle for them during the summer with live shrimp.

Each year Johnny Lynch’s Sporting Goods Store, in New Orleans, sponsors a fishing contest, running from April to September, for largemouth black bass. Over a period of three years, 1949, 1950, and 1951, there were 904 fishermen registered in the contest, of which 355 were from New Orleans. The average brackish water fish entered in the contest weighed 5.04 pounds, and the average non-brackish water fish weighed 3.91 pounds. From this, it can be seen that brackish water fish averaged smaller than other types. During the period of the contest there were 57 fish entered, with only seven fish being caught in brackish water. It is the opinion of the writer that this type of habitat supports as much fishing pressure from the New Orleans area as do the other types of habitat combined. These data indicate that Howze Beach, and other similar bodies of water, for some unknown reason, even though they may produce large numbers of average sized bass, produce few large ones.

Largemouth black bass are very successful in reproducing in the area, a proven by the large numbers of adult fish occurring there. Also, the writer has, on many occasions, seen fingerling bass. According to Swingle (1949: 299), bass and bluegills will not spawn in water having a salinity of 0.5 percent or more. He further states that the minimum salinity is unknown. It is concluded from this, that bass, even though they cannot spawn, can exist in water of higher salt content. At least some of the time the salinity of the study area is lower than 0.5 percent. Whether this is usually true during the spawning season is not known. It is evident that the salinity is usually below the crucial point during the spawning season, or if this is not the case, the bass only need to spawn successfully at infrequent intervals, when conditions are right, to replenish their numbers, or that the race of bass present in such waters can successfully spawn when salinities are higher than 0.5 percent.

Red-eared sunfish find this brackish type of habitat very much to their liking. This is a very popular fish with the sportsmen. Extremely large catches are made during the late winter and spring months. This fish spawns heavily during the spring and fall (Swingle, 1940:299). It is probable that the huge catches made early in the season are from school congregated for spawning or on the spawning beds. During the summer, the schools seem to break up and the huge catches, such as are taken in the spring, are not duplicated.

The stumpknocker bream, (Lepomis punctatus) is extremely abundant. Because of its small size, however, this species is not very popular. The channel catfish (Ictalurus lacuctis) is fairly common, and even though not sought for by the sportsmen, many are caught while fishing for other species. The gizzard shad (Dorosoma cepodianum) is present, but not in any quantity.

Three species of gars are present: the alligator gar, the spotted gar, and longnose gar. The longnose gar is undoubtedly rare. Only one specimen was encountered during the study period. However, the alligator gar and spotted gar are very plentiful. There seems to be some difference in the type of water preferred by each species. Throughout the study period, the alligator gar was seldom encountered outside of the canals. It seemed to prefer deep and open waters. Even at night, very few alligator gars were seen along the shores. The spotted gar was found most often in shallow water, along the shore line. Except under exceptional circumstances, it was most abundant in shallow ponds. The night of August 9, 1951, was such an exception. The water level was minus 30 inches, and large areas of the ponds were without water. This seemed to have forced large numbers of spotted gars into the canals. Even here they kept along the shore line. The majority of spotted gars are under 30 inches in total length. On the night of August 9, while gigging gars, large numbers of small gars, less than twelve inches long, were noted. These were too small to gig. Undoubtedly the average size is less than that indicated by the measurement of those caught. The majority of the alligator gars were from 40 to 50 inches in total length. The only longnose gar encountered was 53 inches long.

Salinity is probably the most important factor determining the kinds of freshwater fish present in the area. During the study no bluegill (Lepomis macrochirus), black crappie (Pomoxie nigro-maculatus) or white crappie (Pomoxie annularis) were seen. Swingle (1949:299) states that bluegills and bass have failed to spawn in ponds having a salinity of 0.5 percent. The minimum salinity that prevents reproduction is unknown, but it is lower for the bluegills than for bass. If this is correct, then the salinity of the study area must be between that which prevents reproduction for bluegills and that which prevent reproduction for bass. It is possible that this is also the limiting factor for crappies. It is concluded that the spotted gar, yellow bas, largemouth black bass, red-eared sunfish and stumpknocker bream are the typical freshwater fish of this type of habitat, and that these species can withstand high and extreme variations in salinity.

Table 4. Aquatic Animals Commonly Encountered in the Study Area.

Human Population

The study region has a low resident population, mostly white. They rent boats, sell bait, fish, or trap for a livelihood. However, there are many sportsmen who visit the area to hunt or fish. Many of these are from New Orleans, while others are from Slidell and other small towns in the vicinity.

Summary

To determine the nature and importance of predation by gars in brackish water, a good habits study of gars, yellow bass and largemouth black bass was made in the Howze Beach Section, located in St. Tammany Parish. The region of study was a typical brackish water habitat with extreme and rapid variations in tide and salinity. Largemouth black bass, red-eared sunfish, stumpknocker bream, yellow bass, spotted gar, and alligator gar, are the typical freshwater fish of this habitat. The most important forage species in the area was found to be the blue crab. For each species, the most important foods were: alligator gar-blue crab; spotted gar-blue crab and fish; largemouth bass-blue crab; yellow bass-shrimp and blue crabs. It was found that gars do not feed very actively during the winter. There was competition for food between gars and largemouth black bass, and between gars and yellow bass. Spotted gars consumed numerous sunfish, which might be beneficial. It is assumed that there is no weight relationship between forage fish and largemouth black bass in this area, as this is based on a direct predator-prey relationship between carnivorous fish and forage fish. Largemouth black bass, in this area, preferred blue crabs and shrimp as food, in preference to fish. Yellow bass, even though of small size, were found to be carnivorous in nature.