WETLANDS, Vol. 3, 1983, pp. 77-89

TRE IMPORTANCE OF OLIGO}iALINE ESTUARINE WETLAND HABITATS TO FISHERIES RESOURCES

Lawrence P. Rozas I and Courtney T. Hackney 2

1 Department of Envirom=ental Sciences, University of Virginia, Charlottesville, Virginia, 22903

2 Department of Biological Sciences, University of North Carolina at Wilmington, Wilmington, North Carolina~ 28406

Oligohaline estuarine wetlands are found at the upper reaches of most estuaries. These wetlands are composed of several habitat types including tidal marshes, tidal creeks, and open-water areas. Twenty-five species of fish representing I! families and three species of invertebrates were identified as economically important and abundant in oligohaline habitats along the northern Gulf and southeastern Atlantic coasts. These include anadromous and catadromous species which use low salinity habitats as migratory corridors and freshwater, estuarine and marine organisms which use these habitats as nursery and feeding areas. The few comparative data available suggest that some oligohaline wetland habitats may be of equal importance to higher salinity marshes for at least two important estuarine species (spot and Atlantic menhaden). Until detailed studies are available for Specific estuaries, oligohaline habitats should be considered as valuable as salt marsh habitats. The value of these habitats as nursery areas should be considered by managers and regulatory agencies when reviewing proposals to modify them.

INTRODUCTION

Estuaries along the Atlantic and Gulf coasts of the United States are important nursery areas for many valuable recreational and commercial species (McHugh 1966; Gunter 1967). Subrahmanyam and Drake (1975), Cain and Dean (1976)~ Shenker sad Dean (1979), Weinstein (1979), and Bozeman and Dean (1980) have shown that the marshes and tidal creeks located in the lower and middle reaches of estuaries are primary nursery habitats for these species.

All of these studies, however, were conducted in saline and mesohaline marshes where salinity was usually greater than 5.0 o/oo. Until recently oligohaline areas (0.5-5.0 o/oo) have been neglected and little quantitative data concerning these systems exists (Hackney and de la Cruz 1981; Rozas and Hackney 1984). Consequently, management and regulatory decisions concerning oligohaline habitats must be made with little scientific information. This paper represents an assessment of the value of oligohaline habitats to Gulf and Atlantic Fisheries.

OLIGOHALINE ESTUARINE WETLANDS

Oligohaline estuarine wetlands are found at the upper reaches of most estuaries on the southeastern Atlantic and Gulf coasts. These wetlands include tidal marshes, tidal creeks, and open-water habitats (e.g. ponds,

77

78 WETLANDS, Vol. 3, 1983

lakes, bays, etc.). Oligohaline systems are best developed along the Gulf coast in the vicinity of the Mississippi River. There are more than 250,000 ha of oligohaline marshes in Louisiana alone (Chabreck and Linscombe 1982).

INHABITANTS OF THE OLIGOHALINE ZONE

The oligohaline zone is an area of complex physical, chemical and biological flux (Morris etal., 197~. Because river discharge fluctuates, the salinity of this region of the estuary may be within the oligohaline range only seasonally. Freshwater conditions usually prevail during the winter-spring period of maximum river discharge and salinities greater than 5.0 o/oo are not uncommon during the summer-fall period of minimum discharge (Rozas 1982; Rogers et al., 1984; Rozas and Hackney 1984).

Only organisms that possess some type of hyperosmotic regulation can survive these conditions (Zhlebovitch 1%9). Consequently, most faunal taxa are poorly represented in this region of the estuary (Remane and Schlieper l~l). Nonetheless, s number of species of fishes and macrofaunal crustaceans frequent these low salinity habitats.

Table l lists the species that regularly use oligohaline habitats during at least part of their life cycle. These data were compiled from studies conducted in oligohaline areas from Chesapeake Bay on the Atlantic coast to the northwestern Gulf of Mexico. Species collected only rarely were not included.

ECONOMIC IMPORTANCE

A large number of species inhabiting the oligohaline zone of estuaries support economically important sport and commercial fisheries along the Gulf and Atlantic coasts. The degree to which these organisms use oligohaline habitats varies considerably. Some species simply pass through oligohaline areas during migration (anadromous and catadr0mous species) while others (some freshwater and estuarine species) inhabit these areas during a portion or all of their life cycles.

~ and ~ S n e c i e s . Anadromous and ca tadromous s p e c i e s must n e g o t i a t e the o l i g o h a l i n e zone d ~ r i u g t h e i r j o u r n e y to freshwater or oceanic spawning grounds. Some of these species use habitats in this part of the estuary in other ways as well. Several anadromous species (blueback herring, Alosa aestivalis| hickory shad, Alosa mediocris; alewife, Alosa ~ A ~ ~ ; American shad, Alosa~h~; and striped bass, M o r o n e ~ use low salinity habitats as nursery areas (Davis and Cheek 1966; Dahlberg 1972; Lippson 1973; Lippaon et al., 1979). Striped bass spawn and feed there also (Lippson 1973; Boy=ton etal., 1981; McHugh 1981; Setzler-Mamilton et al., 1981). The American eel (An~uil]A

is the only catadromous species in North America that uses oligohaline habitats as feeding and nursery areas (Dahlberg 1972; Lippson 1973).

Freshwater SDecies. A number of freshwater fishes can tolerate the low salinity waters of the oligohaline zone. Most of the economically important species that inhabit this region of the estuary belong to two families (Ictaluridae and Centrarchidae). The white catfish (Ictaluru~ catus) on t he Atlantic coast and the blue catfish ( i f ~ fureatus) on the Gulf coast utilize the oligohaline zone as a nursery when young and as

Rozas and

Table I,

Hackney, FISHERIES RESOURCES OF OLIGOHALINE WETLANDS 29

A partial list of the major fish and macrofaunal crustacean species collected in oligohaline habitats along the Gulf and Atlantic coasts. The source and habitat type is given for each species as follows: Gulf coast-(1) Guntex and Shell 1958 (bay and lake), (2) Rounsefell 1964 (tidal rivers and lake), (3) Hernandez 1976 (lake)j (4) Hackney and de la CrBz 1981 (tidal creek); Atlantic coast-(5) Raney and Massmann 1953 (tidal river), (6) Taeatz and Dudley 1961 (tidal river), (7) Dahlberg 1972 [tidal river), (8) Markle 1975 (tidal river), (9) Rozas 1982 (tidal creek and intertidal creeks). Species collected only rarely in a single study are not included.

Family and Species Source and Habitat Type

Fishes Lepisosteidae

L ~ h i ~ ~ (Winchell) osseus (Linnaeus)

Elopidae ~192.1~ Linnaeus

Anguillidae An~uilla rnstrata (Lesueur)

Ophichthidae ~ y ~ i ~ ~ L ~ t k e n

Clupeidae Alosa~.2d~ (Mitchill) Alosa ~ (Mitchill) Alosa ~ (Wilson) Alosa ~ (Wilson) Krmvoortia ~ Goode ~ 2 . . v . ~ (Latrobe) ~ ~ (Lesueur) ] ~ ~ . / . ~ (G~nther)

Engraulidae ~ ~ (Valenciennes)

Esocidae Esox B/~ Lesueur

Synodontidae ~ / ~ [Linnaeus)

Cyprinidae Cvurinus cazpio Linnaeus i ~ J _ ~ ~ A g a s s i z

crvsoleucas (Mitchill) NotroDis ~ (Girard) Notrouis hudsonius (Clinton)

cornoralis (Mitchill) Catostomidae

~ ~ (Mitcbill) Ictaluridae

~ f ~ (Linnaeus) furcatus (Lesueur)

Ictalnrus ~ (Lesueur) ~uunctatus (Rafinesque)

l, 3, 4 5, 7,, 9*, 0

1, 3, 6

4, 5, 6, 7, 0

7, 9*

5, 6", 7, 9, 0 5, 7, 0 5, 0 5, 6, 7, 0 I*, 3", 4* 5, 6", 7, 9", 0 3, 5, 7, 9, 0 I*, 2, 3, 0

I*, 3*, 4*, 5, 6*, 7*,

5, 0

2, 4, 7

3, 0 5, 0 3, 5, 7, 9, 0 5,0 5, 0 5, 0

5, 7*. 8", 9, 0 i*, 2", 3 5, 0 3, 4, 5, 8, 0

8", 9*, 0

80 WETLANDS. Vol. 3. 1983

Table I (Continued).

Family and Species Source and Habitat Type

Noturus g ~ ( M i t c h i l l ) 5, 7 A r i i d a e

Ariua f e l l s (Linnaeus) 1, 2, 3, 4 Ba~re marinus (Mitchill) I. 2. 3

Belonidse ~ marina (Nalbaum) 3. 4. 6. 9. 0

Cyprinodontidae Adiniaz~ (Jordan and Gilbert) 4 ~hV.l~XaXig~ Lacep~de 2*. 3. 6. 0 Fundulus chrvsotus (G~nther) 4,. 7. 0 Fundulun ~ G o o d e and Bean 3 ~ ~ (Lesueur) 5, 0 Fundulus ~randis Baird and Girard 2,, 3, 4,

heteroclitus (Linnaeus) 5, 6, 7", 9*, 0 Fundulus luciae (Baird) 9, 0 Fd~B~LIg/~ (Walbaum) 0 I~~aXXA (Baird) 1, 4", 0

Poeciliidae ~ ~ (Baird and Girard) ~ / d ~ (Lesueur)

Atherinidae Membras~ (Valenciennes) ~i~dti~~ (Cope) Menidia~ (Linnaeus)

Syngnathidae ~ fuscus Storer 7. 0 ~ / M L ~ ~ S ~ n t h e r 4. 7

Percichthyidae Morone ~ (Gmelin) 5. 6. 8,. 0 Moronemissi~sippiensis Jordan and Eigeranaun i, 3 ~ ~ (Walbaum) 5. 8,. 9. 0

Centrarchidae ~ J t ~ L h & ~ ~ (Holbrook) 5 ~ a u r i t u s (Linnaeus) 5, 7 1 ~ ~ (Linnaeus) 5, 9*, 0 L ~ m a r ~ gafinesque 3, 4". 5. 7", 0 l ~ J ~ i K ; ~ (Gunther) 4 Microuterus ~ (Lacep~de) i. 4,. 5. 7. 9. 0 Po~xis ~ (Lesueur) 3. 5, 9, 0

Percidae ~ olmbte~ Storer 5, 0 Pezca ~ (Mitchill) 5. 9. 0

Pomatomidae Po~tomus ~ (Linnaeus) 9. 0

Carangidae Oli~ovlites saurus (Schneider) 4. 6

Gerreidae ~ ~ULE~ Baird 7, 9

Sparidae ~ (Walbaum) 2. 4

~ g h ~ (Linnaeus) 2*. 6. 9

I. 3, 5. 6. 7*. 9". O 3.6. 8

1, 3, 4*, 6 , 0 1", 3 , 5. 6*, 7", 9*, 0 5, 6" , 0

Rozas and Hackney, FISHERIES RESOURCES OF OLIGOHALINE WETLANDS

Table i (Continued).

81

Family and Species Source and Habitat Type

Sciaenidae ADlodinotus ~ Rafinesque Bairdlella chrvsoura (Lscep~de) Cvnoscion~ Ginsburg

nebulosus (Cuvier) ~ ~ = g ~ (Bloch amd Schneider)

xanthnrus Lacep~de

MicroDo~onias undulatus (Linnaeus)

Sciaenovs ~ (Linnaeus) Mugilidae

~i/_@.~111~ Linnaeus ~u~il curema Valenciennes

Polynemidae Polvdactvlus octone~s (Girard)

Eleotzidae ~ ; ~ (Bloch)

nisonis (Gmelin) Gobiidae

Ivricus (Girard) ~ hast~tus Girard Gobionellus ~ (Jordan and Eigenmann)

bosci (eacep~de) Bothidae

s~ilopterus Gfinther dentatus (Linnaeus)

Faralichthvs ~ Jordan and Gilbert Pleuronectidae

Pseudo©leuronectes ~ (Walbaum) So[eidae

Achirus ~ (Linnaeus) Irinectes maculatus (Bloch and Schneider)

Cynoglossidae ~ R ~ (Linnaeus)

CrllstacBans Palaemonidae

~ ohione (Smith) Du2io Holthuis

Penseidae Penaeus aztecus Ires Penaeus ~ (Linnaeus)

Portunidae saDidus Rathbun

Xanthidae ~ ~ (Gould)

i, 3 2, 3, 6, 7, 8, 9, 0 1-, 3*, 4 4, 0 5, 8-, 0 i, 2, 3.. 4, 5, 6-, 7-, B, 9", 0 I*, 2*, 3*, 5, 6", 7, 8". 9*, 0 3, 6

l , 2", 3", 4*, 6", 7*, 9, 0 6"

i, 2, 3

9* 6, 9

4-, 9 2, 9 3, 9* 2*, 3, 4*, 5, 6, 7, 0

1, 2, 3, 7 5, 0 2., 3, 6, 7*, 9*

2-, 4 I*, 2., 3., 5, 6, 7*, 8", 0

2, 7

I*, 3 I*, 3, 4-, 7*, 9*

I*, 2*, 3-, 4, 7 i*, 2*, 3*, 7

I*, 2*, 3*, 4*, 7, 9*

3, 4., 7, 9

* = reported as abundant or regularly collected at least during one season.

0 = listed by Lippson et al. (1979) as occurring in oligohaline habitats of the Potomac Estuary.

82 WETLANDS, Vol. 3, 1983

a feeding area as adults (Rounsefell 1964; Dahlberg 1972; Conner and Truesdale i~3; Lippson 1973). Low salinity habitats are used similarly by channel catfish (Ictalurus ounctstus) along b o t h coasts (Conner and Truesdale i~3; Lippson 1973; Lippson etal., 1979; Hackney and de la Cruz 19m).

Centrarchids may dominate some oligohaline communities during certain times of the year (Merriner etal., 1976; Hackney and de la Cruz 1981). Young centrarchids (pumpkinseed, ~ ~ibbosus; bluegill, ~ ; and largemoutb bass, MicroDterus ~ ) use low salinity habitats as nursery areas and adults use these habitats for feeding (Dahlberg 1972; Hackney and de la Cruz 1981; Rozas and Hackney 1984). Bluegill and largemouth bass may spawn and produce viable young in such areas (Tebo and McCoy 1964; Hackney and de la Cruz 1981).

White perch {Morons ~ and yellow perch (Perca flavescens) use oligohaline habitats as nursery areas and as feeding areas as adults (Mansueti 1960; 1961). In addition, white perch sometimes spawn in these habitats (Mansueti 1961).

~@rine/Estuarine Sgecies. Marine/estuarine species numerically dominate the fauna in the oligobaline region of the estuary (Gunter 1956). Most species in this category enter the estuary as larva and postlarva and use estuarine habitats as nursery areas. These are among the most economically important species.

The Gulf menhaden (Brevoortia patrouus) is one of the most abundant species in low salinity habitats along the Gulf coast (Gunter and Shell 1958; Rounsefell 1964; Conner and Truesdale 1973; Hernandez 1976; Hackney and de la Cruz 1981). Likewise, the Atlantic menhaden (~revoortia f ~ ) comprises a large proportion of the fishes collected in low salinity habitats along the Atlantic coast (Tagatz and Dudley 1961; Lewis et al., 1972; Rogers etal., 1984; Rozas and Hackney 1984). Besides providing important nursery habitat for menhaden, the oligohaline zone may be essential for their development into juveniles (Wilkens and Lewis 1971).

The family Sciaenidae is one of the most economically important families of marine/estuarine fishes, and several members of this family are abundant in low salinity habitats. The sand seatrout ( ~ ~ K ~ ) on the Gulf coast and the weakfish ( ~ ~ on the Atlantic coast use nursery areas in the oligohaline zone (Gunter and Shell 1958; Conner and Truesdale 1973; Lippson 1973; Hernandez 1976; Markle 1976; Lippson etal., 1979). Unlike the sand seatrout, the weakfish is apparently more abundant in the saline parts of the estuary (Dahlberg 1972; Markle 1976).

Atlantic croaker (Micropo~onias ~ and spot ( ~ xanth-rus) are the most abundant sciaenids in oligohaline habitats. Spot show a general increase in abundance relative to croaker from west to east along the northern Gulf coast and up the Atlantic coast to Chesapeake Bay (Nelson 1969i Lippson 1973; Weinstein 1979). Numerous studies along both coasts have shown that Atlantic croaker use low salinity habitats as nursery areas (Massmann 1954; Haven 1957; Gunter and Shell 1958; Tagatz and Dudley 1961; Rounsefell 1964; Hansen 1970; Conner and Truesdale 1973| Choa and Musick 1977; Miglarese et al., 1982). The distribution of young croakers in estuaries is such that a size gradation exists where the smallest individuals are found at the upper reaches (oligohaline areas) of

Rozas and Hackney, FISHERIES RESOURCES OF OLICO~LINE WETLANDS 83

estuaries and larger croaker at the lower reaches (Gunter 1957; Haven 1957; Miglarese et al., 1982). Numerous studies have documented the use of oligohaline habitats by juvenile spot (Massmann 1954; Tsgatz and Dudley 1961; Pacheco 1962; Rounsefell 1964; Hernandez 1976; Rozas and Hackney 1984). Massmann (1954) and Rogers et al. (1984) reported collecting spot in freshwater as well. Spot comprised almost 50 % of the total number of organisms collected from a North Carolina oligohaline marsh (Rozas and Hackney 1984).

The striped mullet ( ~ cephalus) uses the oligohaline zone as a nursery area along both coasts (Tagatz and Dudley 1961; Rounsefell 1964; Dahlberg 1972; Conner and Truesdale 1973). Rounsefell (1964) reported juvenile striped mullet as most abundant in waters of low salinty. Young- of-the-year bluefish (~_O.~/d~K~/Ka/~ use the shallow oligohaline nursery areas of upper Chesapeake Bay and its tributaries (Lippson 1973; Lippson et el., 1979) but were rarely collected in other studies of oligohaline habitats.

Three estuarine flounders (southern flounder, ~ ; summer flounder, ~ ~entatus; and winter flounder, Pseudonleuronectes ~ also use low salinity habitats as nursery areas. The southern flounder is a common species of oligohaline habitats along t h e northern Gulf and southeastern Atlantic coasts (Rounsefell 1964; Dahlberg 1972; Powell and Schwartz 1977) while summer and winter flounders use these habitats for nurseries in Chesapeake Bay (Lippson et el., 1979). In addition, winter flounder also spawn in oligohaline waters (Lippson 1973; Lippson et el., 1979).

Three economically important crustaceans (blue crab, ~ d ~ aapidus; white shrimp, Penaeus ~ ; and brown shrimp, Penaeua aztecus) are commonly collected in some oligohaline habitats (Gunter and Shell 1958; Dahlberg IW 2). Juvenile blue crabs grow rapidly in these nursery areas and adults, especially males, also feed there (Gunter and Shell 1958; Lippson 1973; Miller etal., 1975; Lippson etal., 1979; Rozss and Hackney 1984). Darnell (1959) reported that the smallest crabs tended to s e e k out the freshest and shallowest marginal areas in Lake Pontchartrain, Louisiana. Such behavior patterns result in juvenile blue crabs being most abundant in low salinity habitats (Rounsefell 1964; Tagatz 1968).

Juvenile penaeid shrimp use oligohaline areas as well but a r e apparently much more abundant in this habitat along the Gulf coast. Gunter et el. (1964) reported that postlarval and juvenile white shrimp (15 - 100 mm) were collected in greatest abundance along the Gulf coast in waters of lower salinity (0.5 - i0 o/oo). They found that postlarval and juvenile brown shrimp were most abundant in higher salinities (I0 - 30 o/oo) but still common in salinities below 5 o/oo. Rounsefell (1964) reported that white and brown shrimp were equally abundant in oligohaline habitats and higher salinity waters. Hernandez (1976) reported brown shrimp as the most abundant species and white shrimp seventh in abundance in a shallow oligohaline lake in Louisiana during summer. Dahlberg (1972) collected white shrimp and brown shrimp in a Georgia oligohaline creek but both species were absent in a North Carolina study (Rozas and Hackney 1984).

A total of 25 species representing ii families of fishes and three species of invertebrates were identified as economically important and abundant in oligohaline habitats along the northern Gulf and southeastern

84 WETLANDS, Vol. 3. 1983

Atlantic coasts (Table i). Many of these species are euryhaline and abundant in the more saline portions of the estuary as well. These species may be selecting nursery habitat in the estuary primarily on the basis of factors o t h e r than salinity (Gunter et al., 1964; Clark 1974; Rogers et el., 1984; Rozas and Rackney 1984). Those estuarine species that can tolerate low salinity environments are able to take advantage of the reduced competition, scarcity of predators and an abundant food supply within the oligohaline zone (Rozas and Hackney 1984).

MANAGEMENT OF OLIGOHALINE EABITATS

Few regulatory agencies have attributed as much economic importance to oligohaline marshes as has been given the better-studied salt marshes. In cases where both are considered equally valuable, little if any site- specific baseline data exists to support this ~ud~ement. Data are available, which we have documented above, that suggest the importance of oligohaline habitats in general.

The habitat value (i.e. providing nursery, feeding, and spawning areas) of oligohaline marshes relative to that of salt marshes cannot be fully assessed because few studies have approached the subject on a comparative basis. Many of the studies mentioned previously are difficult to compare because of the different collection techniques employed and the lack of quantitative sampling.

The large data base available for the Cape Fear River Estuary in North Carolina allows some general comparisons for two species (spot and ALlantic menhaden) based upon the area of tidal creeks in low and high salinity marshes. A comparison of the relative densities of these two species during peak recruitment at several locations in the estuary are illustrated by Table 2. Relative densities of spot and Atlantic menhaden

Table 2. Relative densities (mean number of individuals/400 m 2) for spot and Atlantic menhaden at the peak of recruitment in the Cape Fear River Estuary, N. C. Data for oligohaline stations (Stations I, 2 and 3) represent a v e r a g e s of three April 1982 collections (Rozas 1982). The average collection for each station was divided by the approximate area of the intertidal creek at which the station was located and then converted to individuals/400 m 2. Data for the higher salinity stations (Baldhead C r e e k , Shellbed Island, Dutchman Creek, and Walden Creek) are averages of two collections (March, April 1977) for spot and (April, May 1977) for Atlantic menhaden (Weinstein 1979).

Station Spot Atlantic menhaden

Station 1 5,1 82 12 Station 2 5,435 125 Station 3 2,469 695 Baldhead C~eek 1,7 81 II0 Shellbed Island 1,259 24 Dutchman Creek 3,474 373 Walden Creek 2,721 505

Rozas and Hackney, FISHERIES RESOURCES OF OLIGOHALINE WETLANDS 85

during April 1982 at the low salinity stations were comparable to those of the more saline stations reported by Weinstein (19Y9). Weinstein (1979) reported higher densities of Atlantic menhaden (3,821/400 m 2) at Hechtic Creek, a low salinity tidal creek in the upper estuary, than were reported for Stations 1, 2 and 3 (Rozas 1982). Atlantic menhaden may be more abundant in the larger tidal creeks like Hechtic Creek than in small intertidal creeks such as those sampled by Rozas (1982). Nevertheless, Atlantic menhaden were most abundant in the low salinity areas of the estuary. For spot and Atlantic menhaden at least, both habitats seem to be of numerically equal importance.

These two estuarine species support valuable fisheries along the Gulf and Atlantic coasts. Between 1970 and 1979 spot and Atlantic menhaden landings in North Carolina alone averaged almost 4 1/2 and 135 1/2 million pounds, respectively, and were worth $ 573,000 and $ 3,891,000 annually (Department of Commerce 1970-79).

Generalizations from area to area must be viewed with caution, as the many studies cited above found various species dominating essentially the same type of habitat from place to place. Some variations among samples are undoubtedly related to sampling times or collection techniques. Other variations may reflect real differences. For example, estuaries which have strong tidal influences might be more likely to transport postlarvae into oligohaline habitats located in the upper reaches of the estuary.

Based upon the available data, assumptions of low economic importance for oligohaline marshes and streams are unjustified. Detailed studies must be made during the season of larval abundance to determine relative value. Caution should be used with such data because annual variations might be large and vary with spawning success and general condition of the estuary.

CONCLUSIONS

Available studies document the value of oligohaline habitats to many commercially valuable fish and invertebrate species. The few comparable data available suggest that some oligohaline habitats may be of equal importance to higher salinity habitats for at least two commercially important species. Until detailed studies are available for a particular area, oligohaline marshes and stream habitats should be considered as valuable as the protected salt marsh habitats. The value of these habitats as nursery areas should be considered by managers and regulatory agencies when reviewing proposals to alter them.

LITERATURE CITED

Boynton, W. R,, T. T. Polgar, and H. H. Zion. 1981. Importance of juvenile ~triped bass food habits in the Potomac Estuary. Transactions of the American Fisheries Society 110:56-63.

Bozeman, E. L., Jr. and J. M. Dean. 1980. The abundance o f estuariue larval and juvenile fish in a South Carolina intertidal creek. Estuaries 3:89~97.

Cain, R. L. and J. M. Dean. 1976. Annual occurrence, abundance and diversity of fish in a South Carolina intertidal creek. Marine Biology 36:369-379.

86 WETLANDS, Vo]. 3, 1983

Chabreck, R. H. and R. G. Linscombe. 1982. Changes in vegetative types in Louisiana coastal marshes over a 10-year period. Proceedings of the Louisiana Academy of Sciences 45:98-102.

Choa, L. N. and J. A. Musick, 1977. Life history, feeding habits and functional morphology of juvenile sciaenid fishes in the York River estuary, Virginia. Fishery Bulletin 75:657-702.

Clark, S. H. 1974. A study of variation in trawl data collected in Everglades National Park, Florida. Transactions of the American Fisheries Society 103:777-785.

Conner, J. V. and F. M. Truesdale. 1973. Ecological implications of a freshwater impoundment in a low salinity marsh. Pages 259-276 in R. ~. Chabreck (ed.) Proceedings Coastal Marsh and Estuary Symposium. Louisiana State Univ., Baton Rouge, LA.

Dahlberg, M. D. 1972. An ecological study of Georgia coastal fishes. Fishery Bulletin 70:323-353.

Darnell, R. M. 1959. Studies of the life history of the blue crab ( ~ j~pj~ Rathbun) in Louisiana waters. Transactions of the American Fisheries Society 88:294-304.

Davis, J. R. and R. B. Cheek. 1966. Distribution, food habits and growth of young clupeids, Cape Fear River system, North Carolina. Proceedings of Twentieth Annual Conference Southeast Association of Game Fish Commissioners 20:250-260.

Department of Commerce. 1970-79. North Carolina Landings. National Marine Fisheries Service, Washington, D. C.

Gunter, G. 1956. A revised list of euryhaline fishes of North and Middle America. American Midland Naturalist 56:345-354.

Gunter, G. 1957. Predominance of the young among marine fishes found in fresh water. Copeia 1957:13-16.

Gunter, G. 1967. Some relationships of estuaries to the fisheries of the Gulf of Mexco. Pages 621-638 in G. H. Lauf (ed.) Estuaries. American Association for the Advancement of Science, Washington, D. C.

Gunter, G., J. Y. Christmas, and R. Killebrew. 1964. Some relations of salinity to population distributions of motile estuarine organisms, with special reference to penaeid shrimp. Ecology 45:181-185.

Gunter, G. and W. E. Shell, Jr. 1958. A study of an estuarine area with water-level control in the Louisiana marsh. Proceedings of the Louisiana Academy of Sciences 21:5-34.

Hackney, C. T. and A. A. de la Cruz. 1981. Some notes on the macrofauna of an oligohaline tidal creek in Mississippi. Bulletin of Marine Science 31:6 58-861.

Rozas and P~qckney, FISHERIES RESOURCES OF OLICOHALINE WETLANDS 87

Hansen, D. J. 1970. Food, growth, migration, reproduction, and abundance of pinfish, ~ / ~ , and Atlantic croaker, Micropo~_on / ~ , near Pensacola, Florida, 1963-65. Fishery Bulletin 68:135- 146.

Haven, D. S. 1957. Distribution, growth and availability of juvenile croaker, ~igropogon ~ndulatus, in Virginia. Ecology 38:88-97.

~ernandez, M. E. (Project director). 1976. Environmental study of Lake Peigneur, a tidal lake. National Science Foundation Grant No. 76-07972. Univ. of Southwestern Louisiana, Lafayette, LA. 284 p.

Khlebovitch, V. V. 1969. Aspects of animal evolution related to critical salinity and internal state. Marine Biology 2:338-345.

Lewis, R. M., E. P, H. Wilkens, and H. R. Gordy. 1972. A description of young Atlantic menhaden, ~ J ~ , in the White Oak River estuary, North Carolina. Fishery Bulletin 70:115-118.

Lippson, ~ J. 1973. The Chesapeake Bay in Maryland: An atlas of natural resources. John Hopkins University Press, Baltimore, Maryland. 55 p.

Lippaon, A. J., M. S. B aire, A. F. Holland, F. Jacsbs, J. Jensen, R. L. Moran-Johnson, T. T. Polgar, and W. A. Richkua. |979° Environmental atlas of the Potomac Estuary. Martin Marietta Corporation, Baltimore, Maryland. 280 p.

Mansueti, R. l~0. Comparison of the movements of stocked and resident yellow perch, Perca ~ , in tributaries of Chesapeake Bay, Maryland. Chesapeake Science 1:21-35.

Mansueti, R. 1961. Movements, reproduction, and mortality of the white perch, Roccus ~ , in the Patuxent estuary, Maryland. Chesapeake Science 2:142-205.

Markle, D. F. 1976. The seasonality of availability and movements of fishes in the channel of the York River, Virginia. Chesapeake Science 17 : 50-55.

Massmann, W. H. 1954. Marine fishes in fresh and brackish waters of Virginia rivers. Ecology 35:75-78.

McHngh, $. L. 1966. Management of estuarine fisheries. Pages 133-1 54 in A Symposium on Estuarine Fisheries, American Fisheries Society, Special Publication 3.

MeHugh, J. L. 1981. Marine fishes of Delaware. Fishery Bulletin 79:575- 599 •

Merriner, J. V., W. H. Kriete, and G. C. Grant. 1976. Seasonality, abundance and diversity of fishes in the Piankstank River, Virginia (1970-1971). Chesapeake Science 17:238-245,

Miglarese, J. V., C. W. McMillan, and M. R. Shealy, Jr. 1982. Seasonal abundance of Atlantic croaker (Micropo~onias undulatus) in relation to bottom salinity and temperature in South Carolina estuaries. Estuaries 5:216-223.

88 WETLANDS, Sol. 3, 1983

Miller, R. E., S. D. Sulkin, and R. L. Lippson. 1975. Composition and seasonal abundance of the blue crab, ~ ~ Rathbun, in the Chesapeake and Delaware Canal and adjacent waters. Chesapeake Science 16:27-31.

Morris, A. W., R. C. Mantoura, A. J. Bale, and R. J. M. liowland. 1978. Very low salinity regions of estuaries: important sites for chemical and biological reactions. Nature 274:678-680.

Nelson, W. R. 1969. Studies on the croaker, ~ Linnaeus. and the spot, I ~ ~ Lacepede, in Mobile Bay, Alabama. Journal of Marine Science Alabama 1:4-92.

Pacheco, A. L. 1962. Age and growth of spot in lower Chesapeake Bay, with notes on distribution and abundanne of juveniles in the York River system, Chesapeake Science 3:18-28.

Powell, A, B, and F. J. Schwartz. I~7. Distribution of paralichthid £1ounders (Bothidae: Paralichthys) in North Carolina Estuaries. Chesapeake Science 18:334-339.

Raney, E. C. and W. H. Massmann. 1953. The fishes of the tidewater section of the Pamunkey River, Virginia. Journal of the Washington Academy of Science 43:424-432.

Remane, ~ and C. Schlieper. 1971. Biology of Brackish Water. John Wiley and Sons, New York. 372 p.

Rogers, S. G., T. E. Targett, and S. B. Van Sant. 1984. Fish-nursery use in Georgia salt marsh estuaries: the influence of springtime freshwater conditions. Transactions of the American Fisheries Society 113:595-606.

Rounsefell, G.A. 1964. Preconstruction study of the fisheries of ~he e s t u a r i n e a r e a s t r a v e r s e d by the M i s s i s s i p p i R ive r -Gu l f Ou t l e t P r o j e c t . F i she ry B u l l e t i n 63:373-393.

Rozas, L. P. 1982. Utilization of oligohaline intertidal rivulets by fishes and macrofaunal crustaceans in the Cape Fear River Estuary, North Carolina. M. S. Thesis. Univ. of North Carolina at WilminBton, Wilmington, NC. 74 p.

Rozas, L. P. and C. T. Hackney. 1984. Use of oligohaline marshes by fishes and macrofaunal crustaceans in North Carolina. Estuaries 7:213- 224.

Setzler-Hamilton, E. M., W. R. Boynton, J. A. Milhursky, T. T. Polgar, and K. V. Wood. 1981. Spatial and temporal distribution of striped bass eggs, larvae and juveniles in the Potomac Estuary. Transactions of the American Fisheries Society 110:121-136.

Shenker, J. M. and J. M. Dean. 1979. The utilization of an intertidal salt marsh creek by larval and juvenile fishes: abundance, diversity and temporal variation. Estuaries 2:154-163.

Subrahmanyam, C. B. and S. H. Drake. 1975. Studies on the animal communities in two north Florida salt marshes: I. Fish commu~ities. Bulletin of Marine Science 25:445-465.

Rozas and Hackney, FISHERIES RESOURCES OF OLIGOEALINE WETLANDS 89

Tagatz, M. E. i~8. Biology of the blue crab, ~ ~ Rathbun. in the St. Johns River, Florida. Fishery Bulletin 67:17-33.

Tagatz, M. E. and D. L. Dudley. 1961. Seasonal occurrence of marine fishes in four shore habitats near Beaufort, N. C., 1957-1960. U.S. Fish and Wildlife Service, Special Scientific Reports, Fisheries 390, 19 p.

Tebo, L. B,, Jr. and E. G. McCoy. 1964. Effect of sea-water concentrations on the reproduction and survival of largemouth bass and bluegills. Progressive Fish-Culturist 26:99-106.

Weinstein, M.P. 1979. Shallow marsh habitats as primary nurseries for fishes and shellfish, Cape Fear River, North Carolina. Fishery Bulletin 77:33 9-3 57.

Wilkens, E. P, l{. and R. M. Lewis. 1971. Abundance and distribution of young Atlantic menhaden, BrevDorti~ ~ , in the White Oak River e s t u a r y , Nor th Caro l ina . F i she ry B u l l e t i n 69:783-790.