subjected to sporadic or rapid 

 freshwater intrusions. 



DEFINITIONS AND TERMINOLOGIES 



While some would prefer to call 

 that area located between fresh and 

 saline waters, where two waters di- 

 lute each other, an estuary (Hedgpeth 

 1951; McHugh 1966; Lauf 1967; Prit- 

 chard 1967a), others designate it as 

 brackish waters (Dahl 1956; Kinne 

 1964; Caspers 1967). To others the 

 battle rages on in the search for an 

 adequate terminology that defines the 

 freshwater-saline interzone (McHugh 

 1967; Abbott and Dawson 1975; Schubel 

 and Hirschberg 1978). Some even 

 characterize this body of water by 

 inferring it is made up of monotonous 

 or abundant, mainly euryhaline marine 

 fishes (Hedgpeth 1957). I am like- 

 wise at a loss when referring to this 

 stratified euryhaline zone or habitat 

 which flood or freshwater runoff 

 waters convert into a purely fresh- 

 water habitat (Pritchard 1967a). Is 

 it simply an extension of the fresh- 

 water zone or should some new termi- 

 nology be applied to this temporary 

 zone, habitat, or condition? 



The unsettled definition of what 

 is fresh water (Gunter et al. 1974) 

 rages just as that of what is an 

 estuary. For many years fresh waters 

 were defined as those of 0.2 to 0.05 

 percent (Valikanges 1933; Dahl 1956) 

 even though an international attempt 

 was made to classify fresh water as 

 those of 0-0.5 ppt salinity (Sympo- 

 sium in Classification of Brackish 

 Waters 1958). Kinne (1964, 1967) 

 presented good overviews to the prob- 

 lem. Gunter et al. (1974) and Odum 

 (1953) presented excellent reviews of 

 the physiological and environmental 

 influences on estuarine fishes which 

 can be extended to what happens to a 

 fish which finds itself suddenly 

 "trapped" or subject to a runoff 



freshwater intrusion area of a stream 

 or river. I will not resolve, here- 

 in, the question of whether such 

 fishes should be referred to as eury- 

 haline, oligohaline or some other 

 designation (Gunter 1942, 1956; 

 McHugh 1964; Gunter et al. 1974) but 

 add to the list of known occurrences 

 of fresh water and marine fishes that 

 we know live in such waters, with 

 comments on their sizes, and possibly 

 interacting factors. 



METHODS 



The fishes encountered in the 

 runoff zone of the major rivers of 

 North Carolina were captured during 

 the past 12 years (1968-1980) by 

 various sized anchored gill nets and 

 8.0-13.5-m semiballoon otter trawls. 

 Gill net sets were usually for 24 hr 

 and trawl tows were for 0.25 to 0.5 

 hr duration. Specimens captured by 

 gill net, unless too damaged by crabs 

 or decayed by high summer water tem- 

 peratures, or otter trawl were pre- 

 served in the field in 10 percent 

 formalin for later study and/or in- 

 clusion in the fish collection at 

 the Institute of Marine Sciences, 

 Morehead City, North Carolina. 



Environmental variables of water 

 temperature, oxygen, current speed, 

 tide state, salinity were recorded by 

 Taylor temperature thermometers (°C) , 

 direct reading YSI oxygen (ppm)-tem- 

 perature probes, and A/0 ref Tacto- 

 meters for salinity in ppt. Fish 

 lengths were recorded as standard 

 lengths unless a total (tonguefish) 

 or fork length (sturgeon) was more 

 representative . 



DESCRIPTION OF NORTH CAROLINA 



RIVERS AND SOUNDS 



Schwartz and Chestnut (1973), 

 Williams et al. (1973), and Williams 



283 



