Journal of the Southeastern Association of Fish and Wildlife Agencies

Conservation of neotropical landbird migrants will be compromised if attention is not focused on habitat requirements during migration. Habitat use during migration has profound consequences for a bird's (1) ability to satisfy energetic requirements, (2) vulnerability to predators, and (3) exposure to environmental stress. Largely correlative evidence indicates that landbird migrants select among available habitats on the basis of factors intrinsic to the habitat, such as food availability, habitat structure, and cover in relation to predation risk. Management decisions would be simplified if species could be grouped for the purpose of assessing en route habitat requirements, but our study of habitat use among neotropical landbird migrants along the northern coast of the Gulf of Mexico points to species-specific patterns of habitat use.

Because bottomland forests of the lower Mississippi Alluvial Valley (MAV) are valuable as breeding, wintering, and en-route habitat during migration, we investigated the impact of changing land uses in the MAV on avian abundance and diversity at the local and continental scales. Checklist inventories from 5 studies conducted in the MAV during 1985-1992 confirmed that bird species that occur in the MAV represent a substantial proportion of the entire avifauna of eastern North America (ENA). Of 236 landbird species reported for ENA, 200 (85%) occur in the MAV; we recorded 149 landbird species (63%). The frequency distribution of population trends as determined from Breeding Bird Surveys (BBS) varied significantly among species according to migratory status, geographic area, and habitat. Neotropical migrant landbird (NTMB) and temperate species were much more likely to show population declines than increases in the MAV.

Catchability of American shad (Alosa sapidissima) from the Altamaha River, Georgia, was compared with population size of female adult spawners to determine if density-dependent fishing mortality was occurring in that fishery. Mark-recapture techniques and effort and harvest data were utilized to examine this relationship. An inverse power function described the relationship between fishing mortality per unit effort and female population size from 1982 to 1991. The relationship became slightly stronger by holding the flow variable constant. Therefore, shad populations in the Altamaha River are most vulnerable when weak spawning runs are subjected to commercial fishing pressure, and to a lesser extent, when low flows occur.

Cultured shortnose sturgeon juveniles, age 11-330 days, were exposed to different salinity (0-35 ppt) and dissolved oxygen concentrations (2.0-5.0 mg/liter) in a series of experiments designed to examine tolerance levels. Tolerance to increased salinity improved with age. Fish 76 days old experienced 100% mortality in a 96-hour test when exposed to salinities ≥15 ppt while 330-day-old fish tolerated salinities as high as 20 ppt for a duration of 18 hours but exhibited 100% mortality at 30 ppt. Younger fish were also more susceptible to low oxygen concentrations than older fish. In a 6-hour test, fish 64 days old exhibited 86% mortality when exposed to DO concentrations of 2.5 mg/liter. However, sturgeon >100 days old were able to tolerate concentrations of 2.5 mg/liter with <20% mortality.

During 1984-1992, 626 adult shortnose sturgeon (3.5 male:l female) were captured in the Savannah River. Significantly more fish were captured in the lower (rkm 42-75) than the upper (rkm 160-299) river. Radio telemetry data indicated that spawning appeared to occur upriver, between rkm 179 and rkm 278, and that the specific location and time of spawning varied annually. Some individuals spawned in consecutive years, but others apparently did not. Nonspawning fish appeared to remain in the vicinity of the fresh/brackish water interface (ca. rkm 30-40) throughout the spawning season. Most shortnose sturgeon left the freshwater reaches of the river in Spring soon after the spawning season (January-April) and probably did not return until late Autumn/early Winter, just prior to the spawning season.

A total of 4,920 striped bass (Morone saxatilis) were collected from Roanoke River near Weldon, North Carolina, by electrofishing during the spring of 1991 and 1992. Study objectives were to determine sex ratio and age composition of the Albemarle Sound/Roanoke River striped bass spawning stock. Differences in catch per unit effort (CPUE) between years, among year classes, and between sexes were analyzed. Male striped bass represented 83% and 87% of the sample over the 2 years. Nearly all male (99%) and female (91%) striped bass captured were Ages 2 through 4. Ninety-six percent of the fish in 1991 and 89% in 1992 were from the 1988 and 1989 year classes. A greater proportion of striped bass, both male and female, migrated to the spawning grounds at Age 3 than at Age 2 and females did not migrate in equal proportions as males until at least Age 4.

The Louisiana Department of Wildlife and Fisheries has conducted long term monitoring for shrimp since the mid 1960's. For the purpose of monitoring shrimp populations, the State was divided into 7 Coastal Study Areas. Each of these Areas represented a distinct hydrological basin within the coastal zone. Data collected from sampling locations within each of these Study Areas was used to set shrimp seasons on a statewide basis. Data collected during the early years of the monitoring program indicated that the State's shrimp resources could be divided into 3 distinct management zones. In 1975, the Department instituted the zone concept of shrimp management and began opening shrimp seasons at different times along the coast. This program is the basis on which shrimp are managed in Louisiana.

A total winterkill of threadfin shad (Dorosoma petenense) in B. Everett Jordan Lake, North Carolina, facilitated assessment of their role in the growth and condition of black crappie (Pomoxis nigromaculatus). Reductions in size at age and Wr were observed in Age 3 and older crappie in the year of the winterkill. Reestablishment of threadfin shad in the following year led to improvements in crappie population parameters, and within 2 years of the shad winterkill, crappie growth and condition had returned to pre-kill levels. The presence of a strong gizzard shad (D. cepedianum) year class during the season in which crappie conditions otherwise declined established the superiority of threadfin shad as forage for crappie.

We used larval drift nets to assess reproductive output of channel catfish (lctalurus punctatus) in order to determine stocking needs in the Kings, Mulberry, Illinois, and Buffalo rivers in Arkansas. In each river, drift nets were deployed at the head of riffles and fished on random dates from 15 June to 22 July 1991 to determine relative abundance of young-of-year (YOY) catfish. Abundance of YOY catfish, an index of reproductive output, varied significantly among rivers, although all rivers are similar in geomorphology and located in the same physiographic region of the state. The Illinois River had the highest average catch (56.7 YOY channel catfish/net) and the Buffalo River had the lowest (1.0 YOY channel catfish/net). Age structure of adult channel catfish in the Buffalo River verified low reproductive output documented from drift net samples, as no Age 1 catfish were collected in 1991 or 1992 and 93% of the existing population consisted of previously stocked fish.

A standardized stream monitoring program conducted on the Altamaha River, Georgia, from 1988 to 1992 was successful in detecting substantial changes in sport fish populations. Flathead catfish (Pylodictus olivaris) electrofishing catch rates generally increased from 1988 to 1992 reaching a peak CPUE of 90 fish per hour in 1990. CPUE of flathead catfish was significantly different (P < 0.05) between years and sites. Percent composition of flathead catfish in ictalurid samples doubled over the 5-year study period. A concurrent decrease in native bullhead populations was observed in annual creel and electrofishing surveys. Redbreast sunfish catch rates precipitously declined in both electrofishing samples and creel surveys taken from 1988 to 1992. Differences in mean CPUE of redbreast sunfish were significant (P < 0.05).

Radio telemetry and mark-recapture techniques were used to monitor linear ranges of large (TL > 510 mm) flathead catfish {Pylodictis olivaris) in the Big Black River and the Tallahatchie River, Mississippi. Linear ranges of transmitter-tagged fish averaged 0.75 km (SE = 0.09 km, N = 6) in the Big Black River and 1.04 km (SE = 0.13 km, N = 8) in the Tallahatchie River. In the Big Black River, 116 adult flathead catfish were tagged with Floy T-Bar anchor tags. There were 6 recaptures from the Big Black River with all recaptures occurring <2 km from release sites. In the Tallahatchie River, 103 adult flathead catfish were tagged with Floy T-Bar anchor tags. There were 5 recaptures from the Tallahatchie River with all but 1 recapture occurring <1 km from release sites. A stream reach-specific approach is suggested for management of large flathead catfish. For the Big Black River and Tallahatchie River, a resolution of 2 km is recommended for these purposes.

An angler diary survey of the flathead catfish {Pylodictis olivaris) sport fishery in the Yadkin-Pee Dee River system, North Carolina, was conducted (1989-1991) to examine the current fishery and provide a baseline for future comparisons. The objective of the study was to describe the quality of the fishery in terms of fish caught per hour (CPUE), size distribution, and condition (K) of the catch. Forty-four volunteer anglers were recruited to keep records of their fishing trips. Twenty cooperators reported 348 trips. Anglers fished 1,530 hours and caught 338 flathead catfish, a catch rate of 0.22 fish per hour. Eighty-seven percent of the fishing effort was directed at reservoirs, while tailraces received 10% and rivers received 3%. Participants were more successful, however, in tailraces (CPUE = 0.54) than in reservoirs (CPUE = 0.19) or rivers (CPUE = 0.14). Total lengths of captured flatheads ranged from 152 to 1,219 mm. Conditions factors (K) averaged 1.32.

Creel survey and cove rotenone data from 17 reservoirs in Piedmont North and South Carolina were subjected to correlation and regression analysis to examine environmental factors influencing fish production and taxonomic composition and to develop models for the prediction of total harvest and biomass. Summer surface chlorophyll concentration was the best univariate predictor of total harvest (r2 = 0.93) and one of the best predictors of total biomass (r2 = 0.79). The morphoedaphic index was a good predictor of both biomass (r2 = 0.79) and harvest (r1 = 0.83), but explained no more variation than conductivity alone. Mean depth was not a strong predictor of biomass (r2 = 0.55) or harvest (r2 = 0.61), and total phosphorus concentration was not significantly correlated with biomass or harvest. Multivariate models based on phosphorus loading and reservoir morphometry/hydrology explained up to 91% of variation in biomass and 92% of variation in harvest.

The North Carolina Wildlife Resources Commission (NCWRC) Environmental Permit Review Program was evaluated. The objective was to classify and compare a sample of environmental permit reviews conducted in 1989 with permit disposition. A secondary objective was to assess the degree of incorporation of conditions attached to permits recommended by NCWRC personnel for approval with modification. One hundred and ten permit applications were reviewed. State and federal regulatory agencies, with few exceptions, denied fewer permit applications than were recommended for denial by the NCWRC. Survey data indicate 72% of NCWRC recommended conditions for avoiding, minimizing, or compensating for impacts to wetland areas are incorporated into permits.

Research and development studies involving red drum and hybrid striped bass culture in coastal ponds have been seriously impacted by avian predators, especially when overwintering was required. Studies were conducted at the Waddell Mariculture Center to document the effect of predation by birds and also to test various non-lethal control techniques. Use of pyrotechnics, flash tape, "evil-eye" balloons, aerial balloons, and various wire grid patterns over a pond offered only short term protection. Mortality of fish in ponds protected by these devices ranged from 42.0% to 99.7% depending primarily on duration of the studies. Phase II red drum reared in unprotected "control" ponds exhibited mortalities of 79.5% to 83.1% after 1 month and 99.8% after 8 months. Double-crested cormorants were by far the most destructive predator and they quickly learned how to ignore or avoid the various discouragement devices tested.

I estimated variance-mean (s2-x ) relationships for gill net catches of 8 forage and sportfish species plus a composite group composed of all species combined. These relationships explained 75%-95% of the variation in loge(s2). Predictive equations for loge(s2) were back-transformed to a linear scale, adjusted to correct for transformation bias, and substituted into a standard equation for estimating sample size requirements as a function of the desired level of precision and expected sample mean. Sample size requirements for all species increased with an increase in the desired level of precision or with a decrease in the expected mean. Based on statewide mean catches, all species studied can be sampled with a precision ≤0.3 with a sample size of 25 gill nets and most could be sampled with a precision of ≤0.2 with 50 gill nets; these results represent approximate 95% confidence intervals about estimates of mean catch of x ± 0.6x (precision= 0.3) or x ± 0.4x (precision = 0.2).

Size selective predation has been documented in many species of fish. The majority of these studies have focused on the feeding behavior of adults. I examined the size selection predation of largemouth bass Micropterus salmoides ≤200 mm total length (TL), with particular emphasis on shift size bass. Shift size bass (approximately 100 mm TL) were those fish just changing from invertebrate prey to piscivory. Shift size bass were size selective and consumed prey 35% their own TL. As they grew larger, they consumed proportionately smaller sized prey. Whether the decrease was due to selection, opportunistic availability, or increased abundance of small prey is not known.

This study evaluated the relation between young-of-year (YOY) largemouth bass (Micropterus salmoides) density (TV/ha) and monthly rainfall, make-up water, and discharge of a 547-ha power plant cooling reservoir in Bexar County, Texas, for 1983-1992. Young-of-year largemouth bass density and total dilution (rainfall, makeup water, and discharge combined) during January-February were significantly related (r2 = 0.68, P < 0.05). The results of this study suggest that in a eutrophic, closed aquatic system, the total amount and timing of reservoir dilution can be important to the relief of a spawning repressive factor and can help increase YOY largemouth bass abundance.

During 1978-1991, Floy FD-68B "T bar" type tags and Floy internal anchor tags were used on Lake Walter F. George to estimate exploitation of the largemouth bass population. Tag loss and non-reporting of tags by anglers were calculated in an attempt to adjust exploitation and total catch estimates. Over the 5-year period, tag loss averaged 20% per year for Floy FD-68B tag and <1% for the Floy internal anchor tag. Non-reporting of tags by anglers was estimated to be 33%. Based on tag returns, exploitation was estimated to be 23% for fish tagged with FD-68B tags and 28% for fish tagged with internal anchor tags. Estimates of the total catch of tagged bass were 48% and 58% for FD-68B and internal anchor tags, respectively. These estimates differed significantly by tag type used, even when adjusted for tag loss.

Percent year class contribution was evaluated for genetically-marked Florida largemouth bass (Micropterus salmoides floridanus) x northern largemouth bass (A/. 5. salmoides) stocked in 3 Texas reservoirs. Electrofishing catch rate and size structure data were used to determine population characteristics of each study reservoir. Stocking rates of genetically-marked fingerlings ranged from 30 to 200 fish/ha. Post-stocking collections were made by electrofishing at permanent stations over a 4-year period. Town Reservoir, which had the highest largemouth densities and recruitment, had the lowest percent contribution by stocked fish (l%-7%). Conversely, Meredith and Braunig reservoirs, which had lower largemouth bass densities and historical recruitment and reproduction problems, respectively, had relatively high returns (41 %—45%). Year class strength at the time of stocking influenced success at Town and Braunig reservoirs.

An ultrasonic-telemetry study was conducted to compare spatial and temporal distribution and habitat use of Florida largemouth bass (Micropterus salmoides floridanus, FLMB) and northern largemouth bass (M. s. salmoides, NLMB). Twentyfour largemouth bass (12 FLMB and 12 NLMB) were implanted with ultrasonic transmitters and released in Waco Bay, a 1,215-ha major arm of Lake Tawakoni, Texas. Eleven FLMB and 10 NLMB were located at least once during the year-long study period (range 1-24). Average 75% and 95% contour level home ranges for FLMB were 19.0 and 44.2 ha, respectively; for NLMB they were 21.5 and 66.1 ha, respectively. Aquatic vegetation, pier/boathouse, brushy shoreline, and clean shoreline were the most important habitat types selected by both subspecies. Habitat overlap was evident between the subspecies. Both inhabited relatively shallow water, most in water ≤2.1 m deep. However, FLMB were located in deeper water further from shore than were NLMB.

North Carolina implemented delayed harvest regulations in 1992 to diversify trout angling opportunities. Delayed harvest regulations allowed only catch-and-release fishing of stocked catchable-sized trout from 1 March-5 June 1992. Creel surveys were conducted on 2 streams to assess differences in angler trip characteristics, particularly catch rates, between delayed harvest and regular put-and-take (hatchery supported) trout streams. Catch rates of 3.16 and 6.54 trout per hour in delayed harvest areas were significantly higher than those of hatchery supported areas (1.87-2.52 trout per hour). The catch-and-release aspect of the regulation resulted in each stocked trout being captured an estimated 2.4-2.8 times. A higher percentage of nonlocal anglers used the delayed harvest areas and overall >75% of anglers rated their trips as good to excellent. The program was considered a successful addition to North Carolina's catchable trout program and expansion is being considered.

A roving creel survey was conducted on Lake Hartwell, Georgia and South Carolina, in 1992 to evaluate spatial and temporal differences in anglers' awareness of a fish consumption advisory and their fish consumption habits. A higher percentage of Georgia residents were interviewed in areas of Lake Hartwell that included large proportions of the Georgia shoreline. The frequencies of anglers that ate fish they caught from Lake Hartwell and percentages of anglers not aware of the current health advisory were generally higher in these areas. Mean per capita fish consumption estimates were higher in spring and summer than in winter and fall. Within season comparisons of mean per capita estimates among lake strata indicated consumption rates were higher in areas of Lake Hartwell closer in proximity to Georgia and in one particular area encompassed by South Carolina. Anglers consumed an estimated 0.23 kg of fish per month in 1992 lake-wide.

A creel survey was conducted from 1 September 1990 through 31 August 1991 to estimate fishing pressure and catch rates, initial mortality, and value of fishes captured in an entanglement gear fishery at Wright Patman Reservoir, Texas. Mean daily net fishing pressure ranged from 3,508 m/day (fall) to 763 m/day (summer). Commercial nets accounted for 85% of the annual netting pressure. Catch rates of sport and commercial fishes declined as bar mesh size increased from 76 to 102 mm. Smallmouth buffalo (Ictiobus bubalus) was the dominant species represented in entanglement gear, comprising 70% of all fish and 84% of the rough fish/catfish captured. By-catch of sport fishes in nets was highest during winter months (12.7 fish/1,000 m of net) and represented 41% of that season's catch. Crappies (Pomoxis spp.) were the dominant sport species represented in nets, comprising 55% of the sport fish and 8% of all species captured.

A volunteer angler diary program was evaluated as a data source compared to traditional fisheries census techniques (i.e., electrofishing, gill netting, and on site creel surveys). Anglers were supplied fishing diaries and asked to record lengths of fishes caught, location, and time fished in Texas public waters, 1986-1988. Volunteer angler-supplied (ANG) length and catch-per-unit-effort (CPUE) data were then compared to traditional fisheries census data for the same season and water body. Although ANG data were reported for 4,581 trips, 144 reservoirs, and 10 species or species groups, sufficient data for analysis was obtained only for largemouth bass (Micropterus salmoides). Regression analysis of ANG and traditional data indicated significant but variable relations existed for PSD (r2 = 0.28; P = 0.0159), RSD (r2 = 0.56; P = 0.0002), and CPUE (r2 = 0.42; P = 0.0050). Cost of ANG data on a per fish basis was about one-third that of traditional methods.