Geology topics
Publications and source records attributed to J. Jeffery Isely.
This study demonstrates that coded wire tags can be used to mark certain insect larvae without adverse effects on maturation, and that tags are retained through the adult phase in high enough proportion for practical application. Coded wire tags also offer the benefit that marked organisms can be identified to the batch or individual level.
To determine the effects of surgical implantation method and temperature on mortality and transmitter loss, we compared two antenna placements (trailing antenna versus shielded needle) and two suture materials (absorbable versus nonabsorbable) in hybrid striped bass Morone saxitilis × Morone chrysops (227–410 mm total length) that had been surgically implanted with simulated transmitters and held at high (22–29°C) and low (12–18°C) temperatures for 120 d. Fish were individually examined after 7, 30, 60, 90, and 120 d to evaluate suture and wound condition as well as transmitter loss. Neither suture material nor antenna placement affected transmitter loss, mortality, or growth at either high or low temperatures. Absorbable sutures were lost more quickly than were nonabsorbable sutures, but they persisted beyond incision closure at both high and low temperatures. At high temperatures, 50% suture loss occurred by 30 d for absorbable sutures and by 60 d for nonabsorbable sutures. Mortality occurred only at high temperatures but was delayed and was likely caused by peritoneal infection. Transmitter loss was not significant; it occurred only in the low-temperature trial and was caused by pressure necrosis at the incision rather than by suture failure. Temperature significantly affected all responses examined in this study. Significant irritation, infection, and mortality occurred in all treatment groups at high temperatures.
We examined the effects of costocking on growth of hatchery-produced young-of-year brook trout Salvelinus fontinalis and rainbow trout Oncorhynchus mykiss in the laboratory. Fry of both species (brook trout = 0.16 ± 0.01 g; rainbow trout = 0.18 ± 0.01 g; mean weight ± standard deviation) were stocked into 400-L recirculation raceways at a rate of 100 fish/raceway and were held at 12°C. Raceways received either rainbow trout only ( n = 3), brook trout only ( n = 3), or half brook trout and half rainbow trout ( n = 3). Trout were fed a commercial trout feed three times per day at an initial rate of 10% body weight/d, which was reduced to 3% body weight/d by the 6th week of the study as a result of a buildup of excess feed. After 8 weeks of similar treatment, brook trout were significantly larger than rainbow trout (in terms of length and weight) when they were stocked alone. However, rainbow trout were significantly larger than brook trout (in terms of length and weight) in the costocked treatment. A second phase of the study was conducted to evaluate the effect of ration level on growth of costocked brook and rainbow trout using low (2% body weight/d), medium (4% body weight/d), and high (6% body weight/d) ration levels. After 8 weeks, rainbow trout were significantly larger than brook trout (in terms of length and weight) in all costocked feeding treatments. This suggests that behavioral interaction might have resulted in decreased growth of brook trout when they were costocked with rainbow trout.
Adult striped bass Morone saxatilis (N = 30, 656-906 mm total length) were captured by electrofishing during January-March 1998 in the Combahee River, South Carolina, and fitted with radio transmitters. Their exact locations were recorded biweekly through December. From January to early April, striped bass were located in the tidally influenced lower region of the river in water temperatures ranging from 9??C to 18??C. The fish then moved an average of 38.5 km upstream from late April to the end of May when water temperatures ranged from 18??C to 26??C. Striped bass remained in the upper region of the river from late May to September when water temperatures were as much as 5??C lower than in the river's lower regions. Striped bass began to move downstream and were spread throughout the river during September and October in water temperatures ranging from 19??C to 27??C. Combahee River striped bass appear to follow a migratory pattern typical of other southern striped bass stocks. Habitat preference appears to be strongly influenced by temperature. Combahee River temperatures are stable and remain close to the preferred temperatures of striped bass during summer extremes. Therefore, unlike northern populations, southern populations are more likely to remain within riverine habitat during the summer months. Discrete thermal refugia, such as springs, apparently are not used or are absent in the Combahee River. It is possible that striped bass in the Combahee River depend on the entire upper region of the river as a thermal refuge.
Radio telemetry was used to evaluate the seasonal movement, activity level, and home range size of adult brown trout Salmo trutta in the Chattooga River watershed, one of the southernmost coldwater stream systems in the United States. In all, 27 adult brown trout (262-452 mm total length) were successfully monitored from 16 November 1995 to 15 December 1996. During the day, adult brown trout were consistently found in small, well-established home ranges of less than 270 m in stream length. However, 8 of a possible 18 study fish made spawning migrations during a 2-week period in November 1996. The daytime locations of individual fish were restricted to a single pool or riffle-pool combination, and fish were routinely found in the same location over multiple sampling periods. Maximum upstream movement during spawning was 7.65 km, indicating that brown trout in the Chattooga River have the ability to move long distances. Spawning brown trout returned to their prespawning locations within a few days after spawning. Brown trout maintained larger home ranges in winter than in other seasons. When spawning-related movement was deleted from the analysis, brown trout moved more on a weekly basis in fall than in summer. Brown trout were more active in fall and winter than in spring and summer. Apart from spawning migrations, displacement from established home ranges was not observed for any fish in the study. Although summer water temperatures reached and exceeded reported upper thermal-preference levels, brown trout did not move to thermal refuge areas in nearby tributaries during the stressful summer periods.
Efforts are underway to culture the endangered shortnose sturgeon Acipenser brevirostrum for possible reintroduction. As part of a larger project to develop culture techniques for this species, the uptake of nitrite was evaluated in fingerlings (16.5 ± 4.85 g; mean ± SD). Plasma nitrite concentrations increased significantly with exposure time (0–5 d) and dose (0–4 mg nitrite-N/L). Shortnose sturgeon fingerlings were able to concentrate nitrite in their plasma to more than 63 times the environmental concentration. Chloride, as either sodium chloride or calcium chloride, partially inhibited nitrite uptake. However, calcium chloride was a better inhibitor. After previous exposure (2 d at 2.13 ± 0.080 mg nitrite-N/L) plasma nitrite-N decreased from 165.5 to 36.7 mg/L during a 3-d simultaneous exposure to 2.13 ± 0.080 mg nitrite-N/L and treatment with 40 mg chloride/L as calcium chloride. The addition of calcium chloride to the water appeared to be an effective means of preventing nitrite uptake and treating nitrite toxicity in hatchery-reared shortnose sturgeon fingerlings.
Serum cortisol concentrations, plasma glucose concentrations, plasma lactate concentrations, and plasma osmolalities increased in red drum Sciaenops ocellatus (26.0-65.5 cm total length) during angling in estuarine waters (17-33 g/L salinity, 21-31??C). Angling time varied from as fast as possible (10 s) to the point when fish ceased resisting (up to 350 s). The increases in the physiological characteristics were similar in wild and hatchery-produced fish. This study indicates that hatchery-produced red drum may be used in catch-and-release studies to simulate the responses of wild fish.
The 96‐h median‐lethal concentration (96h LC50) of total ammonia nitrogen (ammonia‐N) to fingerling shortnose sturgeon Acipenser brevirostrum was 149.8 ± 55.20 mg/L (mean ± SD, 17.9 ± 0.62°C, pH = 6.8–7.3). Calculated 96‐h LC50 for un‐ionized ammonia‐N was 0.58 ± 0.213 mg/L. The 96‐h LC50 of nitrite nitrogen to shortnose sturgeon fingerlings was 11.3 ± 8.17 mg/L (17.9 ± 0.31°C, <1.0 mg chloride/L, <1.0 mg magnesium/L, 1.8 mg calcium/L, 7.7 mg sodium/L).
Radio telemetry was used to monitor the diel movement of 22 brown trout Salmo trutta (268–446 mm in total length, TL) in the Chattooga River watershed. Forty-seven diel tracks, locating individuals once per hour for 24 consecutive hours, were collected for four consecutive seasons. High variability in movement both within and among individual brown trout resulted in similar seasonal means in total distance moved , diel range, and displacement. The majority of fish moved a total distance of less than 80 m within a diel range of less than 80 m and had a displacement of less than 10 m. Brown trout were more likely to occur in pool habitat independent of season or period of the day. Hourly movement patterns differed among seasons. During the winter and fall, trout moved only around sunrise; during the spring, they moved around sunrise, sunset, and intermittently throughout the night. Large brown trout (>375 mm, TL) were found to move greater total distances and establish wider diel ranges than small brown trout . Overall, most brown trout exhibited restricted diel movement within a single riffle–pool or run–pool sequence.
Juvenile red swamp crayfish (or crawfish), Procambarus clarkii (20–41 mm in total length) were collected from a crayfish culture pond by dipnetting and tagged with sequentially numbered, standard length, binary‐coded wire tags. Four replicates of 50 crayfish were impaled perpendicular to the long axis of the abdomen with a fixed needle. Tags were injected transversely into the ventral surface of the first or second abdominal segment and were imbedded in the musculature just beneath the abdominal sternum. Tags were visible upon inspection. Additionally, two replicates of 50 crayfish were not tagged and were used as controls. Growth, survival, and tag retention were evaluated after 7 d in individual containers, after 100 d in aquaria, and after 200 d in field cages. Tag retention during each sample period was 100%, and average mortality of tagged crayfish within 7 d of tagging was 1%. Mortality during the remainder of the study was high (75–91%) but was similar between treatment and control samples. Most of the deaths were probably due to cannibalism. Average total length increased threefold during the course of the study, and crayfish reached maturity. Because crayfish were mature by the end of the study, we concluded that the coded wire tag was retained through the life history of the crayfish.
Eight‐day‐old striped bass Morone saxatilis (6.17–6.22 mm, total length) were fed twice daily at three feeding rates to produce three growth rates. Fish were sampled once per week for 4 weeks to determine total length and otolith radius. Feed ration treatments resulted in discrete size‐classes of striped bass after 4 weeks with a 27% difference in mean length between the low and high feed ration treatments. No significant differences in slope or intercept for the regression of fish length on otolith radius were observed among treatments, suggesting that slow growth alone may not be sufficient to result in decoupling of the otolith size–fish size relationship in striped bass.