Geology topics

James J. Schaffler

Publications and source records attributed to James J. Schaffler.

4 recordsLinked to original sources

USGS2013

Documenting utility of paddlefish otoliths for quantification of metals using inductively coupled plasma mass spectrometry

RATIONALE The otoliths of the inner ear of fishes record the environment of their surrounding water throughout their life. For paddlefish ( Polyodon spathula ), otoliths have not been routinely used by scientists since their detriments were outlined in the early 1940s. We sought to determine if paddlefish otoliths were useful for resolving elemental information contained within. METHODS Adult paddlefish were collected from two wild, self-sustaining populations in Oklahoma reservoirs in the Arkansas River basin. Juveniles were obtained from a hatchery in the Red River basin of Oklahoma. Otoliths were removed and laser ablation, inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify eight elements (Li, Mg, Mn, Rb, Sr, Y, Ba, and Pb) along the core and edge portions, which were analyzed for differences between otolith regions and among paddlefish sources. RESULTS Differences were found among samples for six of the eight elements examined. Otoliths from Red River basin paddlefish born in a hatchery had significantly lower amounts of Mg and Mn, but higher levels of Rb than otoliths from wild paddlefish in the Arkansas River basin. Concentrations of Y, Sr, and Ba were reduced on the edges of adult paddlefish from both reservoirs compared with the cores. CONCLUSIONS This research shows the utility of using an ICP-MS analysis of paddlefish otoliths. Future research that seeks to determine sources of paddlefish production, such as which reservoir tributaries are most important for reproduction or what proportion of the population is composed of wild versus hatchery-produced individuals, appears promising. Published in 2013. This article is a U.S. Government work and is in the public domain in the USA.

Rapid Communications in Mass Spectrometry↗

USGS2002

Habitat use by striped bass in relation to seasonal changes in water quality in a southern reservoir

Adult striped bass Morone saxatilis (n = 61; 597-914 mm total length) were captured by hook and line throughout Lake Murray, South Carolina, and by electrofishing in the Greenwood Dam tailrace and upper Saluda River above Lake Murray, implanted with temperature-sensitive radio transmitters, and tracked biweekly. During late winter-early spring, striped bass were concentrated in the upstream portions of the reservoir. By midsummer, they were primarily located in the lower embayment of the reservoir, but several fish remained in the tailrace of the upstream dam as well as in a thermal refuge in the Saluda River. After the reservoir began to cool in fall, fish dispersed from the lower embayment and moved upstream toward the headwaters of the reservoir, where they had been captured the previous spring. Several fish returned to locations within 10 m of their original capture locations. Mean movement rates were lowest in winter and summer and highest in spring and fall. Low movement rates in summer were associated with a severe reduction of suitable habitat. In addition to the standard biweekly sampling, a 7.5-km2 section of the lower embayment of Lake Murray was searched every 2 h over a continuous 48-h period from 10 to 12 August 2000. During this period, striped bass were observed to use the same areas on a seasonal basis as they did on a diel basis. However, mean hourly rates of movement were greater than the movement rates calculated for the normal 2-week interval between samples. Changes in location between biweekly samples may not indicate displacement but rather only randomly chosen locations in normal use areas.

Transactions of the American Fisheries Society↗

USGS2002

Effects of antenna placement and antibiotic treatment on loss of simulated transmitters and mortality in hybrid striped bass

We compared the effects of two antenna placements (trailing and nontrailing) and antibiotic treatments (treated and nontreated) on mortality and transmitter loss in hybrid striped bass Morone saxatilis ?? M. chrysops (364 ?? 28 mm total length, 645 ?? 129 g [mean ?? SD]) implanted with simulated transmitters and held in the laboratory for 90 d. Although antibiotic treatment significantly increased the time to first mortality in fish surgically implanted with simulated transmitters (by an average of 14 d), we did not detect an effect on cumulative mortality. We also did not detect an effect of antenna type on the time to first mortality, but cumulative mortality was higher in the trailing antenna groups (50%) than in the nontrailing antenna groups (12%). Three transmitters were expelled during the study, all from trailing-antenna treatment groups, indicating a significant effect of antenna placement on the level of transmitter expulsion. Antibiotic treatment appears to be effective in preventing initial postsurgical infection; however, the antenna may serve as a continuous source of irritation and route of infection into the body cavity. The potential for infection and mortality in experimental animals must be weighed against the improved performance of transmitters with trailing antennas.

North American Journal of Fisheries Management↗

USGS2001

Retention of coded wire tags, and their effect on maturation and survival of yellow mealworms (Coleoptera: Tenebrionidae)

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.

Florida Entomologist↗