Seasonal temperature and power plant chlorination effects on estuarine invertebrates

The influence of seasonal temperatures (15–22°C) on chlorine (0.00, 0.15 and 0.30 mg/L total residual chlorine), T (2, 6 and 10°C), and exposure duration (0.08, 2.0 and 4.0 hr) interaction studies simulating power plant entrainment and effluent discharge conditions was evaluated for opossum shrimp,Neomysis americana and amphipods,Gammarus sp. Seasonal temperature was an important factor affecting the toxicity of the three treatment variables with both of these organisms. Mortality responses were greater at the higher acclimation temperatures.     

Control of the freshwater fouling bivalveCorbicula fluminea by halogenation

Mortality levels for adult and juvenile Asiatic clam,Corbicula fluminea, were determined after exposure to halogens (chlorine, bromine) in 28 to 32-day laboratory and field (industrial water supply) tests. Low levels of mortality (<53%) were generated in laboratory studies on exposure to constant doses of total residual chlorine (TRC) when mean test temperatures were <16C. Mortality levels were elevated (>53%) when test specimens were exposed to comparable TRC levels (0.2 to 1.0 mg/L) at temperatures in excess of 18C. Mortalities generated among adults by an initial 14-day low dose (0.25 mg/L TRC) followed by an 18-day high dose (0.50 to 1.00 mg/L TRC; >80% mortality) were comparable to those from a constant high dose (0.50 to 1.00 mg/L; 60 to 95% mortality). Adults and juveniles were comparably sensitive to halogen concentrations adequate for control. There is no substantial difference in the effectiveness of either chlorine or bromine in controlling adult and juvenile stages ofC. fluminea. Field studies conducted in the spring and fall produced markedly dissimilar results. Mortality levels during the spring field study exceeded 90% after 28 days of exposure to 0.25 mg/L TRC, while ambient temperatures rose from 20 to 25C. Mortality levels not exceeding 23% were observed among test organisms after 28 days of exposure to elevated TRC levels (<0.50 mg/L), while ambient temperatures were declining from 20 to 12C during October and November 1985.     

Control of brackish water fouling mussel,Mytilopsis leucophaeata (Conrad), with sodium hypochlorite

Though the Conrad's false mussel, Mytilopsis leucophaeata, is an important fouling animal in industrial cooling water systems, there are no published reports on the tolerance of this species to chlorination. A series of experiments was conducted to determine the effects of mussel size (2-20 mm shell length), season (breeding versus nonbreeding), nutritional status (fed versus starved) and acclimation temperature (5-30 degrees C) on the mortality pattern of M. leucophaeata under continuous chlorination (0.25-5 mg/L). The effect of mussel size on M. leucophaeata mortality in the presence of chlorine was significant, with 10 mm size group mussels showing greater resistance. At 0.25 mg/L residual chlorine, 2 mm size group mussels took 89 days to reach 100% mortality, whereas 10 mm size group mussels took 109 days. M. leucophaeata collected during nonbreeding season (December-April) was more tolerant to chlorine than those collected during breeding season (June-October). Nutritional status of the mussel had no significant influence on the chlorine tolerance of the mussel: fed and starved mussels succumbed to chlorine at equal rates. The effect of acclimation temperature on M. leucophaeata mortality in the presence of chlorine was significant. At 0.5 mg/L residual chlorine, mussels acclimated at 5 degrees C required 99 days to reach 95% mortality, whereas mussels acclimated at 30 degrees C required 47 days. A comparison of present data with previous reports suggests that resistance of M. leucophaeata to chlorination is higher than other mussel species causing fouling problems in The Netherlands ( Mytilus edulis and Dreissena polymorpha).     

Control of Brackish Water Fouling Mussel, <Emphasis Type="Italic">Mytilopsis leucophaeata</Emphasis> (Conrad), with Sodium Hypochlorite

Though the Conrad's false mussel, Mytilopsis leucophaeata, is an important fouling animal in industrial cooling water systems, there are no published reports on the tolerance of this species to chlorination. A series of experiments was conducted to determine the effects of mussel size (2–20 mm shell length), season (breeding versus nonbreeding), nutritional status (fed versus starved) and acclimation temperature (5–30°C) on the mortality pattern of M. leucophaeata under continuous chlorination (0.25–5 mg/L). The effect of mussel size on M. leucophaeata mortality in the presence of chlorine was significant, with 10 mm size group mussels showing greater resistance. At 0.25 mg/L residual chlorine, 2 mm size group mussels took 89 days to reach 100% mortality, whereas 10 mm size group mussels took 109 days. M. leucophaeata collected during nonbreeding season (December–April) was more tolerant to chlorine than those collected during breeding season (June–October). Nutritional status of the mussel had no significant influence on the chlorine tolerance of the mussel: fed and starved mussels succumbed to chlorine at equal rates. The effect of acclimation temperature on M. leucophaeata mortality in the presence of chlorine was significant. At 0.5 mg/L residual chlorine, mussels acclimated at 5°C required 99 days to reach 95% mortality, whereas mussels acclimated at 30°C required 47 days. A comparison of present data with previous reports suggests that resistance of M. leucophaeata to chlorination is higher than other mussel species causing fouling problems in The Netherlands (Mytilus edulis and Dreissena polymorpha). Received: 18 October 2001/Accepted: 4 March 2002     

Physiological Responses of Hybrid Striped Bass to Aqueous Copper in Freshwater and Saltwater

Copper (Cu) is an abundant trace metal, and although essential at low levels, it is also potentially toxic to aquatic organisms. Mechanisms of toxicity and consequences of exposure vary depending on ionoregulatory status (acclimated to freshwater or salt water). The goal of this research was to examine the responses of hybrid striped bass (Morone chrysops × Morone saxatilis) exposed to Cu in freshwater and 15 g/L salt water. In freshwater, a general dose- and time-dependent pattern of increasing Cu accumulation in gill tissue was evident in fish exposed to aqueous Cu (220 and 447 mg/L) for up to 96 hours. The 96-hour acute median lethal concentration for freshwater-acclimated hybrid striped bass exposed to Cu was 94 mg/L (confidence interval = 62 to 144 mg/L). Plasma osmolality and Na⁺ concentrations decreased in Cu-exposed fish. Freshwater-acclimated hybrid striped bass exposed to aqueous Cu (60 mg/L) for 3 weeks decreased in mass and accumulated Cu in gill, intestine, and liver. In salt water, no mortality occurred, and there were no statistical differences in growth, tissue Cu, or plasma ion concentrations in hybrid striped bass exposed to Cu compared with control fish. Freshwater-acclimated hybrid striped bass were very sensitive to Cu exposure and exhibited responses typical of commonly tested teleost fishes; however, the same sensitivity was not observed in salt water–acclimated fish. An erratum to this article is available at .     

Temperature preference of the crayfishOrconectes obscurus

Acclimation temperature influenced the acute preferred temperature of the crayfishOrconectes obscurus. This species preferred a higher temperature than its acclimation temperature for those acclimation temperatures ranging from 6° to 26°C. When acclimated to 30° and 33°C, the crayfish preferred a lower temperature than its acclimation temperature. The final temperature preferendum is estimated to be approximately 30°C.     

Mercury concentrations in fish from Lake Mead,USA, related to fish size,condition, trophic level,location, and consumption risk

Total mercury (Hg) concentrations were determined in the skeletal muscle of 339 fish collected during the fall of 1998 and spring of 1999 from Lake Mead, USA, the nation's largest human-made reservoir. Five species of fish representing a range of trophic levels and the lake's principal game fishes were studied. Hg generally increased with trophic level and fish size. Median Hg concentrations (ng/g wet mass) were 277 in striped bass, 168 in channel catfish, 160 in largemouth bass, 75 in bluegill, and 8 in blue tilapia. Overall, fish from Las Vegas Bay and Boulder Basin had the lowest Hg concentrations, possibly a result of biodilution in this biologically productive area. In general, fish-mercury advisories might include a warning about consuming fillet from emaciated fish, based on the finding that Hg concentrations in 59 striped bass (captured during a scarce-food season) correlated inversely (r = −0.89, p < 0.001) with a fish nutritional-status factor. This is consistent with starvation-concentration, whereby Hg in fish muscle is lost at a slower rate than the muscle mass. The median concentration found for 139 striped bass corresponds to a recommended risk-based consumption limit of three 8-oz. (227-g) meals per month for a 70-kg adult. Finally, this paper serves as a useful archive for future research and long-term studies of Hg in Lake Mead fish. Received: 13 September 2001/Accepted: 10 March 2002     

Effects of organic and inorganic chemical contaminants on fertilization,hatching success,and prolarval survival of striped bass

The effects of an organic-inorganic chemical contaminant mixture were evaluated on percent fertilization, percent hatch, and prolarval survival of striped bass. All dilutions of the mixture simulated concentrations of various organic and inorganic contaminants found in striped bass spawning habitats. The organic contaminants were Aroclors® 1248, 1254, 1260, chlordane, DDE, chlordecone (kepone), toxaphene, anthracene, benzo(a)anthrene, chrysene, fluoranthrene, fluorene, perylene, pyrene, and phenanthrene; inorganic contaminants were arsenic, cadmium, copper, lead, and selenium. Percent fertilization (24-hr exposure) and percent hatch (48-hr exposure) were not significantly affected by exposure to various dilutions of the contaminant mixture. The full-strength contaminant mixture (all chemicals as listed in Table 2) significantly reduced survival of striped bass prolarvae after 144 hr continuous exposure from the time of spawn. A masked effect may have occurred during initial embryo development that was later observed in the prolarvae.     

Species differences in contaminants in fish on and adjacent to the Oak Ridge Reservation, Tennessee

Risks to humans and other organisms from consuming fish have become a national concern in the USA. In this paper, we examine the concentrations of 137Cs, arsenic, beryllium, cadmium, lead, mercury, and selenium in three species of fish from two river reaches adjacent to the US Department of Energy's Oak Ridge Reservation in Tennessee. We were interested in whether there were species and locational differences in radiocesium and metal concentrations and whether concentrations were sufficiently high to pose a potential health risk to humans or other receptors. Striped bass (Morone saxatilis) were significantly larger than white bass (M. chrysops), and crappie (Pomoxis spp.) were the smallest fish. Lead was significantly lower in striped bass, mercury was significantly higher in striped bass, and selenium was significantly higher in white bass compared to the other species. There were no other species differences in contaminants. White bass, the only species that was sufficiently abundant for a comparison, had significantly higher concentrations of cadmium, lead, and selenium in fillets from the Clinch River and significantly higher concentrations of mercury in fillets from Poplar Creek. The low concentrations of most contaminants in fish from the Clinch River do not appear to present a risk to humans or other consumers, although mercury concentrations in striped bass ranged as high as 0.79 ppm, well above the 0.5-ppm action level for human consumption of some US states.     

Early life stage survival of striped bass in the Delaware River,USA

Four 96-h in situ bioassays were conducted on or near the striped bass spawning grounds in the Delaware River within the States of Delaware, New Jersey and Pennsylvania, USA during 1989 to determine if water quality was sufficient to support larval survival. Tests were accomplished by holding 500 striped bass yolk-sac larvae in each of two 75 L chambers at four locations in the river ranging from north of Philadelphia, PA to Salem, NJ and at one location in the Chesapeake and Delaware Canal. Survival varied significantly among stations; highest survival was in the Chesapeake and Delaware Canal, where it averaged more than 50%. Lowest survival occurred at the station near Salem, NJ, approximately 30 km downriver of the primary spawning grounds, where less than 1% of the larvae survived in any of the tests. Survival at stations closest to the primary spawning grounds was weather-dependent; survival was over 47% during periods of little rainfall, but only 11% following periods of higher than average rainfall.     

Effect of room temperature on tests for diagnosing vibration-induced white finger: finger rewarming times and finger systolic blood pressures

Purpose

This study investigates the effects of room temperature on two standard tests used to assist the diagnosis of vibration-induced white finger (VWF): finger rewarming times and finger systolic blood pressures.

Methods

Twelve healthy males and twelve healthy females participated in four sessions to obtain either finger skin temperatures (FSTs) during cooling and rewarming of the hand or finger systolic blood pressures (FSBPs) after local cooling of the fingers to 15 and 10 °C. The measures were obtained with the room temperature at either 20 or 28 °C.

Results

There were lower baseline finger skin temperatures, longer finger rewarming times, and lower finger systolic blood pressures with the room temperature at 20 than 28?°C. However, percentage reductions in FSBP at 15 and 10?°C relative to 30?°C (i.e. %FSBP) did not differ between the two room temperatures. Females had lower baseline FSTs, longer rewarming times, and lower FSBPs than males, but %FSBPs were similar in males and females.

Conclusions

Finger rewarming times after cold provocation are heavily influenced by room temperature and gender. For evaluating peripheral circulatory function using finger rewarming times, the room temperature must be strictly controlled, and a different diagnostic criterion is required for females. The calculation of percentage changes in finger systolic blood pressure at 15 and 10?°C relative to 30?°C reduces effects of both room temperature and gender, and the test may be used in conditions where the ±1?°C tolerance on room temperature required by the current standard cannot be achieved.

     

Accumulation and Elimination of Cadmium by the Nile Tilapia (Oreochromis niloticus) in differing Temperatures and Responses of Oxidative Stress Biomarkers

The aims of this study were to investigate the accumulation (15 days) and elimination (15 and 30 days) of cadmium (Cd) in the liver, gill, kidney and muscle of Oreochromis niloticus following exposures to different concentrations (1 and 2 mg/L) of Cd at different water temperatures (20, 25, 30 ^oC). Additionally, responses of oxidative stress biomarkers (superoxide dismutase, SOD; catalase CAT; glutathione peroxidase, GPx and malondialdehyde, MDA) of the liver were determined following Cd exposures. In accumulation period, Cd levels increased significantly in all the tissues at all temperatures and tissue accumulation order was kidney?>?liver?>?gill. All tissues, except the muscle, accumulated Cd in relation to exposure concentrations and water temperatures. There was no measurable level of Cd accumulation in the muscle, except in fish exposed to 2 mg Cd/L at 30 ^oC. Likewise, elimination of Cd from the tissues also increased in depends on periods and water temperatures. The order of Cd elimination from the tissues was gill?>?liver?>?kidney. The oxidative stress biomarkers also responded to both Cd exposure and temperature increases. The activities of antioxidant enzymes such as SOD, CAT, GPx and MDA levels in the liver increased in relation to increases in Cd concentrations and water temperatures.

     

Vitamins,fatty acids,and antioxidant capacity stability during storage of freeze-dried human milk

Although freezing is the most common method used to preserve human milk, nutritional and immunological components may be lost during storage. Freeze-drying could increase the shelf life of human milk, while preserving its original characteristics. Seventy-two samples of freeze-dried human milk were stored for different periods of time, up to a maximum of 3?months, at 4?°C or 40?°C. Vitamin C, tocopherols, antioxidant capacity, and fatty acids composition were analyzed. A new HILIC–UHPLC method improving vitamin C determination was also validated. Ascorbic acid and total vitamin C concentrations significantly decreased at both temperatures, while antioxidant capacity only decreased at 40?°C. Fatty acids composition and both γ-tocopherol and δ-tocopherol contents remained unaltered. The stability after storage of freeze-dried milk was higher than that reported for frozen or fresh milk indicating that freeze-drying is a promising option to improve the preservation of human milk in banks.     

Mercury bioaccumulation and biomagnification in Ozark stream ecosystems

Crayfish (Orconectes spp.), Asian clam (Corbicula fluminea), northern hog sucker (hog sucker; Hypentelium nigricans), and smallmouth bass (smallmouth; Micropterus dolomieu) from streams in southeastern Missouri (USA) were analyzed for total mercury (HgT) and for stable isotopes of carbon (δ¹³C), nitrogen (δ¹⁵N), and sulfur (δ³⁴S) to discern Hg transfer pathways. HgT concentrations were generally lowest in crayfish (0.005-0.112 μg/g dw) and highest in smallmouth (0.093-4.041 μg/g dw), as was δ¹⁵N. HgT was also lower and δ¹⁵N was higher in all biota from a stream draining a more heavily populated historical lead-zinc mining area than from similar sites with mostly undeveloped forested watersheds. δ¹³C in biota was lowest at spring-influenced sites, reflecting CO₂ inputs and temperature influences, and δ³⁴S increased from south to north in all taxa. However, HgT was not strongly correlated with either δ¹³C or δ³⁴S in biota. Trophic position (TP) computed from crayfish δ¹⁵N was lower in hog suckers (mean=2.8) than in smallmouth (mean=3.2), but not at all sites. HgT, δ¹³C, δ³⁴S, and TP in hog suckers increased with total length (length) at some sites, indicating site-specific ontogenetic diet shifts. Changes with length were less evident in smallmouth. Length-adjusted HgT site means in both species were strongly correlated with HgT in crayfish (r²=0.97, P<0.01), but not with HgT in Corbicula (r²=0.02, P>0.05). ANCOVA and regression models incorporating only TP and, for hog suckers, length, accurately and precisely predicted HgT concentrations in both fish species from all locations. Although low compared to many areas of the USA, HgT (and therefore methylmercury) concentrations in smallmouth and hog suckers are sufficiently high to represent a threat to human health and wildlife. Our data indicate that in Ozark streams, Hg concentrations in crayfish are at least partly determined by their diet, with concentrations in hog suckers, smallmouth, and possibly other higher-level consumers largely determined by concentrations in crayfish and other primary and secondary consumers, fish growth rates, and TP.     

Increased Mercury and Body Size and Changes in Trophic Structure of Gambusia puncticulata (Poeciliidae) Along the Almendares River, Cuba

The Almendares River is the largest river draining the area around Havana City, Cuba. The watershed is heavily populated and industrialized, which has had a significant impact on the flow and water quality of the river. The main goal of this study was to analyze the spatial variability in dietary habits, nutrient flow (using stable isotope ratios δ¹⁵N and δ¹³C), and mercury (Hg) levels along the Almendares River upstream and downstream of point-source discharges using localized fish Gambusia puncticulata. Stomach contents of G. puncticulata were similar among these sites. However, mean δ¹⁵N values ranged from 6 to 18 ‰ across sites and were lower in fish from downstream than upstream sites, suggesting localized influences of nutrient inputs along the river. δ¹³C values were between –22 and –25 ‰, except at a mid-basin site (–26 to –27‰), indicating that fish relied on similar carbon sources at most sites. Total mercury concentrations ranged from 0.04 to 0.49?μg/g wet weight whole body and were unrelated to the among-site differences in δ¹⁵N, but Hg exceeded the threshold considered to be protective of fish health (0.2?μg/g ww whole body) in the majority of fish from all sites but one. Results of this study indicate that although the dietary habits of this species do not vary across sites, tissue differences in δ¹⁵N, δ¹³C and Hg show little movement of this species among sites. Localized effects of human activities on nutrients and metals may be affecting the health of this species and posing a risk to other consumers in the ecosystem.     

Vaccine storage in pharmacies on the Central Coast of New South Wales

Pharmacies on the Central Coast of NSW were surveyed to assess the ability of refrigerators used for vaccine storage to maintain the recommended temperature range (2 to 8C). Refrigerators used for vaccine storage were monitored over a 3-day period using a temperature data logger. Fifty-nine (59) retail pharmacies were identified. The response rate was 90% (53/ 59) and 52 refrigerators were monitored successfully.
Only 10 (19%) of the refrigerators maintained temperatures wholly within the recommended range for the 3-day monitoring period. The remaining refrigerators were considered in three groups - refrigerators keeping temperatures in the range 0.1 to 11.9C, below 0C and above 8C for most of the time. There were 15 (29%), 12 (23%) and 15 (29%) refrigerators in these groups respectively keeping temperatures in the recommended range for 91%, 19% and 30% of the time. Of the refrigerators achieving temperatures below 0C, none went below -5C and on average they kept temperatures less than 0C for 49% of the time.
This survey highlights the need for vigilance in vaccine storage for immunisation programs to be successful. Of the vaccines affected by freezing, hepatitis B vaccine was identified as being most at risk.     

Dietary vitamin C and vitamin E interact to influence growth and tissue composition of juvenile hybrid striped bass (Morone chrysops (female) x M. saxatilis (male)) but have limited effects on immune responses

Juvenile hybrid striped bass (initially 12.0 g) were fed diets containing deficient, adequate or excessive amounts of vitamin C and/or vitamin E in a factorial arrangement to investigate potential nutritional interaction and effects on immune responses. Nine semipurified diets were supplemented with 0, 25 or 2500 mg vitamin C/kg and 0, 30 or 300 mg vitamin E/kg and fed to fish in triplicate aquaria for 10 wk. Weight gain, feed efficiency, mortality and tissue vitamin levels were significantly (P < or = 0.05) affected by dietary vitamin levels. In addition, a significant interaction between vitamin C and vitamin E was observed. At inclusion levels of 25 and 2500 mg/kg, dietary vitamin C improved feed efficiency and protected fish fed vitamin E-deficient diets from growth depression and mortality. At inclusion levels of 30 and 300 mg/kg, vitamin E prevented mortality in fish fed vitamin C-deficient diets; however, 300 mg vitamin E/kg was necessary to prevent growth depression in vitamin C-deficient fish but was unable to improve feed efficiency. Lysozyme, bacterial killing ability, as well as plasma protein and total immunoglobulin levels of fish were not affected by dietary vitamin levels, whereas respiratory burst activity increased with vitamin E supplementation. Thus, interactions between vitamin C and vitamin E were observed in hybrid striped bass. These interactions may be due to the ability of vitamin C to regenerate vitamin E to its functional form but also suggest an ability of vitamin E to spare vitamin C.     

Influence of steeping conditions (time,temperature, and particle size) on antioxidant properties and sensory attributes of some white and green teas

Abstract

The influence of commonly used steeping times and temperatures, as well as leaf size on the antioxidant activity and sensory attributes of tea were studied. Five unblended white and green tea samples from China and Malawi, infused in hot (70?°C and 90?°C; 7?min) or cold water (room temperature: 15, 30, 60, or 120?min) either as whole leaves or as milled, were analyzed. Total phenolic and flavonoid contents as well as antioxidant power (ABTS assay) were measured. The results show that the maximum extraction efficiency occurs with cold water for 120?min and with hot water at 90?°C and that only in the case of teas from whole, large leaves, the extraction was greater in cold than in hot infusions. Moreover, tea infusions prepared from milled leaves have the greatest antioxidant activity. In the sensory evaluation of some of the tea infusions, white teas were perceived more fragrant than green ones and were judged as the most favorite by the majority of the judges, especially for the brew prepared in cold water from whole leaves; all infusions obtained from the milled leaves in fact have a more bitter and astringent taste.     

Temporal and geographic trends in mercury concentrations in muscle tissue in five species of Hudson River, USA, fish

We analyzed a New York (USA) state database of mercury concentrations in muscle tissue for five species of fish (striped bass, yellow perch, largemouth bass, smallmouth bass, and carp) over a range of locations in the Hudson River (USA) between 1970 and 2004. We used regression models to discern temporal and geographic change in the fish while controlling for a positive correlation between mercury concentration and body mass. Mercury concentrations significantly increased in fish from New York Harbor waters to the mid-Hudson River. Striped bass and yellow perch showed a shallower increase in mercury concentration with river mile than did carp, largemouth bass, and smallmouth bass. Mercury concentrations declined over the 34-year period. These results imply that a geographically restricted source of mercury may be spread throughout the watershed by toxin-laden dispersing species. The increase of mercury toward the north may relate to a point source in the mid-Hudson River, or it may indicate mercury released from the Adirondack watershed. The decline of mercury over three decades corresponds to a reduction of various inputs in the region. The temporal and geographic pattern of mercury in sediments corresponds to the geographic trend of mercury in fish.     

The effects of different vertical air temperatures on mental performance

Mental performance (one-digit-addition test) under conditions of different vertical air temperatures (upper body vs. lower body) was studied in relation to psychological and physiological responses. Six healthy male subjects wearing light clothing were exposed to different vertical air temperatures for 105 min. The lower part of the body was exposed to an air temperature of 30 degrees C in all cases; the upper part of the body was exposed to temperatures of 15 degrees C, 20 degrees C, 30 degrees C and 35 degrees C. The performance in the one-digit-addition test decreased with increased upper air temperature, and upper air temperatures higher or lower than 25 degrees C resulted in increased discomfort. There was little difference between performance at the onset (5 min after exposure) and conclusion (90 min after exposure) at 15 degrees C and 20 degrees C upper air temperatures (UAT). The performance at 90 min, however, declined in comparison with the original value at 25 degrees C, 30 degrees C and 35 degrees C UAT. Mildly uncomfortable ambient conditions where upper air temperatures were cool and lower air temperatures were warm improved performance; however, at 35 degrees C, UAT performances worsened as the subjects felt uncomfortably hot.