AQUATIC HABITAT CONDITION INDEX,STREAM TYPE,AND LWESTOCK BANK DAMAGE IN NORTHERN NEVADA1

ABSTRACT: The quality of stream habitat varies for a variety of natural and anthropogenic reasons not identified by a condition index. However, many people use condition indices to indicate management needs or even direction. To better sort natural from livestock influences, stream types and levels of ungulate bank damage were regulated to estimates of aquatic habitat condition index and stream width parameters in a large existing stream inventory data base. Pool/riffle ratio, pool structure, stream bottom materials, soil stability, and vegetation type varied significantly with stream type. Pool/riffle ratio, soil and vegetation stability varied significantly with ungulate bank damage level. Soil and vegetation stability were highly cross-correlated. Riparian area width did not vary significantly with either stream type or ungulate bank damage. Variation among stream types indicates that riparian management and monitoring should be stream type and reach specific.     

Analysis of potential impacts to resident fish from Columbia River System Operation alternatives

The US Army Corps of Engineers, the US Bureau of Reclamation, and the Bonneville Power Administration initiated the Columbia River System Operation Review (SOR) in 1990. The SOR will assist agencies in comparing the benefits and risks to Columbia River uses and natural resources from alternative strategies for using Columbia River water. Focusing on 14 federal dams within the basin, the agencies are attempting to improve on the efficient and coordinated use of the Columbia River system. An initial screening of all potential strategies of reservoir operation was necessary to reduce the number of possibilities to a limited set for detailed analysis. To that end, the Resident Fish Work Group of the SOR developed spreadsheet models capable of assessing the impacts of different management strategies on resident fish at six storage reservoirs. The models include biological, physical, and hydrological relationships important to resident fish specific to each reservoir. Alternatives that kept the reservoirs near full pool and held stable during the growing season resulted in positive benefits to resident fish at all locations modeled. Conversely, alternatives designed to improve anadromous fish survival with increased instream flow generally had a negative impact on the resident fish in the reservoirs modeled. The models developed for resident fish in the screening analysis phase of the SOR were useful in assessing the relative impact to resident fish from a large number of alternatives. The screening analysis demonstrated that future analytical efforts must consider trade-offs among river uses/resource groups, among reservoirs throughout the basin, and among resident fish species within a reservoir.Pacific Northwest Laboratory is operated by Battelle Memorial Institute for the US Department of Energy under contract DE-AC06-76RLO 1830.     

Review and comparison of wetland impacts and mitigation requirements between New Jersey,USA, Freshwater Wetlands Protection Act and Section 404 of the Clean Water Act

A review of wetland impacts authorized under the New Jersey Freshwater Wetlands Protection Act (FWPA) was conducted based on permitting data compiled for the period 1 July 1988 to 31 December 1993. Data regarding the acreage of wetlands impacted, location of impacts by drainage basin and watershed, and mitigation were analyzed. Wetland impacts authorized and mitigation under New Jersey's program were evaluated and compared with Section 404 information available for New Jersey and other regions of the United States.Under the FWPA, 3003 permits were issued authorizing impacts to 234.76 ha (602.27 acres) of wetlands and waters. Compensatory mitigation requirements for impacts associated with individual permits required the creation of 69.20 ha. (171.00 acres), and restoration of 16.49 ha (40.75 acres) of wetlands. Cumulative impacts by watershed were directly related to levels of development and population growth.The FWPA has resulted in an estimated 67% reduction [44.32 ha (109.47 acres) vs 136.26 ha (336.56 acres)] in annual wetland and water impacts when compared with Section 404 data for New Jersey. For mitigation, the slight increase in wetland acreage over acreage impacted is largely consistent with Section 404 data.Based on this evaluation, the FWPA has succeeded in reducing the level of wetland impacts in New Jersey. However, despite stringent regulation of activities in and around wetlands, New Jersey continues to experience approximately 32 ha (79 acres) of unmitigated wetland impacts annually. Our results suggest that additional efforts focusing on minimizing wetland impacts and increasing wetlands creation are needed to attain a goal of no net loss of freshwater wetlands.     

JUVENILE BLUEBACK HERRING (ALOSA AESTIVALIS) SURVIVAL VIA TURBINE AND SPILLWAY1

ABSTRACT: The 48 h survival of emigrating juvenile blueback herring (Alosa aestivalis) was estimated at 96 ± 6.7 percent in passage through a Kaplan-type turbine and at 88.3 ± 10.7 percent (90 percent confidence interval) over a spillway (3.7 m high and spillage of 1.2 m³/s) of a low-head hydro darn (8.3 m). These results suggest that diversion of juvenile alosids over spillways may not be assumed to be a totally benign strategy without obtaining site-specific data. A remarkable similarity in survival rates of fish observed through turbine routes in this study and others suggests that these trends may be common. However, due to a lack of sufficient data, such a conclusion cannot be made for survival over spillways.     

Innate responses to male sexual harassment in female mosquitofish

Male mosquitofish are very persistent in their sexual activity and harass any female they encounter. Gravid females pay a large tribute to this intense male sexual activity in terms of reduced foraging efficiency. Previous observations have demonstrated that gravid females, when chased by a male, dilute male harassment by moving closer to other females to form shoals. They also approach other males to promote male competition, and when males differ in size, they preferentially target large males, whose harassment is less intense. In this study, we tested whether the modulation of females’ social preferences in response to male harassment is innate or learned. We tested social preference in three groups of females that differed in experience of sexual harassment and in the factors affecting it. Females of the first group were reared without any sexual experience, and pregnancy was induced through artificial insemination. The second group was composed of naive females kept singly with a male; these females experienced sexual harassment but were prevented from experiencing the effects of male–male competition and shoaling on the amount of male sexual harassment. In the third group (controls), females were reared in multi-male, multi-female groups and could experience the modulating effects of social interactions on sexual harassment. When exposed to a harassing male, females of the three groups immediately reduced their distance from another female, approached a group of males or moved toward the larger of two available males. Moreover, the results for these three groups of females were similar to those obtained in wild-caught females that were tested in the same three tests in a previous study (Dadda et al. An. Behav., 70:463–471, 2005). This suggests that the strategies adopted by females in response to male sexual harassment do not need to be learned through specific experience of the social contexts.     

Determination and occurrence of endocrine disrupting compounds,pharmaceuticals and personal care products in fish (Morone saxatilis)

Endocrine disrupting compounds (EDCs), pharmaceuticals and personal care products (PPCPs) have attracted much attention due to widespread contamination in aquatic environment. In this study, we determined 13 EDCs and PPCPs in fish blood, bile and muscle by using gas chromatography-mass spectrometry (GC-MS). The limits of quantitation (LOQ) were in the ranges of 0.23–2.54, 0.22–2.36 ng·mL⁻¹, and 0.24–2.57 ng·g⁻¹ dry weight (dw) for fish blood, bile and muscle, respectively. Recoveries of target compounds spiked into sample matrices and passed through the entire analytical procedure ranged from 65% to 95%, from 60% to 92% and from 62% to 91% for blood, bile and muscle, respectively. The methods were applied to the analysis of fish from a lake in California. Target compounds were relatively low in bile, and only bisphenol A (BPA) and diclofenac were measurable near the LOQ. Seven of 13 compounds were detected in blood, with total concentrations up to 39 ng·mL⁻¹. Only BPA was frequently found in muscle, with mean concentration of 7.26 ng·g⁻¹ dw. The estimated daily intake of BPA through fish consumption for U.S. resident was significantly lower than the tolerable daily intake recommended by the European Food Safety Authority. This study showed that the exposure to the bisphenol A from fish diet is unlikely to pose a health risk.     

Tissue-specific stress and hepatic DNA damage in Pelteobagrus fulvidraco caused by low concentrations of cadmium

Physiological stress and DNA damage in Pelteobagrus fulvidraco induced by continuous exposure to cadmium at concentrations of 170 and 1700 µg/L for up to 28 days was evaluated. The activities of acetylcholinesterase and monoamine oxidase in brain tissue, Na⁺-K⁺-ATPase and glutathione in gill tissue, and superoxide dismutase and catalase in liver tissue were measured. In studying random amplified polymorphic DNA to evaluate cadmium-induced hepatic genotoxicity, both the appearance of new bands and the disappearance of existing bands were observed, as well as increased levels of monoamine oxidase and Na⁺-K⁺-ATPase and decreased activities of antioxidant enzymes. The results suggest that continuous exposure to cadmium at the studied levels can induce biochemical and physiological changes and DNA damage in P. fulvidraco.     

饵料对稀有鮈鲫幼鱼和成鱼生长的影响及摄食优化策略研究

在实验室适宜的饲养条件下,进行不同发育阶段的稀有鮈鲫为期30 d的摄食-生长实验,研究3种饵料在投喂量分别为鱼体湿重的3.0%、4.0%和6.0%的3种摄食水平条件下,对稀有鮈鲫幼鱼(初始湿重为(0.0749±0.02)g)和成鱼(初始湿重为(0.2603±0.06)g)的生长影响。结果表明,不同摄食水平组的稀有鮈鲫幼鱼的相对增重率和特定生长率随摄食水平的增加而增加,但饲料转化率呈下降趋势;而稀有鮈鲫成鱼的相对增重率、特定生长率和饲料转化率的变化趋势基本相同。适宜摄食水平随稀有鮈鲫体重的增加而降低,稀有鮈鲫幼鱼和成鱼的适宜饵料分别为O.S.I.微细颗粒和O.S.I.细颗粒,适宜摄食水平分别为6.0%和4.0%。     

Determination of hemoglobin adduct of a musk xylene metabolite in trout as biomarker of exposure by gas chromatography mass spectrometry

Introduction Nitromusksarewidelyusedassyntheticfragranceingredientsinformulationofsoaps,laundrydetergents,lotions,andbody careproducts,andsoon.Thecommercial anddomesticuseanddischargeofthesecompoundsfrommunicipalsewagesystemshaveledtotheirubiquitousoccurr…     

Modelling the effect of in-stream and overland dispersal on gene flow in river networks

Modelling gene flow across natural landscapes is a current challenge of population genetics. Models are essential to make clear predictions about conditions that cause genetic differentiation or maintain connectivity between populations. River networks are a special case of landscape matrix. They represent stretches of habitat connected according to a branching pattern where dispersal is usually limited to upstream or downstream movements. Because of their peculiar topology, and the increasing concern about conservation issues in hydrosystems, there has been a recent revival of interest in modelling dispersal in river networks. Network complexity has been shown to influence global population differentiation. However, geometric characteristics are likely to interact with the way individuals move across space. Studies have focused on in-stream movements. None of the work published so far took into consideration the ability of many species to disperse overland between branches of the same network though. We predicted that the relative contribution of these two dispersal modalities (in-stream and overland) would affect the overall genetic structure. We simulated dispersal in synthetic river networks using an individual-based model. We tested the effect of dispersal modalities, i.e. the ratio of overland/in-stream dispersal, and two geometric parameters, bifurcation angle between branches and network complexity. Data revealed that if geometrical parameters affected population differentiation, dispersal parameters had the strongest effect. Interestingly, we observed a quadratic relationship between p the proportion of overland dispersers and population differentiation. We interpret this U-shape pattern as a balance between isolation by distance caused by in-stream movements at low values of p and intense migrant exchanges within the same branching unit at high values of p. Our study is the first attempt to model out-of-network movements. It clearly shows that both geometric and dispersal parameters interact. Both should be taken into consideration in order to refine predictions about dispersal and gene flow in river network.