Use of Soil and Water Protection Practices Among Farmers in Three Midwest Watersheds

Data were collected from 1011 farmers in three Midwestern watersheds (Ohio, Iowa, and Minnesota) to assess factors that influence the use of conservation production systems at the farm level. The “vested interests” perspective used to guide the investigation was derived from elements of social learning and social exchange theories. Respondents were asked to indicate their frequency of use for 18 agricultural production practices that could be adopted on Midwestern farms at the time of the study. Responses to the 18 items were summed to form a composite variable, termed “conservation production index,” for use as the dependent variable in multivariate analysis. Eleven independent variables were identified from the theory as likely predictors of conservation adoption, including respondents' perceptions about production costs, output and risks, and perceived importance of access to subsidies, technical assistance, and informational/educational programs. Regression analysis was used to assess the performance of the independent variables in explaining variance in the conservation production index. Explained variance in the three regression models ranged from 2% in the Minnesota watershed to 19% in the Ohio watershed. The researchers concluded that the model had limited utility in predicting adoption of conservation production systems within the three study watersheds. Findings are discussed in the context of conservation programs within the three areas.     

The Effects of Sewage Sludge On Two Life-History Stages of Mytilus Edulis

Adult and embryos of the common mussel 'Mytilus edulis were exposed to dilutions of, respectively, whole and seawater-extracted sewage sludge. the response of adult mussels was measured as change in feeding and respiration rate after four weeks' continuous exposure, while embryo response was assessed as the percentage of normal, D-shaped larvae after 24 hours, exposure. Adult feeding rate was significantly depressed, and respiration rate significantly increased, at the lowest sludge concentration used (0.02%), and the effect appeared to be attributable to the dissolved rather than to the participate phase of the test medium. the developmental EC50 for embryos was estimated to be 0.15% sewage sludge. at dilutions of 1:600 to 1:5000, therefore, the sewage sludge investigated contained unidentified desorbable components toxic to planktonic and benthic life-history stages of a common marine invertebrate.

Aerial application of fenthion, 0.0-dimethyl 0-[3-methyl-4-(methylthio)phenyl] phosphorothioate, is widely used to control adult mosquito populations in the Florida coastal marshes. Although not sprayed on water intentionally, aerial spray may accidentally drift into estuarine, coastal and offshore waters. Laboratory and field studies were previously conducted to determine the assimilation capacity of fenthion in coastal water and its effects on non-target organisms. Fenthion, once deposited to the coastal water, normally undergoes chemical, photochemical and biological processes. the effect of pH, salinity, natural sunlight and biological activities in the coastal water are discussed. the half-life of fenthion in the offshore, inlet coastal water, estuarine and mangrove swamp waters were found to be 21.1, 5.6, 4.2 and 2.9 days, respectively. in natural conditions, photolysis and biological activities are the two dominant pathways for assimilating fenthion in the water. Four aerial field studies were also conducted to investigate the deposition rate of fenthion in the water. the deposition rate of fenthion aerial spray into the coastal water and its acute toxicity on non-target estuarine organisms were determined. After each spray, fenthion concentration was normally increased and peaked at 45 minutes and then gradually decreased. After 24 hours, only a trace of fenthion (0.01 μgL^-1) was detected. Animal toxicity tests conducted in the field included adults of the calanoid copepod, Acartia tonsa, eggs and juveniles of three species of fishes. Statistically, significant mortality occurred only for copepods in one of the four tests. Water quality such as temperature could play an important role in the sensitivity of copepods to the fenthion.     

The uses and implications of avian vocalizations for conservation planning

There is a growing recognition that animal behavior can affect wildlife conservation, but there have been few direct studies of animal behavior in conservation programs. However, a great deal of existing behavioral research can be applied in the context of conservation. Research on avian vocalizations provides an excellent example. The conspicuous nature of the vocal behavior of birds makes it a useful tool for monitoring populations and measuring biodiversity, but the importance of vocalizations in conservation goes beyond monitoring. Geographic song variants with population-specific signatures, or dialects, can affect territory formation and mate choice. Dialects are influenced by cultural evolution and natural selection and changes can accumulate even during the timescale of conservation interventions, such as translocations, reintroductions, and ex situ breeding. Information from existing research into avian vocalizations can be used to improve conservation planning and increase the success of interventions. Vocalizations can confer a number of benefits for conservation practitioners through monitoring, providing baseline data on populations and individuals. However, the influence of cultural variation on territory formation, mate choice, and gene flow should be taken into account because cultural differences could create obstacles for conservation programs that bring birds from multiple populations together and so reduce the success of interventions.