Studies on two stage sludge digestion, 1928-29

At head of title: State of Illinois. Department of registration and education. Division of the state Water survey."Bulletins of the state water survey": 1 leaf at end."Literature cited": p. 92.Enumeration continues from preceding title

Impacts of epizootic ulcerative syndrome on subsistence fisheries and wildlife

Epizootic ulcerative syndrome (EUS), caused by the water mould (Oomycota) Aphanomyces invadans, has spread throughout the world’s major continents over the last 50 years, with the apparent exception of South and Central America. With over 160 susceptible fish species representing 54 families and 16 orders recorded to date, EUS is of international concern and infection with A. invadans is a World Organisation for Animal Health (OIE) listed disease. This paper examines what little has been reported on the impacts of EUS on subsistence fisheries and wildlife, or what can be deduced about those impacts, and concludes that there is a need for systematic data collection on the size and socio-economic importance of subsistence fisheries. Such fisheries are often relied upon by the poorest communities, thus food and nutrition security impacts can be significant. Similarly, impacts on wildlife are poorly documented, emphasising the lack of, and the need for, research on and modelling of the ecosystem-level impacts of EUS and other aquatic animal diseases. The history of EUS and several other aquatic animal diseases also brings into question the effectiveness of current measures for controlling the international spread of aquatic animal diseases and calls for a re-think on how best to meet this ongoing challenge

Diving behaviour of Elseya albagula from a naturally flowing and hydrologically altered habitat

This study investigated the diving behaviour and performance of the bimodally respiring turtle Elseya albagula within the Burnett River, central Qld, Australia. Diving parameters were recorded using pressure-sensitive time-depth recorders for turtles residing within a free flowing versus regulated reach. Maximum submergence time recorded for El. albagula (greater than 3 hours) is among the longest recorded for a voluntarily diving vertebrate, and is attributed to the turtle's ability to respire aquatically. Median dive times logged for El. albagula within the regulated reach (6.7 min) were threefold longer than values recorded for turtles residing within a naturally flowing creek (1.9 min), with discrepancies in dive duration possibly due to the variable hydrologic flows recorded below the weir. No correlation was observed between dive duration and subsequent surfacing intervals, suggesting that dives remained aerobic throughout the study. Despite considerable differences in the magnitude and daily variation of water flow between the two locations, similar diel activity and surfacing trends were recorded for El. albagula. Turtles undertook deep resting dives (> 1.5 m) during the day before moving into shallower habitats (< 1.0m) for the night, while the crepuscular hours were characterized by elevated surfacing frequencies attributed to periods of increased activity possibly associated with foraging

Seasonal changes in the diel surfacing behaviour of the bimodally respiring turtle Rheodytes leukops

The purpose of this study was to determine whether a relationship existed between the diel surfacing trends of the bimodally respiring freshwater turtle Rheodytes leukops and daily fluctuations in specific biotic and abiotic factors: The, diel surfacing behaviour of adult R. leukops was recorded over four consecutive seasons (Austral autumn 2000 - summer 2001) within Marlborough Creek, central Queensland, Australia, using pressure-sensitive time-depth recorders. Additionally, diurnal variations in water temperature and aquatic Po-2 level, as well as the turtle's behavioural state (i.e., active versus resting), were monitored. In autumn and summer, surfacing frequency increased significantly during the daylight hours, with peak levels normally occurring around dawn (0500-0700) and. dusk (1700-1900). However, no consistent diel surfacing trend was recorded, for the turtles in winter or spring, owing to considerable variation among individual R. leukops. Diurnal surfacing trends recorded for R. leukops in, autumn and summer are attributed to periods of increased activity (possibly associated with foraging) during the daylight hours and not to daily variations in water temperature or aquatic Po-2 level. Turtles generally remained at a depth greater than 1 m throughout the day, where the effect of diel fluctuations in water temperature,