Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural systems, but also is linked with a variety of ecosystem services such as bioremediation and provisioning of biomass, as well as an assortment of traditional cultural uses. Numerous physical, chemical, and hydrologic control methods are used to manage invasive Typha, but results are inconsistent and multiple methods and repeated treatments often are required. While this review focuses on invasive Typha in North America, the literature cited comes from research on Typha and other invasive species from around the world. As such, many of the underlying concepts in this review are relevant to invasive species in other wetland ecosystems worldwide.

Knowledge of movement patterns is critical to the management and conservation of inland salmonids. We studied the movements of Bonneville cutthroat trout (Oncorhynchus clarki utah) in a drainage in western Wyoming, USA. Our objectives were to (i) characterize the postspawning movement patterns of adult Bonneville cutthroat trout, (ii) contrast postspawning and summer movement patterns, and (iii) identify factors that disrupt the movements of Bonneville cutthroat trout. Our data showed that postspawning movements of Bonneville cutthroat trout formed a continuum, with fish moving from 0.5 to 82.0 km. Postspawning distance was positively related to fish length. Despite the wide range of movement observed during the spring, fish did not move more than 0.5 km during the summer. A road culvert and an irrigation diversion dam did not seem to pose barriers to the upstream movement of Bonneville cutthroat trout to headwater spawning areas in the spring. However, 23% of radio-tagged fish in 2000 moved into the irrigation diversion ditch as they moved downstream after spawning and subsequently died there. Maintaining drainage connectivity is an important conservation concern for trout populations such as this one, where fish move between complementary spawning and summer habitats.

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SynopsisThe purpose of this study was to determine if body and fin form affected the maneuverability of teleostean fishes as measured by their ability to negotiate simple obstacles. Obstacles were vertical and horizontal rectangular slits of different widths, for which width was defined as the minimum dimension of a slit irrespective of slit orientation. Performance was measured as the smallest slit width traversed. Three species with different body and fin patterns were induced to swim through slits. Species tested were; goldfish Carassius auratus with a fusiform body, anterio-ventral pectoral fins and posterio-ventral pelvic fins; silver dollars Metynnis hypsauchen with the same fin configurations but a gibbose body; angelfish Pterophyllum scalare with a gibbose body and anterio-lateral pectoral fins. Minimum slit widths negotiated were normalized with the length of various body dimensions: total length, maximum width, span at the pectoral fins, and volume '" (numerically equal to mass 'I3). Goldfish had the poorest performance, requiring the largest slit widths relative to these body dimensions. No consistent patterns in performance were found for silver dollars vs. angelfish. There were no differences among species in the ratio of minimum vertical slit width negotiated to that for horizontal slits, indicating fish were equally able to control posture while swimming on their sides. There were also no consistent patterns in the times taken to transit slits. Although the deep-bodied fish were able to maneuver through smaller slits, the most striking result is the similarity of minimum slit widths traversed in spite of the large variation in body form. Body form and fin plan may be more important for maneuvering and posture control during sub-maximum routine activities.