Adult sockeye salmon (Oncorhynchus nerka, N = 179) from six Fraser River populations (British Columbia) were intercepted in continental shelf waters »215 km from the Fraser River mouth, gastrically implanted with acoustic transmitters, non-lethally biopsied for blood biochemistry, gill Na,K-ATPase activity and somatic energy density and then released. Migration behaviour and travel times to the...

Environmental DNA (eDNA) monitoring is a novel molecular technique to detect species in natural habitats. Many eDNA studies in aquatic systems have focused on lake or ponds, and/or on large vertebrate species, but applications to invertebrates in river systems are emerging. A challenge in applying eDNA monitoring in flowing waters is that a species' DNA can be transported downstream. Whether an...

Species such as stoneflies have complex life history details, with larval stages in the river flow and adult winged stages on or near the river bank. Winged adults often bias their dispersal in the upstream direction, and this bias provides a possible mechanism for population persistence in the face of unidirectional river flow. We use an impulsive reaction-diffusion equation with non-local imp...

the sarghaye-sarnish watershed, with elongated shape and about 70.654 km2 area, is located in south of mashhad. sarghaye and sarnish rivers are the main ones in this watershed. the purpose of this study is to investigate grain size varietions based in sedimentary links and its relation to textural parameters such as sorting, skewness and kurtosis, as well as identification of sedimentary lithof...

We used complex hypervariable repeats to evaluate the genetic diversity and structure of Prochilodus costatus (Characiformes), an ecologically and economically important species endemic to the São Francisco River basin. Hydroelectric dams along the river have led to population fragmentation, which can limit gene flow. Restocking from hatcheries has been used to repopulate declining populations....

The timing of downstream migration and detection rates of hatchery-reared Atlantic salmon Salmo salar smolts and stream-reared smolts (stocked 2 years earlier as fry) were examined in the Connecticut River (U.S.A.) using passive integrated transponder (PIT) tags implanted into fish and then detected at a downstream fish bypass collection facility at Turners Falls, MA (river length 192 km). In t...

Surface waters along the Kalamazoo River, USA, were examined for occurrence and population trends of fecal indicator bacteria (FIB) with culture-based and culture-independent methods. The two methods recorded discrepancies in FIB counts, with the culture-independent method revealing more consistent numbers between the river sites. FIB cells that hybridized with the ECO1482 probe were highest in...

in general, estuaries may be classified variously according to inlet dynamics, geomorphology orwhether they are tide or river dominated or, on a combination of all three factors. in kwazulu-natal (kzn),south africa, the four recognised estuary types are temporary opened-closed estuaries (toces), permanently opened estuaries, estuarine lakes and river mouths. since physico-chemical parameters ar...