Patterns of density-dependent growth in juvenile stream-dwelling salmonids

Patterns of density-dependent growth in juvenile stream- dwelling salmonids

Literature data for 19 populations from 16 different studies of six species of stream-dwelling salmonids were analysed to test the hypothesis that density-dependent growth is stronger at low rather than at high population density. Fifteen of 19 populations showed evidence of a significant decrease in growth rate with increasing density. In 11 of these 15 populations, the pattern of density-depe...

Analysis of Movement Patterns of Stream-dwelling Salmonids in Response to Three Survey Methods

Are Block Nets Necessary?: Movement of Stream-Dwelling Salmonids in Response to Three Common Survey Methods

—Fish movement during sampling may negatively bias sample data and population estimates. We evaluated the short-term movements of stream-dwelling salmonids by recapture of marked individuals during day and night snorkeling and backpack electrofishing. Bull trout Salvelinus confluentus and rainbow trout Oncorhynchus mykiss were captured in sufficient numbers to evaluate instream movements and th...

Efficiency of Portable Antennas for Detecting Passive Integrated Transponder Tags in Stream-Dwelling Salmonids

Portable antennas have become an increasingly common technique for tracking fish marked with passive integrated transponder (PIT) tags. We used logistic regression to evaluate how species, fish length, and physical habitat characteristics influence portable antenna detection efficiency in stream-dwelling brown trout (Salmo trutta), bull trout (Salvelinus confluentus), and redband trout (Oncorhy...

Density-Dependent Growth in Juvenile Sockeye Salmon (Oncorhynchus Nerka)

Data gathered over 77 lake-years from 4 coastal British Columbia sockeye salmon nursery lakes suggest that density-dependent growth reductions are only possible at exceptionally high fry densities. In Great Central Lake (n=33 years) and Sproat Lakes (n=30 years) there was no relationship between smolt weight and mean summer fry densities ranging from 760-3800 fry ha -1 . However, in two years w...