Likewise, a successful return to the natal river and arrival to the spawning grounds will be contingent on homing orientation, time spent at sea, timing of return and timing of river entry.
These points are located just at the upper boundaries of the basin, and constitute the main river entry points.
We also considered the migration behaviour of fish with respect to river entry timing (for fish that reached the river) and attempted to pair fish with similar river entry dates and times.
Therefore, energy stored prior to river entry must fuel the river migration, as well as reproductive maturation and mating activities (Brett 1995; Hinch et al. 2005).
Our cohort excluded children who left the community before school entry and who had asthma or wheeze at study entry.
Before each analysis, we excluded people with exit dates before 01/01/85, entry dates after 31/12/01, exit dates before entry dates, or the same entry and exit dates.
Before analysis, all variables were reviewed for accuracy of data entry and missing values.
At various intervals of history, rivers have provided the easiest, and in many areas the only, means of entry and circulation for explorers, traders, conquerors, and settlers.
"How long before the river is clean and usable, I don't know," Cardinal said.
