When fishing a flooded river I always wonder how many fish get swept downstream or over weirs and are never able to make it back up. I always tell myself that it is probably an insignificant amount of fish - but i don't actually know this.
A study at the Nottingham university in 2000 looked at the fish passing over thrumpton weir on the trent over a year period as part of wider project looking at the fish sucked into a local power station.
The study showed that more fish are swept over the weir in summer, these fish far mainly young fish in the first year of their life, either swept over by the force of the current or are swept over when looking for new areas to live (dispersing).
The chart (left) shows the percentage of each fish species being swept over the weir during the year.
Although the study concludes that the number of fish swept over weirs might be insignificant it does show that younger fish are more vulnerable and floods that that happen in the summer months just after the fish have spawned are probably more damaging/ dangerous to fish populations than those in the winter months.
Anyway if you would like to read the study here is the reference:
Carter, K. L., & Reader, J. P. (2000). Patterns of drift and power station entrainment of 0+ fish in the River Trent, England. Fisheries Management and Ecology, 7(5), 447-464.
A study at the Nottingham university in 2000 looked at the fish passing over thrumpton weir on the trent over a year period as part of wider project looking at the fish sucked into a local power station.
The study showed that more fish are swept over the weir in summer, these fish far mainly young fish in the first year of their life, either swept over by the force of the current or are swept over when looking for new areas to live (dispersing).The chart (left) shows the percentage of each fish species being swept over the weir during the year.
Although the study concludes that the number of fish swept over weirs might be insignificant it does show that younger fish are more vulnerable and floods that that happen in the summer months just after the fish have spawned are probably more damaging/ dangerous to fish populations than those in the winter months.
Anyway if you would like to read the study here is the reference:
Carter, K. L., & Reader, J. P. (2000). Patterns of drift and power station entrainment of 0+ fish in the River Trent, England. Fisheries Management and Ecology, 7(5), 447-464.
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