River Restoration for FISH

Question 1

What is the life cycle of fish

Answer 1

Alevins-fry-parr-smolts-adults-lay eggs

Question 2

how long does it take alevins to become fry

Answer 2

3-4 weeks

Question 3

how long do parr remain in fresh water

Answer 3

2-3 years

Question 4

what life stage sees a change from freshwater to seawater

Answer 4

smolts

Question 5

what do fry and parr require for survival

Answer 5

unpolluted well oxygenated water, plenty of food, refuge from very high flows

Question 6

what do juveniles and adults require for survival

Answer 6

unpolluted well oxygenated water, plenty of food, sufficient depth and cover

Question 7

what spawning conditions do fish require

Answer 7

unpolluted well oxygenated water, clean gravels, access to spawning grounds

Question 8

what are the problems with pollution in fish survival

Answer 8

industrial, agricultural, acidicfication

Question 9

what are the erosion problems with fish survival

Answer 9

trampling of banks, and bank erosion, can reduce depth and increase siltation

Question 10

what are the siltation problems with fish survival

Answer 10

forestry agriculture, chokes stream, reduces production and thus reduces food availability

Question 11

what are the barriers to migration problems with fish survival

Answer 11

wiers dams and debris block the paths for fish upsteam and so they cant lay eggs in the places they want to

Question 12

what are the lack of water problems with fish survival

Answer 12

abstractions, diversions and drought induced by climate change, reduce channel depth and size, thus limiting production of food within the channel

Question 13

How can we restore bank erosion

Answer 13

fencing and limited stock access

Question 14

How can we restore widened channels

Answer 14

physical narrowing or marginal planting

Question 15

How can we restore pollution impacts

Answer 15

clean up point source, manage diffuse sources, change forestry type, add buffer reedbeds to stop leaching of chemicals

Question 16

How can we trap and reduced silt

Answer 16

agriculture management buffer zones

Question 17

How can we manage bankside trees

Answer 17

coppicing

Question 18

How can we manage flows

Answer 18

reduce abstraction, compensate flows, flow deflectors

Question 19

How can we remove barriers

Answer 19

remove unessiscary barriers to fish migration, or make current barriers more manageable for fish

Question 20

how high vertically can atlantic salmon clear

Answer 20

1.4 meters

Question 21

how high vertically can brown trout clear

Answer 21

1 meter

Question 22

since when have trent salmon seen decline

Answer 22

late 1800’s

Question 23

how many wiers on the river trent itself alone

Answer 23

19

Question 24

how were fish targeted on the trent

Answer 24

netting in tidal reaches

Question 25

how many people live in the trent catchment

Answer 25

6.5million

Question 26

what are the negatives of a fish ladder

Answer 26

can take up a lot of land, can be expensive, often very large

Question 27

what are the advantages of baffle passes like the denil and the Alaskan A

Answer 27

can be used where there is little area

Question 28

what is different about the larnier fish pass

Answer 28

textured bottom to create flow that fish can swim up

Question 29

what measures can be put in place to improve eel migration upstream

Answer 29

eel brushes, can be other structures like pegs

Question 30

what was the aim of the trent salmon restoration project

Answer 30

identify problems, remove habitats, stock parr, monitor stocks

Question 31

how many parr were added to the trent between 1998 and 2003

Answer 31

780,000

Question 32

what was the performance of the salmon trent project

Answer 32

success, salmon returned for the first time in 70 years,

Question 33

how are fish seen to pass through the barriers

Answer 33

ID salmonid scan, or lasers, or video