Freshwater Conservation

Question 1

Freshwater Diversity

Answer 1

1% of the total volume
41% of all fish species

Question 2

Freshwater declines

Answer 2

83% decline since the 1970s
This is higher than terrestrial and marine

Question 3

Causes of freshwater decline

Answer 3

Exotic introductions ~68%
Pollution ~38%
Hybridization ~38%
Overharvest ~15%

Question 4

British Columbia Freshwater fisheries

Answer 4

81 FW species
4 extinct
Dragon Lake whitefish has 2 species that are extinct (toxaphene poison)
Hadley lake stickleback 2 species catfish invasion
15 exotic introduction

Question 5

Factors for FW diversity

Answer 5

Isolation
Spatial heterogeneity
primary productivity
temporal scale

Question 6

Substrate Alteration

Answer 6

most fish depend on substrate complexity
snags removed for human use
snags are 4% of the area but, 60% of invertebrate biomass (4x more food-mass)
Serves as nursing habitat

Question 7

Channelization

Answer 7

reduce fish/biomass and productivity

Question 8

Mining and tailing ponds

Answer 8

sedimentation, heavy metal contamination
trillions of liters in candada

Question 9

Deforestation of riparian

Answer 9

effects sedimentation, turbidity, bank stability, loss of shading

Question 10

Dams

Answer 10

Influence habitat and migration
sometimes use fish ladders
large reductions to migrating salmon in NA

Question 11

Aswan Dam

Answer 11

Reduces sardines in mediterranean

Question 12

Volga river

Answer 12

90% catch loss in caspian sea

Question 13

Hells Gate Rockslide

Answer 13

This increased water flow velocity
100% block of salmon

Question 14

Introduced species

Answer 14

Transplants within a country and exotics from outside
160 FW introduced species
in all cases introductions lead to declines or extinctions

Question 15

Brazilian introductions

Answer 15

Naturalization of invasives for aquaculture

Question 16

Asian carp

Answer 16

Placed by US gov into sewage ponds to eat the algae
Flooded into Mississippi River where they now dominate
They have migrated up and detected into the Great Lakes

Question 17

Dam Removal vs Invasive Management

Answer 17

Dam removal and fixing the flow characters of the river is valuable, but the removal of invasives is more important

Question 18

Great Lakes

Answer 18

200 native fishes
Canal from Lake Ontario to Lake Erie allows for the invasion of many marine species
Lamprey have decimated lake trout population
Zebra mussel covers most of the benthos
180 species introduced

Question 19

Lake Winnipeg

Answer 19

largest intact watershed
commercial fishing and 25% of Canadas FW catch
major shoreline development and input from many rivers across prairies has led to eutrophication

Question 20

Teck Mines

Answer 20

Zinc and lead smelters in Trail
10 million tonnes of slag per year into the Columbia river
60 million dollars in fines last 20 years

Question 21

Overfsihig

Answer 21

Larely unrecognized and poorly understood