Humans and the ocean

Question 1

when was the first evidence of humans using marine environments for good dated back to

Answer 1

more than 150,000 years ago

Question 2

what did T.H.Huxley in 1883 say

Answer 2

I believe then, that the cod fishery…and probably all the great sea fisheries are inexhaustible, that is to say that nothing we do will seriously affect the number of fish and any attempt to regulate these fisheries seems to be useless

Question 3

define fishing effort

Answer 3

the time spent searching for fish and/or the amount of fishing gear of a specific type used on the fishing grounds over a given unit of time
CPUE= catch per unit effort

Question 4

what are stocks

Answer 4

discrete population of a species, breeding seperelty from other stocks

Question 5

what is maximum sustainable yield

Answer 5

the maximum annual catch which can be taken from a stock, indefinitely without causing population decline

Question 6

outline production from fisheries in 2020

Answer 6

Global= 179 billion tonnes ($401 billion)
84.4 million tonnes of marine capture
30.8 million tonnes of marine aquaculture

Question 7

outline consumption of fish today

Answer 7

25.5kh per capita
88% for direct human consumption
18 million tonnes for fish feed or fish oil

Question 8

outline how fishing affects employment in society

Answer 8

59.5 million emplyed in full time, part time or occasional basis in 2018
- 22 million small scale fisheries

Question 9

what percentage of global catch does china occupy

Answer 9

15

Question 10

give some examples of some of the largest catch of fish species

Answer 10

herrings
anchovies
sardines
menhadens and shads
pollock
tuna

Question 11

what is meant by fishing down the food web

Answer 11

describes the process of first catching top predators, then as they are overfished the fishery becomes dominated by lower trophic species

Question 12

outline some reasons as to why there was push back on fishing down the food web

Answer 12

• evidence was little
• range expansion of fisheries
• similar patterns not found in survey trawl data

Question 13

what is an indicator of overfishing

Answer 13

decline in mean trophic level in catch over time
MLT= calculated based on weight of each species in catch

Question 14

how does fishing affect habitats

Answer 14

habitat destruction
- blast/cyanide fishing on coral reefs
- ghost fishing
- bottom trawling

Question 15

outline bycatch

Answer 15

unselective fishing catches non-target species
- injured or dead