Fisheries And Sea Birds

Question 0

What happens with overfishing?

Answer 0

• overfishing is when we fish more than we want
• fish more than the co system can supply
  Causes
• over productive fishing nets/methods
• health food - omega 3
• human demand
• food preference
• EU guidelines tell us ‘ you can catch x amount of each species but more than that must be thrown back into the water’

Question 1

What impacts do humans have on seabirds and fish?

Answer 1

• Bycatch
• discard
• overfishing

Question 2

What’s involved with discarding?

Answer 2

• Any unwanted or overfished species are thrown back into yeah water
• very few fish survive

Question 3

What information was covered in the ‘Plenty more fish in the sea?’ Video?

Answer 3

• 1.7m tonnes of edible fish in Europe discarded every year
• 23% or almost a 1/4 of fish caught are thrown back
• 43m people at risk of food poverty
• ecosystem can not recover Fish supply’s quick enough
• fisherman disagree with discarding
  Why?!
  CPF control fishery rules of discard
• went through a change of rule although new policy would still estimate 335,000 tonnes of fish discarded

Question 4

What else is there to discard?

Answer 4

• Fisheries fish at the demersal (lowest) level of the sea
  2 strategies used by seabirds

1. birds will search for fish
   - dive for fish
   - feed on natural prey
   - rewarded by quality
   Benefit: nutritionally beneficial
   Cost: diving, find prey
2. Birds search for the boat
   - doesn’t dive
   - feeds on discards
   - rewarded with quantity
   Benefit: little diving required, potentially less searching effort
   Cost: nutritionally poor

Question 5

What is involved in seabird bycatch?

Answer 5

• Birds flock to boat for easy catch of bait or discard
• birds get caught on the fishing lines and drown
• 100,000 albatross are caught on fishing lines every year
• of 22 species of albatross, 19 species are threatened with extinction

Question 6

What fishery research has been done recently?

Answer 6

• a study to identify fishing habits and preference of Northern gannets
• occurred 12miles of welsh coast on greenhorn island
• home to 40,000 pairs of northern gannets

Question 7

What work was done in the gannet study?

Answer 7

Method
Caught gannet
Take biometrics
Attach:
- 30g Gps unit (report location every 2 minutes)
- depth logger (report depth every 10 secs)
Release bird

Return 2 weeks later
Recapture bird
Remove and download data
Release bird

Question 8

What extra data was collected on the fisheries in the gannet study?

Answer 8

each boat has GPS (only report location every 2 hours)
The type of fisheries

Potting- 15% of catch
Longbeam fishing - 42% of catch

ENEVER ET AL 2007

Question 9

What is a bioindicator and why are seabirds bioindicators?

Answer 9

Bioinicator is a species which indicates te healthy of the co system and environment around it

Seabirds are at the top if their food chain so provide good evidence of ecosystem health

Question 10

What can you remember from the bycatch review ( Anderson, small and croxall et al 2011)

Answer 10

Mixed history of fisherman and seabird relationship

• Much time spent on removing bycatch from fishing lines
• Loose bait for fish due to bycatch.
• Reduces fish caught
• conservation favourable for both parties (fisherman: reduced bycatch means more fish and more time. Seabird conservation: increase seabird numbers and have fewer anthropogenic deaths)
• many fisheries don’t follow best practice so bycatch increases
• 9 of 10 fishery fleets provided poor data.
• studies have been done on endangered seabird species but not global species.
• 7 species of petrel threatened (IUCN, 2010)
• species specific studies eg black-browsed albatross

Could not estimate increase or decrease in bycatch due to limited and poor data

Concluded that 160-320,000 birds killed in bycatch every year due I fishing lines