Lecture 1

Question 0

What is the demersal zone of the sea?

Answer 0

Any body of water near or interfacing with the sea bed

Question 1

What is the pelagic zone of the sea?

Answer 1

Anywhere in the water column but not the seabed

Question 2

What is the oceanic zone of the sea?

Answer 2

Where the continental shelf starts and out too sea. Deep sea

Question 3

What is the epipelagic zone of the sea?

Answer 3

Water from 200m to the surface

Question 4

What is the benthic zone of the sea?

Answer 4

Sea bed/under the sea bed

Question 5

Where are industrial fisheries mostly contained to?

Answer 5

Continental shelf and areas of sea from land out to 200m

Question 6

What are the 2 types of fisheries?

Answer 6

Benthic/demersal and pelagic

Question 7

What are the largest environmental concerns of industrial fisheries?

Answer 7

Over exploitation and by catch

Question 8

What is the average size of industrial vessels?

Answer 8

20 gross tonnes. 10-15m in length

Question 9

What are the 2 approaches of fishing?

Answer 9

Active and passive

Question 10

What is active fishing?

Answer 10

Gears moved through water to catch e.g. Trawler

Question 11

What is passive is fishing?

Answer 11

Entanglement in nets or entrapment in static pots/nets

Question 12

What are the 3 classifications of fisheries?

Answer 12

Inshore, pelagic and deep water

Question 13

What are the 3 classifications of teleost fish?

Answer 13

Round, flat and white fish

Question 14

What were nets historically made of?

Answer 14

Hemp

Question 15

What are nets now made of?

Answer 15

Monofilament

Question 16

What are net holes measured on?

Answer 16

EEC net gauge

Question 17

What is the main process of trawling?

Answer 17

Large beam dragged across seabed.

Question 18

How does trawling net select for different fish?

Answer 18

Through net gauge and habitat

Question 19

What are the negative effects of trawling?

Answer 19

Destructive to seabed.
High amounts of by catch
Fuel demanding

Question 20

How does netting work?

Answer 20

Vertical panels of nets

Question 21

What are the 3 different types of netting?

Answer 21

Set nets
Encircling
Purse seining

Question 22

What is long lining?

Answer 22

Long line with lead at the bottom to sink. Use of snap hooks

Question 23

What is potting an example of?

Answer 23

Passive fishing

Question 24

How does potting work?

Answer 24

Selective opening size, escape doors.

Pots set on strings and left for 2-3 days

Question 25

What did frederiksen 2004 find?

Answer 25

Population numbers of black legged kittiwakes decline by more than 50% where Sandeel fishery was active. Need to monitor effects of fisheries on seabirds

Question 26

What did Rice 1989 find?

Answer 26

Active fishing tends to remove adults from the population and enhance whether the set or survival of juveniles

Question 27

What did Barko 2004 find?

Answer 27

High percentage of sea turtles died from passive fishing ethnic yes. Main factors influencing mortality was the depth of net deployment.

Question 28

What did Hinz 2009 find?

Answer 28

Otter trawl impacts are cumulative and can lead to profound changes in benthic communities which can have implications for marine food webs

Question 29

What did Griffiths 2010 find?

Answer 29

Pelagic longline fisheries often catch incidentally large apex predators which causes potential disruption to the ecosystem if the predators exert strong top down control