Exam References

Question 1

Huse et al.

2000

Answer 1

Selectivity of fishing methods

Barnets Sea, Cod & Haddock

Trawler: harvests all fish in path, avoidance reaction bias

Longliner: no exclusion of small fish, caught larger cod than trawler

Gilnet: caught mean largest cod, selects for narrow range but young fat fish may be caught rather than old/slim

Question 2

Glass

2000

Answer 2

Fish exclusion methodd

Square-mesh windows & escape panels: allow fish with upward escape reaction to get out (haddock)

Seperator trawls: eg. horizontal panel of netting to seperate cod end, rely on behavioural differences

no quick global solutions- vary with fishery/region

Question 3

Munoz et al

2010

Answer 3

Enviromental effects of longlining

38 sets, N. Atlantic

weights damage corals incl. vulnerable indicator sp.( small glass sponge)

discards, seabirds- direct mortality

deepwater sharks are 80% of catch (ban 2008)

Question 4

Pauly et al

1998

Answer 4

Fishing down trophic levels

est trophic level of 220sp. from global fishery landing data 1950-1994

mean trophic level declined 3.3 to >3.1%

unstable ecosystem/cascades, unavoidable?
But: quality of landing stats questionable

Question 5

Riesen & Reise

1982

Answer 5

Effects of trawling on enviroment

Wadden Sea, grab samples, 9 sites

increase in r-strategists (polychaetes)

decrease in k-strategists (molluscs and crustaceans)

But: could be due to natural fluctuations/eutrophication

Question 6

Zwolinski et al.

2012

Answer 6

Accoustic trawl

California; sardine, jack makerel, pacific mackerel

gives multispecies info over large areas & is fisheries independent, towards EBM

But: accurate classification of echos difficult for morphologically similar fish

Question 7

Romo-Curiel

2014

Answer 7

Use of fish otoliths

California; white seabass, 3 locations, different sampling techniques

similar estimated growth rates with otolith suggest single pop.

But: v.young and v.old otoliths hard to read

are sampling techniques comparable? representitive of all ages/sizes? biased catch data?

Question 8

Hunter et al.

2004

Answer 8

Fish migrations

DST tags record depth/temp of Plaice, N.sea

18% remained in english channel after spawing: mixing of stocks: should be managed differently

fisheries independent MPAs need to take migrations into account

Question 9

Roberts et al.

2001

Answer 9

Reserves increase catch

St. Lucia, 5 reserves

in 5yrs, artisanal catches increased by 90%

more & larger fish= more offspring

biomass of 5 commercially important families increased by 3% in 3yrs

But: would it work on industrial scale

Question 10

Morandeau at el.

2014

Answer 10

Why do fishermen discard?

Bay of Biscay, on board surveys

83% due to market issues

discards related to regulations minor

problem= selectivity & fishing methods no the quotes and catch composition

But: one area, small n

Question 11

Tyson et al.

2015

Answer 11

Bird behaviour influenced by discards

Lesser black-backed gulls, Wadden Sea

40 tracked via GPS

sig. reduced use of w.sea at weekends when fleets not operating

switched to terrestrial foraging: flexible response

but still shows specialisation to discards

Question 12

Wikelski et al.

2002

Answer 12

Marine Iguanas die from oil

only few killed immediatley- dispersed by strong currents

long term data on 2 pop.s: censuses and permanent marks

Santa Fe pop. 62% mortality

algal pastures didn’t change= deaths caused by sensitive fermenting endosymbionts in hindgut

corticosterone levels correlate w/ mortality

Question 13

Hook & Osborn

2012

Answer 13

Effects of dispersant on diatom

exposure to dispersant= growth inhibition at lower conc.s than oil & dispersant and oil alone

dispersant also= membrane damage

diatom at base of food chain

but: only 1 type of oil tested

Question 14

Li et al.

2015

Answer 14

CE causes respiritory epithelial damage

in vitro: human lungs, in vivo: mice, zebra fish, blue crabs

apoptosis of epithelial cells induced

changed permeability of brachial epithelium

swelling, reduction of airflow

research: effects in wild/ecosystem?

Question 15

Liu et al.

2006

Answer 15

Dispersant= no short term effect on organisms

Louisiana, shrimp, killfish, oyster

83% of each sp. survived after exposure

no sig. difference b/w oil and oil with dispersant

but: only 24 hours

Question 16

Garza-Gil et al.

2005

Answer 16

Economic loss from prestige spill

Galicia, Spain

fisheries closed for 6 months: lost €56 million

tourism income decreased by 20%

clean up costs

€762 million total

cultural/society losses

Question 17

Langhamer et al.

2009

Answer 17

Biofouling & wave power

Sweden: scuba surveys, photographs

bouys dominated by blue muscles

no effect: not heavy enough, increased turbulance not significant

research: can they be enhanced as FADs?

Question 18

Wilhelmsson et al.

2006

Answer 18

Wind turbines as FADs

Sweden: visual scuba transects

fish abundance increases w/ distance to turbines

small fish round FADs can attract commercially important sp.

research: could they be used as part of MPAs
but: human error/visibility/weather

Question 19

Madsen & Boertmann

2008

Answer 19

Geese habituate to wind farms

counted droppings along transects

in 2000: kept distance >100m

in 2008: >40m and between turbines

research: long term, different sized turbines, does avoidance cost energetically/increased predation

Question 20

Koschinski et al.

2003

Answer 20

Reactions of porpoise and seals to turbine noise

recording of noise played back to wild seals and porpoise

seals surfaced further away compared to control

ecolocation clicks increased by a factor of 2

but: recording of 2MW gen. different power/weather?

Question 21

Curtin & Prellezo

2009

Answer 21

EBM review

System of management that views the system as a whole

Need:

imput and output controls

seasonal closures

prohibition of specific fishing methods

models of ecosystem processes

use of MPAs

Question 22

Lindley et al.

2003

Answer 22

Stock Assessment of Cod

data from CPR and ICES

how do enviromental factors affect recruitment?

recruitment neg corr. with abundance of larvae

stronger than corr. with enviromental variables

=due to trophic effects

competition with and predation on plankton

Question 23

Fonteyne et al.

2007

Answer 23

Different methods of measuring mesh

fishery inspectors: wedge gauge

scientists: ICES gauge

=cod ends have lower selectivity than anticipated by scientists

universal OMEGA gauge

wedge gauge liable to human influence

Question 24

Sala et al.

2007

Answer 24

Changing selectivity of trawlers

mediterranean bottom trawls

reduction in selectivity with increased twine size

but: only used one type of net material

only looked at 5 fish sp.

Question 25

Leighton

1983

Answer 25

Birds consuming oil

dosing with crude oil

caused severe hemolytic anemia

Herring gulls & Atlantic puffins

Research: how much do they consume in the wild

Question 26

Burger

1997

Answer 26

Impact of oil on bird foraging

50% foraging time interrupted (personel/vehicles)

control <5%

% of time spent preening sig. increased

Sanderling & Plovers

during stop over- already time stressed

Question 27

Bayat et al.

2005

Answer 27

Sorbents

Polypropylene can sorb 7-9 x it’s weight

simulated seawater experiments

expensive due to recovery of sorbent

Research: promising, agricultural products can be used eg.straw

Question 28

Al-Majed

2012

Answer 28

Oil containment review

Burning: water must be calm & oil thick, smoke = oil rain

Booms & Skimmers: less enviromental impact, expensive

Dispersents: more HCs, don’t work in calm water

Bioremediation: limited by abiotic factors, ineffectic on sunken spills

Question 29

Incardona et al.

2004

Answer 29

PAHs cause mutations in fish embryos

Zebrafish embryos exposed to combinations of PAHs

induced mutations;

cardiac dysfunction, edema, spinal curvature & reduced jaw

different PAHs=different effects

Research: impact performance at later life history stages