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200000
400000
600000
800000
1000000
1200000
1400000
1880 1900 1920 1940 1960 1980 2000 2020
Total fish and shellfish landed into the UK (tonnes)
Thurstan and Roberts, unpublished data
Landin
gs p
er
unit o
f fishin
g p
ow
er
(tonnes p
er
year)
Productivity of bottom trawl fishing
Thurstan et al. (2013) Fish and Fisheries DOI: 10.1111/faf.12034
Down by 25x
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
1930 1940 1950 1960 1970 1980 1990 2000
All species
Demersal fish
Prawns & scallops
Irish Sea fishery landings (tonnes)
Data source: ICES
“The bays of this island certainly abound with a greater variety of the
most choice kinds of fish than any one place I know...”
A journal kept in the Isle of Man: giving an account of the wind etc.,
Volume 1. by Richard Townley, 1791
Bluefin Tuna, Nova Scotia, ca 1920“The middle of [Carlingford] Loch is
deep...and the bottom occupied by
an immense bed of oysters, of which
vast quantities are taken to Dublin
and other towns.” 1836
“Turbot are so abundant in Dundrum Bay, that they are
speared close to the dry strand.”
Capt. Daniels, 1836
“There used formerly to
be a very considerable
fishery in cod and
haddock, and
occasionally in herrings;
but since the trawl
fishing has been so
generally used, there is
literally no such thing to
be got as fish here.”
Evidence of Mr George
Sotheron, Bray, Ireland,
1836
1800 1900 20001850 1950
Hook & line & nets;
abundant big fish
Spread of sail trawlers;
big fish decline, others
increase
Post-war fleet
expansion and
technological advance
WWI
WWIISpread of steam
Trawlers; evidence of
overfishing grows
Spread of prawn trawling
and scallop dredging
Reduced fishing in the wars
leads to some recovery
Abundance o
f bott
om
fis
h
?
Two centuries of change
Transition 1: 1830-1860 - Sail trawlers reduce abundance and
variety of big fish and push out longliners and netters
1800 1900 20001850 1950
Hook & line & nets;
abundant big fish
Spread of sail trawlers;
big fish decline, others
increase
Post-war fleet
expansion and
technological advance
WWI
WWIISpread of steam
Trawlers; evidence of
overfishing grows
Spread of prawn trawling
and scallop dredging
Reduced fishing in the wars
leads to some recovery
Abundance o
f bott
om
fis
h
?
Two centuries of change
Landings of fish soar while abundance declines and seabed
habitat is transformed; technological advances continue
through the 20th century driving down fish abundance further
1800 1900 20001850 1950
Hook & line & nets;
abundant big fish
Spread of sail trawlers;
big fish decline, others
increase
Post-war fleet
expansion and
technological advance
WWI
WWIISpread of steam
Trawlers; evidence of
overfishing grows
Spread of prawn trawling
and scallop dredging
Reduced fishing in the wars
leads to some recovery
Abundance o
f bott
om
fis
h
?
Two centuries of change
Photo: Johnny Woodlock
Transition 3: 1990-present
Prawn trawlers and scallop
dredgers reduce bottom fish,
degrade habitat and push out
bottom-fish trawlers
1800 1900 20001850 1950
Rela
tive p
rofita
bili
ty o
f fishin
g m
eth
od
Why one gear replaces another as fish abundance falls
Hook &
line & nets
Sail
trawling
Steam
trawlingDiesel/otter
trawling
Prawn
trawling &
scallop
dredging
Cod, Brill, Dab, Lemon sole, Plaice, Common sole,
Whiting, Hake, Conger eel, Haddock (all fish larger
than specified minimum landing size)
Fis
h c
au
gh
t p
er
ho
ur
of tr
aw
ling
Cod, Brill, Lemon sole, Plaice, Common sole, Whiting,
Hake, Conger eel, Haddock (all fish larger than
specified minimum landing size)
Fis
h c
au
gh
t p
er
ho
ur
of tr
aw
ling