Global fisheries and conservation
 Before
moving on from fishes to the
tetrapods, I want to devote some time to
fishing.
 It
is a sad fact that global fish stocks have
been enormously depleted and in most
places fish populations are a pale shadow
of their former abundance.
Global fisheries and conservation

For example: Captain John Smith describing
tributaries of the Chesapeake in 1608 “… in
diverse places that abundance of fish lying so
thicke with their heads above the water, as for
want of nets we attempted to catch them with a
frying pan, but we found it a bad instrument to
catch fish with. Neither better fish more plenty
or variety had any of us ever seene, in any place
swimming in the water than in the Bay of the
Chesapeack, but there not to be caught with
frying pans.”
Global fisheries and conservation
 Captain
John Smith again: Having
grounded on an oyster bed in the Potomac
as the tide was going out “…we spied
many fishes lurking amongst the weeds on
the sands, our captaine sporting himself to
catch them by nailing them to the ground
with his sword, set us all a fishing in that
manner, by this devise, we tooke more in
an houre than we all could eat.”
Global fisheries and conservation
 Clearly,
a different level of fish abundance
than we encounter today.
 Similarly
abundant numbers of fish were
described in the waters off New England
and eastern Canada.
The Grand Banks fishery
 John
Cabot voyaged to Newfoundland in
1497. The Milanese ambassador to
London reported what he had heard from
Cabot about the fishing there: “they assert
that the sea there is swarming with fish,
which can be taken not only with the net,
but in baskets let down with a stone, so
that it sinks in the water. I have heard this
Messer Cabot state so much.”
The Grand Banks fishery

Two centuries later Pierre de Charlevoix in 1719
described the Grand Banks of Newfoundland
“What is called the great bank of Newfoundland
… you find on it a prodigious quantity of shellfish, with several other sorts of fishes of all sizes,
most part of which serve for the common
nourishment of the cod, the number of which
seems to equal that of the grains of sand which
cover this bank. For more than two centuries
since, there have been loaded with them two to
three hundred ships annually, notwithstanding
the diminution is not perceivable.”
The Grand Banks fishery
 The
rich fishing grounds off the northeastern
U.S. and eastern Canada result from a
combination of factors.
 The
various banks (the Grand Banks, George’s
Bank, Brown’s Bank and others) are deposits of
moraine left there by glaciers.
The Grand Banks fishery

The water above them is relatively shallow (60300 feet in most places) and they occur at the
confluence of the cold nutrient rich northern
Labrador current and the warm southern Gulf
Stream.

The mixing of these currents combines warmth
and nutrients to produce massive blooms of
plankton that supported huge schools of
mackerel and herring that in turn support cod
and other predators.
The Grand Banks
http://www.immersionpresents.org/photos/albums/userpics/10179/
Grand_Banks_Map.jpg
George’s Bank and Brown’s Bank
http://www.nefsc.noaa.gov/history/timeline/images/georges.jpg
The Grand Banks fishery

In 1992 the Canadian Government placed a two
year moratorium on cod fishing, which was
extended indefinitely and remains in place today.
In 2003 the two main populations of Atlantic cod
were added to Canada’s endangered species
list.
 In U.S. waters cod populations have similarly
plummeted.
 What happened? Industrial fishing happened.
The Grand Banks fishery

Up until the early 20th century, cod-fishing had
been almost exclusively by schooners using
hand lines but then steam trawlers were
introduced to North America. With their greater
fishing power the steam trawlers soon replaced
the schooners and had become common by the
1920’s.

Around the same time fast-freezing technology
was developed and the frozen fillet entered the
marketplace.
Fishing schooner Olympic about 1911.
http://www.pugetsoundmagazine.com/articles/img001/10024/lituya1FVOA.jpg
Norwegian Cod schooner 1930
http://pro.corbis.com/images/US002037.jpg?size=67&uid=%7B15ED58FCEBD7-4EDF-8067-DA989C5D9ECD%7D
Steam Trawler Bellerophon
http://www.maritimelowestoft.co.uk/images/crownies_lowestoft/
bellerophon_large.jpg
The Grand Banks fishery

One of the first fish to be targeted by ships using the new
technology was haddock.

Haddock freezes well (but salts poorly and previously
had been thrown away by fishermen).

Huge spawning aggregations were discovered on the
Georges Bank and heavily fished for.

Catches soared through the 1920’s peaking at 120,000
tonnes in 1929. [1 tonne is 1,000kg about 2,200 lbs]
The Grand Banks fishery

In 1930 an estimated 37 million haddock were
landed in Boston. However, even more were
discarded because small mesh nets caught fish
indiscriminately and more than two juvenile
haddock were discarded for each adult landed.
 Not surprisingly, haddock numbers crashed
falling to 28,000 tonnes by 1934. Landings of
about 50,000 tonnes per year were sustained
into the 1960’s but only because the fishermen
began fishing in new waters.
The Grand Banks fishery
 In
the 1960’s fishing pressure increased
immensely as distant-water fishing fleets
from Europe moved in to fish (national
fishing limits were only 3 miles).
 Fleets
from Britain, Spain, Portugal,
Romania, France, West Germany, Poland,
East Germany and Russia crowded into
the fishing grounds.
The Grand Banks fishery

The European fishing fleets consisted of groups
of factory trawlers supplying mother ships that
processed the catch and these had immense
fishing and processing capacity (thousands of
tons a day) much greater than local fleets.

In an hour a single factory trawler could catch
200 tons of fish, twice as much as a 16th century
ship could have caught in a whole season’s
fishing.
The Grand Banks fishery

Onboard the mother ships, fish was machinefilleted and frozen or turned into fishmeal.
These ships could fish in any kind of weather
and stay at sea for months on end.

In 1965 the Soviet Union had 106 factory
trawlers and 425 smaller trawlers supplying 30
mother ships and together these took 872,000
tonnes of fish [7x the peak annual haddock
catch in 1929].
Russian factory trawler
http://www.greenpeace.org/raw/image_full/international/
photosvideos/photos/russian-factory-trawler-fishin.jpg
The Grand Banks fishery
 Fishing
fleets were able to work
cooperatively to exhaust aggregations of
fish. When a concentration of fish was
found (using the most sophisticated
available search equipment) the trawlers
would aggregate to fish it into oblivion
before dispersing again to seek new
schools.
The Grand Banks fishery
 By
1974 more than 1,000 European
vessels were fishing the banks. Their
catch was more than 2 million tonnes,
which was 3x the Canadian catch and 10x
the New England catch.
 Everything
was taken--juvenile or adult,
spawning or not, regardless of the future
impact on stocks.
The Grand Banks fishery

Two Canadian fisheries scientists, Jeffrey
Hutchings and Ransom Myers, have estimated
that about eight million tons [7.25 million tonnes]
of northern cod were caught between Cabot's
arrival in 1497 and 1750, over the course of 25
to 40 cod generations.

Factory trawlers took the same amount in only
15 years, a period less than the lifetime of a
single cod.
The Grand Banks fishery
 Catches
of fish far exceeded sustainable
yields and fisheries began to collapse.
The haddock fishery in the Gulf of Maine
collapsed in the 1970’s.
 In
1977 following Iceland’s lead the U.S.
and Canada declared a 200-mile limit and
excluded the foreign fishing boats.
The Grand Banks fishery
 But
instead of attempting to hold down
fishing efforts both countries expanded
their fleets.
 Between
1977 and 1982 the number of
New England trawlers increased from 825
to more than 1,400 boats. Domestic
overfishing replaced foreign overfishing.
The Grand Banks fishery
 By
the early 1980’s fishing catches had
risen to twice the level that was
sustainable, but by investing in more
sophisticated equipment fishermen could
still make a living.
 However, at this point fishermen were
killing 60-80% of all the cod, haddock and
flounder in the Gulf of Maine every year.
The Grand Banks fishery
the mid-1980’s U.S. fisheries scientists
saw the collapse coming and pushed for
major cuts in fish landings, but the fishing
industry resisted cuts and it wasn’t until
the mid 1990’s that reductions were
imposed.
 In
The Grand Banks fishery

A similar process played out in Canadian waters.
Canadian fisheries scientists overestimated
sustainable yields of cod based on a series of
bad assumptions. In the 1980’s 5x times as
many cod were being taken as should have
been removed.

Calls to cut back the fishery were ignored and by
1992 the fishery was finished.
The Grand Banks fishery
 Estimates
of the size of the original
population suggest that there were about 7
million tonnes of cod off the Atlantic coast
of Canada in 1505.
 By
1992 the estimate was 22,000 tonnes
(<1/3 of 1% of the original population.).
The Grand Banks fishery

Cod stocks are showing signs of recovery. In
2010 cod stocks in the Grand Banks were
estimated to have increased 69% since 2007.

However, that level is still only about 10% of
1960’s levels.
The Grand Banks fishery

There is some debate about why stock recovery is slow.

However, habitat transformation almost certainly has
played a major role.

Before trawling, the sea bottom on the banks was not a
layer of mud. Rocks outcrops, boulders and stones
provided structure, places for young fish to hide and rich
communities of sponges, crabs, mussels, anemones,
tube worms and other invertebrates flourished.
The Grand Banks fishery

A bottom trawler’s net is held open by large
metal doors weighing thousands of pounds and
the bottom of the bag is kept on the seabed by a
weighted metal cable. Each pass of a net drags
boulders and rocks, buries and crushes
invertebrates and leaves behind a virtual
moonscape.

Bottom trawling is the ecological equivalent of
clear-cutting, but carried out on a much more
massive scale and out of view.
http://newsimg.bbc.co.uk/media/images/40874000/
gif/_40874232_bottom_trawling_416.gif
Sea bottom habitat in Canada (left) and Australia (right)
before trawling (above) and after (below).
http://coralnotesfromthefield.blogspot.com/2007_05_01_archive.html
Trawl net damage
 http://www.youtube.com/watch?v=zikSzUh
UGtA
The Grand Banks fishery
 After
years of bottom trawling the sea bed
has been converted from a rich diverse
ecosystem to a sterile one.
 Unfortunately,
the tragedy of the cod
fishery is just one example of failed
fisheries and the pattern has been
repeated worldwide.
Suggested additional reading

“The end of the line” Charles Clover

“The unnatural history of the sea” Callum
Roberts

“The empty ocean” Richard Ellis

“Four fish: the future of the last wild food” Paul
Greenberg