2. CONTENTS
What is overfishing?
Consequences
Global Levels of Fish Catch
Rising Down the Food Chain
Bycatch
Harmful Methods of Fishing
Bottom-Trawling
No Take Zones
Aquaculture
Bibliography
3. WHAT IS OVERFISHING?
Catching too much fish
for the system to support
by reproduction.
When people catch fish
faster than the fish can
repopulate.
On a global scale we
have enough fishing
capacity to cover at least
four Earth like planets.
4. CONSEQUENCES
If overfishing continues, fish
populations will be reduced
even more, no matter what
measures are taken.
Overfishing not only
depletes the fish but
seriously harms marine
environment.
Because the fish population
has decreased so much,
many other species have
been placed at risk
because they now lack their
major food source.
5. GLOBAL LEVELS OF FISH CATCH
Fish Stocks:
o 52% of fish stocks are fully exploited
o 20% are moderately exploited
o 17% are overexploited
o 7% are depleted
o 1% is recovering from depletion
Between 1950 and 1994, the ocean fishing industry increased the
total catch by 400%.
Global Fish Stocks are expected to Collapse by 2050 at Current
Exploitation Rates.
THE CURRENT LEVEL OF GLOBAL FISH CATCH IS IN NO
WAY SUSTAINABLE!!!
6. GLOBAL LEVELS OF FISH CATCH
The graph points out that current levels of fishing are obviously
7. FISHING DOWN THE FOOD CHAIN
Cause: Commercially valuable, bigger,
slower growing species have been
overfished. (e.g., tuna, cod, snapper)
Effect: They target large quantities of
smaller species of fish with less commercial
value. (squid, sardines, oysters, mussels,
and shrimp)
Less predatory pressure.
Less competition for food.
8.
9. BYCATCH
Living creatures caught
unintentionally by fishing gear.
Unlike target species, bycatch is
unwanted and often unused.
Bycatch may be kept or sold.
Might be thrown back as discard
if not usable.
Handling and exposure
sometimes injure the bycatch,
which may die after being
discarded.
10.
11. HARMFUL METHODS OF FISHING
Gillnetting – A invisible
to fish fine-filament net
used for capturing
mainly salmon, cod and
sardine. Damages other
species.
Cyanide fishing – Cyanide
is used to stun and capture
live coral reef fish. Cheap
and effective but illegal.
12. HARMFUL METHODS OF FISHING
Explosive fishing – the
use of dynamite or other
explosives to kill fish.
Causes for major
destruction of reef.
Long-line fishing – long baited
hooks used to catch swordfish,
tuna, sharks, and turtles.
13. BOTTOM-TRAWLING
Dragging huge,
heavy nets along the
sea floor.
Large metal plates
and rubber wheels
attached to these
nets move along the
bottom and crush
nearly everything in
their path.
Water life forms are
very slow to recover
from such damage.
14.
15. NO-TAKE ZONES
Preserved areas where species are
protected.
Fishing or catching of other marine animals is
prohibited.
Help species regenerate, to restore
population.
Helps species which are not included in no-
take zones to restore population.
16. AQUACULTURE
The farming of aquatic
organisms – keeping
them under controlled
conditions.
Reduces the worlds
dependence on wild
stocks of fish.
Helps to feed the worlds
growing population.
Negative impact on wild
species.
