Marine Fisheries management
Oceans
 Considered the last frontier
 Wide variety of plant and animal life
Oceans
 71 % of Earth’s surface
covered by oceans
 97 % of the Earth’s
water
 Physical and biological
components help
formulate
management
techniques to utilize
marine resources
Physical Characteristics
Four Major Areas
• Zonation
• Salinity
• Temperature Density
• Water Movements
Zonation
 Ocean zones
defined by water
depth and distance
from shore
 Divided vertically
into 3 zones
Zonation
 Photic zone
(sunlit, 660 feet
down)
 Aphotic zone
(vast & dark)
 Benthic zone
(ocean floor)
Salinity
 Concentration of
 Density increases as
salt with in ocean
 Salt is carried from
land by wind and
water
 Salt content &
temperature effects
water density
salinity rises and
temperature falls
 Heavier water sinks
– colder & saltier
 Lighter water
remains near
surface – warmer &
less salty
Temperature Denisty
 Moves & transports heat from equator to poles
 Temperature changes occur in different
latitudes of ocean and different depths
Water Movements
 3 types of water
movement
 Waves
 Tides
 Currents
Water Movements
 Waves can be wind generated, internal,
catastrophic, stationary
 Wind generated – most common, consists of sea,
swell and surf
 Internal – underwater in depths of ocean
 Catastrophic – caused by storms, earthquakes
(tidal wave or tsunami)
 Stationary – found in bays or calmer water (surface
moves up and down)
Water Movement
 Tides are specialized
waves from
gravitational
attraction of sun and
moon
 Occur at same time
 High and low tide
roughly 6 hours apart
Water Movement
 Currents flowing of the ocean driven by
heating and cooling, gravity, wind and
differences in water density
Biological
 Marine animal life can
be divided into 4 major
groups
 Microscopic Marine
Animals
 Marine Fish
 Marine Shellfish
 Marine Mammals
Microscopic Marine Animals
 Most common
plankton, particularly
zooplankton
 Plankton staple for
many species from tiny
fish to whales
 Zooplankton related to
crabs and shrimp
Marine Fish
 4 major marine fish
economically
 Salmon
 Tuna
 Menhaden
 Flounder
Marine Fish
 Less economically
important fish species
 Haddock
 Herring
 Cod
 Mackerel
Marine Shellfish
 4 major shellfish
 Shrimp
 Oyster
 Crabs
 Lobster
Marine Mammals
 Marine mammals
differ form other
marine life
 Warm blooded
 Lungs for
breathing
Marine Mammals
 4 main marine
mammals
 Whales
 Porpoises
 Walruses
 Fur seals
Ocean Summary
 Vast resource
 Potentially untapped
food source
 Harvest from this
source must be
economically and
ecologically sound