Marine Fisheries Management Ocean can be considered the

Marine Fisheries Management

Ocean • can be considered the last frontier on this planet • unique physical characteristics

Ocean • can support wide variety of plant and animal life

Physical Characteristics • four major areas • zonation • salinity • temperature density • water movements

Zonation • classify ocean zones • depth measurements • temperature changes • pressure variations • light penetration

Zonation • depth and light penetration are the two most common methods • five zones

Zonation • supratidal • intertidal • neritic • bathyal • abyssal

Zonation • supratidal and intertidal • above the water level • are omitted in some classifications

Intertidal • sometimes called the littoral zone • area between high and low tide

Neritic • begins at the water line • contains more biological substance than any other part of the ocean • 10 -200 miles wide

Neritic • 200 -600 feet deep • zone stops at the end of the continental shelf • site of huge dumping of industrial and city wastes

Bathyal • contains the continental slope and rise • is regarded as a geologically active area • underwater avalanches and slides common

Abyssal • ocean deep zone • reaching depths of 5, 000 meters • trenches may extend to more than 6, 000 meters

Abyssal • trenches are referred to as the hadal zone • scarcity of food • increased water pressure • lack of dissolved oxygen

Abyssal • animal life must be specialized to live • must be able to obtain nutrients from rich sediments on the ocean floor

light penetration • euphotic zone - “twilight zone” • part of the ocean where sunlight penetrates the water • supports plant and animal life that requires sunlight to live

Euphotic zone • from the surface to about 600 feet beyond the horizontal shelf • below the euphotic is the cold, dark Abyssal zone

Salinity • concentration of salts within ocean water • concentrations and types of salts vary throughout the ocean

Salinity • most commonly found salt compounds consist of: • sodium - Na • chlorine - Cl • magnesium - Mg

Salinity • calcium - Ca • potassium - K

Salinity • defined as the number of grams of dissolved salt in 1, 000 grams of sea water • symbol for expressing salinity is %o

Salinity • ranges in the ocean from 33%o to 38%o • average is about 35%o

Temperature Density • the ocean is a giant heat pump that moves and transports heat from the equator to the poles

Temperature Density • temp changes occur as you move both to a different latitude and different depths

Temp stratification • three layers • mixed surface layer • middle thermocline layer (101, 000 meters) • deep water layer (1, 000 6, 000 meters)

Thermocline • below the light penetration depth • suggests that there is a transfer of heat vertically as well as horizontally

Density • mass per unit volume • dependent upon salinity • temperature • pressure

Density • changes result from evaporation and heating of the ocean’s surface • higher temps -lower density • density increases as the pressure and depth increase

Water Movements • waves • tides • currents

Water Movements • dictates temperature, salinity, nutrient levels as well as animal and plant life

Waves • classified as: • wind generated • internal • catastrophic • stationary

Wind generated • most common • sea • swell • surf

Wind generated • sea wave is an irregular wave with no systematic pattern • sea wave travels at different heights and changes direction as it moves

Wind generated • swell waves are uniform with similar dimensions • travel together because of their similar speed

Wind generated-swell • remain at a constant speed as they travel but decrease in height • sometimes travel across an entire ocean

Wind generated • surf wave is on occurring close to shore • water particles move in an orbital motion • toward the beach

Wind generated - surf • less depth • energy is directed toward the shore

underwater internal • found with the temperature changes in the depths of the ocean • travels more slowly but has a greater height

Catastrophic waves • massive power behind them • caused by storms, hurricanes and landslides on shore • commonly known catastrophic wave is the tidal wave

Stationary wave • occur in bays and calmer waters • does not move horizontally • water surface moves up and down

Tides • specialized waves caused by the gravitational attraction of the sun and moon on the earth • tides occur at very exact times with one-half lunar day

Tides • 12 hours 25 minutes between high tides • lunar day is longer than the solar day • tides occur 50 minutes later each day

Tides • an area will have either one high tide and one low tide each day (diurnal) • or two high tides an two low tides each day (semidiurnal)

Tides • when the sun and the moon line up with the earth a strong tide is produced • this happens every 14 days at the time of the new and full moons

Tides • this exceptionally high tide is called the spring tide • when the sun and moon are at right angles with each other • occurs during the half moon

Tides • an exceptionally low tide is produced • called neap tide

Currents • most common are surface currents, turbidity currents and bottom currents • surface currents, which are caused by the prevailing winds

Currents - surface • reach velocities of about 3 knots • 1 knot = 1. 15 mph

Currents • when a hurricane reaches shore or an earthquake occurs, landslides can occur • landslides can produce a turbidity current underwater

Currents • in the deep water become the bottom currents • responsible for moving sediments on the ocean floor

Currents • transporting water from the Atlantic Basin to the southern Atlantic Ocean

Life • the ocean is a wonderland of plant and animal life • storehouse of food and nutrients is virtually untapped

Life • with proper management the ocean could provide wide relief to the world food problem

Animal life • divided into four major groups • microscopic • marine fish • marine shellfish

Microscopic • most common are the plankton • zooplankton • staple food for species ranging from tiny fish to whales

Microscopic • many zooplankton are related to marine crabs and shrimp • plankton concentration varies • average concentration is one tenth of a gram per cubic meter of water

Microscopic • some scientists suggest harvesting plankton because they contain the nutrients and amino acids found in human food

Microscopic • would require filtering over one million gallons of water with sophisticated nets to collect one pound of dry plankton material

Marine Fish • four most important marine fish species are: • salmon • tuna • menhaden

Marine Fish • these species make up the world fishing markets • less economically important species include: • haddock, herring, cod, and mackerel

Salmon • seven main species • Atlantic • Cherry • Chinook • Chum

Salmon • Coho • Pink • Sockeye

Salmon • range in size from 16 inches long and weighing 5 pounds to 36 inches and 25 pounds • live in both the Atlantic and Pacific Oceans

Salmon • begin life in fresh water • migrate to the ocean to live and grow • Atlantic Salmon make the trip repeatedly

Salmon • Pacific species • include all or the seven except the Atlantic • spawn only once and die soon afterward

Salmon • spawn in shallow streams during late summer or early fall • female finds a rocky stream bed where she digs a saucer shaped nest with her tail

Salmon • male salmon stays close by to guard the female • she deposits her eggs in the nest and the male fertilizes them

Salmon • procedure is repeated upstream • female will lay 2, 000 10, 000 eggs during this spawning time

Salmon • eggs hatch in 3 -4 months • fry retreat to the gravel bottom to try to avoid predators - birds and other fish

Salmon • young salmon live off food in the yolk sack attached to their stomachs • some species move toward the ocean immediately

Salmon • some stay in fresh water for up to 3 years • adult salmon remain in the ocean from 6 months to 5 years before returning to fresh water to spawn

Salmon • Once the salmon reaches fresh water it stops eating and depends on body fat for energy • male develops a hooked snout

Salmon • some species develop a hump on their backs • quality of the meat is decreased at this time as the salmon loses some of its flavor

Salmon • management practices to protect and preserve • fish ladders to help salmon over dams • artificial spawning channels

Salmon • temp and water flow are controlled in the channels • use of hatcheries • construction of escarpments which allow a certain number of fish to spawn

Salmon • have also been used to control other rapidly producing fish species • coho salmon was introduced into the great lakes to control alewives

Salmon • commercially are caught in nets and sold • fresh • frozen • smoked and canned

Salmon • main fishing countries are: • US • Japan • Canada

Tuna • member of the mackerel family • leading game fish in the US

Tuna • three most commercially important types are: • albacore • skipjack • yellowfin

Tuna • species range in size from the 10 foot long, 2, 000 pound northern bluefin to the 2 foot long 10 pound frigate

Tuna • are fast swimmers • reach speeds of up to 45 mph • Does not have the ability to push water through its gills

Tuna • must swim continuously in order to live • caught by bait fishing, long lining and purse seining • bait fishing involves using live bait to attract tuna

Tuna • long-lining • reel out a line up to 75 miles long • may have as many as 2, 000 hooks

Tuna • purse seining • using nets called purse seines to catch fish • tuna usually travel below schools of porpoises

Tuna • pilots locate the porpoises from the air and radio the location to the boats • major problem is that many porpoises are netted at the same time

Tuna • netting of porpoises is accidental and unlawful

Menhaden • also known as bony fish or fatbacks • live in the Atlantic Ocean and feed on plankton • swim in schools close to the ocean’s surface

Menhaden • easy to catch • 12 -18 inches long • weigh about 1 pound at maturity

Menhaden • most are used in products such as livestock feed, soap, and fertilizer, rather than human food

Flounder • also called “Plaice” • lives on the sandy and muddy bottoms of bays • have a flat body with both eyes on the same side of the head

Flounder • feed on shrimp and small fish

Marine shellfish • shrimp • oysters • crab • lobster

Shrimp • most economically important of the marine shellfish • live in salt and fresh water • excellent swimmers

Shrimp • large shrimp - called prawns • feed from the ocean floor • can grow to 12 inches in length

Shrimp • most common used for food is the Peneid shrimp • hatched from eggs laid in the ocean • female may lay 500, 000 to 1 million eggs

Shrimp • as the young shrimp move toward shore • 80 percent are lost to predators • shrimp settle in bays and river mouths until 5 -7 mos

Shrimp • then move back to deeper water for breeding • female dies soon after laying her eggs

Shrimp • nets called trawls are dragged on the ocean floor • once netted, shrimp are sold frozen or canned • leading countries are US, Japan, India

Oyster • type of mollusk • shellfish with a two-piece shell protecting a soft inner body • live in mild or warm climates

Oyster • Oysters of the Persian gulf and the Pacific Ocean are responsible for making pearls

Oyster • female oyster lays about 500 million eggs each year, spraying them into the water • young oysters, called spat, hatches 10 hours later

Oyster • about the size of the point of a needle • within 24 hours the shell starts to form • young oyster attaches to a rock

Oyster • where it spends the rest of its life • some live up to 20 years • greatest enemies include: humans, fish, crabs, starfish and oyster drills

Crabs • third economically important marine shellfish • habitats range from shallow waters close to shore to deep waters of the ocean

Crabs • 4500 different kinds of crabs • most common - Atlantic lives in burrows on saltwater streams

Crabs • largest is the Alaskan King Crab • can weigh up to 12 pounds! • Most sought after crab by American and Japanese fishermen

Lobster • American Lobster lives on ocean bottoms near the shore in both the Atlantic and Pacific Oceans • averages 12 -24 inches in length

Lobster • weigh from 1 - 20 pounds • feeds by burrowing into a hole with only its claw at the edge

Lobster • as prey comes close to the claw it quickly becomes the lobster’s next meal • main food consists of crab, snails, small fish and other lobsters

Lobsters • female carries her eggs under her tail for 11 -12 months • every 2 years she lays 5, 000 100, 000 eggs by shaking the eggs from eggshells

Lobsters • eggs will quickly rise to the surface • young will drift on the surface for three to five weeks • easy prey for birds and fish

Lobsters • young then sink to the ocean floor where they spend the remainder of their life • life span up to 15 years

Lobsters • caught in traps called pots • allow the lobster to enter but vertical wooden bars confuse the lobsters and prevent them from finding their way out

Lobsters • traps are checked daily • two lobsters in confinement will fight till one dies • claws are immobilized with a rubber band to prevent injury to other lobsters

Lobsters • Lobsters are kept together for shipping so immobilizing the claw is important

Marine Mammals • differ from other marine life in two important ways • warm blooded rather than cold blooded

Marine Mammals • mammals have lungs as breathing devices rather than gills • necessary to come to the surface to breath

Marine Mammals • main marine mammals are • whales • porpoises • walruses • fur seals

Whales • include the largest mammals that have ever lived on the earth • the largest blue whale was 100 feet long and weight 136 metric tons

Whales • divided into baleen whales and toothed whales

Baleen Whales • obtain their food by straining plankton from the seawater • through plates called whalebone

Baleen Whales • ten different types • three major groups • right, gray, and rorqual

Baleen Whales • Right include the bowhead • black right - longest baleen, averages 60 feet long • pygmy baleen- smallest baleen

Baleen • gray are black to gray in color and dotted with white blotches • feed from the ocean floor

Rorqual baleen • fastest whale • able to flee the whaler’s harpoon until the introduction of the diesel engine

Rorquals • sometimes referred to as finback • fin protrudes from their back

Rorquals • most common include • blue • bryde’s • fin • humpback

Rorquals • minke • sei • common food is small shrimp like animal called krill

Toothed whales • have a lower set of peglike teeth • over 65 different kinds of toothed whales

Toothed whales • five major groups • sperm • beaked • belugas and narwhales

Toothed Whales • dolphins and porpoises • river dolphins

Sperm Whale • largest toothed whale • about 60 feet in length • blue gray to black in color • enormous square head

Sperm whales • live in the tropical waters • feed off of squid, barracuda and sharks

Whales • usually seasonal breeders • mating during the winter months • male - bull • female - cow

Whales • migrate to the equator for mating • most baleen whales migrate • most toothed whales do not migrate

Whales • pregnancy lasts 10 -12 months • when the calf is born it weighs nearly 4000 pounds • 23 feet long

Whales • cow nurses her offspring for about 7 months • because of the rich milk, some calves can gain as much as 200 pounds a day

Whales • travel in herds of 100 - 1, 000 • adult male will form a harem school consisting of himself, his females and their young

Whales • nursery groups of females and young and bachelor groups of males also travel along with the harem

Migrating • mothers and young lead the herd • followed by males and non pregnant females • pregnant females at the rear

Whales • average life span is 15 years for a porpoise and 40 years for a baleen whale

Fur Seals • seals are divided into three groups • eared - includes fur seals and sea lions • earless • walruses

Fur Seals • most sought after seal because eof its soft coat • US annual catch of fur seals amounts to over $3. 5 million

Fur Seals • spend the winter off the coast of California and the summer in Alaska • male seal is called a bull and weighs between 500 and 700 pounds

Fur Seals • female is called a cow • weighs 50 -100 pounds • bears one offspring per year • offspring are called a pup, whelp, or calf

Fur Seals • bulls arrive at the breeding grounds called rookeries in May or June • stake out their territories • about 40 feet in diameter

Fur Seals • cows arrive in July • immediately join a harem and bear their young • cow mates again 1 - 2 weeks after the birth of the pup

Fur Seals • bull is always being challenged by other bulls for his territory • usually must be at least 10 years old before he develops enough strength to defend

Fur Seals • main predators include sharks • killer whales • and parasitic round worms • humans

Fur Seals • thousands killed annually at their breeding ground for fur • 1911 North Pacific Fur Convention • Japan, Russia, Canada, and the US

Fur Seals • set a limit to the number of seals that can be harvested each year • Only Russia and the US can harvest 30, 000 a year

Fur Seals • each country gives 15% of harvest to Japan and 15% to Canada • US sealing is conducted by the government

Fur Seals • money is deposited in the US Treasury • 70% of money is returned to Alaskan gov’t. • 30% goes to the National Marine Fisheries Service

Walrus • the only tusked seals • live in the Arctic, North Atlantic, and North Pacific Regions

Walrus • their bodies have developed flippers that make them excellent swimmers • during winter and spring months, walruses drift on floating ice pieces

Walrus • spend summers resting on shorelines • main food is clams • Eskimo is the most common user of Walruses

Walrus • meat is used for food • hides for shelter • oil for lamps

Estuarine Ecosystem • area where freshwater source opens into the ocean • called an estuary

Estuary • transition area supports a variety of life that is found nowhere else • life that can withstand rapid changes in salinity, temperature and density

Estuary • continuously receives fresh water from the rivers and streams and salt water from the tides and currents

Estuary • transitional zone • has characteristics common to neither rivers or the ocean

Estuary • usually shallow and turbulent • results in high amount of oxygen in the water

Estuary • tides cause the area to be nutrient rich • rivers bring nutrients to the estuary from above and the tides bring nutrients from the ocean

Estuary • acts as a nutrient trap • bacteria count is high because of the high oxygen content

Estuary • rapid decomposition of organic wastes • breakdown of organic matter to soluble nutrients causes plant life to prosper

Estuary • high plant life attracts large numbers of plant eating fish • life in the estuary is grouped into three groups • 1. Species that travel a short distance to the estuary

Estuary • 2. Species found in both the estuary and in other parts of the ocean • 3. Species whose entire life cycles are in the estuary

Estuary • economically important to marine fisheries • 90% of the marine fish harvested either comes from the estuarine ecosystem or passes through it

Estuary • best known life in the estuary include: fish larvae • oysters • clams, crabs • lobsters, shrimp

Estuary • problems facing estuaries include conflict between land developers and fishermen

Estuary • shorelines are the most sought after types of real estate • some estuaries have been used as a dumping ground

Estuary • dumping destroys natural habitat

Artificial Ocean Cultivation • scientists have developed ways to artificially propagate marine animals • this form of agricultural production is called aquaculture

Artificial Ocean Cultivation • most commonly farmed marine resource crop is the oyster • research is also being conducted with shrimp, salmon and milkfish

Oysters • live in estuarine waters • close to shore • makes them one of the easiest marine animals to raise

Oysters • improving habitat is first step • providing a place for larvae to attach • control parasites and predators

Oysters • French Scientists have developed a special algae as an improved food for the oysters to grow more quickly.

Oysters • Japan’s most productive oyster farm • Inland Sea near Hiroshima • water flow and mineral content are correct

Oysters • very desirable oyster producing area • only management item needed is a stopping apparatus to which the larvae can attach

Oysters • Japanese oyster farms consist of bamboo poles tied together and floating on barrels • wires are hung from the poles to a depth of 20 feet

Oysters • wires hold clam shells • act as the stopping place for oyster larvae • In July and August, billions of oyster larvae attach to the artificially hung shells

Oysters • larvae are thinned to the correct amount • midseason - October - wires are pulled and young oysters are cleaned and brushed which helps them grow

Oysters • harvested in January and February • standard oyster raft measures 35 -40 feet square • may own as many as 100 rafts

Oysters • number of barrels needed to support the raft increases as the oysters grow and weigh it down

Oysters • feed on plankton • costs are low • average yield is about 13, 000 pounds of oyster flesh per acre farmed

Oysters • shells are cleaned and sold for poultry grit and lime • Japan can attribute its successful oyster farming both to low labor costs and to preservation of habitat

Oysters • pollution of waters has almost stripped every other nation of an economically feasible oyster industry

Laws and Regulations • who owns the ocean • how many miles offshore can a country claim • who owns the mineral resources on the ocean floor

Laws and Regs • development of fishing policy • fish cannot be claimed as property like land wildlife can

Laws and Regs • recent legislation is aimed at conservation • variety of commissions and committees have been formed

Laws and Regs • most deal with regulation of one specific resource ie: fur seals, whale, tuna • major examples include: • Inter-American Tropical Tuna Commission (IATTC)

Laws and Regs • International Commission for Northwest Atlantic Fisheries (ICNAF) • International North Pacific Fisheries Commission (INPFC

Laws and Regs • International Whaling Commission (IWC) • most commissions are formed after a resource develops problems

Laws and Regs • commissions are only as strong as their member nations want them to be • most recent attempt to develop ocean regulations is the UN’s Law of the Sea