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Marine Fisheries Management

Marine Fisheries Management. Original Power Point Created by Linda Rist Modified by Georgia Agricultural Education Curriculum Office June 2002. Ocean. can be considered the last frontier on this planet unique physical characteristics. Ocean.

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Marine Fisheries Management

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  1. Marine Fisheries Management Original Power Point Created by Linda Rist Modified by Georgia Agricultural Education Curriculum Office June 2002

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

  3. Ocean • can support wide variety of plant and animal life

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

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

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

  7. Zonation • supratidal • intertidal • neritic • bathyal • abyssal

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

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

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

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

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

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

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

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

  16. 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

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

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

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

  20. Salinity • calcium - Ca • potassium - K

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

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

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

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

  25. Temp stratification • three layers • mixed surface layer • middle thermocline layer (10-1,000 meters) • deep water layer (1,000 - 6,000 meters)

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

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

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

  29. Water Movements • waves • tides • currents

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

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

  32. Wind generated • most common • sea • swell • surf

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

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

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

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

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

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

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

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

  41. 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

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

  43. 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)

  44. 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

  45. 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

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

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

  48. Currents - surface • reach velocities of about 3 knots • 1 knot = 1.15 mph

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

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

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