This document provides a summary of key concepts about ocean water and ocean life: 1) Ocean water is complex, containing dissolved salts, metals, and gases that allow life to evolve special adaptations like symbiosis. 2) Major sources of ocean salts include chemical weathering of continents and volcanic eruptions. 3) Ocean life is divided into plankton, nekton, and benthos based on how they move and where they live. 4) Factors like sunlight, distance from shore, and water depth define distinct marine life zones in the oceans.

1. Chapter 15 Ocean Water and Ocean Life

2. Introduction Can people drink salt water? No and yet we are composed of 55-75% salt water… Ocean water is very complex containing salts, metals, and dissolved gases.

3. Ocean life has had to evolve and adapt special methods to successfully live in the oceans… 2 examples: mitochondria – invaded a celled organism and both benefited chloroplast – provided plants with the ability to perform photosynthesis Both of these examples were independent organisms before forming a symbiotic relationship as they do today. These examples allowed organisms to survive and adapt.

4. Salinity Salinus = salt Salinity is the total amount of solid material dissolved in water. It is a ratio of the mass of the dissolved substances to the mass of the water Salinity is usually expressed in parts per thousand (ppt) or 0/00 Dissolved salts in seawater is about 3.5% or 35 0/00 .

5. Salinity NaCl ********* Magnesium chloride Sodium sulfate Calcium chloride Potassium chloride Sodium bicarbonate Potassium bromide Hydrogen borate Strontium chloride Sodium fluoridene

6. Sources of Sea Salts The majority of ocean salts came from a build up of animal wastes. Life started in the ocean and wastes have accumulated ever since. Any other source of salt is secondary to animal wastes

7. REAL Sources of Sea Salts are….. 1. Chemical weathering of the continents. 2.3 billion metric tons per year = amount of runoff from streams and rivers 2. Volcanic eruptions – major source of gases, elements, and fresh water. Think about it. Where is the water come from to fill the oceans? Volcanic activity Since they occur underwater, volcanoes add a tremendous amount of minerals to the water practically every day.

8. Processes Affecting Salinity The normal range of ocean salinity is 33 0/00 – 38 0/00 1. large amounts of fresh water is added from precipitation, runoff, icebergs, sea ice melting 2. Evaporation removes large amounts of water thus increasing salinity 3. Polar regions have seasonal changes… summer when ice melts salinity decreases…..winter when ice freezes salinity increases

9. Salt does not become part of sea ice. How is this possible? When the temperature of water reaches 4 0 C , it become very dense and solids like salts tend to drop out and dissolve in water that is warmer. SO…ice at the North Pole in the Arctic Ocean is fresh water ice.

10. Temperature Variation The ocean’s surface temperature varies with the amount of solar radiation received. This is a function of latitude. Temperature drops with depth. Light cannot penetrate depths below 1000 meters. Below that temperatures don’t vary much and stay just above freezing.

11. Thermocline – is the layer of the ocean between 300 meters and 1000 meters, where there is rapid changes in temperature. It creates a vertical barrier too many forms of sea life. High latitudes do not experience a Thermocline. Why? Very little temperature changes

12. Ocean Density Density – mass per unit of volume. Density changes in seawater determine its vertical position in the ocean. Warmer water rises while cooler water sinks. Fresh water rides on top of more dense seawater.

13. Factors Affecting Seawater Density Salinity Temperature Surface water is affected by temperature more and deeper water is affected by salinity more. Temperature is the major factor that affects the density of seawater. Cold water high in salt is some of the densest water in the world. Seawater is most dense at _____ Celsius. 4 0

14. Pycnocline ??????? Pycnocline – the layer in the ocean where density changes rapidly with depth….between 300 meters and 1000 meters. It presents a significant barrier between the low density water above and the high density water below. The pycnocline is not present in high latitudes because the density of the water is about the same throughout.

15. Ocean layering Surface zone – the mixed zone – is the area of the surface created by mixing of water by, waves, currents, and tides. Temperatures are uniform here and change with latitude and season.

16. Transition layer – below the mixed layer and the deep zone, this area contains the thermocline and the pycnocline . About 18% of ocean water is here…….

17. Deep zone – Sunlight never reaches this zone. Water density remains high and constant. About 80% of ocean water is here. At high latitudes the very cold water at the surface sinks creating deep water currents .

18. Diversity of Ocean Life Marine organisms are classified by how they move and where they live.

19. Plankton all organisms that drift in ocean currents. Algae, very small animals, and bacteria. Phytoplankton – can perform photosynthesis… diatoms Zooplankton – animal life… includes larval stages of many marine organisms like fish, crab, lobsters, and sea stars. This is the first step in the oceans variety of food webs

20. Nekton can perform free locomotion. They can determine their position within the ocean and travel long distances when they migrate. Fish, squid, marine mammals, marine reptiles, etc.

21. Angler fish

22. Eel trying to eat

23. Jelly fish

24. Shark

25. Archer fish

26. Sea dragon

27. Scorpion fish and puffer

28. Hammerheads hunting

29. Sea snakes

30. Sea horse

31. Manta ray

32. Sharks

33. Blue Whale

34. Cleaner Fish

35. Deep Sea Fish These fish can live at depths in excess of 10,000 ft.

37. Benthos organisms that live on or in the ocean bottom. Most tend to live in areas of algae and seaweed. Plenty of sunlight reaches the bottom. Some live on the ocean bottom where very little if an light ever reaches. These organisms tend to be scavengers or predators. examples: clams, oysters, scallops, shrimp, lobster, sea urchin, sand dollars, star fish, coral, and etc……...

38. Sea Anemone

39. Coral Reproduction

40. Crabs

41. Filter feeders

42. Worms

43. Hiding Out

44. Benthos Variety

45. Shrimp

46. Sponges

47. Mollusks

48. Starfish

50. Marine Life Zones Three factors are used to divide the ocean into distinct life zones….. 1. availability of sunlight photic zone – sunlight can penetrate The clarity of ocean water is affected by : amount of plankton suspended sediment decaying organic particles

52. amount of sunlight is affect by atmospheric conditions time of day season of the year latitude

53. euphotic – near the surface, where photosynthesis takes place… this zone can reach 100 meters in depth.. This is the basis of all oceanic food webs. Below 100 meters Enough light for animals to avoid predators Find food Locate mates There is no light below this zone

55. 2. The distance from shore divided into zones based on there distance from shore intertidal zone –where the land and ocean meet and overlap… between high and low tides Harsh due to waves crashing on the shore, dry periods, rapid changes in temperature, salinity changes, oxygen concentrations Neritic zone – covers the continental shelf… often shallow for sunlight to penetrate to the ocean floor.

56. It covers only 5% of the ocean floor, but produces large amounts of biomass and numbers of species. It supports 90% of all commercial fishing. Oceanic zone – near the surface many nutrients sink making this area less productive than perhaps it should. This results is small populations

57. 3. water depth – Open ocean at any depth – pelagic zone – animals here swim or float freely benthic zone – seafloor at any depth – animals that crawl or burrow abyssal zone – subdivision of the benthic zone…. Includes the deep ocean floor extremely high pressure

58. low temperatures no sunlight sparse food food sources: decaying matter from the surface (filter feeders), parts of organisms (grenadier, tripodfish, hagfish)

59. bioluminesce – ability to produce light through chemical processes or via luminescent bacteria living symbiotically in organisms… 50% of all deep sea organisms can produce light special cell structures called photophores produce the light for…………. attract prey define territory communicate with others avoid predators

60. Dumbo Octopus

61. Vampire Squid

62. Hatchet fish

63. Pacific Vampire fish

64. hydrothermal vents – occur near oceanic ridges… ocean water seeps into the ocean crust, becomes super heated and escapes back into the ocean… This mixing of the heated water with cold ocean water causes minerals to precipitate out causing the water to appear black and smoky. The chemicals from the vents becomes food for bacteria which produce sugars and other nutrients for organisms that live there…. Tube worms

66. Ocean Productivity Primary productivity – is the production of organic compounds from inorganic substances through photosynthesis and chemosynthesis Photosynthesis – to use light energy to convert water and carbon dioxide into energy rich glucose compounds. Chemosynthesis – process by which certain microorganisms create organic molecules from inorganic nutrients using chemical energy. Example: bacteria in hydrothermal vents use hydrogen sulfide as an energy source

68. Two factors influence a region’s photosynthesis productivity are: availability of nutrients and amount of solar energy . Lack of nutrients is a limiting factor…… Ocean productivity is uneven because of the uneven distribution of nutrients throughout the photosynthetic zone.

69. Productivity in Polar Regions This area experiences 3 months of continuous darkness and three months of continuous daylight. Diatom productivity peaks in May… Zooplankton feeding on them peaks in June. Fresh water from thawing ice provides phytoplankton with an opportunity to stay near the surface instead of sinking because of water density. Upwelling from warm currents traveling north provide much needed nutrients ….. Solar energy or lack of is the major limiting factor because photosynthesis is inhibited.

70. Productivity in Tropical Oceans Productivity is low in open ocean tropical regions. Since light can penetrate to a greater depth here a permanent thermocline forms and prevents mixing. Productivity is limited because of a lack of nutrients .

71. Productivity in Temperate Oceans Middle latitudes….. productivity is limited by both amount of solar radiation and lack of nutrients …. The mid-latitudes experience changes in these factors seasonally. Winter – nutrient concentration is highest but productivity is very low. Solar energy is limited and the angle of solar radiation is greater than in summer. Phytoplankton doesn’t grow much

72. Spring – Increased solar energy can penetrate ocean water to a greater depth. A spring plankton bloom occurs with increased solar radiation and available nutrients. A thermocline develops trapping algae and creating a demand for nutrients in the euphotic zone. Nutrients become depleted quickly so productivity decreases sharply. Lack of nutrients is the limiting factor .

73. Summer - Solar energy increase and a strong thermocline is established. This prevents mixing so surface nutrients are depleted and deeper waters cannot replenish them. Phytoplankton remains low .

74. Fall – Solar energy decreases and the thermocline breaks down. Nutrients return to the surface as winds increase and surface waters mix with deeper waters. This condition creates a fall plankton bloom, which is less dramatic than the spring bloom. This fall bloom is short lived. Solar energy becomes the limiting factor as winter approaches.

75. Oceanic Feeding relationships Trophic levels- Chemical energy stored in mass is transferred to the animal community mostly through feeding. Algae – zooplankton – larger algae and plants – carnivores – larger carnivores Each feeding stage is a trophic level Transfer energy: transfer of energy between levels is inefficient. 2% of light energy is changed into food and made available to herbivores

76. Food chains and food webs Food chain – is a sequence of organisms through which energy is transferred Primary producers – herbivores – series of carnivores Top carnivores generally feed on a number of varieties of organisms Animals that feed through a food web rather than a food chain are more likely to survive because they have alternative foods to eat should one of their food sources diminish or disappear .