1. Life in the Ocean Chapter 13

2. Life, Energy, and FOOD! All life needs energy Energy is the ability to do work Identify different forms of energy: Chemical, Mechanical, Electrical, Nuclear, Thermal, Radiant, Sound, Potential, Kinetic, Gravitational Life forms need energy to build complex systems from simple molecules. Life forms manipulate energy to meet the organism’s needs

3. Laws of Thermodynamics related to Life 2 nd Law of Thermodynamics shows that over time systems tend to breakdown, become disorganized. ◦ Entropy is a measurement of this breakdown process. What are some examples of entropy? ◦ Agingrusting metalsfading colors A flow of energy decreases entropy!

4. The Sun’s ENERGY is key Electromagnetic Spectrum

5. Sun Empowering Life Organisms with chlorophyll convert photon energy into chemical potential energy (glucose). These organisms are called producers Photosynthesis Equation ◦ 6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O 2 Chemosynthesis alternative, anti-Sun! ◦ Is the production of usable energy directly from energy-rich inorganic molecules

6. Primary Productivity Primary productivity is the synthesis of organic materials from inorganic substances by photosynthesis or chemosynthesis. (Units: gC/m 2 /yr) Main organic material produced is glucose Main source of carbon for glucose is dissolved CO 2. (hmmm, climate change?) 90 -96% of oceanic carbohydrates are produced by phytoplankton.

7. Marine vs. Terrestrial Productivity Global net productivity of organic materials ◦ Marine ecosystems produce 35-50 billion metric tons/year ◦ Terrestrial ecosystems produce 50-70 billion metric tons/year Yet, total producer biomass is 1 – 2 billion metric tons in the ocean to 600 – 1,000 billion metric tons on land Which is more effective at producing organic materials?!

8. Terms so far 2 nd Law of Thermodynamics Entropy Chlorophyll Photosynthesis Chemosynthesis Primary productivity Biomass Primary producer

9. How do you feed? Autotrophs or primary producers chemically generate their own food within themselves. Heterotrophs rely on others for their food. Primary consumers, herbivores, are animals that eat primary producers. Secondary consumers eat the primary consumers, and so on…till we get to Top consumer, top carnivore, or apex predator, typically nothing eats this organism

10. Basic Elements Needed to Live 23 of 119 elements common to all life forms Carbon, hydrogen, oxygen, and nitrogen make up 99% of the mass of all living organisms. Carbohydrates, lipids, proteins, and nucleic acids are the main categories of chemicals found in life.

11. Elements in Cycles Biogeochemical cycles support and sustain living organisms with a large-scale transport between the chemical reserves and the organisms themselves. Elements are always on the move through-out the environment.

12. Carbon Cycle Largest of all biogeochemical cycles Considered the basis for life because it builds long chain molecules. Carbon moves through the marine environment in these three ways: ◦ Incorporated into plants and animals ◦ Respired by animals as CO2 ◦ Excreted back into seawater as dissolved carbon dioxide ◦ Ex. A typical marine plant, uses 45% of C for growth, 45% for respiration, and 10% lost as DOC

13. Carbon Cycle Illustrated

14. Nitrogen Cycle Nitrogen is needed for the formation of proteins, chlorophyll, and nucleic acids Found in the ocean as N 2, dissolved organic nitrogen (DON), and as dissolved inorganic ions (nitrite, nitrate, and ammonium) Most organisms cannot use free nitrogen in the air or ocean. Bacteria and cyanobacteria are needed to fix the nitrogen with hydrogen and oxygen

15. Still Cycling Nitrogen As plants assimilate the fixed nitrogen, animals pass the nitrogen along through the food chain. Eventually this nitrogen is excreted as ammonium and urea back into the environment. Nitrifying bacteria breakdown ammonium and urea into nitrates Denitrifying bacteria convert nitrates into nitrite and nitrogen gas, which is lost to the atmosphere Nitrogen & Phosphorus Cycles

16. Physical Factors A physical factor is any aspect of the physical environment that affects living organisms. The ocean provides a milder, less variable set of physical factors for marine life to flourish. light, temperature, dissolved nutrients, salinity, dissolved gases, acid-base balance, and hydrostatic pressure Marine physical factors include: light, temperature, dissolved nutrients, salinity, dissolved gases, acid-base balance, and hydrostatic pressure

17. Biological Factors Biological factors are generated by an organisms interaction with their environment. The following are examples: ◦ Food sources ◦ Reproductive needs ◦ Predator/prey relationships ◦ Instinctive behaviors ◦ Communication

18. Power of Light Light penetrates the ocean at different depths depending on the following: ◦ Number and type of suspended particles ◦ Number of organisms with chlorophyll which reflects green light ◦ Blue light penetrates deepest. ◦ Red light is absorbed near the surface

19. Light Zones Photic zone is the uppermost layer of seawater lit by the sun. This zone extends down100 meters near the coast to 590 meters in the tropical Pacific. ◦ Euphotic zone is the upper part of the photic zone where photosynthesis occurs ◦ Disphotic zone is below the euphotic zone where it is too dim for photosynthesis to occur. Aphotic zone is the permanently dark layer of seawater beneath the photic zone. Most of the ocean never sees the light of day

20. Thinking Critically The 2 nd Law of Thermodynamics states that entropy tends to increase with time. But living things tend to become more complex with time. How can this be? Researchers believe there may be as many as 100 million species living on or in the Earth. If we know about a million or so species, where are the other 99 million? Are Are you ready for what’s next? Take Take out a sheet of paper…

21. Quiz Ch. 13 worth 30 points Answer the following: 1. How is entropy countered in nature? 2. Can there truly be an apex predator? ◦ Defend your response 3. Briefly explain how carbon moves through the environment.

22. Temperature Basics The average temperature of the world ocean is a few degrees above freezing. Heat is a form of energy produced by the random vibration of atoms or molecules. Temperature is the measure of the atomic and molecular vibration in a substance, indicated in degrees.

23. Hot vs. Cold An increase in temperature increases the rate at which chemical reactions occur. All living organisms have a metabolism. Metabolic rate is the speed at which energy-releasing chemical reactions occur within an organism. The metabolic rate roughly doubles with a 10 °C increase in temperature.

24. In COLD Blood! A vast majority of marine life is cold blooded or ectothermic. An organism that is ectothermic has an internal temperature very close to the temperature of its surroundings. Complex animals, such as mammals, birds, and some larger, faster fish, are warm blooded, or endothermic. Endothermic animals have a high internal temperature.

25. Dissolved Nutrients A nutrient is a compound required for the production of organic matter. Main inorganic nutrients are nitrogen and phosphorus. ◦ Nitrogen is usually found as nitrate NO 3 and is used to build proteins, chlorophyll, and nucleic acids. ◦ Phosphorus is usually found as phosphate PO 4 and is used to build bone and tissues.

26. Salinity Salinity is a measure of the dissolved solids in seawater. Salinity varies around the world, from a low of 6‰ in the Baltic Sea to a high of 40‰ in the Red Sea. A change in salinity affects the following: ◦ Physically damage cell membranes ◦ Alter protein structures ◦ specific gravity and density of seawater, thus changing the buoyancy of an organism ◦ Water balance in cells

27. Dissolved Gases Oxygen does not dissolve readily in water. There is about 100 times more oxygen in the atmosphere than in the ocean Carbon dioxide is much more soluble and reactive in seawater. The ocean contains 60 times more CO 2 than the atmosphere. Physics note: Colder water contains more gas at saturation than warmer water. Photosynthesis at the surface lowers the concentration of CO 2 and increases the amount of dissolved O 2.

28. pH Scale Seawater is slightly alkaline at pH of 8. Dissolved substances in seawater act as buffer to pH changes

29. Hydrostatic Pressure Hydrostatic pressure is the weight of the water pressing down from above. At high pressure gases become more soluble, some enzymes are inactivated, and metabolic rates for a given temperature tend to be higher.

30. Diffusion, Osmosis, and Active Transport Diffusion is the movement – driven by heat-of molecules from a region of high concentration to a region of low concentration Osmosis is the diffusion of water through a membrane. Active transport is osmosis at the expense of energy

31. Classifications of the Marine Environment A zone is an area of homogeneous features Pelagic zone is the open water divided into the neritic zone and oceanic zone. Neritic zone is near shore over the continental shelf. Oceanic zone is the deep water beyond the continental shelf.

32. Classifications of the Marine Environment Benthic zone is the actual bottom of the ocean. Littoral zone is the intertidal area or band of coast alternately covered and uncovered by tidal action. Bathyal zone covers the seabed on the continental slope. Abyssal zone covers the ocean depth beyond the continental slope. Hadal zone is the deepest seabed, found as trench walls and floors.

33. Theory of Evolution Evolution is the ability of living things to change through time to fit their physical and chemical environment, to become more efficient at extracting energy, to colonize locations capable of sustaining them.

34. Theory of Evolution Natural Selection is the process for how living organisms might evolve with the passage of time. More offspring are produced than can survive to a reproductive age Random variations occur, some of these are passed along via genetics Favorable traits are passed along, unfavorable traits tend to die out Organisms with favorable traits are termed selected The natural environment does the selection, the selected possess the favorable traits required to survive, unless the environment changes

35. Evolutionary Changes Mutations are an inheritable change in an organism’s genes. Most mutations are unfavorable. Some mutations are favorable and enhance the survivability of the organism. Natural selection takes a great deal of time. Evolution by natural selection is the accumulation of favorable structural or behavioral traits is known as adaptations. A species is a group of interbreeding organisms that is reproductively isolated from all other forms of living things.

36. Theory of Intelligent Design The theory of intelligent design is a combination of law, chance, and design— the activity of a mind or some form of intelligence that has the power to manipulate matter and energy. Living systems look designed for a purpose. Interactions between species provide evidence of intelligent design.

37. Systems of Classification Taxonomy is the study of biological classification. A natural system of classification relies on an organism’s evolutionary history and developmental characteristics. Carl Linnaeus, 1707 – 1778, was a Swedish naturalist that first began to organize the natural world. His system for naming, ranking, and classifying organisms is still in wide use today. He is considered the Father of Taxonomy

38. Kingdoms of Life Monera = bacteria, single chromosome, asexual reproduction, extreme metabolic diversity, no nucleus. Archaea = “super bacteria” extra capabilities due to extra genes, can live in extreme environments Protista = usually unicellular, sexual or asexual, great genetic diversity Fungi = usually multicellular, sexual or asexual, release enzymes to breakdown food Plantae = multicellular photosynthetic autotrophs, sexual or asexual reproduction Animalia = multicellular heterotrophs, sexual or asexual reproduction