Presentation on theme: "Warm Up 2/19-20 Most ocean water is located in which zone?"— Presentation transcript:
1 Warm Up 2/19-20 Most ocean water is located in which zone? a. mixed zone c. surface zoneb. transition zone d. deep zoneWhich ocean zone does sunlight penetrate?a. aphotic zone c. neritic zoneb. photic zone d. abyssal zoneWhich of the following best describes the ocean bottom?a. quiet c. coldb. dark d. all of the aboveAnswers: 1) d. 2) b. 3) d.
3 Primary ProductivityPrimary Productivity – the production of organic compounds from inorganic substances through photosynthesis or chemosynthesisPhotosynthesis – the use of light energy to convert water and carbon dioxide into energy-rich glucose moleculesChemosynthesis – the process by which certain microorganisms create organic molecules from inorganic nutrients using chemical energyTwo factors influence a region’s photosynthetic productivity: the availability of nutrients and the amount of solar radiation, or sunlight
5 Concept CheckWhat factors influence a region’s photosynthetic productivity?Sunlight and nutrient availability
6 Productivity in Polar Oceans Polar regions experience continuous darkness for about three months of winter and continuous illumination for about three months of during summerProductivity of phytoplankton, mostly single-celled algae, peaks in MayAs soon as the phytoplankton develop, zooplankton come in to eat themIn summer, melting ice creates a low-salinity, low-density region on the surface that will not readily mix with the deeper waters; helping the phytoplankton to continue producingThe availability of solar energy is what limits photosynthetic productivity in polar areas
8 Productivity in Tropical Oceans Productivity is low in tropical regions of the open oceanLight penetrates much deeper into tropical oceans than in temperate and polar watersSolar energy is available year-roundA permanent thermocline prevents mixing between surface waters and nutrient-rich deeper waters; it is a barrier that cuts off the supply of nutrients from deeper watersProductivity in tropical regions is limited by the lack of nutrients
10 Productivity in Temperate Oceans In temperate regions, which are found at mid-latitudes, a combination of these two limiting factors, sunlight and nutrient supply, controls productivityWinter: productivity is low, due to the low angle of the sun and shallower sunlight penetrationSpring: phytoplankton bloom due to an increase in nutrients and sunlight, nutrient supply is in greater demand and limits productionSummer: nutrients depleted from spring “bloom” are not able to be replenished from deep waters due to a sharp thermocline, phytoplankton population will remain lowFall: nutrients return to the surface, as the summer thermocline breaks down, and another “bloom” of phytoplankton occurs (short-lived due to decreasing sunlight)
13 Concept CheckWhat limits primary productivity in tropical oceans? Why?The availability of nutrients; solar energy is available year round but nutrient are trapped in deeper waters because the permanent thermocline prevents mixing between surface water and deeper water.
14 Oceanic Feeding Relationships As producers make food available to the consuming animals of the ocean, energy passes from one feeding population to the nextTrophic Level – a nourishment level in a food chain; plant and algae → herbivores → carnivoresThe transfer of energy between trophic levels is very inefficientFood Chain – sequence of organisms through which energy is transferred, starting with the primary producerFood Web – a group of interrelated food chainsAnimals 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
17 Concept CheckWhat advantage do organisms in a food web have over those in a food chain?Organisms in a food web have alternative foods to eat if one of their food sources diminishes or disappears.
18 Assignment (Due 2/21) Read Chapter 15 (pg. 422-437) Do the Chapter 15 Assessment #1-32 (pg )Study for Chapter 15 Quiz!!!
19 Cool Down Describe the transfer efficiency between trophic levels. Very inefficient; as little as 2%Explain why producers are always the first trophic level in a food chain or food web.Producers are organisms that are able to use light or chemical energy to produce glucose. Consumers cannot produce their own food and rely on producers as a food source.What is one thing you learned today that you never knew? Explain.