Warm Up 2/11/09Warm Up 2/11/091) Which of the following is NOT a process that

decreases the salinity of seawater?a. icebergs melting c. runoff from landb. precipitation d. evaporation

2) In addition to salinity, what factor affects the density of seawater?a. salt content c. latitudeb. temperature d. depth

3) Ocean salinity is usually expressed in ____.a. charts c. parts per thousandb. chemical formulas d. parts per billion

Answers: 1) d. 2) b. 3) c.

The Diversity of Ocean The Diversity of Ocean LifeLife

Chapter 15, Section 2Chapter 15, Section 2

Classification of Marine OrganismsClassification of Marine Organisms

Marine organisms can be classified according to Marine organisms can be classified according to where they live and how they movewhere they live and how they move

PlanktonPlankton include all organisms—algae, animals, include all organisms—algae, animals, and bacteria—that drift with ocean currentsand bacteria—that drift with ocean currents

Phytoplankton – Phytoplankton – the algae that undergo the algae that undergo photosynthesisphotosynthesis

Zooplankton – Zooplankton – animal planktonanimal plankton NektonNekton include all animals capable of moving include all animals capable of moving

independently of the ocean currents, by independently of the ocean currents, by swimming or other means of propulsionswimming or other means of propulsion

The term The term benthosbenthos describes organisms living on describes organisms living on or in the ocean bottomor in the ocean bottom

PlanktonPlankton

Phytoplankton

Zooplankton

NektonNekton

BenthosBenthos

Marine Life ZonesMarine Life Zones

The distribution of marine organisms is The distribution of marine organisms is affected by the chemistry, physics, and affected by the chemistry, physics, and geology of the oceangeology of the ocean

Three factors are used to divide the ocean Three factors are used to divide the ocean into distinct marine life zones: the into distinct marine life zones: the availability of sunlight, the distance from availability of sunlight, the distance from shore, and the water depthshore, and the water depth

Availability of SunAvailability of Sun Photic Zone – Photic Zone – the upper part of the ocean into the upper part of the ocean into

which sunlight penetrateswhich sunlight penetrates The clarity of seawater is affected by many The clarity of seawater is affected by many

factors, including the amount of plankton, factors, including the amount of plankton, suspended sediment, and decaying organic suspended sediment, and decaying organic particlesparticles

The euphotic zone is the portion of the photic The euphotic zone is the portion of the photic zone near the surface where light is strong zone near the surface where light is strong enough for photosynthesis (usually no deeper enough for photosynthesis (usually no deeper than 100 meters)than 100 meters)

Below the photic zone is the Below the photic zone is the aphotic zoneaphotic zone, , where there is no sunlightwhere there is no sunlight

Photic ZonePhotic Zone

Concept CheckConcept Check

What is the difference between the photic What is the difference between the photic zone and the aphotic zone? zone and the aphotic zone?

Sunlight penetrates the photic zone; no Sunlight penetrates the photic zone; no sunlight reaches the aphotic zone.sunlight reaches the aphotic zone.

Distance from ShoreDistance from Shore Intertidal Zone –Intertidal Zone – the area where the land and ocean the area where the land and ocean

meet and overlapmeet and overlap The The intertidal zoneintertidal zone is a narrow strip of land which is is a narrow strip of land which is

alternately covered and uncovered between high and alternately covered and uncovered between high and low tideslow tides

Neritic Zone –Neritic Zone – covers the gently sloping continental covers the gently sloping continental slopeslope

The The neritic zoneneritic zone is often shallow enough to put all of it is often shallow enough to put all of it in the in the photic zonephotic zone, and is so rich with life that it , and is so rich with life that it supports 90% of the world’s commercial fisheriessupports 90% of the world’s commercial fisheries

Oceanic Zone –Oceanic Zone – area beyond the continental shelf area beyond the continental shelf Surface waters in the oceanic zone tend to not have Surface waters in the oceanic zone tend to not have

many nutrients as they sink down to the deep ocean many nutrients as they sink down to the deep ocean floorfloor

Intertidal ZoneIntertidal Zone

Water DepthWater Depth

Pelagic Zone –Pelagic Zone – open ocean of any depth open ocean of any depth Animals in the Animals in the pelagic zonepelagic zone swim or float freely swim or float freely Benthic Zone –Benthic Zone – includes any sea-bottom includes any sea-bottom

surface regardless of its distance from shoresurface regardless of its distance from shore The The benthic zonebenthic zone is mostly inhabited by is mostly inhabited by benthosbenthos

organismsorganisms Abyssal Zone –Abyssal Zone – a subdivision of the a subdivision of the benthic benthic

zonezone; includes the deep-ocean floor, such as ; includes the deep-ocean floor, such as abyssal plainsabyssal plains

The The abyssal zoneabyssal zone is characterized by high water is characterized by high water pressure, consistently low temperature, no pressure, consistently low temperature, no sunlight, and sparse lifesunlight, and sparse life

Marine Life ZonesMarine Life Zones

Marine Life ZonesMarine Life Zones

Hydrothermal VentsHydrothermal Vents Seawater seeps into the ocean floor through Seawater seeps into the ocean floor through

cracks in the crustcracks in the crust The water is super-heated and saturated with The water is super-heated and saturated with

minerals, and escapes back into the oceanminerals, and escapes back into the ocean The minerals precipitate out, giving the water The minerals precipitate out, giving the water

the appearance of black smoke (black the appearance of black smoke (black smokers)smokers)

At some hydrothermal vents water At some hydrothermal vents water temperature of 100temperature of 100ºC or higher support ºC or higher support communities of organisms found nowhere else communities of organisms found nowhere else in the worldin the world

Hydrothermal VentsHydrothermal Vents

AssignmentAssignment

Read Chapter 15, Section 2 (pg. 428-432)Read Chapter 15, Section 2 (pg. 428-432) Do the Chapter 15 Assessment #1-32 (pg. Do the Chapter 15 Assessment #1-32 (pg.

443-444)443-444) For Section 2: Do #’s 5-8, 16-19, 32For Section 2: Do #’s 5-8, 16-19, 32