Chapter 13 The Marine Habitat Most organisms live

Chapter 13: The Marine Habitat

Most organisms live in euphotic zone Sunlight n Nutrients n Marine algae n Other organisms need algae n Directly or indirectly n

Classification n Three domains n Archaea n Bacteria n Eukarya

Classification n Four Kingdoms n Protista n Fungi n Plantae n Animalia Fig. 13 -1

Taxonomy Kingdom n Phylum n Class n Order n Family n Genus n Species n Fig. 13 -4

Classification of marine life n By life style n Plankton floaters Phytoplankton n Zooplankton n Baterioplankton n n Plankton make up most of Earth’s biomass

Phytoplankton Fig. 13 -2

Zooplankton Fig. 13 -2

Nekton active swimmers Fig. 13 -4

Benthos bottom dwellers n n n Epifauna Infauna Nektobenthos Fig. 13 -5

Marine life n Marine environment stable n No need to adapt to many different conditions 98% benthic n 2% pelagic n

Adaptations to ocean: Viscosity n Buoyancy Cooler water more viscous n Warmer water less viscous n n Organisms with appendages Common warmer water n Less common cooler water n n Small size resists sinking

n n Small size resists sinking for plankton Nekton streamlined Fig. 13 -10

Temperature n Stenothermal n n Open ocean, deeper Eurythermal n n Shallow coastal water Open ocean, surface

Salinity Euryhaline n Stenohaline n

n Marine hypotonic fish Drink water n Secrete salt n Concentrated urine n Fig. 13 -14

Diffusion n Molecules move from higher concentration of substance to lower concentration Fig. 13 -12 b

Osmosis n Fig. 13 -13 Water molecules move through semipermeable membrane from less concentrated to more concentrated

Dissolved gases Gas solubility depends on temperature n Gills exchange oxygen and carbon dioxide in water n Marine animals die if not enough oxygen in seawater n

Water is very transparent Shallow water fish good vision n Transparent bodies (jellyfish) n Counter shading n Disruptive coloration n Cryptic Coloration n Bioluminescent n

Pelagic (open ocean) n Biozones Neritic n Oceanic n Epipelagic n Mesopelagic n Bathypelagic n Abyssopelagic n Fig. 13 -19

Sunlight zones Euphotic n Disphotic n Asphotic n

Benthic biozones Subneritic n Suboceanic n Littoral n Sublittoral n Abyssal n Hadal n

End of Chapter 13: The Marine Habitat