Chapter 13: The Marine Habitat

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

Classification Three domains Archaea Bacteria Eukarya

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

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

Classification of marine life By life style Plankton floaters Phytoplankton Zooplankton Baterioplankton 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 Epifauna Infauna Nektobenthos Fig. 13-5

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

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

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

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

Salinity Euryhaline Stenohaline

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

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

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

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

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

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

Sunlight zones Euphotic Disphotic Asphotic

Benthic biozones Subneritic Suboceanic Littoral Sublittoral Abyssal Hadal

End of Chapter 13: The Marine Habitat