Life on the Sea Floor

Review Benthic environment Benthic environment Regions of land above/below water Regions of land above/below water Supralittoral, Littoral, Sublittoral, Bathyal, Abyssal, Hadal Supralittoral, Littoral, Sublittoral, Bathyal, Abyssal, Hadal Life Groups Life Groups Plankton (floaters/drifters; at/near surface) Plankton (floaters/drifters; at/near surface) Nekton (swimmers) Nekton (swimmers) Benthos (at/near bottom) Benthos (at/near bottom) Importance of Benthic Organisms Importance of Benthic Organisms Food resources, Commercial harvests Food resources, Commercial harvests

Seaweeds Not plants just plant-like algae/protist Not plants just plant-like algae/protist Found in Euphotic zones Found in Euphotic zones Provide food, shelter, attachment Provide food, shelter, attachment Adapted to deal with tidal, current, and wave action Adapted to deal with tidal, current, and wave action Holdfast, Stipe, blades, air-filled structures Holdfast, Stipe, blades, air-filled structures Groups based upon pigments Groups based upon pigments Green-chlorophyll (ROY BIV) Green-chlorophyll (ROY BIV) Brown-fucoxanthin Brown-fucoxanthin Red-phycoerythrin and phycocyanin Red-phycoerythrin and phycocyanin

Seaweed Groups

Plants Few marine plants Few marine plants Eelgrass Eelgrass Areas of less wave action; Pacific/Atlantic Areas of less wave action; Pacific/Atlantic Turtle grass- Gulf of Mexico only Turtle grass- Gulf of Mexico only Surf grass Surf grass Areas of more turbulent areas Areas of more turbulent areas Marsh grasses Marsh grasses Dominate estuaries/salt marshes Dominate estuaries/salt marshes Mangrove Trees-tropics only Mangrove Trees-tropics only

Animals More than 150,000 species More than 150,000 species 80% are epifauna (live on/attached to bottom) 80% are epifauna (live on/attached to bottom) 20% are infauna (buried in sediments) 20% are infauna (buried in sediments) Can be sessile or motile Can be sessile or motile Larvae is all motile to prevent overcrowding and for colonization of new areas Larvae is all motile to prevent overcrowding and for colonization of new areas Type of substrate, temperature, pH, salinity, exposure to air, Oxygen levels in water, water turbulence, pressure all influence type of life found in benthic environments Type of substrate, temperature, pH, salinity, exposure to air, Oxygen levels in water, water turbulence, pressure all influence type of life found in benthic environments

Rocky Shores Extreme environment Extreme environment Distribution based on ability to cope Distribution based on ability to cope Intertidal Zonation Intertidal Zonation Varies with local conditions Varies with local conditions Distinct arrangement of organisms Distinct arrangement of organisms

Tidal Pools Receding water trapped in a depression Receding water trapped in a depression Organisms are specialized to deal with changes in salinity and temperature Organisms are specialized to deal with changes in salinity and temperature Deeper pools mean greater volume of water which means a more stable environment Deeper pools mean greater volume of water which means a more stable environment

Sand & Mud Mostly detritus feeders buried in the sediments Mostly detritus feeders buried in the sediments Anoxic layers have little/no oxygen present Anoxic layers have little/no oxygen present

Sea Floor Bioturbation Bioturbation Organisms such as sea cucumbers and worms that continuously disturb and rework sediment so that there is a well-mixed uniform layer on the sea floor Organisms such as sea cucumbers and worms that continuously disturb and rework sediment so that there is a well-mixed uniform layer on the sea floor

Fouling & Boring Fouling organisms Fouling organisms Settle and grow on pilings, docks, boat hulls Settle and grow on pilings, docks, boat hulls Boring organisms Boring organisms Drill or bore their way into substrate Drill or bore their way into substrate

Symbiosis Relationship between two organisms living closely together Relationship between two organisms living closely together Mutualism Mutualism Commensalism Commensalism Parasitism Parasitism

Coral Reefs Location in tropics (23.5 degrees N & S) Location in tropics (23.5 degrees N & S) Colony of polyps that make calcium carbonate Colony of polyps that make calcium carbonate Need for survival Need for survival Warm water Warm water Clear water Clear water High wave energy High wave energy Shallow water Shallow water Symbiotic relationship with Zooxanthellae Symbiotic relationship with Zooxanthellae Can be found in deep water Can be found in deep water

Threats to Coral Reefs Overfishing Overfishing Poverty Poverty Predation Predation Coral Bleaching Coral Bleaching Diseases: CLOD, Black Band Diseases: CLOD, Black Band Increase sedimentation Increase sedimentation

Harvesting Benthic Creatures Commercial harvesting Commercial harvesting Algae and their extractions Algae and their extractions Therapeutic uses Therapeutic uses