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Most diverse part of the richest part of the ocean
- Coral reefs
- -subtidal, tropical
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reef building species
Schleractinian
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Coral growth
- 1. Layers of CaCO3
- 2. Grow up and outward
- 3. Columns
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Coral shapes
- 1. Plate-like
- 2. Foliceous
- 3. Columnar
- 4. Massive
- 5. Branching
- 6. Encrusting
- 7. Free-living
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Coral Bleaching: Sources of warm water
- 1. Extreme low tide
- 2. Power plants
- 3. El Nino
- 4. Climate change
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Factors influencing reef growth
- 1. Salinity
- -sensitive to low salinity
- 2. Sediment
- - fine sediments can smother polyps
- sources: mining, logging
- 3. Pollution
- -pesticides, toxic waste
- -excess nutrients: sewage, fertilizers
- -CO2, & ocean acidity
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Reef Types
- 1. Fringing
- - Narrow band near shore
- -most vulnerable to human impact
- 2. Barrier
- -Separated from shore by lagoon
- 3. Atolls
- -Ring around island or central lagoon, off-shore
- 4. Deep-water coral mounds
- - up to 6,000m
- -no zooxanthellae
- -filter feed only
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Simplest and most common type of reef
Fringing reef
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Atolls:Formation
- 1. Volcanic island
- 2. Fringing reef forms
- 3. Island slowly sinks
- 4. Reef expands
- 5. Lagoon forms
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Mutualism: Coral + Zooxanthellae
- 1. Corals: Protection and nutrients
- 2. Zooxanthellae: food and assist in building skeleton
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External nutrient cycling
- Fishes + Macroalgae + Coral
- 1. Fishes consume algae
- 2. Invertebrates, excrete nutrients as waste
- 3. Nutrients absorbed by algae/coral
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Coral reefs: Other nutrient sources
- 1. Nitrogen fixation
- -cyanobacteria
- 2. Currents
- - Influx of low concentrations of nutrients
- 3. Reef visitors
- - animals feeding elsewhere bring in nutrients as waste
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Corals: Other primary producers
- 1. Turf algae
- 2. Cyanbacteria
- 3. Coralline algae
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Crown of Thorns Sea Star
- 1. Everts stomach over large parts of coral colony
- 2. Digests living tissue
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Damselfish gardeners
- 1. Guard territory
- 2. Remove undesirable algae
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Coral competition
- 1. Space limitation
- -Hard substrate
- -Access to light
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Corals: fast growth
1. Grow up and out shading neighbors
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Corals: Slower growth
- Attack
- 1. Medenterial filaments: digest away each other's living tissue
- 2. Sweeper tenatacles: packed with nematocysts
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Algae limitations
Nutrients and grazing
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Deep sea:food source
- Marine snow
- 1. Organic detritus from above
- 2. Chemical seeps/vents
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Most abundant fish on earth
- 1. Bristlemouths
- 2. Lanternfishes
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Mesopelagic fishes
- 1. Small size
- 2. Generalist feeders
- - long, sharp teeth
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Mesopelagic: Adaptations
- 1. Large, extremely sensitive eyes
- 2. Coloration: Camouflage
- 3. Body shape: Not streamlined, lateral compression
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Counterillumination
Match light produced by photophores to downwelling light
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Bioluminscense
- 1. Communication
- 2. defense
- 3. attraction
- 4. hunting
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Mesopelagic vs deep sea
- 1. Bigger brain
- 2. Larger gill filaments
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Deep Sea: Reproduction
- 1. Hard to find mate
- - Bioluminescense
- - Pheromones
- 2. Hermaphrotism
- 3. Parasitic males
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Most abundant organism on sea floor
- Meiofauna
- -lives in crevices of sand particles
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Bottom dwelling fishes
- 1. Larger size
- 2. More active and muscular
- 3. Scavengers
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Deep sea scavengers
- 1. Hagfishes
- 2. Rattails
- 3. Sleeper sharks
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Evolution of fisheries
- 1. Simple gear
- - Harpoons
- 2. Ships
- -more space, speed, distance
- 3.Refrigeration
- 4. Machines + technology
- -Larger nets, stronger, heavier
- -GPS, sonar
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Gill nets
designed to trap bony fish by gills
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Purse seine
- designed to encircle entire schools of fish
- -Target: tuna
- - Bycatch: Dolphins, sharks, turtles
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Trawls
Bulldozing a forest to catch a deer
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Longlines
- baited hooks
- - designed to attract and hook pelagic or benthic species
- -Target: tuna, halibut
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Trolling
- -Baited hooks are towed behind boat
- Target: tuna, salmon
- -less bycatch
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Pots & Traps
- 1. Baited cages/traps
- 2. Targeted: crabs, lobsters
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Artisinal fisheries
- 1. Local, low-tech gear, small boats
- 2. Important local food source
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Types of pollution
- 1. Thermal: heat
- 2. Sound: ships, sonar, drilling
- 3. chemical: urban, agricultural
- 4. Physical: marine debris
- 5. Biological: invasive species
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