1.3 Aquatic Biomes - APES

Salinity

How much salt there is in a body of water, determines which species can survive & usability for drinking (Fresh Water vs. Estuary vs. Ocean)

Depth

Influences how much sunlight can penetrate and reach plants below the surface for photosynthesis

Flow

Determines which plants & organisms can survive, how much O₂ can dissolve into water

Temperature

Warmer water holds less dissolved O₂ so it can support fewer aquatic organisms

Freshwater: Rivers & Lakes 

Rivers have high O₂ due to flow mixing water & air, also carry nutrient-rich sediments (Deltas & flood plains = fertile soil)

• Lakes = Standing bodies of fresh H₂O (key drinking H₂O source)

Littoral

Shallow water with emergent plants

Limnetic

Where light can reach (photosynthesis)

• No rooted plants, only phytoplankton

Profundal

Too deep for sunlight (No photosynthesis)

Benthic

Murky bottom where inverts (bugs) live, nutrient-rich sediments 

Freshwater: Wetlands

Area with soil submerged/saturated in water for at least part of the year, but shallow enough for emergent plants 

• Plants living here have to be adapted to living with roots submerged in standing water (cattails, lily pads, reeds)

Benefits of Wetlands:

• Stores excess water during storms, lessening floods

• Recharges groundwater by absorbing rainfall into soil 

• Roots of wetland plants filter pollutants from water draining through

• High plant growth due to lots of water & nutrients (dead organic matter) in sediments

Estuaries

Areas where rivers empty into the ocean

• Mix of fresh & salt water (species adapt to this)

• High productivity (plant growth) due to nutrients in sediments deposited in estuaries by the river

Salt Marsh: Estuary habitat along the coast in temperate climates, breeding ground for many fish/shellfish species 

Mangrove Swamp: Estuary habitat, along the coast of tropical climates

• Mangrove trees with long, stilt roots stabilize the shoreline & provide habitat for many species of fish/shellfish

Coral Reef

Warm shallow waters beyond the shoreline; most diverse marine (ocean) biome on earth

• Mutualistic relationship between coral (animal) and algae (plant)

  • Coral take CO₂ out of ocean to create calcium carbonate exoskeleton (the reef) & also provide CO₂ to algae

Both species rely on the other:

• Coral couldn’t survive w/o energy from algae

• Algae need the home of the reef & CO₂ from the coral

Intertidal Zones

Narrow band of coastline between high/low tide

• Organisms must be adapted to survive crashing waves & direct sunlight/heat during low tide

• Shells & tough outer skin can prevent drying out (desiccation) during low tides 

Different organisms are adapted to live in different zones

Open Ocean 

Low productivity/area as only algae & phytoplankton can survive in most of ocean

So large though, that algae & phytoplankton of ocean produce a lot of earth’s O₂ & absorb a lot of atmospheric of CO₂

• Photic Zone = Area where sunlight can reach (Photosynthesis)

• Aphotic Zone (Abyssal) = Area too deep for sunlight