Aquatic Ecology Life of the Wet Things

Marine vs. Fresh Marine = Salt water Freshwater = Non-salty water Estuaries, Coastlines, Coral reefs, Coastal marshes, Deep ocean Freshwater = Non-salty water Lakes, Ponds, Stream, Rivers, Inland wetlands

Major Types of Aquatic Life Plankton – Free floating Nekton – Strong swimming Benthos – Bottom dwelling

Advantages of Living in Water Natural buoyancy Less energy spent on support Usually limited fluctuations of temperature Nutrients usually available Waste/toxins diluted

Limiting Factors of Life at Different Depths Three major zones Surface Middle Bottom

Limiting Factors of Life at Different Depths Life limited by following factors at different depths Temperature Sunlight DO Nutrients

Limiting Factors of Life at Different Depths Temperature drops as depth increases

Limiting Factors of Life at Different Depths Sunlight can only penetrate about 100ft (30m) Euphotic Zone

Limiting Factors of Life at Different Depths DO Varies by temperature and depth Comes mostly from atmosphere Can be added to by producers Depleted by consumers

Limiting Factors of Life at Different Depths

Limiting Factors of Life at Different Depths Nutrients Affected by upwelling Phosphorus (phosphates) most limiting in freshwater Nitrogen (nitrates) most limiting in saltwater

Saltwater Life Zones Importance of oceans 71% of planet Heat sink Major role in hydrologic cycle Has a somewhat large influence in the earth’s weather patterns Ok, not so large, more like HUGE Gigantic reservoir for CO2

Saltwater Life Zones Two major life zones Coastal Zone Open Ocean On top of the continental shelf 10% of ocean/90% of ocean life High primary and net productivity Open Ocean

Saltwater Life Zones

Saltwater Life Zones

Saltwater Life Zones Estuaries and Tidal Zones Salt and freshwater mix Temperature and salinity vary Runoff Tidal flow Huge cleaning affect on environment

Saltwater Life Zones Coastal Wetlands Covered by salt water most of the year Breeding grounds/habitat for wildlife Filters waste/toxin Buffers shores against damage Bays, Mud flats, Salt marshes

Saltwater Life Zones Rocky and Sandy Shores Intertidal Zone Between low and high tide Rocky shores Pounded by waves, but still lots of life Barrier beaches Life must dig

Saltwater Life Zones Human impact on coastal zones 2/3 of human life live within 100 miles of a coast California has lost 91% of its original coastal wetlands

Saltwater Life Zones Coastal wetlands very vulnerable to pollution Easy to trap pollutants Coral reefs decreasing due to human destruction

Saltwater Life Zones Open ocean Three life zones based on penetration of sunlight Euphotic Bathyal Abyssal

Saltwater Life Zones Euphotic Photosynthesis takes place Low nutrients High DO

Saltwater Life Zones Bathyal and abyssal zones COLD Low DO High nutrients Life includes Deposit feeders Filter feeders Tragedy of Commons

Things to Remember While Googling Its abyssal, not abysmal.

Freshwater Life Zones Dissolved salt <1% by volume Two types Standing Flowing

Freshwater Life Zones About 1% of earth’s surface, but 41% of known fish

Freshwater Life Zones Closely connected to their surrounding terrestrial biomes. Why?

Freshwater Life Zones Dissolved salt <1% by volume Two types Standing Flowing

Freshwater Life Zones About 1% of earth’s surface, but 41% of known fish

Freshwater Life Zones Closely connected to their surrounding terrestrial biomes. Why?

Freshwater Lakes Lake Zones

Freshwater Lakes Littoral zone Shallow Near shore Rooted plants stop growing outside the zone Rich in nutrients High in biological diversity Rooted plants, decomposers, and the usual suspects

Freshwater Lakes Limnetic zone Like the euphotic zone Enough light for photosynthesis Limits depth of limnetic zone Starting with plankton, simple food web

Freshwater Lakes Profundal zone Deep, open water Too deep for photosynthesis Fish only

Freshwater Lakes Benthic zone It’s the bottom. Mostly decomposers and detritus-feeders

Types of Freshwater Lakes Two types Oligotrophic Eutrophic

Types of Freshwater Lakes Oligotrophic Poorly nourished

Freshwater Lakes

Types of Freshwater Lakes Oligotrophic Deep with steep sides Crystal-clear blue or green water

Types of Freshwater Lakes Eutrophic Well-nourished

Freshwater Lakes

Types of Freshwater Lakes Eutrophic Lots of nutrients for producers Nitrates and phosphates Usually shallow and murky During summer, bottom may have low DO

Season Changes in Lakes Water is cool, especially when frozen Makes water unique Also helps lakes survive wickedly cold winters Wickedly meaning not like “Mr. Williamson, it’s cold in here” or “It’s freezing outside in the F-quad”

Season Changes in Lakes

Season Changes in Lakes Lake layers Epiliminon Thermocline Hypoliminon

Season Changes in Lakes Winter Top layer freezes Insulates lower layers from “wicked” cold DO ok in epiliminon, not so good in hypoliminon

Season Changes in Lakes

Season Changes in Lakes Spring Ice melts and warms, reaching max density Sinks forcing nutrient rich water from bottom Helped by winds Spring overturn

Season Changes in Lakes

Season Changes in Lakes Summer VERY definite stratification Causes bottom to loose DO and nutrients

Season Changes in Lakes

Season Changes in Lakes Fall Epiliminon cools and becomes more dense Sinks, causing cooler, nutrient rich water to rise DO good everywhere

Freshwater Streams and Rivers Consists of runoff Watershed

Freshwater Streams and Rivers Three zones Headwater or source zone Transition zone Flood plain zone

Freshwater Streams and Rivers Source zone Cold water Fast moving Lots of DO Organisms well adapted to environment

Freshwater Streams and Rivers

Freshwater Streams and Rivers

Freshwater Streams and Rivers Transition zone Deeper channels Slower water Warmer water

Freshwater Streams and Rivers Flood plain zone Slow moving Murky

Freshwater Streams and Rivers Importance of inland wetlands Food source and habitats Improved water quality Reduced flooding and erosion Replenish groundwater

Freshwater Streams and Rivers Human impact Loss of wetlands due to Agriculture (80%) Mining Forestry Oil/gas extraction Urban development

Freshwater Streams and Rivers Mitigation banking Replacing lost wetlands with equal area of sime type Doesn’t work well

Freshwater Streams and Rivers Best course of action Prevention

Aquatic Life Zones Why are they important? How do humans impact them? How does species diversification relate?