Ecology: The study of how organisms interact with each other and the environment

• Most are connected to some form of energy

  1. Autotrophs: Organisms that can create their own energy

     1. Photoautotrophs: Use light

     2. Chemoautotrophs: Use chemicals

  2. Heterotrophs: Organisms that must consume other organisms for energy

LEVELS

• Species: An organism that creates a viable offspring

  • Critical that their offspring can also produce offspring

• Population: A group of organisms of the same species living in the same place at the same time

• Communities: Various populations (multiple species) in a general area

• Ecosystem: All the communities and all of the physical features of the environment

ENERGY PYRAMID

• 90% of the energy is lost as heat

• The best way to be efficient in getting more energy is by being at the bottom of the pyramid

  • This is why the most abundant organisms tend to be primary producers/towards the bottom

Intraspecific competition: Competition between organisms of the same species

Competitive exclusion: When one organism outcompetes the other for resources

• Competitive exclusion is the most common outcome

Resource partitioning: Sharing the resources amongst themselves

• Less common

• Sharing the resources in different ways or at different times

• EX) Giraffes eat leaves at the top of a tree while an impala feeds on leaves at the bottom

INTERACTIONS THAT HAVE LED TO CO-EVOLUTION

Symbiont: Something that has developed a long-term relationship with another organism. Tend to be smaller than the host.

Mutualism: When the symbiont and the host both benefit from the relationship (+, +)

• EX) Clownfish and other sea anemone provides protection for clownfish, clownfish clean off debris/provides nutrients

Commensalism: One organism is benefitting while the other is unharmed (+, 0)

• EX) Sharks and Remora-- Remora stick to shark underbellies to get free transportation. The sharks are unharmed for the most part. An exception is when the remora grow too big and sink the shark down.

Parasitism: Symbiont benefits and the host is harmed in some way (+, -)

• Greenland sharks and copepods-- referred to as ommatokoita: The parasite latches onto the shark’s eye, destroying its corneal tissue to go after its blood source, rendering the shark blind and destroying their immune system in the process

ESTUARIES

Estuary: A low-lying area that gets both freshwater and seawater mixed into it

• Tends to have a large accumulation of sediment because they often are cut off from the ocean (no waves)

• Usually you would find fine sediment like mud and clay

• A nursery ground for ALL types of organisms

  • Invertebrates, fish, sharks, marine birds, etc.

  • However, NO marine mammals

    • Mainly because there are no waves, etc. If they are in an estuary, they’re likely sick

• Rest stop for migrating birds

  • Less so nowadays because of human development

• Highly polluted because of cities upstream that dispose of trash

  • Acts as a filler for the ocean because all of the pollutants settle in the estuaries

4 TYPES OF ESTUARIES

1. Coastal Plane Estuary

• The most common type of estuary

• It is right next to the ocean and low-lying enough that it fills up during the high tide

  • EX) Bolsa Chica Estuary in California, USA

2. Tectonic Estuary

• Results from sinking land due to earthquakes

• Earth’s tectonic plates run into/fold up underneath each other, creating depressions

• Steep-walled river valleys created by the advancing glaciers

  • EX) San Francisco Bay

3. Bar-built estuaries

• Accumulation of sand that cuts off rivers from the ocean

• Streams or rivers flowing into bar-built estuaries typically have a low water volume during most of the year

4. Fjord

• Results from sinking land due to glaciers

• The glaciers carve out a deep, steep valley

• Glaciers retreat/the ocean rushes in to fill the narrow, deep depression

MAIN CHARACTERISTICS OF AN ESTUARY

1. Sediment

• Fine sediment

• Takes a long time to settle out

• Turbidity is very high

• Not much sunlight penetrates through the sediment

  • As a result, there is not much algae or plant growth in the water

2. Salinity

• During low tides: More freshwater

• During high tides: More saltwater

• Stenohaline: Can tolerate small changes in salinity

• Euryhaline: Can tolerate large changes in salinity

3. Temperatures

• Temperature fluctuations normally due to the shape of the estuary

• Freshwater tends to be colder than saltwater

REGIONS OF AN ESTUARY

1. Water Habitat

• Largest habitat in an estuary

• Typically where most organisms are found, but usually the diversity isn’t that high in comparison to other habitats

  • However, the abundance of those organisms is greatly increased

2. Marsh Habitat

• Where all the plants are found at the edge

• Where all marine plants are found

• These habitats are in charge of removing pollution from the water

3. Mudflats

• The smallest of the habitats

• Are only visible during the low tide

• The only way that prober-type birds can feed

• Primary production of bacteria and microscopic algae