Freshwater Biomes Test

Freshwater

Less than 1% salt

Saltwater

More than 2.5% salt

Brackish

A mixture of freshwater and saltwater, formed when the two meet

What percent of water does freshwater make up on the planet?

Less than 3%

Properties of water

• Salinity (chemical property) - <1% --> freshwater; >2.5% --> saltwater

• Temperature (physical property)

• Dissolved oxygen (chemical property) - temp dependent; temp up, O2 down; temp down, O2 up

• Turbidity (physical property) - cloudiness/how much sediment is in the water

• pH (chemical property) - pH of ocean --> 8.1; pH of freshwater --> 6.5-8

What do aquatic plants do?

• Help improve water quality by filtering it

• Keep sediment rooted in the ground

• Provide oxygen to the water (which in turn helps keep other aquatic life alive)

Plankton

• Primary producer of aquatic ecosystems

• Float

• Zooplankton has some control over where is goes and eats other plankton

• Phytoplankton photosynthesises

Nekton

Free swimming organisms/animals

Benthos

Animals that live on the floor of aquatic ecosystems

Floor of aquatic ecosystems

• Recieve the least amount of sunlight, making it the coldest and lacking in plants

• Decomposers get energy from dead organisms falling from above

Lakes and ponds

• No official difference between a lake and a pond

• Static (unmoving/still) water

• Usually lack biodiversity since there aren’t many ways for new species to arrive

• Have three distinct zones (there’s another flashcard more ab this dw)

• Mixing during the spring and fall cause a more uniform distribution of temperature and nutrients

Rivers and streams

• Get their source of water from melting snow and galciers

• Flow downhill toward sea level where they empty into the ocean

• Typically colder, cleaner, and faster moving

• Have less biodiversity at there source than at any other part of the river

• Slow down and widen in the middle, where they peak in biodiversity

• The area of land around the river that drains into the river is referred to as the watershed or river system

• Pollution is brought to the river mouth, which has the highest levels of nutrients and turbidity (these levels also limit biodiversity tho)

Estuary

• Where rivers meet the ocean

• Typically surrounded by wetlands

Zones in lakes and ponds

• Intertidal - shore area, where water meets the land

• Littoral - open water near the surface

• Benthic zone - lowest area; deep, open waters

Chesapeake Bay geography

• It’s name comes from the Algonquin word “Chesipioc,” meaning great shellfish bay

• Goes from Havre de Grace MD to Norfolk VA

• Holds over 15 trillion gallons of water

• It’s watershed has around 18 million people and an area of about 64,000 sq miles

• Includes states like DE, MD, PA, VA, WV, and NY, as well as Washington DC

• It’s five major tributaries are the James, Potomac, Rappahannock, Susquehanna (the largest one of them all; supplies 50% of it’s freshwater and lots of pollution), and York

Chesapeake Bay habitats

1. Wetlands - marsh around where the rivers meet the ocean

2. Estuaries - rivers flowing into the Bay

3. Open water - open water of the bay

4. Riparian Forests - buffer forests around the bay

5. Bay grasses - Bay grasses on the floor of the shallower parts of the bay

6. Oyster Reefes - 3D oyster reefs

Chesapeake Bay species

• Bay grasses - provide shelter for small fish, keep the bay floor rooted and prevent sediment, and filter water; on the decline due to poor water chemistry and low turbidity, making it harder for sunlight to reach

• Oysters - provide habitat and food for small fish, break up storm surges and waves, adults filter 50 gallons of water per day

• Blue crab - towards the top of the food chain, scavengers that help with decompotision

Issues affecting the Chesapeake Bay

1. Dead zones due to eutrophication (this is like when there’s a ton of nutrients in the water so things like algae start to grow, and as they die, they use up oxygen, creating dead zones)

2. Air pollution dissolving into the water (pollution in the air falls into the water, contaminating it)

3. Climate Change

4. Loss of bay grass (caused by degraded water quality and climate change)

5. Loss of oyster population (over-harvesting, disease, poor water quality, etc.)

6. Loss of wetlands (caused by shoreline development, sea level rise, and invasive species)

7. Loss of riparian forests (caused by development, leading to woodland loss)