Aquatic Ecosystems

Aquatic Life Zones

There are three categories of marine life based on where plants and animals

have adapted to live. Plankton, organisms that move passively with the water

currents, inhabit the upper layers of the water column. Animals that are strong

swimmers are called nekton and live in the open water and middle layers. Plants

and animals that live on and near the ocean floor are called benthos.

*Plankton, nekton and benthos life in BOTH freshwater and saltwater ecosystems!!!

Wetlands (Freshwater and Marine)

-Filters water-Absorbs excess water to prevent flooding-Buffers shorelines from erosion-Provides habitats-Also recreation, agriculture (rice & cranberries)

**Wetlands are areas of standing water that

support aquatic plants. Marshes, swamps, and

bogs are all considered wetlands.

-Threats: Development!!

Lakes and Ponds

In the nutrient rich Littoral Zone there is abundant and diverse aquatic life.

In the Dark cooler waters of the Benthic Zone, there is decaying matter, insect larva and decomposers.

Rivers and Streams

-No plankton in moving water (head

water)

-Fish have adapted to the fast moving

water

-Plants on rocks have rhizoids

*As rivers move away from the source, they warm up and become wider and slow-moving.

Swamps-Flat poorly drained-Found near streams-Dominated by trees

Coral Reefs-Coral polyps secrete calcium carbonate to make up their exoskeleton.-These polyps contain nematocysts or stinging cells.-Coral requires clear clean water to survive.

-About 27 % are in danger

from human activity.

-The Danger is that coral

is a very slow growing

habitat.

Most reef-building corals contain photosynthetic algae, called zooxanthellae, that live in their tissues. The corals and algae have a mutualistic relationship. The coral provides the algae with a protected environment and compounds they need for photosynthesis. In return, the algae produce oxygen and help the coral to remove wastes. Most importantly, zooxanthellae supply the coral with glucose, glycerol, and amino acids, which are the products of photosynthesis. The coral uses these products to make proteins, fats, and carbohydrates, and produce calcium carbonate

Estuaries -An area in which fresh water from a river mixes with salt water from the ocean.-As two bodies of water meet, mineral rich sediment falls to the bottom.-Estuaries have rich sediment and are very productive ecosystems

Mangroves-Swamps located in the tropical and subtropical areas.-Roots of trees protect the coastline from erosion.-Much has been lost to pollution and development.

Rocky and Sandy Shores-The shore is home to many very hardy creatures and has the ability to protect inland areas from the violence of the ocean.

*Rocky and sandy coasts are vulnerable

because humans find them attractive and want

to live near them. An increasing proportion of

the humans live by the coast, putting pressure

on coastal habitats.

Open Ocean

Water absorbs sunlight. Usable sunlight tra

vels only

100 meters or 330 feet into the water. Lower th

an that

there are no plants. Most plant life

is near the shore or

the surface.

In the open ocean most life occurs near the surface where phytoplankton grows.

THREATS: Over fishing Pollution Run off

Ocean Depths-In the depths of the ocean, animals feed on what falls down from the surface.

*Sulfur feeding bacteria: make up the base of the food chain near hydrothermal vents.

Arctic and Antarctic

-Because of the cold, the only significant source of food for any organisms in the area is from the sea.

-Any damage to the area is slow to recover due to the harsh environment.