freshwater and saltwater ecosystems

Oxygen

A vital gas needed by aquatic animals; low levels can cause harm.

Food Chain

A linear sequence showing how energy and nutrients flow from one organism to another.

Food Web

A complex network of interconnected food chains in an ecosystem.

Phytoplankton

Microscopic plants in aquatic environments that form the base of the food chain.

Zooplankton

Microscopic animals that feed on phytoplankton.

Biomagnification

The increasing concentration of toxins in organisms at higher levels of the food chain.

Toxins

Harmful substances that can accumulate in organisms and cause health issues.

Algal Bloom

A rapid increase in algae growth due to excess nutrients, leading to oxygen depletion.

Nutrients

Essential substances (like nitrates and phosphates) required for plant growth in aquatic habitats.

Chemosynthesis

A process by which certain bacteria convert chemicals from sea-floor vents into energy, forming the base of food chains in those ecosystems.

Detritus

Decaying organic matter that provides nutrients in aquatic environments.

Currents

Movements of water that help mix nutrients and gases in aquatic systems.

Sea-floor vents

Openings in the ocean floor that release hot water and minerals, supporting unique ecosystems.

Aquatic

Relating to water.

Freshwater

Water with low salt concentration, found in rivers, lakes, and ponds.

Saltwater

Water that contains a high concentration of salt, primarily found in oceans.

Plankton

Tiny floating plants and animals that drift in water currents, crucial for the aquatic food web.

Phytoplankton

Microscopic plants in water, essential for oxygen production.

Zooplankton

Microscopic animals that feed on phytoplankton.

Adaptation

Changes in organisms that help them survive in their environments.

Gills

Organs in aquatic animals that extract oxygen from water.

Holdfast

Structure that anchors seaweeds to the ocean floor.

Continental shelf

Underwater landmass where the ocean is relatively shallow, rich in marine life.

Crest

the top of a wave

Trough

the bottom of a wave

Wavelength

distance between two crests

Ocean current

a large, moving flow of water in the ocean

Surface current

the top layer of moving water in the ocean

Tides

the rise and fall of ocean water

Longshore current

movement of water along the shore

Tidal range

the difference between high tide and low tide

Spring tides

high and low tides that occur when the Moon, Earth, and Sun are aligned

Neap tides

smaller high and low tides that occur when the Moon and Sun are at right angles.

Currents

Large-scale movements of water within the ocean, including surface currents and deep ocean currents that influence temperature and nutrient distribution.

Salinity

The measure of dissolved salts in water, usually expressed in parts per thousand (ppt).

Sodium chloride

The main salt found in ocean water, commonly known as table salt.

Ecosystem

A community of living organisms and their environment, where oceans serve as Earth's largest ecosystem.

Tectonic plates

Large, rigid pieces of the Earth's lithosphere that move and interact, shaping the ocean floor and landforms.

Continental slope

A steep drop-off at the edge of a continental shelf, leading to the ocean basin, usually descending to depths of about 3 km.

Ocean ridges

Long undersea mountain chains formed by volcanic activity, marking the youngest areas of the sea floor.

Ocean trenches

Deep, narrow canyons at the edge of ocean plates formed when one plate is pushed beneath another, like the Mariana Trench.

Abyssal plains

Flat, deep areas of the ocean floor, formed by thick sediment deposits and typically found between mountain ranges and trenches.

Continental shelf

The submerged, gently sloping edge of a continent that extends into the ocean, varying in width from less than 30 km to up to 300 km.

Watershed

An area of land where surface water drains into a common set of streams and rivers that flow into a larger body of water.

Drainage Basin

Another term for a watershed.

Spring

A natural opening in the Earth's crust where groundwater returns to the surface.

Drainage Divide

The line that separates watersheds, typically found around hills or mountains.

Confluence

The point where two flowing bodies of water, such as rivers, meet to form a larger channel.

Tributary

A stream or river that flows into a larger river but does not flow directly into a sea or ocean.

Flood Plain

Flat, dry land beside a stream, river, or lake that is covered by water during a flood.

Subwatershed

A smaller watershed within a larger watershed system.

Estuary

An area where one or more rivers meet the ocean or sea, characterized by brackish water.

Brackish Water

Water that has a salinity level between freshwater and seawater.