Aquatic Biomes Flashcards

Aquatic Biomes Overview

• Aquatic biomes are categorized into freshwater (streams, rivers, lakes, wetlands) and marine (estuaries, coral reefs, open ocean).

Characteristics of Aquatic Biomes

• Key defining factors include salinity, depth, and water flow.

Streams and Rivers

• Comprised of flowing fresh water, originating from underground springs or runoff.
• Streams (creeks) are narrow and carry small water volumes; rivers are wider and transport larger volumes of water.
• Rapids exist in fast-moving water, mixing air and water, enhancing oxygen levels for fish.

Threats to Aquatic Systems

• Major threats to streams and rivers include excess nutrients and pollutants.

Lake Zones

• Lakes are divided into four zones: littoral, limnetic, profundal, and benthic.

Littoral Zone

• The shallow area near the shore is rich in soil and water, supports algae and emergent plants, and is a primary site for photosynthesis.

Limnetic Zone

• A zone of open water where rooted plants can't survive; composed mainly of phytoplankton, extending to the limit of sunlight penetration.

Profundal Zone

• Dark, deep water region where sunlight doesn't reach; no photosynthetic producers exist, nutrients aren't recycled efficiently, and decomposing bacteria consume oxygen.

Benthic Zone

• The lake's muddy bottom, located beneath the limnetic and profundal zones.

Lake Classifications

• Lakes are classified by productivity: oligotrophic (low productivity), mesotrophic (moderate productivity), and eutrophic (high productivity).
• Oligotrophic lakes are clear with low nutrient levels; increasing nutrients from human activities threaten their clarity.

Freshwater Wetlands

• Aquatic biomes that are submerged or saturated with water for part of the year, supporting emergent vegetation. Includes swamps, marshes, and bogs.

Swamps

• Wetlands with emergent trees, such as the Great Dismal Swamp.

Marshes

• Wetlands dominated by non-woody vegetation like cattails and sedges.

Bogs

• Acidic wetlands characterized by sphagnum moss and spruce trees.

Ecosystem Services of Wetlands

• Wetlands contribute to environmental health by slowing runoff, reducing floods, recharging aquifers, providing bird breeding habitats, and filtering pollutants.

Marine Biomes

• Categorized into salt marshes, mangrove swamps, intertidal zones, coral reefs, and the open ocean.

Salt Marshes

• Coastal marshes with non-woody emergent vegetation, highly productive ecosystems that serve as habitats for spawning fish and shellfish.

Estuaries

• Coastal areas where freshwater from rivers meets ocean saltwater, productive zones for plants and algae, filtering contaminants effectively.

Human Impact on Wetlands

• Over half of wetlands have been drained for agriculture or development, significantly disrupting ecosystems and eliminating breeding grounds for various species.