By: Lauren Clark Aquatic Biomes

What is an aquatic biome? Any mass of water Determined by abiotic factors like: Salinity Depth Amount of light Distance from land Temperature http://geog.uoregon.edu/envchange/clim_animations/gifs/tmp2msm.gif

Vertical Zonation Photic zone – sufficient light for photosynthesis Aphotic zone – not enough light for photosynthesis Benthic zone – sand and sediment Abyssal zone – deep ocean, very cold, low nutrients Pelagic zone – further from land, surface to bottom

Horizontal Zonation of Lakes Littoral zone – shallow water with light going to the bottom Limnetic zone - water with light penetrating, but only enough to support plants. Profundal – beyond light penetration. Only living things adapted to dark live here.

Lakes Mostly Land locked Freshwater Classified: Low in nutrients Oligotrophic Lakes Low in nutrients High Oxygen Deep Eutrophic Lakes High in Nutrients Low Oxygen Shallow

Thermal Stratification Upper layer of water is warmed by the sun Does not mix with water underneath Mostly occurs in warmer climates and in summer

Rivers and Streams Characterized by speed and volume of water Headwaters – source, cold, clear, rapid, higher oxygen Farther along – “higher order”, slower, warmer, less oxygen, turbid

River Continuum Concept Streams are gradients Downstream processes are connected to upstream processes Different organisms present at different areas

Wetlands Land either permanently or temporarily saturated with water Marshes, swamps, bogs, etc. Amphibians and reptiles common

Estuaries Where the fresh water meets the salt water Select few organisms adapted to salinity Temperate – salt marshes Tropical – Mangrove forests

Oceans Largest of all ecosystems Some say richest biodiversity Zones – intertidal (next to shore), netric (about 200m to the continental shelf), and oceanic (beyond netric)

Intertidal Zones Can be dry land or underwater depending on tide Creates gradient in organisms that live here Organisms separate based on tolerance to harsh conditions

Coral Reefs Structures that allow enough life for photosynthesis Cnidarian spores on calcium carbonate structures Most productive and diverse ecosystem

Decline of Coral Reefs Close to land, on fringes of islands Human activity and climate change threaten coral reef “Why are coral reefs so important?”

Kelp Beds Similar to corral reefs Temperate climate Kelp growing up from ocean floor

Sources https://stroudcenter.org/continuum/ https://www.rmbel.info/lake-trophic-states-2/ https://www.britannica.com/science/lacustrine- ecosystem#ref6891 https://courses.lumenlearning.com/boundless- biology/chapter/aquatic-biomes/ http://www.ucmp.berkeley.edu/glossary/gloss5/biome/aquatic.htm l