Topic 2 – Ecosystems

Bell Ringer: Ride the Waves The marine ecosystem that is exposed to regular and extreme changes in its surroundings is the intertidal zone. During high tide, the intertidal zone is covered by seawater. During low tide, this area is exposed to air, sunlight, and heat. 1. What types of organisms would you expect to find living in the intertidal zone? 2. What characteristics do you think these organisms have that enable them to live in this zone?

What are we learning today? Benchmark Objectives SC.912.L.17.2 – Explain the general distribution of life in aquatic systems as a function of chemistry, geography, light, depth, salinity, and temperature. Explain that different types of organisms exist within aquatic systems due to chemistry, geography, light, depth, salinity, and/or temperature.

What is the essential question? What are the characteristics of aquatic ecosystems?

What factors affect life in aquatic ecosystems? Aquatic organisms are affected primarily by the water’s depth, temperature, flow, and amount of dissolved nutrients.

Water Depth Water depth strongly influences aquatic life because sunlight penetrates only a relatively short distance through water. The sunlit region near the surface in which photosynthesis can occur is known as the photic zone. The photic zone may be as deep as 200 meters in tropical seas, but just a few meters deep or less in rivers and swamps.

Water Depth Photosynthetic algae, called phytoplankton, live in the photic zone (Producers/autotrophs they do photosynthesis). Zooplankton—tiny free-floating animals—eat phytoplankton. (heterotrophs) Low Medium High Phytoplankton Levels Below the photic zone is the dark aphotic zone (no light), where photosynthesis cannot occur. Oxygen levels are lower the deeper you go

Zoo  animal zooplankton Phyto  Plant phytoplankton Plankton  drifter

Water Depth Many aquatic organisms live on, or in, rocks and sediments on the bottoms of lakes, streams, and oceans. These organisms are called the benthos, and their habitat is the benthic zone.

Temperature and Currents Aquatic habitats are warmer near the equator and colder near the poles. Temperature in aquatic habitats also often varies with depth. The deepest parts of lakes and oceans are often colder than surface waters.

Nutrient Availability Organisms need certain substances to live, such as Oxygen (colder waters holds more oxygen then warmer water), nitrogen (DNA & Proteins), potassium, and phosphorus (DNA). Upwelling allows nutrients to move from the bottom of the ocean to the surface which supports marine productivity, by stimulating the growth and reproduction of primary producers such as phytoplankton and they attract hundreds of species throughout different trophic levels Nutrients move upward from the bottom (where they would be lost) of the ocean to the surface where most fish species are

Currents and their importance Where cold currents flowing from the polar seas and the warm currents from the low latitudes converge there are major fishing grounds. There the chemical nutrients on the floor of the sea can be mixed upward so that they are readily available to fish in surface waters where there is sufficient light and adequate quantity of oxygen

Freshwater Ecosystems What are the major categories of freshwater ecosystems? Freshwater ecosystems can be divided into three main categories: rivers and streams, lakes and ponds, and freshwater wetlands (bogs, swamps, and marshes)

Rivers and Streams (fresh water) Animals in many rivers and streams depend on terrestrial plants and animals that live along their banks for food.

Lakes and Ponds (fresh water) The food webs in lakes and ponds often are based on a combination of plankton and attached algae and plants. Plankton is a general term that includes both phytoplankton and zooplankton. Water flows in and out of lakes and ponds circulating between the surface and the benthos, distributing heat, oxygen, and nutrients. Gizmo Pond Ecosystem Gizmo Pond Ecosystem

Freshwater Wetlands A wetland is an ecosystem in which water either covers the soil or is present at the surface for at least part of the year. Wetlands are often nutrient- rich, highly productive, and serve as breeding grounds for many organisms. Freshwater wetlands purify water by filtering pollutants

Freshwater Wetlands Three main types of freshwater wetlands are freshwater bogs, freshwater marshes, and freshwater swamps. What lives here? Mammals, Birds, Reptiles, amphibians, insects and many more Freshwater Marsh in Canada (herbaceous rather woody plants) Swamp in Florida (more woody plants) Freshwater Bog (Peat-accumulating–> decaying plant matter)

Estuaries Saltwater wetlands are called estuaries and contain brackish water (more salt than fresh but less than the sea) occur where a river (freshwater) meets the sea (salt water). Estuaries serve as spawning and nursery grounds for many ecologically and commercially important fish and shellfish species including bluefish, striped bass, shrimp, and crabs. Migratory birds also live in these habitats. Why are estuaries so important? Healthy estuaries are critical for the continued survival of many species of fish and other aquatic life, birds, mammals, and reptiles Atlantic coast salt marsh

Estuaries Many are shallow, which means that enough sunlight reaches the benthos to power photosynthesis. Mangrove swamps are tropical estuaries that have several species of salt-tolerant trees, collectively called mangroves. The largest mangrove area in America is in Florida’s Everglades National Park. Mangrove Estuary in the Everglades

Acid Rain (changes the chemistry of an aquatic ecosystem) Acid rain causes a cascade of effects that harm or kill individual fish, reduce fish population numbers, completely eliminate fish species from a body of water, and decrease biodiversity. the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch Who is more sensitive to pH? Who is more tolerant of pH change?

Marine Ecosystems  How do ecologists usually classify marine ecosystems? Ecologists typically divide the ocean into zones based on depth and distance from shore. Starting with the shallowest and closest to land, marine ecosystems include the intertidal zone, the coastal ocean, and the open ocean.

Marine Ecosystems This diagram shows the different zones in an ocean.

Intertidal Zone Organisms in the intertidal zone are submerged in seawater at high tide and exposed to air and sunlight at low tide. These organisms are subjected to regular and extreme changes in temperature and are often battered by waves and currents. Such as, barnacles and seaweed permanently attach themselves to the rocks, sea urchins, sea stars, and crabs

Coastal Ocean The coastal ocean extends from the low-tide mark to the outer edge of the continental shelf—the relatively shallow border that surrounds the continents. Water in the coastal ocean is brightly lit, and is often supplied with nutrients by freshwater runoff from land. As a result, coastal oceans tend to be highly productive. Kelp forests and coral reefs are two important coastal communities.

Coral Reefs They occupy less than 0.1% of the world's ocean surface coral reefs form some of the most diverse ecosystems on Earth provide a home for 25% of all marine species, including fish, clams, worms, crustaceans, starfish, sponges, tunicates and sea anomies Kelp Forest (a type of seaweed which is a type of algae) recognized as one of the most productive and dynamic ecosystems on Earth Coastal Ocean

Open Ocean More than 90 percent of the world’s ocean area is considered open ocean. Depth ranges from 500 m along continental slopes to more than 10,000m in ocean trenches. The open ocean is divided into two zones based on light penetration—the photic and aphotic. Most diverse Warmer Less pressure Most Light Less Diverse Colder High pressure No light

The Open Ocean Photic Zone The open ocean typically has low nutrient levels and supports only the smallest species of phytoplankton. Still, because of its enormous area, most photosynthesis on Earth occurs in the sunlit top 100 meters of the open ocean. Whales, tuna, herring and sharks live here

The Open Ocean Aphotic Zone The permanently dark aphotic zone includes the deepest parts of the ocean. photosynthesis cannot occur, so the usual foundation of food webs, phytoplankton and cyanobacteria (blue green algae), are absent (Chemosynthesis may occur) Some animals that live in the aphotic zone include the gulper eel, giant squid, smaller squids, anglerfish, vampire squid, and numerous jellyfish, and fish that make their own light.

Unusual Watery Place The Dead Sea is so salty that the only thing that lives there is a type of bacteria called a halophile (salt lover) It is so salty that you can float in it

Unusual Watery Place At Deep sea vents, organisms get their food directly from the vents themselves. This process is known as chemosynthesis (no light needed). Bacteria in the water actually feed on what would otherwise be a lethal soup of noxious chemicals. Smaller animals feed on these bacteria, and these smaller animals provide food for the larger animals. It is an entire ecosystem totally separate from the world of light

Ocean Acidification decrease in the pH of the Earth's oceans caused by the uptake of carbon dioxide (CO 2 ) from the atmosphere 30–40% of the carbon dioxide released by humans into the atmosphere dissolves into the oceans, rivers and lakes It causes corals and some plankton to have a hard time creating their hard deposits Thus, ongoing acidification of the oceans also poses a threat to the food chains connected with the oceans

Can a fresh water fish live in salt water or vice versa? Aquatic Cartoon

Exit Ticket Where can photosynthetic algae most likely to be found? Describe the water in an estuary. The pH of the water in several lakes in Norway and Sweden had decreased to below 5.0 due to an increase in acid rain. What will most likely happen in these lakes? Are you likely to find zooplankton in the aphotic, benthic zone of an ocean? Explain. Describe one way a freshwater wetland differs from a lake or pond. Why are estuaries commercially important?