Transcript File
Section 2 Large Marine Ecosystems of the world Objectives To understand relationships between organisms within ecosystems To identify the connection between environment, biodiversity and ecological niches Review Binomial nomenclature created by Linneaus in the mid-1700s Each species has a two part name 1st – generic name (genus) 2nd – specific name (species) Terms to Know! Term Definition Habitat Place where organisms live Ecological Niche The role of an organism within an ecosystem Species A group of similar organisms that can interbreed and produce fertile offspring Population Organisms of the same species, living in the same area Example Community All the different species living in a habitat at the same time Ecosystem Living organisms and the chemical and physical factors which influence them With a partner, take 2-3 minutes and come up with marine examples of the terms listed above! The ecosystem is affected by… Abiotic Factors Biotic Factors ECOSYSTEM The ecosystem is affected by… Abiotic Factors Biotic Factors ECOSYSTEM What identifies an ecosystem: Biotic Abiotic Living components of an Nonliving components of an ecosystem ecosystem Greek meanings: Bio = living tic = of or pertaining to A = not; without List 5 examples of each! Marine Ecosystem Example http://vimeo.com/28417462 Rocky Shore – organisms living here, linked together by flows of energy forming a food web, and their environment Animals must be able to adapt to changing tides Habitat Example Hydrothermal vent – provides habitat for species of tube worms Population Example Ghost crabs (Ocypode saratan) living in the sandy shores Mollusc community on a rocky shore (all different species of molluscs) Species Examples Skipjack tuna (Katsuwomus pelamis) Red mangrove trees (Rhizophora mangle) Ecological Niche Examples Ecological niche of great white shark = top predator Organisms which occupy similar niches will tend to compete with each other for Resources Food Space in their habitat Biodiversity Takes into account: # of different species present Range of habitats and ecosystems Examples: CORAL REEFS High biodiversity w/ many species present SANDY SHORE Low biodiversity w/ few species present Quadrat A square used in ecology and geography to isolate a sample, usually about 1m2 or 0.25m2 Used to investigate the diversity of organisms in a suitable habitat (example: rocky shore or sandy shore) Section 2 of Marine Ecosystems Relationships between organisms Symbiosis The relationship between 2 different organisms, where BOTH derive some benefit from the relationship Examples Corals and zooxanthellae Cleaner fish and grouper Chemosynthetic bacteria and tubeworms Parasitism Relationship between organisms where 1 organisms benefits at the expense of the other (the host) Parasites obtain nutrients from host Ectoparasites Live on OUTSIDE of the host Example: Fish lice Endoparasites Live INSIDE host (digestive system, attached to gills, muscle tissue) Example: nematodes (roundworms) living in fish Trophic Levels “feeding levels” in a food chain or a food web Producers 1st trophic level Primary consumers2nd trophic level Secondary consumers 3rd trophic level More Terms… Term Definition Producer Organisms which synthesize organic substances from simple organic compounds using light from the Sun Consumer An organism that obtains its energy by feeding on other organisms Primary Consumer Feed on plant material (AKA Herbivore) Secondary Consumer Feed on herbivores ((AKA Carnivore) Predator An animal that catches, kills, and eats another animal Predator-Prey Relationship Factors which affect # of predators in an ecosystem Availability of food As the # of prey increases the # of predators increases As the # of prey decrease the # of predators decrease http://vimeo.com/45154593 What would a graph of this relationship look like? With a partner create a graph? Be prepared to explain your graph! Predator-Prey Graph Chemosynthesis Symbiotic bacteria convert H2S into organic material: H2S + CO2 + O2 + H20 CH2O + H2SO4 Hydrogen sulphide is the primary energy source for hot vents and cold seeps What is a Shoal? Large numbers of fish of the SAME species and approximately the SAME size. Referred to as a ‘school’ when the group of fish is swimming together in a coordinated way. Benefits of Shoaling 1. Hydrodynamic efficiency Groups of fish save energy when swimming together Benefits of Shoaling 2. Predator avoidance: a) Confusion effect: It is difficult for predators to pick out individual prey from groups b) Many eyes effect as size of group increases, the task of scanning for predators can be spread out Benefits of Shoaling 3. Foraging Advantages : Time taken to find food is decreased 4. Reproductive Advantages: Provides increased access to potential mates Types of shoalers Fish can be obligate or facultative shoalers: Obligate – spends all their time shoaling or schooling and may become agitated when separated from the group (examples: tuna, herring, anchovy) Facultative – shoal only some of the time, perhaps only for reproductive purposes (examples: Atlantic cod) What is Succession? The gradual process of change that occurs in community structure over a period of time Example Succession As plant communities change the animal communities change. Succession at Hydrothermal Vents One of the first animal species to inhabit the area around a hydrothermal vent is the tube worm Tevnia. Tevnia is replaced by the larger and faster growing tube worm Riftia. Riftia tubeworms can grow up to two meters long. This adult tubeworm that has been removed from its white tube. Riftia Tevnia Tevnia are usually white, but this clump of worms is stained brown from iron in the vent fluids. The largest worm in this clump (with more white color) is a different species - a Riftia tubeworm. What is a Whale Fall? When a whale dies, the carcass sinks to the sea floor…this is known as a “whale fall” The video below shows the gradual change in the community structure over time Feast in the Deep Boneworms on Dead Whales in Monterey Bay Extreme & Unstable Environments Tend to have LOW biodiversity! Example 1: UNSTABLE Sand-easily dries out and easily eroded by wind and water currents pressure, Example 2: EXTREME hydrothermal vents-high high temperature, high pressure -harder to survive but specific species do Hydrothermal Vents and Cold Seeps Support Diverse Communities The path of water associated with a hydrothermal vent. Seawater enters the fractured seabed near an active spreading center and percolates downward, where it comes into contact with rocks heated by a nearby magma chamber. The warmed water expands and rises in a convection current. As it rises, the hot water dissolves minerals from the surrounding fresh basalt. When the water shoots from a weak spot in the seabed, some of these minerals condense to form a “chimney” up to 20 meters (66 feet) high and 1 meter (3.3 feet) in diameter. As the vented water cools, metal sulfides precipitate out and form a sedimentary layer down-current from the vent. Bacteria in the sediment, in the surrounding water, and within specialized organisms make use of the hydrogen sulfide (H2S) in the water to bind carbon into glucose by chemosynthesis. This chemosynthesis forms the base of the food chains of vent organisms. Bottom current Precipitation FeO(OH) MnO2 Chimney Precipitation CaSO4 FeS Sedimentation Seawater seepage Basalt H2S in water Basalt Precipitation FeS, FeS2, CuFeS2 350ºC (660ºF) 350ºC Stepped Art (660ºF) Fig. 16-21, p. 453 Stable & Favorable Environments Tend to have HIGH biodiversity! Example: Coral Reefs Specialized Niche Narrow range of food Generalized Niche Exploit a wider range of food requirements Live in specific habitat sources Live in wider range of habitats Example: Butterfly fish Territorial Live closely w/corals and anenomes Ex: Tuna Migratory Feed on many different species of fish Why do habitats with high biodiversity tend to contain narrow ecological niches? Each species has its OWN niche within the ecosystem What would happen if the niches overlapped? INTERSPECIFIC COMPETITION and one species will die out! Narrow niches reduce overlap and therefore reduce competition