Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download Unit 6:Marine Ecology - SAFE-T
Document related concepts
Transcript
Unit 6:Marine Ecology Marine Ecology Objectives: Explain how the study of ecology relates to oceanography. Describe patterns and relationships between biotic and abiotic factors among marine ecosystems Explain the relationship between productivity, the flow of energy, and the structure of marine food webs. Understand the premise of biomagnification. Gain an understanding of symbiotic relationships in marine ecosystems. What is Ecology? Ecology: the branch of biology that deals with the relations of organisms to one another and to their physical surroundings. Includes all living (biotic) and nonliving (abiotic) portions of an ecosystem Abiotic—Nonliving parts of an ecosystem Organisms that do NOT exhibit characteristics of life EX: Water, Oxygen, Salt Biotic—Living parts of an ecosystem Organisms that do exhibit characteristics of life EX: Fish, Squid, Seaweed What does it mean to “Live”? All living things: Are made of cells (Unicellular or Multicellular) Reproduce (Sexually or Asexually) Have a genetic code (DNA/RNA) Grow and Develop Have a metabolism (Need energy) Respond to the environment (stimulus and response) Evolve (populations evolve, individuals do NOT) How does energy flow through and ecosystem? Energy Flow Energy can be obtained in 3 ways Photosynthesis Chemosynthesis Consuming Energy is LOST as we go up the food pyramid or food web Trophic Levels Base (1st Level): Autotrophs or Primary Producers (plants) Producer: makes its own food EX: Seaweed 2nd Level: Herbivores or Primary Consumers (Plant eaters) Consumers: eat other things, cannot make their own energy EX: Small fish 3rd Level: Secondary Consumers (eat primary consumers) EX: Crab Top (4th Level): Predators Generally eat meat (Carnivores) EX: Shark Omnivores: Eat both plants and animals Scavengers: Eat leftover remains Decomposers: Breakdown dead organic matter Food Web /Food Chain Food Chain: Shows one possible path energy could take Energy goes to the organism that is doing the consuming Food Web: Shows all of the paths energy could take Energy could go to a variety of organisms depending on who eats who Plankton Productivity (primary productivity)—make their own food using the sun AKA Phytoplankton (Phyto=light) Highest productivity = near shores, lots of nutrients here Lowest productivity = tropics, small amounts of nutrients -The base of a marine food chain or web depends upon phytoplankton which are very small photosynthetic organisms (make their own food through photosynthesis) -These phytoplankton provide the primary source of the essential nutrients that cycle through our ocean's many food webs. What is biomagnification? Biomagnification: the concentration of toxins in an organism as a result of its ingesting other plants or animals in which the toxins are more widely disbursed. Toxic contaminants that can cause health problems Toxins: Mercury, Lead, algal blooms What are symbiotic relationships? Symbiotic Relationships Relationships between organisms Mutualism-Both organisms benefit EX: Coral and Clown Fish Parasitism-One organism benefits (parasite) and the other is harmed (host) The parasite does not try to kill the host, it wants to live in the host as long as possible. The host can live with the parasite or die. EX: Leeches on fish Commensalism-One organism is helped and the other is neither helped nor harmed EX: Barnacles on turtles or whales Zones of Ocean Zones of the Ocean and Intertidal Zone Zones of the Ocean & Intertidal Zone Objectives: Explain the general characteristics of the littoral zone. What are the pelagic and benthic zones? What are the divisions of the pelagic and benthic zones? Identify organisms that live in each zone. Photic & Aphotic Zone Photo=Light Photic Zone Surface layer of the ocean that receives sunlight Photosynthesis takes place About 260 feet Aphotic Zone Under the photic zone Does not receive light Pelagic Zones Pelagic = Open Water, things that swim Neritic Pelagic Animals that live close to shore in open water or near the shore Oceanic Pelagic Open water, far out, deep water 4 sections of the Oceanic Pelagic Oceanic Pelagic Zones (Water Zones) Epipelagic Zone Mesopelagic Zone Bathypelagic Zone Abyssopelagic Zone Hadalpelagic Zone Epipelagic Zone Epipelagic--the uppermost layer that gets sunlight. Most predators use vision to catch their prey. Have large eyes in order to see their prey. One adaptation is small size for prey animals. Most epipelagic fish will have a streamlined shape to allow them to cut through the water more easily Important adaptation if you are constantly swimming. Have a lot of muscle mass in order to be strong swimmers. Coloration is another important adaptation. Most "upper" fish have countershading--dark on top and silvery on bottom. Helps them blend in depending on whether they are being viewed from above or below. Another is "clear" coloration (think jellies) that makes prey harder to see. Mesopelagic Zone Mesopelagic--the twilight zone that is dimly lit; typically between 350-3000ft. Not much light, but still enough to tell the difference between day and night. Many organisms will leave the surface during the day and return at night. These organisms are known as "vertical migrators". This allows organisms to remain at a constant level of low light at all times. Typically have a swim bladder (buoyancy). Have well-developed muscles and bones, and are usually somewhat streamlined. Migration behavior is believed to be due to the organism following its food (zooplankton eats phytoplankton at night so fish come up) but the more common theory is this allows organisms to maintain their slow metabolism by remaining in cooler waters. These migrators may be elongated or "skinny" (laterally compressed) to make traveling up and down through the water column more efficient. Fish that are not migrators and are "sit and wait" predators lack a swim bladder Have flabby muscles and watery flesh. Because they do not go anywhere, streamlining has either not evolved or has disappeared and these organisms are much rounder. Different colors of light are absorbed at different rates. Red wavelengths are absorbed first while blue and green last the longest. This means that, in the darker waters, a red organism will not have a wavelength to reflect back and will appear black. This is why many mesopelagic and abyssopelagic animals are red (because you can't see them). Because of the dark water/lack of light many of these organisms have larger eyes in order to allow to absorb as much light as possible. For those organisms in the lower mesopelagic zone (the nonmigrators), these eyes may be tubular and directed upward since they are trying to see things silhouetted above them. In the upper mesopelagic zone fishes still have silvery upper bodies in order to blend with light coming down However, as you get deeper many of the fishes have photophores on their belly that are used to camouflage themselves or to confuse predators and/or attract prey. Food in this area is not abundant. This has led predators to be opportunistic feeders. Many fish have large mouths so that they can attempt to eat any organism they come across. They also have gill rakers so that small things can't get away. They are very careful not to waste any food!! Since these fish are still preyed upon, size typically remains fairly small. Bathypelagic & Abyssopelagic Bathypelagic & Abyssopelagic: DEEP water, below 3000ft, no light. These fish are "stuck" in this area as they cannot migrate vertically. Most of these are "sit and wait" predators or they will use bioluminescence to attract their prey. At this depth, swim bladders cannot function because gas cannot be produced. Most fish in this layer do not have swim bladders or their swim bladders are filled with wax—for bouyancy Fish in this environment have difficulties obtaining food This means they have less energy to build muscles; therefore they are weak and flabby. Since food is so hard to come by, fish have very large mouths and teeth and often have "extendable" stomachs to accommodate large prey. Most of these organisms are longer as they have a lateral line that runs down their back. It helps them feel movement in the water caused by other organisms. Coloration here includes black, red, transparent or even white as there is no visible light (all wavelengths have been absorbed). Eyes are reduced in size or absent as they are not needed. Size in the deep ranges from small to gigantic (think giant squid!). Oftentimes, these fishes have a very good sense of smell in order to smell their next meal from miles away. Benthic Zones (Land Zones) Intertidal Zone Sublittoral Zone Bathyl Zone Abyssal Zone Hadal Zone Littoral Zone (AKA Rocky Shore Ecosystem) Intertidal Zones or Littoral Zone: Marine aquatic environment that is submerged at high tide and exposed at low tide Organisms that live here must be able to adapt to different salinities, pounding waves, a range of temperatures, and exposure to air. 4 Sections of Intertidal Zone: Spray Zone: above high tide, receives splashes from waves, very few organisms live here. High Tide Zone: covered during high tide, organisms must be able to survive long periods of air exposure. EX: barnacles, sea stars, crabs, snails, some seaweed. Mid Tide Zone: Exposed by low tide but covered by high tide, area stays wet longer. EX: crabs, barnacles, algae, mussels, sea lettuce, sponges. –rock pools can form allowing small fish, shrimp, sea urchins to live Low Tide Zone: always has some water. EX: seaweed, crabs, sea anemones, algae, sponges, grass, worms, mussels, isopods, sea cucumber Putting all the ZONES together Why would any animals live in the harsh, intertidal environment? Abundant Sunlight Allows algae and other plants to grow and support lots of animals Continual waves bring nutrients and oxygen Food is abundant Rocks provide surfaces to cling to and lots of hiding places Marine Ecosystems Marine Ecosystems Objectives: Identify different types of marine ecosystems/communities. Identify the organisms that live in each ecosystem/community. Sandy Beach Beach sand is a combination of minerals, living and dead organisms. (different materials and sizes of particles) Sand is important because it reduced the wear and tear on the coastline and helps reduce erosion Beach sand includes algae, worms, mollusks, and submerged fish Kelp Forest & Seaweed Kelp forests can be found around the world and in cool waters—because they require the nutrients found in cold waters In ideal conditions (sun, nutrients, temperature) kelp can reach up to 60 meters Sea Otters were almost hunted to extinction They fed on the kelp some However sea urchins will consume the holdfast (anchor) of the plant eventually killing the plant The sea otters also eat the sea otters Over hunting the sea otter caused the sea urchin population to increase which harmed the kelp population Thus the sea otters are needed to help maintain both population Estuary Estuary: an area where the ocean tide and a river meet Estuaries are rich in nutrients (catch run-off) and biologically productive These ecosystems are susceptible to eutrophication Eutrophication: an overabundance of nutrients that causes an ecological imbalance Estuaries act as a filter and filter out nutrients and pollution in the water (kidneys of the biosphere) Organisms living here must be able to survive in a changing salinity Estuaries provide a sheltered environment for juvenile organisms Salt Marsh Located in estuaries and along the coast in nutrient rich area 2 parts Upper Marsh: rarely flooded by tides, less osmotic stress—more stable Lower Marsh: usually flooded, organisms must be able to tolerate osmotic stress EX: Halophytes—plants that are adapted to survive in salt water Seagrasses Grasses that can live in saltwater environments (usually submerged unless there are very low tides) These grasses help stabilize sediments and provide shelter Their root systems are intertwined Take oxygen out of the water Reproduce by releasing pollen Do no need freshwater Mangrove Swamp -These swamps are important because they act as nurseries for marine organisms who are usually important commercially and economically. Mangrove trees are halophytes (live in saltwater) Adaptations: strong roots, large plants that hold soil in place 3 types Red mangroves: grow above waterline, filter saltwater through roots and excrete the salt (reverse osmosis—active transport) Black mangroves: roots grow in sediment below the waterline, aerate their roots with small tubes (bring air from surface into roots), eliminate salt through sacrificial leaves White mangroves: can tolerate saltwater but live mostly on the high tide line. Coral Reefs Coral reefs are highly diverse Coral reefs are vulnerable and fragile Coral polyps have a mutual relationship with zooxanthellae to obtain all the nutrients needed. Corals can be damaged by stress from environmental factors such as temperature If corals get too stressed they will begin to bleach themselves (they will lose color and become white) Deep Sea The Abyssal Zone Whale Falls Hydrothermal Vents & Cold Seeps Hadal Depths The Abyssal Zone Very limited light and cool to cold temperatures The abyssal zone covers ~30% of Earth’s surface No photosynthesis, thus no primary producers Deep sea organisms rely on “marine snow” Dead organisms, sediment, and waste products Lots of diversity among deep sea organisms These organisms must be able to adapt to the challenges of living here Lack of sun Low temperatures Limited food Must have the ability to capture food (adaptation) Whale Falls Whale falls are created when a whale dies and sinks to the ocean floor. The carcass brings an immense amount of food to an area where food is scarce. Mobile Scavenger Phase: Within days of the carcass landing, scavengers have arrived and are feasting on the decaying flesh. Once the bones have been picked clean the community moves into next stage Enrichment-Opportunist Phase: All of the little particles of decaying matter that settled on the seafloor enriched the sediments. This brings small organisms such as worms and mollusks that will feed on the sediment as well as the bones. Sulfophilic Phase: based completely off of the skeleton. Bacteria break down oils and produce sulfide. Then they use the sulfide to undergo chemosynthesis. This allows for clams, snails, crabs, mussels, etc to eat the organic matter (sugar) produced by the bacteria like at the other communities. Hydrothermal Vents & Cold Seeps Chemosynthesis occurs around hydrothermal vents The bacteria eat the sulfides (bacteria=base of food web) Cold Seeps are areas where hydrocarbons and sulfiderich fluids seep out from underlying rock on the ocean floor Cold compared to hydrothermal vents Chemosynthesis also takes place here Hadal Depths (Ocean Trenches) Hadal Zone is located in the deep sea trenches Range from 5000 to 6000 meters and can be deeper Not much is known about this area due to the constraints on technology But scientists have found that there is life here but it is limited life Polar Ecosystems The Arctic The Antarctic The Arctic The arctic circle is a ring of shallow continental shelf that is unbroken A frozen sea Most of the sea is frozen on top of the earth Challenges: reduced sunlight under the ice Life is scarce , challenging environment Organisms that live here must have special adaptations—antifreezing compounds in their blood, low metabolisms Edge of the cap: sun melts the ice, cold water sinks, warm currents churn up nutrients. The Antarctic A continent During the winter Antarctica gains mass and in the summer the ice melts and it reduces its area The melting to the ice increases bioproductivity The salty cold water sinks because it is denser causing an upwelling Nutrients from the deep ocean is pushed to the surface Organisms living here have adaptations to help them survive Slower metabolism Anti-freezing characteristics
