Coral Reef Gabbi Sanchez & Hope Laroche
Biotic Density of zooplanktonDensity of living coral polypspopulations of fishpopulations of molluskspopulations of echinodermspopulations of benthic crustacea Abiotic temperature of the watersalinity of the waterpH of the waterother dissolved minerals in the watersuspended inorganic particles in the water (i.e. small clay bits, if near shore)amount of sunlight reaching the coral reef (which can be affected by suspended inorganic particles)dissolved oxygen level in the watercurrent strengthdepth / pressure Biotic and abiotic features
Examples of Symbiotic Relationships between Organisms • The goby fish and a shrimp. • The shrimp digs and cleans up a burrow in the sand in which both the shrimp and the goby fish live. The shrimp is almost blind, leaving it vulnerable to predators when above ground. In case of danger the goby fish touches the shrimp with its tail to warn it. When that happens both the shrimp and goby fish quickly retract into the burrow. • Reef-building corals and coral polyps. • The coral polyps live inside the Reef-building coral tissue. The coral polyps consume the waste products of the coral and turn the waste into substances usable by the coral for growth and maintenance. It is certain death for the coral if there is an absence of the polyps for too long. • Boxer crab and small anemones. • The Boxer crab carries a pair of anemones in its claws. When predators approach the Boxer crab it waves the anemones, which present their stinging tentacles. The Boxer crab gets protection and the anemones get the particals of food that are dropped by the crab. • Clown fish and Anemones • The clown fish receives protection from the anemones, while the anemones receive food drawn by the clownfish.
Trophic levels • Trophic level 1 • The first level in the ocean consists of marine plants which include phytoplankton, seaweeds and some seagrasses. These are the primary producers which fix energy from the sun and make it available to life forms in the other trophic levels • Trophic level 2 • At this level, the organisms involved are hugely diverse and have an equally diverse way of making use of the food sources from the first trophic level. These include the browsers and grazers, filter feeders and deposit feeders • Trophic level 3 • This level is comprised of carnivores, which actively hunt down and eat the herbivores from level two. Many animal groups are included, but this is where the fish come into their own. Fish are a highly diverse group and although some exist in level two as grazers, the majority is in the third and higher levels • Trophic level 4 • This is another level of carnivores, which hunt down and eat lower-level carnivores and herbivores. They are usually swift, voracious hunters because they have to capture a lot of prey to gain the energy that they require • Trophic level 5 • There can be a whole chain of fish preying on one another and lengthening the chain considerably, but at the top of the pyramid is the ultimate predator. In this case, it’s the shark
Food web • On coral reefs there are three major types of producers: • Cyanobactera or blue-green algae: these species also fix nitrogen and enhance nutrient availability • Seaweeds: these include both conspicuous macro-algae and the less conspicuous but very abundant turf algae. Seaweeds are heavily grazed by herbivores • Reef-building or hematypic corals: corals are producers due to tiny plants that live inside their bodies called zooxanthellae • There are 2 types of primary consumers • Herbivores: animals that eat plants (sea urchins, surgeonfishes, parrotfishes) • Corallivores: animal that eats corals (butterflyfishes)
Importance/Examples of the Cycles Water Cycle: • Precipitation happens when it rains or snows. This comes from the clouds. The water goes into the ground, rivers, lakes and oceans. • 2. Evaporation is when the sun heats the water and changes some of it to gas. 3. Water Vapor: This is the gas that is formed through evaporation. It rises and forms clouds. 4. When the water vapor gets too heavy, it falls to the ground. If it is warm it falls as rain. If it is cold it falls as snow. You can also have sleet or hail.
Nitrogen Cycle: • Nitrogen is constantly combined and uncombined with other elements to form essential and nonessential compounds for life. + Here are the three major contributors of nitrogen: + 1 Introduced organisms. Every living organism, from fish to algae, all have great quantities of assimilated nitrogen in their tissues. 2 Food inputs. Dead or alive, foods are organic masses, and possess the same nitrogenous attributes as the decorative living organisms you introduce. 3 Inorganic inputs. There are two major sources for inorganic nitrogen: the atmosphere and introduced water. Atmospheric nitrogen (N2) is incorporated
Nitrogen Cycle The nitrogen cycle is composed of 4 basic steps. • Ammonia: Ammonia (NH3) initially enters the system via biological waste. These wastes mineralize into the compound ammonia. Ammonia is a very toxic compound. Bacteria which colonize rock and sand surfaces utilize ammonia as food and convert it into a new compound called nitrite. • Nitrite: Nitrite (NO2) is only slightly less toxic than ammonia. Fortunately, there are other types of bacteria that also colonize sand and rock surfaces which consume nitrites as food and convert them into nitrates. • Nitrate: Nitrate (NO3) is a relatively harmless compound. Nitrates tend to accumulate in the reef system if it is not setup correctly. Fish can tolerate fairly high nitrate levels, but most corals do not. Nitrate is also a plant fertilizer, so its accumulation can lead to algae problems. • Nitrogen: The nitrates can be further processed by special types of bacteria which convert the nitrates into harmless nitrogen gases which escape into the atmosphere. When the process includes this step, the nitrogen cycle is completed. The bacteria which perform this last step of the process only live in oxygen poor (anaerobic) areas.
Nitrogen Cycle Carbon Cycle
Carbon Cycle • The chemicals and nutrients in the water can help or hinder the growth of marine life. • All living organisms are based on the carbon atom • Carbon compounds can be solid, liquid, or gas under conditions commonly found on the earth's surface. Because of this, carbon can help form solid minerals (such as limestone), 'squishy' organisms (such as plants and animals), and can be dissolved in water or carried around the world through the atmosphere as carbon dioxide gas. The attributes of the remarkable carbon atom make possible the existence of all organic compounds essential to life on earth. • The dissolved CO2 in the oceans is used by marine biota in photosynthesis.
Populations and communities • Coral reefs are biological assemblages adapted to waters with low nutrient content, and the addition of nutrients (called eutrofication) favors species (as algae, seaweed …) that disrupt the balance of the reef communities. Some algae are toxic, and both plants reduce the levels of sunlight and oxygen, killing of other marine organisms as fish and coral. Especially the addition of nutrients such as phosphates and nitrates are very damaging to reefs. High nitrate levels are toxic to corals, while phosphates slow down the growth of coral skeleton. Poor water quality has also been shown to encourage the spread of infectious diseases among corals.
Succession • Early colonizers may have developed quickly and not have lasted long, and then are gradually replaced by slower growers. • Increasing species dominate & create larger diversity as new species settle. >>> Increase in competition • Fast growing encrusting and branching corals (Acropora, Pocillopora) may dominate for 1-2 decades. • Fragile, and may be damaged/reduced by storm action, crown-of-thorns starfish predation, bleaching etc. • Underlying slow-growing massive corals (e.g. Porites, Favids) may eventually dominate, or form a mixed community of old/young corals)
Succession • Some species are specialized to colonize new surfaces (fast growing, dominate surfaces, and stop others) • A new surface (wave-scoured sea floor, volcanic lava, shipwreck, scientific plate) is colonized by a sequence of organisms: • bacteria-microalgae • coralline algae/sponges/ascidians • macro algae (large seaweeds) • coral larvae • Because of relatively frequent disturbances on reefs, and different effects on different parts of a reef, coral reefs include a range of community ages: • recovering or ‘pioneer communities’ • intermediate communities • mature communities.
Clown Fish • Niche • Protecting anemone. The anemone is important for the ecosystem, and by keeping them safe they are benefitting the ecosystem. • Adaptations • Have more rounded caudal fins that enable them to make quick darting movements • Able to bleach itself in color at night and hide within the anemone tentacles • Special ability to be completely immune to anemone • Rely on Other factors • few ocean predators • their greatest threat is humans. • There are only ten out of more than one thousand types of anemone that are able to host these fish. • Anemone save them from other big predators
Yellow tang fish • Niche • Adaptations • Spines protruding near their tail, they use it as a defense and as an anchor while sleeping • Rely on other factors • This fish is very territorial, especially in the presence of another tang fish • Herbivore, wild grasses, algae and other plant life in general
Fan Coral • Niche • The fans provide shelter for many little critters, which can only be found when looking really closely. • Adaptations • The surface of a fan coral tends to be rough and slightly horny, and it is resilient in addition to flexible, ensuring that sea fans can withstand heavy currents. • Rely on Other factors • Because fan coral cannot actively hunt its prey, it requires strong currents to provide enough nutrition. • extremely vulnerable to human interference, as careless divers can break off arms, destroying decades of growth, and trawlers routinely rip out fan coral as they dredge the bottom of the ocean for fish. • Fan corals are also vulnerable to deliberate harvest for commercial profit, and to nutrient runoff, which can trigger algae blooms which cloud the water, making it difficult for fan coral to live.
Anemone • Niche • sea anemone benefits from the products of the algae's photosynthesis, namely oxygen and food in the form of glycerol, glucose, and alanine • Adaptations • When the hair is touched, it mechanically triggers the cell explosion, a harpoon-like structure which attaches to organisms that trigger it, and injects a dose of poison in the flesh of the aggressor or prey. This gives the anemone its characteristic sticky feeling, noted upon touching; the poison is a mix of toxins, including neurotoxins, which paralyze the prey. • Rely on other factors • closely related to corals, jellyfish, tube-dwelling anemones, and Hydra • Each nematocyst contains a small vesicle filled with toxins—actinoporins—an inner filament and an external sensory hair
Ecological Problem: Coral Reef Bleaching • Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic coral polyps and/or a reduction in photosynthetic pigment concentrations in polyps residing within scleractinian corals. • Coral reef bleaching is caused by various anthropogenic and natural variations in the reef environment including sea temperature, solar irradiance, sedimentation, xenobiotics, subaerial exposure, inorganic nutrients, freshwater dilution, and epizootics. • Coral bleaching events have been increasing in both frequency and extent worldwide in the past 20 years. Global climate change may play the largest role in the increase in coral bleaching events, and could cause the destruction of major reef tracts and the extinction of many coral species.
Coral Reef Bleaching: Restoration Plans • If we can reduce some of the other direct stresses from human activities on coral reefs, like pollution from nonpoint sources, perhaps that may also enable reefs to cope better with indirect threats like climate change. • Creating more protected areas for coral reefs may help them better withstand the rigors of too-warm water and be less vulnerable to mass bleaching
Works Cited: • http://en.wikipedia.org/wiki/Symbiosis • http://oceanworld.tamu.edu/students/coral/coral3.htm • http://jrscience.wcp.muohio.edu/fieldcourses06/PapersMarineEcologyArticles/Symbiosisonthecoralreefsf.html • http://220.127.116.11/search?q=cache:qIfNgbFt36oJ:classshares.student.usp.ac.fj/MS306/Lectures/Lecture%252013%2520Succession,%2520disturbance%2520%26%2520phase%2520shift%2520(MS%2520306.L.12)%2520(3).pdf+coral+reef+succession&cd=7&hl=en&ct=clnk&gl=us • http://www.reefscapes.net/articles/articles/2002/nitrogencycle.html • http://www.reefcorner.com/Manual/nitrogen_cycle.htm • http://www.enchantedlearning.com/subjects/ocean/Watercycle.shtml • http://www.abcteach.com/CoralReef/watercycle.htm • http://jrscience.wcp.muohio.edu/fieldcourses04/PapersMarineEcologyArticles/TheChemistryoftheOceansan.html • http://www.ucar.edu/learn/1_4_2_15t.htm • http://www.wisegeek.com/what-is-fan-coral.htm • http://tolweb.org/treehouses/?treehouse_id=3390 • http://www.marinebiology.org/coralbleaching.htm
http://en.wikipedia.org/wiki/Sea_anemone • http://en.wikipedia.org/wiki/Coral_reef • http://www.crikey-adventure-tours.com/coral-reef-food-web.html • http://en.wikipedia.org/wiki/Reef • http://www.enchantedlearning.com/biomes/coralreef/coralreef.shtml