Coral Reef Environment - الصفحات الشخصية

Coastal & MarineEnvironmentChapter3Coastal & Marine EnvironmentCoral ReefEnvironmentMazen AbualtayefAssistant Prof., IUG, Palestine

Coastal & MarineEnvironmentChapter3Contents What is coral reef?Its ImportanceThreatsArtificial reef

Coastal & MarineEnvironmentChapter3Invertebrate: الالفقاريات Solitary: االنفرادي Anemones: شقائق النعمان Cnidarians: الكائنات المجوفة What is coral? It’s a living organism!Sun Coral Polyps It is an invertebrate, Coral reefs are the largest structuresbuilt by a living organism, The organisms that build coral reefs areadapted to intertidal conditions as wellas life on the continental shelf, The reefs themselves are created by thecalcium carbonate that is deposited bypolyps living in large colonies, The main structure of the reef is actuallyfossils of polyps that lived in the past(hermatypic), There are polyps in the reef that do notcontribute to the structure – these arecalled ahermatypic corals, Coral is cousins to jellyfish andanemones (Cnidarians).

Coastal & MarineEnvironmentCoral Builds Reefs?Chapter3 The animal portion of the reef iscalled a polyp The polyp absorbs calciumcarbonate out of the water The calcium carbonate is used tobuild the reef

Coastal & ducation/kits/Reefs Corals BuildCorals can build three types of reefs:– Fringing: grows close to shore– Barrier: also grows close to shorebut has a lagoon separating itfrom the shore– Atoll: a ring of coralthat surrounds a'lagoon-island'lagoon, often growson a submergedmountain orvolcanocorals/media/coral04a 240.jpgCoral Reef Atoll

Coastal & MarineEnvironmentAhermatypic CoralsChapter3Precious CoralSoft CoralBlack CoralSea FansSea WhipsGorgonians

Coastal & MarineEnvironmentChapter3Sea Fan This is a sea fangrowing on a coralboulder. A sea fan is a type ofsoft coral. By watching themovement of the fan,you can tell thedirection of the seacurrents.

Coastal & MarineEnvironmentChapter3FungiaStar Coral ColonyPhysical characteristics of coralSize One of the largest corals, Fungia(mushroom coral), is a solitary coralthat can extend 25cm in diameter. Colonial coral polyps are muchsmaller and average 1-3mm indiameter. Coral colonies also vary in size.Some corals form only smallcolonies. Others may form coloniesfew meters high. Star coral(Montastrea annularis) coloniesreach an average height of 3-4m.

Coastal & MarineEnvironmentChapter3Pigments: أصباغ Physical characteristics ofcoralColor Natural pigments in coral tissueproduce a range of colorsincluding white, red, orange,yellow, green, blue, and purple. Algae that live within the tissuesof some corals may make thecoral appear brown, green, ororange.

Coastal & MarineEnvironmentChapter3Where can you find coralreefs? Coral is found all over the world:– Tropical– Temperate– Polar Only tropical corals build reefsCoral reefs around the world

Coastal & MarineEnvironmentChapter3Importance of Coral Reefs 0.2% of world’s oceans Habitat for 1/3 of marine fishes Habitat for tens of thousands of otheranimals The rainforests of the oceans Protection to coastlines Economic resources Biodiversity Natural beauty

Coastal & MarineEnvironmentImportance of Coral ReefsChapter3 Protection to coastlines:– absorb energy of ocean waves– reduce erosion of shoreline– storm damage– flooding

Coastal & MarineEnvironmentImportance of Coral ReefsChapter3 Economic resources:– Fisheries for food– Fisheries for jobs– Tourism– Building materials– Aquarium trade

Coastal & MarineEnvironmentImportance of Coral ReefsChapter3 Biodiversity:– The rainforests of the sea– Genetic diversity– Pharmaceuticals

Coastal & MarineEnvironmentImportance of Coral ReefsChapter3 Natural orida2/background/coralspawning.html

Coastal & MarineEnvironmentImportance of Coral ReefsChapter3 375 billion in environmental goods and servicesReefs at Risk 1998 m

Coastal & MarineEnvironmentCoral Reefs –Support, Nurture, Protect, ProvideChapter3

Coastal & MarineThreats to coral and coral reefsEnvironmentinvasive species andstarfish outbreaksChapter1)3Natural2) Anthropogenic of human originbleachingdeforestation, soil erosion,sediment & nutrient loadingdestructive fishing practicesoverfishing

Coastal & MarineEnvironment1. Natural disturbances thataffect corals and coral reefs?Chapter3Smothering: الخانق Hurricanes: Physical damage, smothering, destruction ofother ecosystems upon which coral reefs depend Tsunamis: Physical damage, erosion, possible disruptionof reproduction and recruitment Volcanoes: Depends upon where volcano occurs, Heat,smothering and sedimentation Earthquakes: Little direct impact, Indirect impacts(triggers tsunamis, coastal landslides) Predators & competitors: see next slide Bleaching: see next slide Pathogens: see next slidehttp://volcano.und.nodak.edu/vwdocs/current volcs/montserrat/montserrat.html

Coastal & MarinePredatorsEnvironmentChapter3 crown of thorns starfishsnails القواقع parrotfish الببغاء butterfly fishCrown of Thorns Sea StarParrotfishDamsel Fish

Coastal & MarineEnvironmentChapterCyanide fishing kills coral3HealthyAfter cyanide exposure

Coastal & MarineCompetitorsEnvironmentReefs are often covered with algaeChapter3algaeAlgae growth is often followedby Yellow-band diseasehttp://catbert.er.usgs.gov/african dust/algae.html

Coastal & MarineEnvironmentChapter3CompetitorsalgaeAlgae comes in green, brown and redBay Islands, Honduras, 2000It smothers and kills healthy coral

Coastal & MarineBleachingEnvironmentChapter3Bleaching: تبيض http://orbitnet.nesdis.noaa.gov/orad/coral bleaching index.html Color in coral comes from the photosyntheticsymbiotic algae that live within the tissue of the coral Loss of zooxanthellae Causes:– higher than usual ocean temperature, algae die and areexpelled and coral dies soon after. The optimaltemperature for corals is a small range (24-29 C) andeach coral species has a specific “bleaching threshold”– sharp changes in salinity– heavy UV light exposureZooxanthellae are golden-brown intracellular ofvarious marine animals and protozoa, especiallycorals. Zooxanthellae provide the host with energyin the form of translocated reduced carboncompounds, such as glucose, glycerol, and aminoacids, which are the products of photosynthesis.Zooxanthellae can provide up to 90% of a coral’senergy ges/mccarty and peters/coral/Bleach.htm

Coastal & MarineEnvironmentChapter3PathogensDiseases on the rise:– new pathogens– land pathogens (Aspergillus)– occurring at all depths– More susceptible when ccarty and peters/coral/Bbd.htm

Coastal & MarineEnvironment2. Anthropogenic threats tocoral reefsChapter3Anthropogenic: الصنعية Overfishing Development Mining and dredging Recreation

Coastal & MarineOverfishingEnvironmentEcological n ects/view.acs?object id 545

Coastal & MarineEnvironmentOverfishingDestructive fishing practiceChapter3

Coastal & MarineEnvironmentChapter3Development Sediment smothering Freshwater input Pollutants & nutrients (sewage,pesticides, fertilizer, heavy .wcmc.org.uk/marine/data/coral ve.com/homepages/mccarty and peters/coral/c-intro.htm

Coastal & MarineEnvironmentChapter3Mining for constructionmaterials and dredging Destruction of reef structure Stirs up sedimentRecreationAnchors, boats, flippers, hands, feet Kill animal tissue Skeleton science/habitat/influences.html

Coastal & MarineEnvironmentSynergistic effectsChapter3Insult: أذى Interaction of natural changes &human activity Multiple insults

Coastal & MarineEnvironmentGlobal climate changeChapter3 Reduced reef building Increase in frequency and intensity ofhurricanes Increases in bleaching Increased in disease

Coastal & MarineEnvironmentSynergistic effectsChapter3CORAL DOMINATEDALGAL DOMINATED

Coastal & MarineEnvironmentReefs worldwide areThreatenedChapter3 11% of reefs have been lost 16% of reefs severely damagedPristine: أصلي 60% of studied reefs threatened byhuman activities No pristine reefs left

Coastal & MarineEnvironmentChapter3Reefs are dying all over theworld

Coastal & MarineEnvironmentChapter3Today, 65% of the worlds reefs aredying (US Coral Reef Task Force, NOAA)

Coastal & MarineEnvironmentChapter3Consider Cancun Only 12 families lived on this forestedisland until the 1970s Then the tourist industry arrived Today, 2.6 million people visitCancun each year The island is bare, its forests longgone Sewage facilities process only onequarter of the daily flow The rest goes straight into the sea

Coastal & MarineEnvironmentChapter3Sick Coral This is a lotof coral thatdied fromdisease. It is beingovergrownby colorfulspongesand algae.

Coastal & MarineEnvironmentSponges increase while CoralsdecreaseChapter3 Sponges have increased in numbers recently because ofpollution and nutrient runoff coming from the surroundingislands. Corals are very sensitive to environmental changes andwill die from pollution, too many nutrients and seasurface temperature changes.

Coastal & MarineEnvironmentChapter3This little fish is hiding amongst the finger and soft coral

Coastal & MarineEnvironmentChapter3

Coastal & MarineEnvironmentWhen reefs die Chapter3 Fish populations disappearFishermen lose their livelihoodBeaches and shorelines wash awayLand areas erode from wavesTourists find somewhere else to diveLocal economies can be devastated

Coastal & MarineEnvironmentChapter3Artificial ReefsAn artificial reef is one or more objects of natural orhuman origin deployed purposefully on the seafloor toinfluence physical, biological, or socioeconomicprocesses related to living marine resources. Artificialreefs are defined physically by the design andarrangement of materials used in construction andfunctionally according to their purpose. Items used inreef construction add vertical profile to the benthicenvironment. They may be either assembled expresslyas a reef or acquired after being used for another,usually unrelated, purpose.The definition of artificial reef has been changing in themodern era of reef-building, which is only 50 years old.Accidental shipwrecks have been classified at times asartificial reefs. Recent proposals have suggested theincorporation, secondarily, of various objectives soughtwith artificial reefs to structures already deployed forother purposes. A notable example is the recognitionthat harbor breakwaters can be designed to achieve“ecofriendliness”.

Coastal & MarineEnvironmentChapter3Mimic: يحاكي Why constructing artificialreefs and possible impactsThe construction of artificial reefs is carriedout due to various factors. These, in order ofsignificance, are:1- Provide environmental enhancement (for example: toget rid of solid waste, non-hazardous waste, in orderto increase the operation period of landfill sites).2- Mitigate for damages to reefs due to unsustainableman-made activities (ship groundings, dredging,burial, pollution).3- Restore damaged reefs (natural events: storms,tsunamis, etc.)3- To mimic a reef habitat for tourism purposes to attracttourists.4- To mimic reef habitats to aggregate fish communitiesand increase fish stocks.5- Assist with shoreline stabilization.

Coastal & MarineEnvironmentChapter3Shoreline stabilization

Coastal & MarineEnvironmentAquaculture: تربية األحياء المائية Chapter3One of the newest purposes for artificial reefsis to provide sites for submarine viewing andnature based tourism, especially in cleartropical waters. (Photograph courtesy of R. Brock.)

Coastal & MarineEnvironmentChapter3Items used in reefconstruction addvertical profile to thebenthic environment.Artificial reefs are influenced by, andinfluence, natural and human forces in theaquatic environment. Evaluation depends onthe objectives for the reef as defined by userinterests and may address physical,chemical, biological, and economic factors.

Coastal & MarineEnvironmentChapter3A diverse group of interests have need toevaluate the performance of artificial reefsfor various economic, social, andecological purposes.