So You Think You Are Alone Corals
-
Upload
mark-mcginley -
Category
Documents
-
view
431 -
download
0
Transcript of So You Think You Are Alone Corals
![Page 1: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/1.jpg)
More Learnin’
So You Think You Are Alone
![Page 2: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/2.jpg)
Microbes Are Smallest Forms of Life
![Page 3: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/3.jpg)
From American Museum of Natural History
![Page 4: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/4.jpg)
![Page 5: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/5.jpg)
![Page 6: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/6.jpg)
![Page 7: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/7.jpg)
Big Humans
![Page 8: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/8.jpg)
Big Animals
![Page 9: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/9.jpg)
Tallest Trees
• Giant Sequoia, California
• 115 meter, 385 feet
![Page 10: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/10.jpg)
Largest Plants
• Quaking Aspen
– Populus tremuloides
• aspen clone growing near Salt Lake City, Utah,
– weighs more than 6,000 tons
– 43 hectares
– 47,000 individual stems.
![Page 11: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/11.jpg)
Largest Organisms
• Fungi - Oregon
• Honey Mushroom
– Armillaria ostoyae
• 2,200 acres (890 hectares)
• at least 2,400 years old
![Page 12: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/12.jpg)
Tallest Buildings
![Page 13: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/13.jpg)
Great Wall of China
8,851.8 kilometers (5,500 miles)
![Page 14: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/14.jpg)
Great Barrier Reef
• stretches over 2,600 kilometers (1,600 mi)
• area of approximately 344,400 square kilometers (133,000 sq mi).[
![Page 15: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/15.jpg)
Great Barrier Reef From Space
![Page 16: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/16.jpg)
Barrier Reefs
Thickest reef almost 1 mile thick.
![Page 17: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/17.jpg)
Coral reefs are largest biogenic structures on Earth
• What does this have to do with microbes?
![Page 18: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/18.jpg)
Coral Reefs
• Thick layer of calcium carbonate covered by thin layer of living organisms
– Built up over long periods of time
![Page 19: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/19.jpg)
Cnidarians
![Page 20: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/20.jpg)
Phylum Cnidaria
![Page 21: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/21.jpg)
Cnidarian Morphology
![Page 22: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/22.jpg)
22
Coral Polyps
![Page 23: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/23.jpg)
Coral Polyps
![Page 24: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/24.jpg)
Coral Feeding
![Page 25: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/25.jpg)
Scleractinian Corals (reef building corals)
• secrete CaCO3
• external skeletons secreted by epidermis
![Page 26: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/26.jpg)
Coral Skeleton
![Page 27: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/27.jpg)
27
Hard Corals
![Page 28: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/28.jpg)
Corals are animals, so why do we care about coral reefs in this class?
• Cool
• Incredibly diverse
• Very important economically
• http://www.underseaproductions.com/demo_reels/marine_life_behaviour_video_footage.html
![Page 29: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/29.jpg)
Energetics and Ecosystems
• Energy is required to do work
– Biological work
• Maintaining concentration gradients across membranes– Active transport
• Biosynthesis– Breaking down and building up bio molecules
• Movement– Cilia
– Muscles
![Page 30: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/30.jpg)
First Law of Thermodynamics
• Energy can not be created or destroyed
– It can only be converted from one form to another
– Forms of energy
• Electromagnetic
• Kinetic
• Nuclear
• Potential
![Page 31: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/31.jpg)
Photosynthesis
• The most important energetic process taking place for life on earth
– Converts electromagnetic energy from the sun (released by fusion reactions in the sun) to potential energy stored in the chemical bonds of glucose
![Page 32: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/32.jpg)
Cellular Respiration
• Energy stored in the chemical bonds of glucose is converted into energy stored in the chemical bonds of ATP
• ATP releases that energy
– Used to do biological work
![Page 33: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/33.jpg)
Energy Flow Through Ecosystem
• Sun
• Plants– Primary producers
• Herbivores– Primary consumers
• Carnivores– Secondary consumers
• Decomposers
• Energy lost as heat to environment
![Page 34: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/34.jpg)
Flow of Energy From One Trophic Level to the Next is Inefficient
• Only about 10% of energy captured by plants is passed on to primary consumers
• About 10% of energy captured by primary consumers is passed on to secondary consumers
![Page 35: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/35.jpg)
Energy Pyramid
![Page 36: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/36.jpg)
Biomass Pyramid
![Page 37: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/37.jpg)
Forests
![Page 38: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/38.jpg)
Prairies
![Page 39: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/39.jpg)
Deserts
![Page 40: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/40.jpg)
Coral Reef Video
• Schooling Fish
• http://www.underseaproductions.com/demo_reels/schooling_fish_video_footage.html
![Page 41: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/41.jpg)
Coral Reef Video
• http://www.underseaproductions.com/demo_reels/seascapes_video_footage.html
• How many plants do you see on this video?
![Page 42: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/42.jpg)
Coral Reefs
• Do not see many aquatic plants (algae) on coral reefs
• Yet coral reefs are teeming with life and are one of the most diverse communities on the planet
• How can this be?????
![Page 43: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/43.jpg)
The Mystery of the “Inverted Energy Pyramid”
![Page 44: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/44.jpg)
Missing Primary Producers
• Two possibilities
1) Maybe plants are photosynthesizing but the plant material is eaten by herbivores as fast as it is produced.
- Therefore we don’t see a build up of plants
![Page 45: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/45.jpg)
Lots of Herbivores Living or Coral Reefs
![Page 46: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/46.jpg)
Biogenic Sand
![Page 47: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/47.jpg)
Long-spined Urchin (Diadema antillarum)
![Page 48: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/48.jpg)
Results of Overfishing and Diadema Die-off
![Page 49: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/49.jpg)
Missing Primary Producers
• In undisturbed reefs, primary productivity of algae is rapidly removed by the herbivores
• But calculations of rate of photosynthesis by algae was not enough to explain the energy and biomass at higher tropic levels
![Page 50: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/50.jpg)
Missing Primary Producers
• Not looking in the right place.
• Scientists (and the video we just saw) looked all over the coral reef for primary producers
– Needed to look “inside” of corals
![Page 51: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/51.jpg)
Symbiotic Zooxanthellae
![Page 52: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/52.jpg)
CORAL REEFS - ZOOXANTHELLAE
--- Are group of algae called dinoflagellates (also form red tides).Symbiodinium spp.)
--- Are different colors; brown, green, yellow.
--- Dinoflagellates mutualistic with other groups; sea slugs, giant clams, tunicates.
--- Can live outside host
![Page 53: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/53.jpg)
Classification of Life
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species
• King Phillip Chooses Only Fancy Green Sox
• 5 Kingdom system– Animals
– Plants
– Fungi
– Protistans
– Monerans
![Page 54: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/54.jpg)
Classification of Life3 Domains
From the University of California Museum of Paleontology
![Page 55: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/55.jpg)
Domain- Archaea
• 2 distinct groups of Prokaryotes based on DNA
• Those "bacteria" that lived at high temperatures or produced methane clustered together as a group well away from the usual bacteria and the eukaryotes.
• Divided prokaryotes into two Domains
![Page 56: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/56.jpg)
Archaea
• Archaeans include inhabitants of some of the most extreme environments on the planet. – rift vents in the deep sea at temperatures well over
100 degrees Centigrade.
– hot springs
– in extremely alkaline or acid waters
– inside the digestive tracts of cows, termites, and marine life where they produce methane
– in the anoxic muds of marshes and at the bottom of the ocean, and even thrive in petroleum deposits deep underground.
![Page 58: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/58.jpg)
Domain-Eukaryota
• Five Kingdoms
– CHROMISTA (Kelps, diatoms, haptophytes)
– FUNGI (Fungi)
– METAZOA (Animals)
– PLANTAE (Plants)
– PROTISTA (Protists)
![Page 59: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/59.jpg)
Kingdom Protista
• ALVEOLATES---Apicomplexa (Apicomplexans) ---Ciliata (Ciliates) ---Dinoflagellata (Dinoflagellates) ---Foraminifera (Forams)
• Chlorophyta (Green algae) • Choanoflagellata• CHROMISTA (Stramenopiles) • Diplomonadida• Euglenida• Kinetoplastida (Bodonids and trypanosomes) • Myxomycota (Slime molds) • Parabasalia• Pelobionta (Pelomyxa) • Radiolaria (Radiolarians) • Rhodophyta (Red algae) • Testaceafilosea (Testate Amoebae
![Page 60: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/60.jpg)
Dinoflagellates
• Diverse unicellular protists
• Many are photosynthetic
• Some species are capable of producing their own light through bioluminescence
![Page 61: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/61.jpg)
Mutualistic Relationship Between Corals Polyps and Zooxanthellae
• Mutualistic interaction
– Interaction between two species in which both species benefit
– Examples???
![Page 62: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/62.jpg)
Green polyp tissue, red zooxanthellae
Coral – Zooxanthellae Mutualism
• Zooxanthellae provide corals:– Energy (photosynthesis
products) and as a by-product ability to grow and reproduce fast enough to produce reefs.
– Zooxanthellae can provide up to 90% of a coral’s energy requirements
• Corals provide zooxanthellae with:– Protection from predators
via Cnidarian nematocysts.
– Removal of dissolved organic material from water column (to keep water clear)
– Waste products useful for algal photosynthesis (nitrogen and phosphorous)
• )
![Page 63: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/63.jpg)
Coral-Zooxanthellae Mutualism
• Explains one aspect of the distribution of coral reefs
• Coral Reefs are found
– Shallow water
– Near continents
– Tropical
– Eastern sides of continents
![Page 64: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/64.jpg)
Distribution of Corals
![Page 65: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/65.jpg)
Coral reefs limited to the “photic zone”
• Zooxanthellae require light for photosynthesis
– Corals limited to relatively shallow water
![Page 66: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/66.jpg)
Photic Zone
![Page 67: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/67.jpg)
Coral Reef Zonation
• There are consistent patterns of zonationon coral reefs with increasing depth– Water absorbs light so
there is less light as depth increases• Thus, ability of
zooxanthellae to provide corals with energy decreases with depth
![Page 68: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/68.jpg)
68
Coral Species Change Growth Form at DepthPlating in Star Coral (Monastrea)
![Page 69: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/69.jpg)
More Sponges and Fewer Corals at Greater Depths
![Page 70: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/70.jpg)
Mutualisms
• Important for the two participant species to be able to find each other
• How do they do this?
![Page 71: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/71.jpg)
Maternally passed from parent to offspring
-vertical transmission
Transmission of Zooxanthellae
![Page 72: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/72.jpg)
Coral Life Cycle
• Corals can reproduce sexually or asexually– Zooxanthellae easily
passed from parent to offspring in asexual reproduction
• Corals also reproduce sexually– Egg and sperm– Mothers can place
zooxanthellae in eggs
![Page 73: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/73.jpg)
Sexual Reproduction in Corals
• Some species of corals release both eggs and sperm in the water– Fertilization occurs in the water column
• Spawners
• Other species hold the eggs but release the sperm in the water– Fertilization occurs in the Mom, later release larvae
• brooders
– Maternal transmission of zooxanthellae occurs more often in brooders than spawners
![Page 74: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/74.jpg)
Transmission of Zooxanthellae
- Environmental transmission each new generation
- Free-living Zooxanthellae enter new corals each generation
• This is very important for some of the issues we will talk about later
![Page 75: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/75.jpg)
Benefits of Coral ReefsFisheries
![Page 76: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/76.jpg)
Benefits of Coral Reefs Protect Shore
![Page 77: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/77.jpg)
Benefits of Coral ReefsTourism
![Page 78: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/78.jpg)
Benefits of Coral ReefsBiodiversity
![Page 79: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/79.jpg)
![Page 80: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/80.jpg)
Decline of Caribbean Coral Reefs
![Page 81: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/81.jpg)
Threats to Coral ReefsStorm Damage
![Page 82: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/82.jpg)
Threats to Coral ReefsCrown of Thorns Starfish
![Page 83: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/83.jpg)
83
Threats to Coral ReefsSiltation
![Page 84: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/84.jpg)
Threats to Coral ReefsAlgal Blooms
![Page 85: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/85.jpg)
Threats to Coral ReefsDynamite fishing
![Page 86: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/86.jpg)
Threats to Coral ReefsCoral Bleaching
![Page 87: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/87.jpg)
Coral Bleaching
![Page 88: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/88.jpg)
Coral Bleaching
![Page 89: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/89.jpg)
Coral Bleaching
• Environmental stress puts a strain on the symbiotic relationship
– fresh water dilution
– sedimentation
– subaerial exposure
– solar irradiance
– temperature
![Page 90: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/90.jpg)
Coral Bleaching
• Fresh water dilution and sedimentation are local conditions so coral bleaching due to these factors is limited to certain small areas.
• Solar irradiance and especially temperature are stressors that cause coral bleaching on a global scale
– Potentially a much bigger problem
![Page 91: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/91.jpg)
Coral Bleaching
![Page 92: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/92.jpg)
Coral Bleaching
• Polyps can live for a while without the zooxanthellae, but growth rate is greatly reduced
– If stress is eliminated the zooxanthellae may return to the polyps and the coral recovers
– If stress continue for too long, then the polyps will die
![Page 93: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/93.jpg)
New Guinea
![Page 94: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/94.jpg)
Temperature and Coral Bleaching
• Coral reefs are vulnerable to increased temperature, which causes corals to lose their symbiotic algae in a process called coral bleaching.
• Small increase in water temperature is enough to trigger bleaching
• Over the last 30 years, average ocean temperatures have increased 0.3 to 0.4 degrees Celsius.– Mass coral bleaching episodes have increased
dramatically over the last 2-3 decades.
![Page 95: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/95.jpg)
Temperature and Coral Bleaching
• El Nino events can change the pattern of ocean currents and bring warmer water to reefs
– 16 % of the world’s coral reefs experienced bleaching in 1997-1998
• mortality approaching 90% in some places
– about half of damaged reefs have not recovered.
![Page 96: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/96.jpg)
Mechanisms of Coral Bleaching
• Not well understood
• Often talk about polyps “expelling zooxanthellae”
– This may or may not be an accurate word choice
• This discussion might benefit from a better knowledge of about theories of mutualisms
![Page 97: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/97.jpg)
Mechanisms of Coral Bleaching
• Zooxanthellae may be lost from polyps “unintentionally”
• Cell Adhesion Dysfunction
– High temperature shock could result in cell adhesion dysfunction between the cnidarianendodermal cells and the zooxanthellae cells.
• Cell adhesion dysfunction would cause the detachment and loss of zooxanthellae from the coral.
![Page 98: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/98.jpg)
Mutualisms
• Mutualisms are interactions between two species in which both species benefit
– Often think of species behaving altruistically
• Probably more complicated then that.
![Page 99: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/99.jpg)
Mutualisms
• Species are involved in mutualisticrelationships because the benefits of interacting with the other species are larger than the costs of that interaction
– If something happens to alter the benefits and costs then species might “reconsider” whether or not they want to be involved in the relationship
• Whether or not they can do anything about it can vary from system to system
![Page 100: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/100.jpg)
Zooxanthellae may “choose” to leave the polyps
Stressed corals may give provide zooxanthellaefewer nutrients for photosynthesis
- less benefit to the mutualism
If the fitness of algae living independently is greater than the fitness of algae living in polyps then the algae may “decide” to leave the polyp and exist independently.
![Page 101: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/101.jpg)
Polyps may “Expell” Zooxanthellae
• Coral polyps might “decide” to end the relationship with the zooxanthellae if
– The costs of hosting zooxanthellae increase
– The benefits received from the zooxanthellaedecrease
![Page 102: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/102.jpg)
Polyps may “Expell” Zooxanthellae
• Stress might alter the physiology of the zooxanthellae and cause them to release compounds that are harmful to polyps (perhaps free oxygen radicals)
• Polyps will release the zooxanthellae rather than suffer the effects of the toxins.
![Page 103: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/103.jpg)
Polyps may “Expell” Zooxanthellae
• Adaptation Mechanism
– If certain strains of zooxanthellae cannot function when stressed, the polyps expell these zooxanthellae to leave their tissues open to be recolonized by a different strain of zooxanthellaethat are better adapted to the current environment
![Page 104: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/104.jpg)
Coral Diseases
• Coral diseases are another threat to coral reefs
• Coral diseases were first identified in the 1970s and their prevalence has increased since then
![Page 105: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/105.jpg)
Black-band Disease
• Black-band disease is characterized by a blackish concentric or crescent-shaped band, 1 to 30 mm wide and up to 2 m long, that “consumes” live coral tissue as it passes over the colony surface, leaving behind bare skeleton.
![Page 106: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/106.jpg)
Black-band Disease
• The disease is caused primarily by a cyanobacteria– sulfide-oxidizing
bacteria, sulfur- reducing bacteria, other bacteria and nematodes, ciliate protozoans, flatworms and fungal filaments also are present.
• The photosynthetic pigments of the dominant cyanobacteriagives the band its maroon to black color
![Page 107: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/107.jpg)
Black-band Disease
• The dead skeleton will be attacked by boring algae, boring sponges, boring clams, and parrot fish which will gnaw away the skeleton
– remove about 1 cm per year.
• This means that in 100 years, a 1-meter high coral head will be completely consumed and converted to sediment.
![Page 108: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/108.jpg)
White-band Disease
• White-band disease was first identified in 1977 on reefs surrounding St. Croix. It is now known to occur throughout the Caribbean where it is believed to only affect staghorn and elkhorncorals.
• This disease is characterized by tissue that peels or sloughs off the coral skeleton in a uniform band, generally beginning at the base of the colony and working its way up to branch tips
• The band ranges from a few millimeters up to 10 cm wide, and tissue is lost at a rate of about 5 mm per day
![Page 109: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/109.jpg)
White-band Disease
• The cause of White-band Disease is unknown.
– unusual aggregates of rod-shaped bacteria were found in the tissue of corals affected by White-band Disease
• scientists have not determined the role of this microorganism
![Page 110: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/110.jpg)
White-band Disease
• Since the 1980s, Acroporacervicornis has been virtually eliminated from reef environments throughout the Caribbean.
• In the U.S. Virgin Islands, populations of Acropora palmata declined from 85 percent cover to 5 percent within 10 years
• White-band disease currently is the only coral disease known to cause major changes in the composition and structure of reefs
![Page 111: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/111.jpg)
Yellow Blotch Disease
• Affects only star corals in the genus Montastraea and the brain coral Colpophyllia natans
• First identified in 1994 in the lower Florida Keys. It is now known to occur throughout the Caribbean
![Page 112: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/112.jpg)
Yellow Blotch Disease
• Yellow blotch disease begins as pale, circular blotches of translucent tissue or as a narrow band of pale tissue at the colony margin, with affected areas being surrounded by normal, fully pigmented tissue.
• As the disease progresses, the tissue first affected in the center of the patch dies, and exposed skeleton is colonized by algae . The area of affected tissue progressively radiates outward, slowly killing the coral.
![Page 113: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/113.jpg)
Yellow Blotch Disease
• The rate of tissue loss by corals afflicted with YBD averages 5 t 11 cm per year, which is less than that of other coral diseases.
• However, corals can be affected for many years, and the disease can affect multiple locations on a colony.
• Though the cause of Yellow Blotch Disease remains unknown
![Page 114: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/114.jpg)
Red-band Disease
• Red-band disease consists of a narrow band of filamentous cyanobacteria that advances slowly across the surface of a coral, killing living tissue as it progresses.
• Affects massive and plating stony corals, and also sea fans throughout the wider Caribbean. – exposed skeletal surfaces are
rapidly colonized by algae and other competing organisms.
![Page 115: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/115.jpg)
Sea Fan Aspergillosis
• Caused by the pathenogenic fungus Aspergillus sydowii.
![Page 116: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/116.jpg)
Why has the prevalence of coral diseases increased so much in the last
40 years?
• One theory is that anthropogenic stresses on the environment have made corals more susceptible to infection by coral diseases
![Page 117: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/117.jpg)
Dust Hypothesis
• Changes in global climate and land use in Africa resulted in severe droughts in the Sahara and Sahel of Africa starting in the 1970s.
![Page 118: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/118.jpg)
Dust Hypothesis
• Hundreds of millions of tons of African dust are transported annually from the Sahara and Sahel to the Caribbean and southeastern U.S.
• A similar dust system in Asia carries dust from the Gobi and Takli Makan deserts across Korea, Japan, and the northern Pacific to the Hawaiian Islands, the western U.S., and as far eastward as Europe.
![Page 119: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/119.jpg)
I’ve cleaned this dust off of boats in the Caribbean.
![Page 120: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/120.jpg)
Dust Hypothesis
• African and Asian dust air masses transport nutrients (iron, nitrates, other nutrients), pollutants, and viable microorganisms that may adversely affect human health and downwind ecosystems such as coral reefs.
![Page 121: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/121.jpg)
Dust Hypothesis- Mechanisms
• interfere with a coral's immune system, making it more susceptible to disease pathogens.
• induce pathogenicity in a microorganism in the reef environment.
• trigger a rapid increase in the number of pathogenic microorganisms.
• fuel macroalgae or phytoplankton growth– has been shown for Red tides in the Gulf of Mexico
• directly deposit pathogenic microorganisms.
![Page 122: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/122.jpg)
![Page 123: So You Think You Are Alone Corals](https://reader034.fdocuments.in/reader034/viewer/2022052606/5a67dcf17f8b9afa468b5d9b/html5/thumbnails/123.jpg)
Lots of topics for future research about the role of microbes in coral reef
ecosystems