East Coast MARE Ocean Lecture Jan 30, 2013 - Corals: Changes with Climate

  • 129 views
Uploaded on

East Coast MARE hosted an Ocean Lecture & Educators’ Night for K-12 teachers focused on bringing ocean literacy to students in New Jersey. Ms. Jeana Drake of Rutgers University presented the …

East Coast MARE hosted an Ocean Lecture & Educators’ Night for K-12 teachers focused on bringing ocean literacy to students in New Jersey. Ms. Jeana Drake of Rutgers University presented the scientific lecture on Jan 30, 2013. For more information visit http://coseenow.net/mare/opportunities-resources/ocean-lecture-educators-night/.

More in: Education
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
129
On Slideshare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
0
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Tali Mass & Jeana Drake January 30, 2013
  • 2. Focus on climate change1. Changing ocean temperatures 2 - 4oC (3.6 - 7.2oF) global average increase by year 21002. Changing sea level 1.5 – 10 mm/year (0.06 – 0.4 inches/year) global average increase to year 21003. Changing ocean pH Average surface ocean pH decrease from 8.2 to 7.8 by year 2100
  • 3. Conditions preferred by corals•  Temperature: 23-25°C;•  Light: for photosynthesis;•  Salinity required;•  Clean, clear water, sediment free;•  Well oxygenated water produced by strong wave action
  • 4. Coral’s ideal environmentCoral reefs are concentrated in a band aroundthe equator between 30°N and 30°S latitude.
  • 5. Types of Reefs•  Fringing reef – reef that is directly attached to a shore or borders it with an intervening shallow channel or lagoon.•  Barrier reef – reef separated from a mainland or island shore by a deep lagoon.•  Atoll reef – a more or less circular or continuous barrier reef extending all the way around a lagoon without a central island.
  • 6. Darwin’s Theory of Reefs
  • 7. Class: Scyphozoa Class: Hydrozoa Class: Anthozoa Ahermatypic Sea anemone Hermatypic
  • 8. Types of CoralsHard corals (hermatypic): secrete a limestone (CaCO3) exoskeleton around itself as protection. This exoskeleton remains even after the organism dies.Soft corals (ahermatypic): tree-like and flexible with a skeleton within their bodies giving them shape but allowing movement with the waves
  • 9. Growth forms
  • 10. Basic structurez •  Polyps = basis of life on reef. •  Produce calcium carbonate skeleton as they grow. •  Polyp growth = symbiotic relationship between the coral animal and zooxanthellae (algae). •  Zooxanthellae photosynthesize and give sugars and fats to polyp. Veron (1986)
  • 11. Communication, allocation and Colonial coral polyps translocation between polyps
  • 12. •  Corals feed on zooplankton•  Tentacles help capture food•  Tentacles contain stinging cells
  • 13. Symbiotic relationship with zooxanthellae  Algae in the coral polyp produce oxygen and organic products for the polyp  Coral polyps produce carbon dioxide for the algae and give protection
  • 14. ReproductionCorals reproduce either asexually by budding or by sexually releasing gametes (sperm and eggs). Sexual reproduction Asexual reproduction Fertilization can occur within Budding occurs when a new a coral known as “brooding” zygote grows onto another one or outside of a coral known and remains attached, as “broadcasting” separating only when mature. .
  • 15. SEX ON THE REEF: Broadcast spawning
  • 16. Morphology and physiology: adaptation to local environment 1. Water depth 2. Water movement5m50m Photo by Shai Einbinder Mass et al. MEPS, 2007 Veron & Pichon, 1976
  • 17. Seawater Carbonate System pH , totalCO2 + H2O CH2O + O2 photosynthesis alkalinity- unchanged pH , totalCH2O + O2 CO2 + H2O respiration alkalinity- unchangedCa2+ +2HCO-3 CaCO3 + CO2 + H2O calcification pH , total alkalinity- changed Bjerrum plot (Zeebe, 1999)
  • 18. A Study of a Mesophotic Coral Ecosystem5m 5m60 m Photo by Shai Einbinder 50 m Photo by Shai Einbinder Stylophora pistillata
  • 19. Study Objectives•  Coral metabolism and calcification due to:   Light acclimation•  What response variables to measure (3 things):   1. Oxygen   2. pH   3. Alkalinity•  Things to vary (i.e.; when/where would these be different?):   1. Day/Night   2. Depth•  Hypotheses:   1. Calcification rates higher during the day than at night.   2. Shallower coral have higher maximum photosynthesis but lower pigment concentration than deeper corals.
  • 20. The Inter-University Institute for Marine Sciences in Eilat 21
  • 21. Methods
  • 22. Methods•  The deep water colonies were carried inside black bags to the experiment site (~5 m depth)•  We placed the colonies at a light level of the origin growth place. PAR (%) ~ noon 0 20 40 60 80 100 0 10 20 30 Depth (m) 40 July 50 60 Feb 70 80 90 100
  • 23. Methods•  Tissue analysis:   Pigment (chlorophyll a & c) concentration•  Diel cycles of photosynthesis and calcification were studied using a submersible Stylophora pistillata respirometer (AIMS, Australia).
  • 24. Results & DiscussionPhotoacclimation - Pigments Stylophora pistillata
  • 25. Results & Discussion Photoacclimation - Max. Photosynthetic Rate Maximum Photosynthetic Rate P max µmole o2 cm-2 h-1 0.00 .02 .04 .06 .08 .10 .12 .14 .16 5 10 50Depth (m) July Feb 65 n=3, Kruskal Wallis ANOVA p<0.05
  • 26. Results & Discussion Photoacclimation - Dark Respiration Dark Respiration µmole o2 cm-2 h-1 0.0 -.2 -.4 -.6 5 10 50Depth (m) July Feb 65
  • 27. Results & Discussion Calcification Day & night calcification (µmol CaCO3 cm-2 h-1) -4 -2 0 2 4 6 8 10 12 5 10 50Depth (m) July day July night 65 Feb day Feb night 24h experiment, n=3
  • 28. Summary•  Photosynthesis and calcification are light dependent•  Photo-acclimation of endosymbiotic algae with depth –  Pigment Concentration –  Maximum Photosynthetic Rate –  Respiration•  Light enhances calcification, calcification rates: –  Diel Cycle - Night vs. Day –  Depth - Deep vs. Shallow
  • 29. Corals in the FutureGiven what we learned in this study, how do you think coral calcification might be affected by:1. increasing temperature?2. sea level rise?3. decreasing surface ocean pH?