Unit 3 Topic 2 changes on the reef Flashcards
Anthropogenic factors
Factors derived from human activities such as:
- Pollution
- Coral mining
- Ocean acid
- Dredging
Climate Winners and losers
Climate losers are reefs that die before the year 2042
Climate winners are reefs that die after 2042
Abiotic factors that impact coral reefs
- Surface runoff
- Salinity fluctuations
- Climate Change
- COTS outbreak
- Overfishing
- Oil Spills
The Holocene
The current era:
No evidence of coral bleaching or ocean acidification can be found in coral cores dating back to 6000 years.
Shelford’s Law of Tolerance
A law stating that the abundance or distribution of an organism can be controlled by certain factors including climate topographic and biological requirements.
Ecological effects of organisms after a bleaching event
Likely to have reduced growth rates, decreased reproductive capacity, increased susceptibility to disease, and elevated mortality rates.
Requirements for coral recovery after a bleaching event
Good water quality, open hard substrates, presence of Coraline algae, and temperature.
Coral cores
Provide information on changes in weather patterns and events affecting the composition of coral.
Differences between saltwater and freshwater pH
Ocean pH: 8 Freshwater pH: 7
The ocean has a higher pH due to the bicarbonate system involving dissolving minerals.
The carbonate system
Regulates the pH of seawater and controls the circulation of CO2.
Atmospheric carbon dioxide implications
Increases ocean pH and global temperature
Ocean Chemistry
Ocean acidification is occurring because excess carbon dioxide in the atmosphere is being absorbed at the surface of the ocean. This excess CO2 results in more hydrogen ions which increase acidity
Carbonate compensation depth (CCD)
The depth in the sea at which the rate of disolution of solid calcium carbonate equals the rate of supply. Cold temperature and high pressure result in higher acidity resulting in the dissolution of carbonate. Upwelling forces the CCD to be higher.
Oceans capacity
The ability to absorb CO2 is changing due to factors such as temperature and primary productivity (Phytoplankton)
Carbonate ions and concentration
The more acidic the ocean is, the harder it is for an organism to form a shell. This is because as ocean pH decreases, calcite and aragonite levels (which are crucial for shell growth) decrease.
