Climate Change & Marine Species Flashcards
how much of the Earth is ocean?
70%
What are oceans reservoirs for?
nutrients
Gases (e.g: CO2)
Heat distribution
Is marine life more or less stable than terrestrial?
Marine is more stable
How is water needed for some species reproduction?
Allows for external fertilisation
What are 3 uses of water
Redistribute heat Dissolve salt Hold nutrients and gases Used for external fertilisation Removes waste products Chemical reactions occur here
what is NPP
Net primary production = the rate of photosynthetic carbon fixation minus fraction used for cellular respiration and maintenance of plankton, benthic plants/ algae, or microbes
How much of the global NPP does the ocean provide
~50%
What are 3 factors that affect NPP
Light conditions in ocean surface (photic zone = where photosynthesis occurs)
nutrient flux
nutrient regeneration
Where does photosynthesis occur in the ocean
The photic zone
What 3 things influence enviro factors that affect NPP
Physical, chemical and biological processes
Why are marine organisms useful in climate change?
Nutrient cycling (specifically, carbon cycle)
Name 3 ways climate change is impacting marine environments
- Altered ocean circulation e.g. El Niño
- Increase in storm activity
- Melting sea ice
- Rising sea levels
- Increased coastal erosion
- Coral bleaching
- Ocean acidification
- Invasive species
Briefly explain how El Ninos work
Winds decrease and surface current reduces
Warm water spreads across to East Pacific
Trade winds weaken - allows Warm Pool waters to travel back to the east
Changes cause evaporation and precipitation in Eastern Pacific and Americas
what can - changes to water currents and wind patterns cause?
Anoxic dead zones (warmer water = less oxygen)
what is coastal squeeze
Seatown defences result in intertidal zone loss
rising sea levels squeeze remaining habitat against sea walls
How does El ninos effect biodiversity?
Causes sea levels to rise
Causes species to move northwards with warmer conditions
(therefore extends non-native species = introduced species)
Also effects timing of spawning, growth rate, survival of fish larvae
What climate factor affects coral reefs
Rising sea TEMPS
warmer waters damages them
Name 4 threats to coral reefs
Fishing practises Overfishing Tourism Pollution Sedimentation Mining Climate Change
What are corals?
They are small animals that secret a calcium carbonate skeleton
What are coral reefs particularly important
They have symbiotic relationships with algae living in their tissues (zooxanthellae)
What is the name of the algae that coral has a symbiotic relationship with?
Zooxanthellae
When does coral bleaching occur?
When water is too warm for too long
What happens during coral bleaching?
Coral polyps get stressed - spit out the algae
Coral no longer has zooxanthellae to produce corals’ food
Corals die, macroalgae takes over, smothers the reef
What are some impacts of coral bleaching?
Impacts local community income (fisheries, ecotourism)
Impacts biodiversity - cascade effect on food chain
Causes competition between coral and seaweed
in 2016, what happened to the great barrier reef?
93% of the reefs were affected by bleaching
22% died
what causes ocean acidification?
increases in co2 in atmosphere dissolves in oceans forming a weak carbonic acid (H2CO3)
pH of ocean drops by 0.2-0.4
what organisms are most at risk of ocean acidification?
those that make calcium carbonate exoskeletons - gastropoda & crustaceans
Why are gastropoda and crustaceans most at risk of ocean acidification?
because acidification can deform/ dissolute shells
what are 3 causes of ocean acidification
Burning fossil fuels
Deforestation
Carbon Pollution
(Anything that causes increased CO2 in atmosphere)
If organisms can no longer biomineralize calcium carbonate, what affect does this have on the ecosystem?
whales mostly eat gastropoda - will no longer have a food source
Whales are needed to filter water so no food = no whales = more water pollution
