Flashcards in 3. Aquatic Ecosystems Deck (11)
How will UV radiation effect the ocean?
UV radiation interacts with other natural and anthropogenic sources and the result is unknown
Peachy et al., 2005 - exposure to pollutants can worsen effects of UV exposure
Algae and invertebrate larvae esp vulnerable, incl. coral algae
How will acidification impact the oceans?
pH drop of 0.3-0.5 by 2100
Relatively large change
Some biota sensitive eg. reduced growth in mussels, gastropods and sea urchins
Invertebrates more vulnerable - food chain!
Less calcification so less shell formation
What impact will have reduced calcification have in the oceans?
Lower pH so less CO32- so less calcium available
Less shell formation
Lower latitudes particularly vulnerable
Effects diatoms - huge food source
Reef building corals unavailable - 10-40% calcification drop
How will changing ocean temperatures effect the ocean?
Some spp already close to upper thermal limit
Heat causes dissociation of endosymbiotic algae from coral
They provide coral nutrients and coral provide shelter
No algae means less nutrients, starvation and death
14% coral gone, 35% seriously threatened
Will impact toursim and fisheries
Worse than UV!
What will rising sea levels do to marine ecosystems?
May outpace accretion rates of coral reefs, salt marshes and mangroves
Salt marshes vital for accretion keeping pace
Upward shift in species distribution
Bad for slow growing taxa
Issues with light penetration, food availability
How will increased storm events impact the ocean?
Intertital and shallow subtital systems vulneravle to repeated storms
8-12 years for reef recovery
Larvae may be moved to wrong place
Upswell may damage them
Upswell, more nutrients from seabed, algal blooms and toxins
How will surface warming impact the ocean ecosystem?
Mixed by wind and swelling
Warmth and nutrients leads to blooms
Warming reinforces stratification therefore less nutrient input to surface
Less primary production
Do the chemistry for the oceans cause u smart now
CO32- + 2H+ (equilibrium arrow) H2CO3
Lower pH means more H+ which drives the equilibrium so less CO32-
Less CO32- means less...
CO32- + Ca2+ -> CaCO3
Summarise Brander, 2010
Primary production may increase at high latitudes due to less mixing with lower depths, despire fewer nutrients
Hard to impact what result changes in PP will have
PP changes will be regional due to El Nino
Warming could increase pathogens eg. MSX disease
Short term threats to fisheries:
events, fishing, pollution, invasives, degredation, which will reduce resillience to mid and longer term threats
Long term impacts unknown
Mid policy controlled
Sumarise Lovelock et al., 2015
Mangroves support fisheries, protect the coast and sequest carbon
Mangroves can migrate landwards but anthropogenic barriers
Some will struggle to survive even small rises
Thailand and S.E Asia particularly vulnerable