Marine Biodiversity

Question 1

What is bioturbation?

Answer 1

The physical effects of animals on their substratum (sediment)
Typically from benthic macroinvertebrates.

Question 2

What does most of the sea bed contain?

Answer 2

Soft sediments, which underpin nutrient cycling and ventilation.

Question 3

Why is sediment oxygen concentration important?

Answer 3

Influences:
- Biomass
- Rate of decomposition , regneneration of nutrients.

Question 4

What is sediment profile imaging used for?

Answer 4

To measure bioturbation.
Luminophores (sand based sediments) are dyed (fluoresces in UV) and spread on the sediment surface. The vertical spread of luminophores are recorded.

Question 5

What are PET/CT scans used for in the ocean?

Answer 5

To measure turbation and bioirrigation.
CT: gives 3D model of structural info on biogenic structures (burrows)
PET: gives 3D info on flow dynamics

Question 6

How do you scale an individual measurement into an ecosystem scale?

Answer 6

• Define an ecosystem-level metric
• Define biotic components that might influence this e.g. animals, bioturbation
• Experimentally perturb the system

Question 7

What does increasing biodiversity mean?

Answer 7

Increased complementarity through functional redundancy (if one species is knocked out, the function carries on because there is more than one species doing it)

Question 8

What are blue carbon ecosystems?

Answer 8

Highly productive ecosystems, e.g. seagrass meadows, mangrove forests.
Account for >50% of global carbon burial

Question 9

How much of the sea floor is covered in BCE?
How many have been lost?

Answer 9

~0.5%
~50%