Lecture 1 - Water Properties Flashcards
What proportion of the Earth’s surface is covered by oceans?
Over 70%
What is the average ocean depth?
3,730m
What is the average ocean volume?
1,328 km3
What percentage of the living space on the planet does the ocean provide?
99%
What percent of water available on the globe is contained in the ocean?
97%
What proportion of animal phyla are found in marine environments?
32/33
Name the only animal phyla that can’t be found in marine environments.
Onychorphora
Give the microorganisms found in a single 1ml drop of seawater.
- 10 million viruses
- 1 million bacteria
- A thousand protozoans and algae
How many species of marine plants and animals are there?
Nearly 250,000
Why is sea life older than life on land?
Because life originated in the sea
What percentage of the Earth’s biomass is made up of marine microbes?
50%
What proportion of the Earth’s surface area is taken up by coral reefs?
0.1%
What percentage of marine biodiversity is hosted by coral reefs?
25%
What percentage of marine biodiversity is composed of invertebrates?
80%
What percentage of oxygen we breathe comes from the ocean?
How?
30-50%
Phytoplankton absorb CO2 and release oxygen into the air.
Without the heat-absorbing capacity of the ocean, how much would the atmosphere have warmed from climate change?
36 degrees
What percentage of global protein use by humans comes from oceans?
7%
What percent of the world’s population lies on the coast?
What percent is expected to lie on the coast by 2025?
- Currently: 50%
- 2025: 75%