Marine Conservation

Question 1

Why are marine systems important ?

Answer 1

Food production:
- 17% of global meat comes from the ocean
- Over 80% of that comes from wild fisheries

Gas Exchange
- sink for carbon dioxide
- Source of oxygen

Question 2

How marine systems are different from land

Answer 2

Physical structure

Connectivity

Observation and monitoring

Question 3

Physical structure

Answer 3

Mixing only penetrates to 200m - Epipelagic (25%)

Light only penetrates to ca. 1000m - Mesopelagic (20%)

Rest is always dark - Abyssopelagic (55%)

Question 4

Connectivity

Answer 4

Ocean circulation

Nutrient falls - marine snow

Diel migration

Question 5

Observation and monitoring

Answer 5

Remote sensing

Over 80% of ocean unexplored

Good news about the epipelagic

Question 6

Comparing marine and terrestrial biodiversity

Answer 6

Arthropods:
- 100,000,000 on land
- 117,000 in freshwater
- 68,400 in the sea

Mammals:
- 5,000 on land
- 100+ freshwater
- 125 in the sea

Fishes:
- 13,000 freshwater
- 18,000 marine

Question 7

Other key axes of biodiversity

Answer 7

Morphological diversity

Biomass
- Bristlemouth most abundant vertebrate species on earth (in trillions)
- Artic krill (300-400 trillion)

Higher-level taxonomy
- 35 animal phyla in the ocean (14 exclusively marine)
- 11 animal phyla on land
(1 exclusively terrestrial)

Question 8

How is marine biodiversity distributed?

Answer 8

For all, highest abundance/biodiversity at equator

Question 9

What factors currently threaten marine biodiversity?

Answer 9

Overfishing

Climate change

Resource development and extraction

Land use

Question 10

Threat: Overfishing

Answer 10

Global population has doubled since 1950 (so has the average amount of fish a person eats)

Increasing demand for food

—> Shrinking populations and size of catch, shifting fisheries (new areas and new species)

Question 11

Threat: Climate change

Answer 11

Extreme weather
- storm damage
- changes in freshwater runoff

Increased temperature
- physiological stress

Increased carbon dioxide
- ocean acidification

Question 12

Threat: Resource development and extraction

Answer 12

Increasing demand for fuel, minerals, sand
- Erosion
- Habitat destruction
- Pollution

Question 13

Threat: Land use

Answer 13

Over 600 million people live along the world’s coastlines
- Nutrient runoff and other pollution
- Freshwater use
- Coastal development

Question 14

What is the current state of marine biodiversity?

Answer 14

244,397 described marine species

12,924 assessed; 1,125 under threat

Question 15

Big challenges

Answer 15

Taxonomic lag

Incomplete threat assessments

Hard to estimate extinction rates and population trends from what we know

Expensive

Connectivity and scale require cooperation for migration