Week 13: Uses and abuses of the ocean

Question 1

Renewable resource

Answer 1

Naturally replaced by the growth of marine organisms or by other natural physical processes

Question 2

Non-renewable resources

Answer 2

Oil, gas, solid mineral deposits are present in ocean in fixed amounts and cannot be replenished over time spans as short as human lifecycles

Question 3

Types of marine resources

Answer 3

1. Physical
2. Biological
3. Energy
4. Non-extractive

Question 4

Physical marine resources

Answer 4

Deposition, precipitation, accumulation of useful substances in ocean (mineral deposits, oil, gas, water)

Question 5

Biological marine resources

Answer 5

Animals, plants and algae collected for human usage or used as feed for other animals

Question 6

Energy marine resources

Answer 6

Extraction of energy from ocean water

Question 7

Non-extractive marine resources

Answer 7

In place use of the ocean (transportation, recreation, waste disposal)

Question 8

Types of physical marine resources

Answer 8

1. Hydrocarbon deposits
2. Sand/gravel and mineral deposits
3. Freshwater- extracted from sea water

Question 9

Types of biological marine resources

Answer 9

1. Carrageenan- red algae (rhodophyta): binds food together ex. dog food, chocolate and toothpaste
2. Alginate - brown algae (phaeophyta): used to make water based products thicker or creamier ex. ranch dressing and hand creams
3. Agar- red algae: food thickener and jelling agent

Question 10

Are present day fisheries sustainable?

Answer 10

Some… BUT
- 90% of worldwide stocks of tuna, cod etc have disappeared bc of overfishing

Question 11

Bycatch

Answer 11

Unwanted species caught in fishing net and thrown overboard

Question 12

What is marine pollution?

Answer 12

When substances or energy are introduced into the ocean by nature or humans and it changes the quality of water or affects the physical, chemical or biological environment

Question 13

What is a pollutant?

Answer 13

Something that causes damage by interfering directly or indirectly with the biochemical processes of an organism (naturally occurring or man-made)

Question 14

Response of an organism to a pollutant

Answer 14

Depends on its sensitivity to the quantity and toxicity of that pollutant

Question 15

Marine pollution - OIL

Answer 15

One of the most widely reported and recognizable forms of pollution

Question 16

What percentage of natural oil seeps occur?

Answer 16

47%

Question 17

Crude oil

Answer 17

Not easily dissolvable, form insoluble layers on surface
The dissolvable components are harmful to juvenile marine organisms
Larger in volume and more frequent

Question 18

Refined oil

Answer 18

Contains synthetic chemicals which are biologically active components
Present for longer periods of time

Question 19

What is a common key stone species?

Answer 19

Sea otters

Question 20

Why are sea otters considered key stone species?

Answer 20

Critical to maintaining health of ecosystem
Eat sea urchins which eat holdfasts of kelp
If sea otter population decreases, kelp dies, biodiversity is lost

Question 21

What species can be harmed by oil pollution?

Answer 21

Whales, sea otters, tuna larvae

Question 22

How do we clean up oil spills?

Answer 22

1. Dispersion (chemicals break it up)
2. Burning
3. Skimming
4. Wave action- forms tar bars
5. Consumed by bacteria
6. Photooxidation

Question 23

Biomagnification/ bioaccumulation

Answer 23

A pollutant builds up and is amplified as organisms each organisms with have been in contact w the pollutant

Question 24

The mercury cycle

Answer 24

Mercury cycles through Earth’s atmosphere, ocean and rock
In ocean, mercury is converted to monomethyl mercury (MMhg), a neurotoxin that moves up food chain and becomes highly concentrated in tuna, swordfish, seafood

Question 25

Where are MMhg levels highest in ocean?

Answer 25

Near top of low oxygen zone btwn 100 and 400 metres below the surfaceB

Question 26

Biomagnification and the Hg cycle

Answer 26

1. Ionized mercury in seawater and sediments cannot enter bacterial cells 2. Some bacteria use sulphate for respiration when O2 is low, expelling sulphide 3. Sulphide combines w ionized mercury in seawater to from mercuric sulphide which can diffuse into bacterial cells 4. Inside bacterial cells, monomethyl mercury is created and diffuses into seawater to be taken up by phytoplankton

Question 27

Minamata disease

Answer 27

Severe Hg poisoning Neurological damage Congenital

Question 28

Persistent organic pollutants (POPs)

Answer 28

Harmful organic compounds Stable, low biodegradability Sources from pesticides, industrial chemicals and solvents

Question 29

What is marine debris?

Answer 29

Any persistent solid material that is manufactured or processed Directly or indirectly, unintentionally or intentionally disposed of or abandoned into the marine environment

Question 30

Most common type of marine debris

Answer 30

Plastic

Question 31

Plastics

Answer 31

Not biodegradable Attract other toxic substances Differing buoyancies (float and/or sink)

Question 32

Ghost net

Answer 32

Lost, abandoned, discarded nets/ fishing gear

Question 33

Turtles and plastic

Answer 33

Eat it, think their full, die of starvation

Question 34

Grey whales and plastic

Answer 34

Baleen whales feed on ocean bottom by scooping everything up

Question 35

Microplastics

Answer 35

Microfibres and microbeads Too small to be filtered out **hard for organisms to differentiate btwn phytoplankton and microplastics as food

Question 36

Open ocean and plastics

Answer 36

Surface circulation concentrates buyoant plastics into subtropical gyres ex. Western garbage patch and eastern garbage patch

Question 37

What percentage of marine debris will sink to ocean floor?

Answer 37

70%

Question 38

How do we know that the ocean water is warming?

Answer 38

Stopping of overall global thermal circulation Metabolic needs of fish are increasing Most importantly, sea level rise (sea ice is melting)

Question 39

Sea level

Answer 39

measure of the average height of the surface of the sea; sea level not uniform

Question 40

Global (eustatic) sea level

Answer 40

Average height of ocean around world (this is rising)

Question 41

Local sea level

Answer 41

Height of water measured along coast relative to a specific point on land

Question 42

Causes of regional diff in sea levels

Answer 42

1. Diff temp 2. Ocean currents 3. Changes to average winds and atmospheric pressure 4. Post-glacial rebound 5. Changed to amount of water on land 6. Gravitational adjustments owing to the loss of ice

Question 43

Main drivers of sea level rise- eustatic

Answer 43

1. Add or remove water (glacial vs interglacial) 2. Chang water temp (thermal expansion)

Question 44

Why can sea level rise or fall regionally?

Answer 44

Changes in land elevation- land moves relative to sea level - Tectonic (land uplifted or subsides) - Isostatic adjustment

Question 45

Sea level fall

Answer 45

Tectonic uplift of mountain is going at a faster rate than rate of sea level rise

Question 46

Sea level rise

Answer 46

Sea level is rising at a faster rate than tectonic uplift of mountain

Question 47

Impacts of sea level rise

Answer 47

Coastal flooding Exacerbates storm impacts Accelerates coastal erosion