Human Noise

Question 0

What is sound and how is it measured?

Answer 0

Sound is a pressure wave measure in frequency

Question 1

How much faster does sound travel underwater than in air?

Answer 1

5 times faster

Question 2

What can affect sound propagation in water?

Answer 2

Water temperature, salinity and pH

Question 3

Water can be reflected, compressed or refracted at what boundaries?

Answer 3

Bottom, surface or thermocline

Question 4

Natural noise sources include?

Answer 4

Earthquakes, ice, break waves, rain on the surface, bubbles and spray

Question 5

Human noise sources include?

Answer 5

Shipping, seismic surveys, naval activities, recreation, science, fisheries and construction

Question 6

Shipping contributes noise at what frequency?

Answer 6

5-500 Hz (low)

Question 7

Seismic surveys work at what frequencies?

Answer 7

Concentrated at <300 Hz but spills out into higher frequencies (up to 15kHz)

Question 8

Naval sonar uses what kind of sound?

Answer 8

Mid-low frequencies

Question 9

Construction noise includes…

Answer 9

Detonations and pile driving (100Hz - 10kHz)

Question 10

ADCP

Answer 10

Acoustic Doppler current profiler - high frequency sound to measure ocean currents

Question 11

ATOC

Answer 11

Acoustic thermometer of the oceans climate

Question 12

Impacts of noise on marine life…

Answer 12

Death (stranding), injury (PTS + TTS), increased stress, changes in behaviour and masking

Question 13

Many species are protected under what law?

Answer 13

Habitats Directive (EU) and Marine Mammal Protection Act (USA)

Question 14

What are the attempts to mitigate human noise?

Answer 14

MMOs on naval and seismic vessels, sounds stop when marine mammals are sighted
Acoustic deterrents around pile driving
Avoidance of critical times and locations

Question 15

What are two examples of increased stress levels in marine animals?

Answer 15

1. Increased stress in whales from shop noise

2. Reduced growth and reproduction in brown shrimp

Question 16

EIAs

Answer 16

Environmental Impact Assessments - monitoring and mitigation often required under these assessments

Question 17

How is sound propagation altered by climate change?

Answer 17

Carbon dioxide emissions make it more transparent to low-frequency sound

Question 18

Why is sound important on the sea?

Answer 18

Travels 5x faster than in air and is main sense for marine animals as light only penetrates the shallow depths

Question 19

What do marine organism use sound for?

Answer 19

Prey location
Navigation
Mate attraction
Socialising

Question 20

Human noise overlaps what?

Answer 20

All species sound from fish to mammals

Question 21

What do TTS and PTS stand for?

Answer 21

Temporary and Permanent Threshold Shift

Question 22

Increase a stress can cause what 3 major changes in behaviour?

Answer 22

Displacement
Vocalisations
Surfacing patterns

Question 23

MSFD

Answer 23

Marine strategy framework directive - puts threshold in place for marine noise in selected but can’t fine anyone for breaking this threshold