Marine Noise Flashcards
What are ADCP?
Acoustic dock current profilers
What is the distance from pile driving that causes TTS in cetaceans?
10m
What has noise in the north sea caused harbour porpoises to do?
Louder voalisations
What do naval sonars cause in whales?
Rapid decompression
What is the distance from pile driving that causes PTS in cetaceans?
5m
What is a decibel?
Logarithmic unit used to express ratio between two values of a physical quantity
What is sea state?
How rough the surface of the sea is
What does the sea bed do to sound?
Absorb, reflect or refract
What is the main sense for marine organisms?
Hearing
What are sources of human noise?
Boat traffic, sonar, resource extraction, fisheries
What legislation is there against noise?
No specific legislation
What type of frequencies travel further?
Low
What is the distance from pile driving that causes PTS in pinnipeds?
20m
Where abouts in water does sound travel faster?
Near the surface
What can cause cause?
Displacement
What is the wenz curve?
Determines sea state
What is the problem with the frequencies of seismic surveys?
Energy spills out into high frequencies
What are sources of natural noise?
Earthquakes, ice, turbulence, waves, rain, bubbles, marine line
What can be done whilst we wait for legislation against sound to come in?
Ramp up sound levels, acoustic deterrents
What is sound?
Pressure wave
What do MMOs do?
Stop activity when animals are seen or heard in the zone of influence
What is MSFD?
Marine strategy framework directive
What does ADCPs do?
High frequency sounds to measure ocean currents
What is the distance from pile driving that causes TTS in pinnipeds?
40m
What does sound need to make it noise?
Context
What are naval sonars used for?
Find other people under the water
What does the airgun in a seismic survey do?
Sends high energy sound into seabed to find oil
What are behavioural changes caused by noise?
Vocalisation, surfacing patters
What is PTS?
Ear is so damaged so the threshold is pushed
What are the 2 types of death caused by noise?
Stranding/bends
What is the problem with PTS and TTS?
Not hearing conspecifics to mate, not being able to perceive predators
What are the 2 types of injury?
Permanent or Temporary Threshold shfits
What is TTS?
Ability to perceive sound changes based on experiences you’ve just had
Why does water propagate sound better?
Properties
What does low frequency sound travel through?
Deep sound channel
Where is noise from shipping most concentrated?
Around ports and shipping lanes
What are some impacts of sound?
Death, Injury, Stress, Changes in behaviour, Masking
How do naval sonars work?
Beams out sound at different frequencies and determines where other boats are
What does PTS mean?
Permanent threshold shift
What do particles in sound do?
Oscillate
What can affect the propagation of sound?
Temperature, salinity, pH
How has sonar being linked to causing death?
Gas bubbles in the liver - rushing up to the surface because of shock
What does construction cause in marine mammals?
Temporary displacement from wind farms
What does shipping mostly contribute?
5-500Hz
What is descriptor 11?
Thresholds about noise in ports not exceeding a certain number of decibels
What are MMOs?
Marine mammal observers
What is the range that construction should be built away from animals?
100m
Which descriptor in MSFD is in relation to noise?
Descriptor 11
How is hormone concentration in whales tested?
From poo
How doe seismic surveys work?
Sound bounces off sea bed, heard by receivers and processed on a boat
How can climate change alter the propagation of sound?
Warmer water, more carbon
Where does most noise from shipping come from?
Propeller rotation, flow noise, engine, dynamic positioning
What is noise?
Unwanted sound
What does TTS mean?
Temporary threshold shift
What does shipping cause in right whales?
Stress
How much faster does noise travel in water compared to air?
5 times
What is sound comprised of?
Longitudinal waves and oscillating particles
What is frequency dependent on?
Body size
Why is ramping up sound better?
Scares off animals - not physically injur
What is masking?
When noise interferes with organism’s ability to hear
What is sound refracted or compressed by?
Boundaries of the sea
What are ATOC?
Acoustic thermometry of oceans climates
What are seismic surveys most used by?
Oil industry
How is sound used in scientific research?
Play back experiments - how the brain responds to different sounds
What are MMOs on?
Naval and seismic vessels
What does the wenz curve predict?
Average number of noise inputs into the sea
What kind of frequency does a sound with short wavelength have?
High
What does Hz mean?
Signal running at one cycle per second
