1. Marine environmental awareness course
Underwater noise
Name – Date

2. Shipping noise Contents Introduction Use of sound underwater
Sources of underwater noise
Impacts of underwater noise
The role of shipping
Solutions 2
Photo credits: P. Gallego/North Sea Foundation

3. 1. Introduction Marine animals use sound underwater
Ships became motorized and grew in size: human-related underwater noise increased
Underwater noise interferes with the use of sound by animals
Difficult for animals to avoid disturbance
Photo credits: Rijkswaterstaat/North Sea Foundation

4. 2. Use of sound underwater
In the ocean, visibility is limited
Sound travels faster and further in water
Marine mammals use sound as a primary sense
Photo credits: NOAA’s Ark, animal collection / Karen Varndell 2008, Marine Photobank

5. Use of sound by marine mammals
Communication
To maintain social order
To attract mates
To demonstrate fitness
Bond between calf and mother
To stimulate cooperation
To warn for danger
Echolocation
Navigation
Photo credits: NOAA’s Ark, animal collection / ProSea

6. Use of sound by other animals
Many species of fish and invertebrates use sound
to attract mates
to ward off predators
Toadfish
Spiny lobster
Photo credits: NOAA’s Ark, animal collection

7. 3. Sources of underwater noise
Natural sources
Biological
Physical
Human activities
Photo credits: ProSea / Rijkswaterstaat / North Sea Foundation

8. 4. Impacts of under water noise
Human produced sounds cause problems:
Loud background noise
Same-frequency sounds
Masking of important sounds
Treshold shift
Sudden pressure change
Change of behaviour
Ship strikes
Photo credits: NOAA Maryland Department of Natural Resources

9. Source: R. Kastelein

10. 5. Role of shipping Past decades: more and bigger ships
Large ships produce relatively loud and low-frequency sounds
Photo credits: North Sea Foundation / ProSea

11. Shipping increases underwater background noise in general
Frequency band of vessel noise, 10Hz – 1 kHz, overlaps with the frequencies generally produced by whales, seals and sea lions
Illustration credits: NOAA

12. 6. Solutions Underwater noise of shipping not regulated
Recognised as an issue by IMO – MEPC
Technically possible to construct quieter ships, including adaptions to propellers

13. Questions?