Mapping Snapping Shrimp Noise In The Indian Ocean Region: Impact On Sonar.


The Project discusses the impact of snapping shrimp on sonar systems in the Indian Ocean Region (IOR). Snapping shrimp are a major source of high-frequency noise in the ocean and their activities and habitation in shallow waters affect the efficiency of sonar systems used for navigation and communication with other vessels.

The Project describes the challenges faced in dealing with the large band of operating frequency of shrimps and their interference with sonar, the natural phenomena and human activities affecting their habitations, and the impact of environmental factors on sonar’s performance. It also highlights the need to analyze the correlation between various parameters like frequency, depth, and transmission loss to improve sonar’s efficiency in the IOR.

Key highlights
  • The use of sonar in underwater navigation and communication has been impacted by high levels of noise in the ocean, particularly from snapping shrimp.
  • The Indian Ocean Region (IOR) is an important location for marine life, including crustaceans, but has not received as much attention as polar or temperate waters.
  • The overlap in frequency bands between sonar and snapping shrimp makes it difficult to operate sonar effectively in shallow waters where shrimp are common.
  • The impact of natural phenomena like climate change and human activities like shipping and oil drilling further complicate sonar performance in the IOR.
  • To improve sonar efficiency, it is necessary to analyze correlations between factors like frequency, depth, and transmission loss, and to use advanced modeling techniques like point processes.
Key Challenges
  • Interference of shrimp noise with sonar: The large band of operating frequency of snapping shrimp overlaps with sonar frequency, making it difficult for sonar to operate effectively.
  • Effect of natural phenomena: Climate change and global warming are affecting the habitat of snapping shrimps, leading to variations in their behavior and distribution.
  • Transmission loss: The speed of sound varies with depth, and rains produce high ambient noise, which adds up to transmission loss, reducing sonar’s capability.
  • Three-dimensional sound transmission: Sound transmission in the ocean is three-dimensional, and transmission loss versus horizontal range alone is not sufficient information for most operational situations.
Major Opportunities
  • Developing new techniques to reduce noise and improve sonar performance in the presence of shrimp noises.
  • Conducting further studies on shrimp noises to better understand their impact on communication between vessels and fine-tune sonar parameters accordingly.
  • Using soundscapes to map shrimp locations in the seabed, which can act as acoustic screens for submarines and other vessels.
  • Investing in research and development of more effective and powerful underwater telemetry systems to enhance national security.

“Many studies and researches indicate that increase in biological noise in ocean decreases the detection range of sonar drastically.”

Shreyash Gupta, Dr(cdr) Arnab Das