Noise
Channel Islands

Why is it a concern?

A higher volume of shipping traffic and larger commercial ships have caused anthropogenic noise in the ocean to increase over the past few decades within the Channel Islands National Marine Sanctuary. In Southern California in particular, ocean noise has increased significantly since the 1960s. Although large commercial ships account for most of this increase, other sources of noise are military activities, construction, oil and gas production, and smaller boats. Effects from high decibel noise, especially at close range, can cause acute physiological effects in living marine resources, such as tissue damage in lungs and ears and ruptured or hemorrhaged body parts. Other effects include masking of important signals (such as those used for echolocation, inter-species communication, and predator-prey cues), behavioral alterations (such as changes in migration patterns or abandonment of important habitats), and adverse effects to animal energy and physiology. Additionally, fish and invertebrates may experience damage to eggs, reduced reproduction rates, and physiological or morphological damage.

There have been several studies in the CINMS investigating the acoustic environment and the different inputs to the sanctuaries "noise budget". Researchers working in CINMS are also studying the impacts of anthropogenic noise on Sanctuary ecology, for example impacts of noise on fish recruitment, foraging, and reproduction.

Overview of Research

Science Needs and Questions

• Initiate Sanctuary-wide noise monitoring, including a hydrophonic monitoring program to gauge ambient sound levels within CINMS, identify what sound sources are significant and at what levels they occur in the Sanctuary, and track changes in these values over time.
• Study hearing capabilities of Sanctuary wildlife, including further study of received sound level impact thresholds (e.g., frequency, amplitude and exposure durations that induce behavioral response, physical trauma, and cumulative impact, etc.) for individual species resident in the Sanctuary.
• Study anthropogenic noise impacts on Sanctuary ecology, including examination of effects from particular noise sources (e.g., large vessel traffic) on special biological communities.
• Research indirect anthropogenic noise impacts to Sanctuary ecology, including a more detailed understanding of the secondary ecological impacts of noise pollution (e.g., ecological consequences of possible cetacean avoidance of waters near shipping lanes, and effects of ambient noise levels on recruitment of Sanctuary fish species and their predators).

Education and Outreach Material

Anthropogenic Noise and the Channel Islands National Marine Sanctuary; How Noise Affects Sanctuary Resources, and What We Can Do About It

Discovery of Sound in the Sea offers many resources related to the issue of noise in the ocean.

Podcast on Noise and Soundscapes in National Marine Sanctuaries with Dr. Leila Hatch 

References

Haren, Angela M. "Reducing noise pollution from commercial shipping in the Channel Islands National Marine Sanctuary: a case study in marine protected area management of underwater noise." Journal of International Wildlife Law and Policy 10.2 (2007): 153-173.

McKenna, M. F., et al. "A quieting ocean: Unintended consequence of a fluctuating economy." The Journal of the Acoustical Society of America 132.3 (2012): EL169-EL175.

McKenna, Megan F., et al. "Underwater radiated noise from modern commercial ships." The Journal of the Acoustical Society of America 131.1 (2012): 92-103.

McKenna, Megan F., Sean M. Wiggins, and John A. Hildebrand. "Relationship between container ship underwater noise levels and ship design, operational and oceanographic conditions." Scientific reports 3 (2013).

Polefka, S. 2004. Anthropogenic noise and the Channel Islands National Marine Sanctuary, a report by the Environmental Defense Center. Adopted by the Channel Islands National Marine Sanctuary Advisory Council. Unpublished report.