Friday, February 14, 2014

A quieting ocean: Unintended consequences of fluctuating economy.

            Climate change, conservation, energy, overpopulation, and pollution may be the most talked about environmental issues today. Public leaders have even down played some and voters saying, “it is junk science” or “it can be improved all the time.” Well, out all of the ones I have mentioned, I think it would be hard for anybody to down play pollution. What do you think of when you hear the word pollution? For me it is the Cuyahoga River. It caught on fire not once, but twice! It made Cleveland infamous though and it carries on today. It did spark a progression for change though. The Clean Water Act established better standards for our waterways. However, there is a different kind of pollution that does not get as much attention as say air or water. Do you ever think how noisy our environment is? How do you handle noise? Do you find noise disrupting at all?

            Lets delve a little deeper. What do you think about ocean noise? Have you ever thought about it? Mind you, we are terrestrial organisms, but marine organisms suffer the same implications from noise pollution as we do. In a 2012 publication, scientists looked at ocean noise and found correlations between ship noise, economic trends, and regulations on the shipping industry.

            Increased ocean noise poses a potential threat to marine animals that depend on sound for a myriad of ecological functions. This study was trying to better understand and reduce noise in marine habitats. The researchers used statistical correlations between regional commercial ships (ships that stayed close to California) and measured low-frequency sounds they emitted. They first looked at these ships when the economy sank (no pun intended) and then when regulations from the California legislator enacted new rules on the shipping industry. They were able to evaluate the trade-offs (and the economic costs) in noise pollution reduction with economic drivers to make additional efforts in reducing noise in the ocean.

            In the end, the statistical analysis the scientist did revealed small reductions in noise frequency with the changing economy and commerce regulations. Specifically, when one ship a day did not sail, one decibel was decreased in the area in in question. During the economic slump, noise levels were significantly reduced by about 40 hertz. They did not notice any significant change in noise levels when new regulations were impose. They did notice the great costs regulations impose on shipping (roughly $19 billion). The scientist point out that legislation needs to be focused on how ships are built and not on regulating how they run.

            In summary, the researchers focus on low-intensity, chronic noise, rather than high-intensity, short duration noise. Determining the ecological and organismal impact of these noises is difficult to document damages. This is due in large part to a very large habitat (the ocean) and organisms do not stay in one place for long. Physiological impacts are also a concern. However, as research on ocean noise continues, we will be better to evaluate it and find solutions that reduce them significantly to the point were oceanic impacts will be minimal (hopefully nothing).

Source: McKenna et. Al,: A quieting ocean. J. Acoust. Soc. Am. 132, September 2012.


  1. I enjoyed learning more about ocean noise. I never really take the time to stop and think about how noise from ships impacts the species in the ocean that are sensitive to sound and even use it as a means of communication. I think it is easy for us as humans to just look at boats as a means of transportation. Before reading this, one of the only threats I thought that boats posed to the ocean was pollution and disturbance. I had never considered noise as a disturbance before.

  2. This in interesting! I actually have thought about ocean noise recently, not the kind from ships that you talked about though. Like Alison said, I never considered the effects of noise pollution from ships and their impact on the ocean.
    I saw a show (I think on Discovery) that discussed Navy underwater sonar testing and how it was negatively affecting the nearby marine life. I also read an article that mentioned that dolphins and whales have been found with perforated eardrums, supposedly due to the low-frequency sonar.

  3. I honestly never thought about noise pollution in the ocean. In fact, I think one would assume that since the ocean can get so deep, noise would barely affect the organisms living in it at all. It's interesting to find out that it's the opposite! The only "pollution" that I thought boats gave out was air, oil, etc- definitely not noise.