The International Maritime Organization (IMO) has adopted the first-ever comprehensive guidelines on shipping noise.  The voluntary guidelines mark the first step toward a longer-term goal of bringing noise factors into planning for both ship design and shipping routes.

This marks the successful completion of a six-year process, largely spearheaded by NOAA, the US Coast Guard, and their German counterparts at IMO. The US Chamber of Shipping, a trade organization, has also been engaged from the start.  While the guidelines are voluntary, leading some observers to question their value, it is expected that many key players will begin to work with the guidelines in coming years. In general, the shipping industry is far more willing to design new ships to be quieter, than to retrofit older ships. Ed. note: one fascinating insight from the early IMO process was that global shipping noise may be dominated by relatively few unusually loud ships in each size class. 

In this ocean noise map created by NOAA, the darkest areas represent noise about 60dB above natural ambient levels

As summarized by NRDC, the new guidelines mark a milestone in ocean noise awareness on several fronts, as they:

• recognize that shipping noise can have short-term and long-term impacts on marine life, especially on marine mammals;
• call for measurement of shipping noise according to objective, available international standards;
• identify computational models for determining effective quieting measures;
• provide guidance for designing quieter ships and for reducing noise from existing ships, especially by minimizing the roar produced by ship propellers, in a process known as cavitation; and
• advise owners and operators on how to minimize noise through ship operations and maintenance, such as by polishing ship propellers to remove fouling and surface roughness.

UPDATE, 6/4/14: In 2012, the International Organization for Standardization (ISO) developed formal standards for the measurement of underwater sound from ships.  ISO standards provide detailed specifications that assure consistency in what is being measured (frequencies, reporting metrics), and how (distance from sound source, conditions, etc.).  Combined with the IMO guidelines, shipping companies now have the tools they need to provide clear information on the noise footprint of their vessels and the design choices they make to reduce noise; although neither the IMO nor ISO specify specific limits or targets for ship noise, they provide standardized ways of reporting on the noise of ships.  RINA Services, which provides a wide range of independent marine certifications, has just added a new voluntary notation, DOLPHIN, that combines the IMO and ISO reporting standards, and gives shipowners a third-party certification option to specify commercial vessels which have implemented solutions to minimize radiated underwater noise.

Earlier this month, Leila Hatch, one of NOAA’s leading experts on ocean acoustics and a long-time researcher in and around Stellwagen Bank National Marine Sanctuary, presented an hour-long talk on ocean noise.  It’s been archived on the Open Channels website, and is available for streaming and download on Vimeo.  

It’s by far the best introduction I’ve seen to this wide-ranging topic, including some basic information on ocean noise, along with a good summary of ongoing work at NOAA to map ocean noise and to learn more about how shipping noise, in particular, can impinge on whales’ communication space. Highly recommended!!

Listening to our Sanctuaries: Understanding and Reducing the Impacts of Underwater Noise in Marine Protected Areas from OpenChannels on Vimeo.

Deepwater Wind, which recently won the first-ever competitive lease auction for US offshore wind, has signed an agreement with a consortium of environmental organizations that affirms its intention to minimize potential impacts on critically endangered Right whales. The wind farm’s location, in Rhode Island Sound, is host to foraging Right whales each spring; the agreement delays any pile-driving activity until after May 1, when whales have generally moved north.  In addition, pile driving later in the year will take place only during the day, when any lingering whales can be more easily seen.

The agreement marks an important step forward in marine conservation, with wind energy developers agreeing to key provisions that the Navy and oil and gas exploration companies have resisted: changing their operational schedule to avoid times of particular biological importance in a given area, and agreeing to limit loud noise-making activities to daylight hours.

The current agreement covers pre-construction activities, including pile-driving five foundations, for meteorological towers and perhaps test turbines (the press release does not specify). The Deepwater ONE wind farm will ultimately be home to 150-200 turbines; construction of that phase of the project will create a significant noise footprint, and we will hope that the company agrees to continued protective conditions at that time. A similar agreement by Deepwater for its smaller 5-turbine Block Island Wind Farm does cover the actual construction period; that press release does not mention daylight-only construction, but does delay construction until May. However, a broader agreement between environmental groups and several wind developers does include a provision precluding pile driving at night or in heavy fog; one hopes that this good-faith agreement will indeed be reflected in actual final operational plans.