Ship strikes of whales have been recognized as a growing concern worldwide. Documented ship strikes from NOAA National Marine Fisheries Service data from 1988-2011, occurring just within the Gulf of the Farallones and Cordell Bank sanctuaries region, total 20 whales killed by ships (i.e., death caused by vessel collision or carcass exhibited signs of trauma consistent with vessel collision) and an additional 10 injured and possibly killed (i.e., collision observed, but final status unknown). The true number of ship strikes could be at least 10 times higher than the number documented.
Anthropogenic noise in the ocean, including off the California coast, has increased exponentially over the past 60 years, largely due to the increased number, size, and tonnage of vessels in the commercial fleet. The sanctuaries, given their coincidence with the Traffic Separation Scheme adjacent to San Francisco Bay ports, are especially susceptible to increased amounts of anthropogenic noise. Commercial vessels are responsible for relatively loud, low-frequency underwater noise. This ship noise overlaps significantly with the frequency range used by many cetacean species, especially with low-frequency vocalizers such as blue, fin, humpback, and grey whales, and can cause what is known as masking. Masking occurs when increased levels of background noise reduce an animal's ability to detect relevant sounds and can hinder prey detection and reduce the range of communication.
Protecting endangered species and sanctuary resources is a priority issue for the National Oceanic and Atmospheric Administration. As of November 2014, Greater Farallones National Marine Sanctuary has taken the following steps to reduce the risk of vessel strike to whales:
The Traffic Separation Scheme was modified at the approach to San Francisco Bay on June 1, 2013. Next steps include:
- Promote studies to be performed by students and non-sanctuary researchers to provide research and analyses to determine the level of compliance by commercial vessels to modified lanes.
- Continue to monitor whales through ACCESS and analyze probability of co-occurrence within the sanctuaries.
- Determine if the northern lane is providing optimal protection to whales by reducing co-occurrence of ships and whales in the Traffic Separation Scheme using ACCESS data and analyses lead by non-sanctuary researchers and students.
Greater Farallones and Cordell Bank sanctuaries are experimenting with targeted voluntary speed reductions this whale season (2014-2015). NOAA is requesting vessels slow-down to ten knots or less only in one of the three lanes at the approach to San Francisco Bay. Voluntary speed restrictions are based on near real-time data and are limited to smaller areas, which may make cooperation from commercial vessels more feasible. Next steps include:
- Assessing the level of cooperation to voluntary speed reduction requests
- Conducting cost-benefit analysis of level of cooperation vs. expense of real-time monitoring and staff resource needs
Greater Farallones sanctuary and the West Coast Region have communicated with shippers through the following methods:
- Broadcast and Published Local Notice to Mariners
- Whale Alert 2.0 - a smart phone application developed by Conserve IO, which is intended to be used by whale watching enthusiasts to document whale sightings in real-time. This information can be used to identify large groups of whales, not previously observed by researchers and can assist managament by defining areas where targeted assessment can be focused.
- Education/outreach poster for ship's bridge developed in collaboration with National Marine Fisheries Service and the Pacific Merchant Shipping Association.
- Letters to agents and shipping lines asking for cooperation with voluntary speed restrictions.
- Maintenance of an email listerve that provides updates on whale season, sightings, strikes, and voluntary speed reduction requests.
- Broadcasts over NOAA Weather Radio
The West Coast Region Sanctuaries with several partners (National Marine Fisheries Service, Pacific Merchant Shipping Association, Point Blue, Conserve IO, International Fund for Animal Welfare, Cascadia Research) have been implementing a near-real time whale sighting network through these methods:
- Whale Alert 2.0 - (described above). Spotter Pro - smart phone/tablet application for researchers and naturalists to document whale sightings in near-real time, which includes a level of search effort vital to determine where areas that were searched and zero whales were observed.
- Opportunistic Aerial Surveys - using USCG cooperative hours to determine locations of high levels of whales and to determine when request for voluntary speed reductions should be cancelled.
- Commercial Vessel Observations -National Marine Fisheries Service, working with Cascadia Research, has conducted ride-alongs on commercial vessels to spot whales in the shipping lanes. Funding is limited, but preliminary data indicates that these vessels are very valuable observation platforms.
- Whale Watch Vessels - Interpretative staff on whale watch vessels provide whale sighting information through Spotter Pro. This has limited viability due to the low levels of commercial whale watching companies in our region.
Channel Islands National Marine Sanctuary is experimenting with an incentive program to slow vessels down (which will also reduce underwater noise). Funding is minimal and through a one-time grant. GFNMS will review the results of this incentive program.
Greater Farallones sanctuary is partnering with Point Blue and Cordell Sanctuary to continue ACCESS cruises to compile and analyze daytime whale sightings data.
Greater Farallones sanctuary is working with San Francisco State University faculty and Point Blue to identify geography graduate students to analyze AIS data and determine the response by shippers to voluntary vessel speed requests in 2012-2014
Cordell Bank National Marine Sanctuary is close to being a node for establishing baseline soundscapes in the sanctuary through passive acoustic monitoring.
Additionally, National Marine Fisheries Service is developing acoustic guidance for assessing the effects of anthropogenic sound on marine mammal species. The guidance provides acoustic threshold levels for onset of permanent threshold shift and temporary threshold shifts for all sound sources. Greater Farallones sanctuary is tracking this process and intends to move forward with NOAA on this issue.
For more information on what NOAA is doing to protect whales from ship strikes, visit our national site.