2008-2009 Disentanglement Season Summary

Background Information

The Hawaiian Islands Humpback Whale National Marine Sanctuary (HIHWNMS) receives, and when appropriate, responds to, reports of humpback whales, and other marine animals in distress. The Sanctuary works closely with NOAA Fisheries’ Pacific Islands Regional Office (PIRO) and their Marine Mammal Response Network, Hawaii’s Department of Land and Natural Resources, NOAA’s Office of Protected Resources and their Marine Mammal Health and Stranding Program, the United States Coast Guard, and NOAA’s Office of Law Enforcement. The Sanctuary works under NOAA Fisheries’ Marine Mammal Response Program and Hawaii’s Department of Land and Natural Resources, but leads and coordinates response efforts involving entangled humpback whales around the main Hawaiian Islands through a community-based network. The Hawaiian Islands Disentanglement Network (HIDN) is a collaborative effort between, the state and federal agencies already mentioned, local whale researchers, the tour industry, fishermen, and many private citizens. The primary objectives of the Network are to provide safe and authorized response to entangled large
whales (hopefully freeing some from life threatening entanglements in the process) and to gather valuable information from these response efforts that may mitigate entanglement threat and other threats, like ship strikes, in the future. NOAA Fisheries’ Marine Mammal Health and Stranding Response Program (MMHSRP; permit # 932-1489-08) authorize all marine mammal response efforts in the US.

	HIHWNMS, MMHSRP Permit #932-1489

The Hawaiian Islands Disentanglement Network, now in its 8th season, comprises over 120 members who have received various levels of training in order to support large whale response efforts statewide. More than 163 hours of training have been provided since 2002. To support the Network’s response efforts, caches of specially designed equipment have been established on the islands of Hawaii, Maui, Oahu, and Kauai.

	Figure 1: Entanglement threat outreach and training effort
	Ed Lyman

To date, the Sanctuary has received over 255 reports of marine mammals in distress and the Network has mounted more than 100 (on-the-water or in-the-air) responses1. In a majority of these reports (130) the observer indicated that the animal was entangled. Sixty-four (64) of the entanglement reports were confirmed as truly involving entangled humpback whales and represent as many as 41 different animals. Since 2003, the Network has freed 11 humpback whales of gear, and responded and assessed 3 animals as not having life threatening entanglements. Unfortunately, the Network has responded on numerous occasions only to not locate the entangled animal. The biggest contributor to an unsuccessful response is not being able to re-locate the animal. If there is no standby vessel, then an entangled whale ends up being a rather large needle in an even larger haystack.

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	Figure 2: Humpback whale entanglement reports by season
	Ed Lyman

The Network does not or cannot respond to every report of an entangled whale. Past responses and thorough vetting of initial entanglement reports has shown that approximately 50% of reports here in Hawaii were misreported or could not be confirmed. Examples of misreports include: white-flippered humpback whales interpreted as carrying gear; animals in the proximity of gear, but not entangled; reflections off the wet backs of animals interpreted as buoys; calves being interpreted as gear; and surface behaviors, like breaching, being interpreted as animals trying to throw an entanglement. In addition, many reports come in too late in the day, represent animals too far offshore, or in conditions that are not conducive (e.g. rough sea state) for mounting rescue efforts. In those cases when an on-water response should and could be mounted, the Network has a 44% success rate freeing entangled humpbacks of all or significant amounts of gear.

	Figure 3: On-water/air entanglement responses by season
	Ed Lyman

Since 2003, the Network has removed nearly 3,000 feet of entangling gear from humpback whales in Hawaii. Animals have been confirmed entangled in local fishing gear (traps and net), mooring gear, marine debris, and actively fished gear set as far away as Alaska. To date, 8 humpbacks reported entangled in Hawaii have been confirmed to have gear from Alaska. Six of these represent commercial pot gear. The greatest known straight-line distance (accounting for obstacles) a whale may have carried gear is over 2,400 nm (between Wrangell, Alaska and the island of Maui).

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Summary of 2008-2009 Season Disentanglement Reports and Efforts

~ As many as 8 humpback whales reported and confirmed entangled in gear.

~ Six of the 8 entangled animals were initially sighted within the Sanctuary.

~ Most of the reports and initial sightings were in the lee of Maui (3 off Maui, 1 off Kauai, 1 off Oahu, 1 off Lanai, and 2 off the island of Hawaii).

~ Six reports involved adults and 2 were subadults.

~ The Sanctuary mounted 12 on-water responses to five of these reports.

~ The United States Coast Guard mounted at least 5 responses towards entangled whales. On two occasions Coast Guard transported crew and gear, and provided standby support towards rescue efforts. Aerial support was provided on at least two events.

~ Research organizations, Hawaii Marine Mammal Consortium, Center for Whale Studies, Whale Trust, Hawaii Whale Research Foundation, Hawaii Institute for Marine Biology, and Jupiter Foundation, assisted on numerous occasions.

~ Tour industry platforms from Pacific Whale Foundation, Blue Hawaiian Helicopters, Hawaiian Rafting Adventures, Maui-Molokai Sea Cruises, Maui Dive Shop, and Sunshine Helicopters assisted a record number of times and were instrumental in providing multiple sightings that allowed for multiple response efforts.

~ Support was also provided by Hawaii’s Division of Aquatic Resources (Kona office), Kahoolawe Island Reserve Commission (KIRC), and Molokai Air.

	Figure 4: Initial reports of entangled humpback whales
	Ed Lyman

During the 2008/2009 humpback whale season (November 1, 2008 – May 10, 2009), the Sanctuary received 64 reports of distressed animals; 25 of these involved entanglements. Nineteen (19) reports were confirmed as entangled humpbacks, representing as many as 8 different animals. While the total number of reports of entangled whales and number of different animals was on par with many past season, the number of confirmed entanglement reports was much higher. Much of the difference was due to fewer misreports and a greater number of repeat sightings (re-sights) compared to past seasons. In the past, approximately 50% of the reports were unconfirmed either due to lack of information or misreporting. However, only 6 reports were unconfirmed this season, representing only 25% of the reports. The increase in confirmed reports and re-sightings may be a result of an increase in outreach (see figure 1) and community involvement. Nearly 20 hours of dedicated outreach on entanglement threat and response was performed, in addition to continued use of a disentanglement website and email alerts.

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The Network mounted 23 on-water and in-air responses to entangled whales this past season. This represented twice as many responses compared to the average number of responses (avg= 11.25, n=45) over the past several seasons. The greater number of responses was also likely due to the increase in reporting and higher quality of reports. One animal first sighted off the Big Island on March 20 was re-sighted on 8 different occasions (see figure 5). Thus, the greater number of response efforts in part represent the greater number of multiple efforts put into some of these animals. In fact, all three humpback whales that were actually worked on involved multiple efforts. Two of the 3 animals were freed of significant amounts of gear, 3 animals were not re-located, 1 animal could not be responded to (reported several days later), 1 was partially freed by a fisherman, and 1 animal was not freed of gear even though rescue efforts were attempted on 3 different occasions.

	Figure 5: Re-sight locations of entangled humpbacks
	Ed Lyman

Once again, the Network received considerable assistance from the on-water boating community. For instance, many of the initial reports and re-sights were called in by tour boats. Many whale research organizations, including Center for Whale Studies, the Hawaii Marine Mammal Consortium, Hawaii Whale Research Foundation, Hawaii Institute for Marine Biology, and Whale Trust, also played an important role in relocating, assessing, documenting, and standing by entangled animals. The US Coast Guard once again provided both surface and aerial assets that were instrumental in many marine mammal response and rescue efforts. They also assisted the Sanctuary directly with vessel operations. Blue Hawaiian Helicopters and Sunshine Helicopters provided valuable aerial support. These groups and organizations made the difference between not responding to these distressed marine mammals and providing a professional, safe, and many times, successful response to reports to entangled and ship-struck animals. Mahalo.

Read about the specific entanglement cases from the 2008-2009 whale season.


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