by David Mattila
Whales have been getting entangled in man-made ropes and nets, probably, since the first fishermen began to use these materials to catch fish thousands of years ago. However, before the advent of synthetic materials large whales likely ripped through this gear; any that was carried away with them may have deteriorated before it could become life-threatening. But with the introduction of strong synthetic ropes and nets after World War II, whales were more susceptible to being held by the gear and drowned. Even if they broke free, any gear remaining on the whale (even a single tight wrap of rope) could stay with them for years, sometimes causing a protracted death. Fishermen have certainly released whales if they found them entangled in their gear as, at the very least, they did not want to lose their gear. (Fishermen, in fact, are the only individuals known to have lost their lives while trying to release an entangled whale.)
In 1979, Dr. Jon Lien began the first formal whale release program, in Newfoundland, Canada. His motivation was both to save endangered whales, and to save fishermen the hardship of lost or heavily damaged gear. New techniques were developed in 1984 by the Provincetown Center for Coastal Studies (PCCS) for removing gear from free-swimming whales, and new research techniques have been developed to understand the scope and impact of large whale entanglement.
Extrapolating from fisheries observer records, it has been estimated that 308,000 whales, dolphins and porpoises (collectively “cetaceans”) die each year as bycatch; however, estimates for large whales were recognized to be low. A significant advance was made through the studies of characteristic wounds and scars on surviving whales conducted by the New England Aquarium and PCCS on populations of New England right and humpback whales. Using the data collected by New England researchers and disentanglement teams, it was estimated that the average time that it took an entangled North Atlantic right whale to die, if not rescued, is six months. The cause of death in these cases was often a slow deterioration due to starvation, or chronic infection.
In 2007, Norway brought this serious welfare issue to the attention of the International Whaling Commission (IWC). The IWC is the only global intergovernmental organization dealing with all conservation and management issues related to large whales. For several decades, the IWC’s scientific committee had been investigating the scope and impact of large whale entanglement as bycatch, but this was the first time that the welfare aspects of this issue were brought to the attention of the member countries. As a result, Australia, Norway and the United States convened several meetings and workshops in order to understand the global scope and impact of this problem, see what various countries might be doing, and determine what the IWC might do to resolve it. Two workshops convened the directors of all existing formal entanglement response programs (i.e., Australia, Canada, New Zealand, South Africa, United States), and several consensus agreements were produced.
Firstly, after reviewing all of the best current information available, it was agreed that this problem occurs anywhere that whales of any species encounter entangling materials (rope, net and certain debris) in the water column. But due to the strength and mobility of whales, and the lack of reporting infrastructure, the vast majority of entanglements occur unobserved and/or unreported. The experts also realized that, while preventing entanglements is the ultimate answer and goal, in the meantime there needs to be a serious initiative to build capacity in most coastal nations—both to help whales immediately and to gather information in order to make progress toward the ultimate goal of prevention.
The response program directors recognized that in addition to conservation, animal welfare, and economics, there is another pressing reason to undertake the capacity building. That is that more and more frequently, due in part to increased visibility on the Internet and through social media, well-meaning but untrained people are attempting to release entangled whales, resulting in many serious injuries and near-fatal interactions. These attempts, as with releases by fishermen, also often leave a small but lethal wrap on the whale, and if any information is gathered, it is of little use toward prevention. Professional disentanglement programs—as they work to release individual whales—place a high importance on gathering information that will ultimately lead to solving the problem.
Thus, a panel of expert advisors was formed to (1) establish principles and guidelines for entanglement response (“best practices”), (2) develop a strategy and curriculum for building capacity, and (3) advise the 88 countries of the IWC. This panel, its principles and guidelines, and the capacity building plan were formally endorsed by the member countries at the 2012 IWC meeting in Panama. The principles and guidelines apparently represent the first such internationally agreed upon “best practices” for the rescue of any marine animal. To help carry out this initiative, the United States “loaned” one of the experts (the author) to the IWC Secretariat for two years.
Since the establishment of this initiative, and working formally through the appropriate governments and agencies, over 500 scientists, conservationists, government managers, and others have been engaged in over 20 countries—including Argentina, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Ecuador, Korea, Mexico, Norway, Panama, the United Kingdom, and many South Pacific Island countries. The first step is to provide an overview seminar for scientists and governments, followed by detailed training and assistance with setting up entanglement response networks, if requested. These have been conducted for Argentina, Brazil, Ecuador, Mexico and the United Kingdom. Over the remainder of this year, more detailed training is scheduled for Panama and the French- and English-speaking Caribbean. It is hoped that this initiative may become a permanent part of the work of the IWC, as there are many other areas where capacity building is urgently needed (e.g., Africa, Asia, Indonesia, the Middle East, and other parts of Europe and the Americas).
However, even in areas with long-standing effective entanglement response networks, we know that only 1 in 10 entangled whales are reported. Some of these may free themselves (and receive telltale wounds), but others are never seen and/or reported. And so, prevention of entanglements in the first place is clearly the answer. Fortunately, gathering relevant information and stimulating ideas for prevention are part of both the “best practices” and the capacity-building curriculum. Therefore, as the capacity to respond is expanded, so is the pool of motivated responders who may ultimately come up with the best information and ideas that lead to solving this global conservation, economic, safety, and welfare problem.
David Mattila got started studying whales thanks, in part, to a grant from AWI’s founder, Christine Stevens, agreed to over a cup of tea in 1977. Since then, he has studied humpback whales throughout many of the world’s oceans, worked with Stormy Mayo—now director of the Right Whale Habitat Studies research project at PCCS—to invent techniques to release entangled free-swimming whales (1984), and assisted the National Oceanic and Atmospheric Administration (NOAA) to form the Atlantic Large Whale Disentanglement Network (1996). In 2001 he was hired as research coordinator by NOAA’s Hawaiian Islands Humpback Whale National Marine Sanctuary and, with Ed Lyman, established the entanglement response network there. In 2011 he was loaned (seconded) by the United States to the IWC Secretariat, in order to work on the initiative described in this article.
IWC workshop reports with agreements, recommendations, best practices and strategy for capacity building can be found at:
A good description of the disentanglement technique can be found at:
For accurate video documentaries about disentanglement:
Entanglement response in other countries: