Marine mammal scientists are stepping up calls for action to safeguard whales in Latin American waters and around the world, citing rising threats to the animals along their migratory routes.

They point to a recent analysis in which experts collaborating with the conservation group World Wildlife Fund (WWF) highlight the need to protect “blue corridors”—migration routes that include habitat where whales feed, mate, give birth and nurse their young.

The analysis taps three decades of tracking information on over 1,000 migratory whales from more than 50 research groups at institutions including Oregon State University, the University of California, Santa Cruz and the University of Southampton. Published in February, it outlines how whales are encountering increasing threats in their critical ocean habitats.

“Cumulative impacts from human activities—including industrial fishing, ship strikes, chemical, plastic and noise pollution, habitat loss, and climate change—are creating a hazardous and sometimes fatal obstacle course,” said Chris Johnson, Global Lead for whale and dolphin conservation at WWF, when the report was issued on Feb. 17. “The deadliest by far is entanglement in fishing gear, killing an estimated 300,000 whales, dolphins and porpoises each year. What’s worse, this is happening from the Arctic to the Antarctic.”

Scientists agree these hazards are why six whale species are now classified as endangered or vulnerable by the International Union for Conservation of Nature. They say whale populations have not recovered as hoped following the approval of a moratorium on commercial whaling in 1986 by the International Whaling Commission (IWC), the United Nations agency that oversees the conservation of whales. Among the more alarming examples is the plight of the critically endangered North Atlantic right whale (Eubalaena glacialis), whose population has reached its lowest point in 20 years—only 336—according to the WWF report.

In Latin America, the humpback whale (Megaptera novaeangliae), though not currently listed as endangered, is the focus of concern largely because its preference for relatively shallow coastal waters puts it in the path of harmful human activity. “From 2016 to date we have registered 236 whales trapped in [fishing] nets,” says Eduardo Nájera, WWF Mexico’s coordinator for marine habitats, referring to data from Mexico’s Pacific coast. “Of these, 88% were humpback whales. This year alone we have rescued six whales from nets.”

Volunteer rescue squads
Humpbacks migrate between their Alaska feeding grounds and Mexico’s Pacific waters, where they give birth and raise their young from December to April. Mexico is not the only place where they risk entanglement. Nájera recounts how a humpback whale rescued by volunteers in Nayarit state’s Bahia de Banderas, had been dragging a buoy that was later traced to an Alaskan crab fishery.

Green groups in Baja California have protocols for rescuing whales that run afoul of fishing gear. They draw on some 180 volunteers to conduct rescues, typically using poles with blades at the tip to cut away netting or buoy lines. Rescues can last eight hours as volunteers struggle to free the mammals, which are stressed and in many cases injured.

“It is a high-risk job that requires special training as some of the species weigh the equivalent of four or five cement trucks,” says Nájera. “While volunteers have a great attitude and we are constantly improving [rescue] strategies, the challenge is to take it to the next level so these teams are made up of permanent staff. But funding for that has not been available.”

To reduce whale deaths from ship strikes, conservation groups are calling on the International Maritime Organization (IMO), the UN agency that regulates global shipping, to do more to prevent such collisions. The IMO has imposed ship reporting requirements in certain regions and adjusted certain shipping-lane routes. Such measures are proposed to the organization by regional or national authorities and must win a simple-majority vote of the IMO’s 175-member states to be approved. “If [IMO members] decide to adopt a country’s proposed measure, ships from all flag states have to adhere to those rules within that nation’s waters,” says Natasha Brown, spokesperson for the IMO.

Unreliable enforcement
A major drawback, however, is that the IMO does not conduct the monitoring or enforcement needed to implement the measures it adopts, leaving each country to do so. In 2014 the IMO adopted a recommendation for ships to reduce their speed to 10 knots in Pacific waters near Panama from Aug. 1 to Nov. 30. However, the measure was not granted mandatory status, notes Héctor Guzmán, a senior staff scientist at the Smithsonian Tropical Research Institute who helped develop and present the Panamanian proposal.

“Following implementation, we carried out our own research to see how effective the measure was and found that fewer than 80% of the ships were adhering to the recommendation,” says Guzmán. “If science and research present the facts and we are aware there is a problem, why are there so many requirements involved in adopting measures that we know would help and are desperately needed? Instead of complicating the process, the IMO should be using the information that is already available to create regional and sub-regional maritime plans, rather than waiting for each country to approach them. They should be actively approaching regions.”

Juan Capella, a marine biologist and chief scientist at Whalesound, a whale research organization based in Punta Arenas, Chile, expresses similar frustration. Capella says whale conservation throughout South America has been hobbled by what he describes as a slow and complicated process to establish safeguards.

In the Magellan Straits of southern Chile, where vessels must navigate among hundreds of islands, “the geography does not leave room for route changes to avoid natural habitats,” he says. “However, reducing shipping speed would certainly reduce the risk of collision with marine mammals, yet the measure remains at the discussion stage in the IMO. It could take months or years to be adopted.”