This week marks the 40th anniversary of the global moratorium on commercial whaling, a momentous achievement that turned the course for long persecuted cetacean species. Slow to reproduce, whales were nearly wiped out altogether in the 20th century, with an estimated three million killed for profit.

I gave my heart to the campaign for whales at an early age, and I have spent a good portion of my life as an advocate for them. As a child living in a Massachusetts coastal town, I wrote a short report on their plight, which my mother dug up and shared with me a quarter century later, just before I left for my first meeting of the International Whaling Commission. It’s a cherished memory at so many levels.

We don’t see too many quick and easy victories in our work, and the fight to end whaling has been no different. The global moratorium agreed upon by the IWC in 1982 and implemented in 1986 was the result of a long struggle waged by many organizations, including ours. The moratorium was tough to secure and we’ve fought to preserve it against repeated efforts by a few outlier nations determined to undermine it.

From the vantage of 40 years, we can rightly call the moratorium one of the greatest conservation and animal protection measures of all time. Hundreds of thousands of whales have been spared from the harpoon since it took effect, and it has prevented the extinction of several species and population groups. It has bought essential time for whales, facilitating their gradual recovery after decades of catastrophic decline. I am proud of the role played by so many colleagues, past and present, in this crucial work. Many of them have become close friends, our bonds forged in the crucible of diplomacy.

That said, commercial whaling, now carried out only by Iceland and Norway under formal objection to the moratorium and Japan by virtue of having left the IWC, is just one of many threats to whales. Many populations remain depleted or endangered, as bycatch, climate change, entanglement, marine debris, ship strike and toxic pollution pose urgent and unprecedented hazards. The complete end of commercial whaling—when it does come—will not extinguish the need for global commitment to ensure the well-being and future of whales. It will only bring other problems into sharper focus and push us to find new solutions.

To guarantee a safe and healthy future for whales, we’re going to need strong leadership from governments, nongovernmental organizations and other partners throughout the international community. That’s why we’ve championed efforts to transform the IWC from an organization that once set and managed whale quotas into one equipped to address pressing contemporary challenges to the survival of whales, coordinating its work with other stakeholders. Working with members of its Scientific Committee and other parties, we’ve helped to set the IWC on a remarkable path to leadership in research, policy and practice concerning whales. We’re bringing pressure to bear on the three nations that still conduct commercial whaling (last February, Iceland set a deadline to phase it out by 2024). Finally, we’ve been spreading the word about the sentience and strong social bonds of whales and the critical roles they play in marine ecosystems. We have so much yet to learn about whales, and from them.

From the start, our organization has been willing to take on the big fights for animals. Each fight has its own dynamics, its own strategic demands, its own goals and benchmarks. In that sense, eliminating the use of fur or the cruelty of the puppy mill, ending the shark fin and dog meat trades, achieving the full replacement of animals in cosmetics testing, bringing an end to the use of dogs in research and testing or halting the worst factory farming practices are quite different. But there are commonalities, too, and the most important one is this: It can take a long time to succeed in those fights, and to keep them in the win column. But win them we will, because we’re willing to stay at it for as long as it takes. And we’re grateful to have you standing with us.

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