Japanese whalers are back in the Southern Ocean, aiming to kill 333 minke whales — ostensibly for the purposes of scientific research — under special permits issued by their government. In our view, the science behind Japan's whaling activity has not passed a reasonable standard of peer review.

We are members of the International Whaling Commission's Scientific Committee (IWC-SC), plus one independent expert witness (M. Mangel) whose evidence contributed to the March 2014 negative ruling on Japan's JARPA II whaling permit by the International Court of Justice (ICJ; see A. S. Brierley Nature 520, 157; 2015). In 2015, Japan submitted a new whaling proposal (NEWREP-A). The IWC-SC coordinated two rounds of review, including one by an independent expert panel that concluded that lethal sampling had not been justified. Numerous IWC-SC members recommended exploration of widely used non-lethal alternatives (see, for example, A. M. Polanowski et al. Mol. Ecol. Resour. 14, 976–987; 2014) before killing is resumed.

Japan claims to have “sincerely taken into account” the IWC-SC's opinion, but, as on previous occasions, has failed to alter its plans in any meaningful way and is proceeding to kill whales under a self-determined quota. In October 2015, Japan also rejected the jurisdiction of the ICJ on this issue.

We believe that further discussion of special-permit whaling at IWC-SC under the present procedure — in which the opinion of proposers is afforded equal weight to that of referees — is a waste of time. The IWC urgently needs to develop a process of scientific review that results in clear decisions that can be respected by all.