The conference in Doha heard proposals to protect a number of marine species, including corals, sharks and bluefin tuna. All were rejected except a proposal for one shark species.
“MEPs noted with regret that Japan and China, who had a very clear position to keep marine species out of CITES, achieved their goals,” said the European Parliament in a statement.
They are also said to have regretted the weak role played by the EU, which was "too busy trying to reach a common position".
The bluefins will be on the agenda next at the meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT) in Paris later this year.