The Whole Foods grocery chain has reportedly begun putting warning labels on some of the seafood it sells suggesting that customers may not want to buy it. Not because there is any risk to consumers, apparently, but because that species may be "overfished" and being depleted in the environment. Green means "abundant," yellow means "may be overfished" or not fished sustainably, and red ("AVOID") means "is definitely suffering" for those same reasons.
Yes, Whole Foods did offer an explanation for why it is still selling the seafood it urges you to avoid.
"The reason why we're continuing to carry these species," said a man described as the "Whole Foods Seafood Supervisor," is that "we want to give [our] vendor-partners an opportunity to make changes to their operations." He didn't explain why Whole Foods didn't just tell them it was not going to buy the semi-endangered species anymore until they got their act together (the vendor-partners, not the fish).