Filter feeder gap between the two rows of baleen plates lets the water in together with the prey, while the baleens filter out the water. Rorquals such as the blue whale, in contrast, have smaller heads, are fast swimmers with short and broad baleen plates. To catch prey, they widely open their lower jaw — almost 90° — swim through a swarm gulping, while lowering their tongue so that the head's ventral grooves expand and vastly increase the amount of water taken in. Baleen whales typically eat krill in polar or subpolar waters during summers, but can also take schooling fish, especially
Whale conservation feed at a higher trophic level than baleen whales in the food chain (other high-up animals such as sharks, swordfish and large tuna show similarly high levels of mercury contamination). Organochloride pesticides HCH and HCB are also at higher levels in toothed species, while minke whales show higher levels than most other baleens. The red meat and blubber of (toothed) long-finned pilot whales in the Faroe Islands show high toxin levels, which has a detrimental effect on those who eat it. However, in Norway, only the red meat of minke whales is eaten and the levels of toxins conform to