It has been discovered that rivers which have seen a decline or disappearance of anadromous lampreys, loss of the lampreys also affects the salmon in a negative way.
人们发现，在溯河性七鳃鳗数量已经减少甚至消失的河流，七鳃鳗的减少也对鲑鱼产生了负面的影响。