Whale food chain. They have large reserves of blubber, more so for toothed whales as they are higher up the food chain than baleen whales. Lactating mothers can pass the toxins on to their young. These pollutants can cause gastrointestinal cancers and greater vulnerability to infectious diseases. They can also be poisoned by swallowing litter, such as plastic bags. Advanced military sonar harms whales. Sonar interferes with the basic biological functions of whales—such as feeding and mating—by impacting their ability to echolocate. Whales swim in response to sonar and sometimes experience decompression sickness due to rapid changes in depth. Mass strandings
Channel types discussed above), rapid/plane bed, step-pool and cascade unit morphologies. Channel types A wide variety of river and stream channel types exist in limnology, the study of inland waters. All these can be divided into two groups by using the water-flow gradient as either "low gradient channels" for streams or rivers with less than two percent (2%) flow gradient, or "high gradient channels" for those with greater than a 2% gradient. Low gradient channels of rivers and streams can be divided into braided rivers, wandering rivers, single thread sinuous rivers (meandering), and anastomosing rivers. The channel type developed depends on stream