The sound created from ships' propellers is of similar frequency range a few whales use to communicate. Researches show that whales alter their sounding patterns when in noisy places.

Researchers have decided to study the stress hormones of whales in connection to the sound created from ship propellers. Results show that whales are less stressed during light shipping seasons.

Faeces, which were gathered and analyzed in 2001, demonstrated a lower level of stress hormones, which is known as glucocorticoid hormones, in a period when only a few ships are out to the ocean. A significantly higher level of metabolites of stress hormones are recorded during the summer, a time when marine traffic went back to normal.

For the study, they used the North Atlantic right whale. This specie has been declared extinct due to the hunting conducted by most Basque people hundreds of years ago. However, another reason for its extinction was discovered not so long ago by recent scientists.

Researchers from the New England Aquarium in Boston, US lead by Dr. Rosalind Rolland discovered a significant increase in the population from 350 to 490 species in a span of ten years.

Most North Atlantic right whales can be seen in North America heading to the Bay of Fundy during the late summer to search for food.

A team of researchers conducted a five-year project that started with gathering and examining right whales' faeces. They made it possible by bringing in trained dogs on boats to track down and detect smells of faecal matters.

According to Dr. Rolland, the team worked together using different boats. Everyone knows what they are going to do, which is why the researching despite being in different boats went out successful. Cooperation between the groups was easy to handle.

Presently, the research team is planning to develop a study that would relate the level of stress hormones to ocean noise in different locations.