The ocean has been the scene of battles between warring humans for centuries. During the 20th century new forms of sea warfare were developed. This has continued to have a negative impact on the creatures who live in this environment.
Sonar is very important for naval ships, even during peacetime. This technology allows vessels to know if a hostile submarine is their vicinity. Unfortunately sonar also appears to harm some of the largest creatures of the sea. More research needs to be done on the effects that this has on whales.
However, evidence already suggests that these creatures suffer some form of physiological damage due to sonar. They have been observed rapidly changing their depth and course when encountering sonar. Sometimes they even suffer bleeding to their ears and eyes. It is possible that some cases of whale beaching are a consequence of sonar.
Sadly, sea life has also been directly used during ocean combat. For instance, the US Navy continues to have a programme for training dolphins to locate underwater mines. In 2000 international news was made with the revelation that Iran had bought dolphins from the Russian military which had been trained to perform suicide attacks.