Read the introduction of an essay about sea otters. Did you know that sea otters can stay underwater for four minutes? Sea otters are amusing and peaceful creatures that are a benefit to the environment and protected by law. Once hunted for their fur almost to extinction by the early twentieth century, today there are upwards of 150,000 sea otters. Their funny way of floating on the water’s surface to sleep, as well as their methods for hunting and eating, make them a delight to study. By developing an appreciation for this unique aquatic mammal, it is hoped that they will stayed protected for many years to come.
Which sentence is the thesis statement?