Our afternoon was full of charismatic marine mammals. We quietly approached rafts of sea otters as we headed out of Idaho Inlet. They were resting on their backs, with their heads and flippers out of the water to conserve heat. These critters have a high and efficient metabolism and need to eat twenty-five percent of their body weight each day. Their food consists of a variety of marine invertebrates that they dive for and bring to the surface to eat. Portions of Southeast Alaska were repopulated with transplanted otters after overexploitation during past centuries. This population has been expanding. Mostly males are found in Idaho Inlet, while females and young stay close to kelp beds.
While we were watching the smallest of marine mammals, we noticed spouts, flukes and backs of forty-ton humpback whales that were also in the area to feed. We went for a closer look and spent the remainder of the afternoon with these animals. Small groups of two to five whales swam in synchrony. They were surfacing, exhaling and diving with such energy that we surmised they must have been feeding. A plankton sample we collected indicated a very rich marine ecosystem. We recorded some vocalizations with a hydrophone to see if there were sounds associated with their behaviors. Occasionally a whale surfaced with its mouth partly open, slapped its tail or pectoral fins forcefully on the water’s surface, or jumped clear of the water - like the one in the photo.