Mission Blue – Peter Tyack
Onstage on the Mission Blue voyage, Peter Tyack took the audience on a journey of the underwater world of sound, and explained the amazing ways whales use sound and song to communicate across hundreds of miles of ocean. Peter Tyack is a senior scientist in biology at the Woods Hole Oceanographic Institution conducting research on acoustic communication and social behavior in marine mammals.
He has studied the the social behavior and acoustic communication in bottlenose dolphins, sperm whales, humpback whales, gray whales, and right whales learning how these animals use sound to perform critical activities, such as mating, and locating food. This made him sensitive to the possibility that these critical behaviors might be disrupted by human-made sounds in the ocean, like sonar, oil rigs, motorboats, shipping traffic.
Hawaiian Islands Humpback Whale Report
NOAA has produced a report on the health of humpback whales within the Hawaiian Islands Humpback Whale National Marine Sanctuary. The report provides a summary of the status of humpback whales (Megaptera novaeangliae) and their related habitats in the sanctuary, pressures on those resources, current condition and trends, and management responses to the pressures that threaten the health of humpback whales and their habitat.
The sanctuary was designated to protect the humpback whale and its breeding and calving waters around the main Hawaiian Islands. This area encompasses 1,370 square miles and supports more than half of the North Pacific humpback whale population. Although their overall population is increasing in the sanctuary, their health rating is “fair” because of an increase in reported collisions, entanglements, and associated impacts.
Entanglement and whale-vessel collisions have been widely identified as the primary human cause of mortality for humpback whales, both in Hawaii and around the world. Therefore, these two issues have been identified as immediate and pressing concerns for the sanctuary. This report reaffirms why humpbacks need protection. Through management, resource protection, education, outreach, research and cultural activities, the sanctuary strives to protect humpback whales and their habitat in Hawaii.
This condition report also includes the most up-to-date information from SPLASH (Structure of Populations, Levels of Abundance and Status of Humpbacks). The SPLASH project represents the largest and most complete examination of humpback whale migrations in the world and has revealed a far more complex pattern of movements than had been previously documented. You can read the entire condition report on the health of humpback whales here.
Humpback Whale Season Ending
The first whale sighting in the Hawaiian islands for the 2009-2010 season was at the end of October, and now the time is coming to say good-bye to the humpback whales as they migrate north to Alaska for the summer. The whales need to return to cooler waters so they can feed upon the large schools of small fish that are the mainstay of their diet.
The Hawaiian Islands Humpback Whale National Marine Sanctuary is the nation’s primary mating and calving grounds for the endangered humpback whale. The population of North Pacific humpback whales has recently been increasing about five percent each year. During the Sanctuary Ocean Count in March, volunteers spotted 1,208 humpback whales off the coast of Maui.
The Pacific Whale Foundation reported three sightings of humpback whale calves without their mothers this season. Calves may be without their mothers for a number of reasons – either the mother was accidentally separated from her calf, or she abandoned the calf after deciding it had a health problem which would not allow it to reach maturity, or that the mother died shortly after birth.
Just as the whales do not arrive all at once, they do not depart all at once. Immature whales of both sexes that are still growing and not yet ready to breed usually depart early. Mature males stay here as long as mature females are around (no surprise there). Mothers and young calves are often the last ones to leave Hawaii allowing the calves grow as fat and strong as possible before making the 3,000 mile migration. Mothers will have lost nearly 10,000 pounds by the time they return to the feeding grounds.
In 2009 the last whale sighting in Hawaiian waters occurred as late as mid June.
Humpback Whale Calves
Humpback whales become reproductively mature when they are between five and eight years of age. They mate during their winter migration to Hawaii, and eleven to twelve months later, upon their return to winter breeding grounds, the mother gives birth to a single calf. A fifty foot mother will give birth to a calf approximately fifteen feet long and weighing around two tons. The newborn instinctively swims to the surface within 10 seconds for its first breath. The mother begins feeding her newborn about 100 pounds of milk each day for a period of around six months, then the calf is sustained through a mixture of nursing and independent feeding for six months more. The mother’s milk is pink in color and exceptionally high in fat content (50%) which allows the calves to gain weight quickly. It is imperative for them to develop a thick layer of blubber prior to their 3,000-mile migration back to the cold Alaskan waters. After weaning, the calf has doubled its length and has increased its weight five times, attaining a size of about thirty feet and ten tons.
In Hawaii, humpback whales typically belong to groups consisting of two to three individuals for relatively short periods of time. The longest association between individual whales is when the mother cow, remains with her calf for a year during nursing. The mother generally never lets her calf stray more than a body length away for very long. They spend the first year or so of the calf’s life together, and the calf learns valuable survival lessons in this short amount of time, and is then weaned and separated. In many instances, cow and calf are accompanied by another adult known as an escort. Escorts can be of either sex, but are most often reported to be males, and remain with them for only a short time. Usually, a female humpback will bear one calf every two or three years, with an average life span between 40 and 50 years.
Humpback Whales Healthy In Hawaii
Humpback Whales are increasing their numbers in Hawaii by a healthy 6 to 7 percent each year. Humpback whales of the Northern Pacific Ocean undertake a great migration from Alaska covering about 3500 miles one way. Considered an endangered species, the Humpbacks are doing well in Hawai’i's protected waters. Now numbering about 10,000, they will mate, calve, and nurse their young in Hawaii before returning.
One way to study the population size of the humpback whales is the Hawaiian Islands Humpback Whale National Marine Sanctuary’s annual whale count, where hundreds of volunteers go to 60 sites on the last Saturdays of January, February, and March to count whales. More than 800 volunteers showed up in January and counted whales from the shores of Oahu, Kauai, and the Big Island, with some seeing as many as 6 whales within a 15-minute interval. Here are the average numbers of whales sighted per 15-minute count period on each island:
O’ahu – 3 whales
Kaua’i – 2 whales
Big Island – 6 whales
Again on the last Saturday in February and March, volunteers will fan out along the shores of O’ahu, Hawai’i and Kaua’i for the sanctuary’s annual whale count. The count provides key population and distribution information on humpback whales around the Hawaiian Islands. The Pacific Whale Foundation will conduct its own whale count on Maui. If you would like to volunteer and be a part of this success story see Humpback Whale Ocean Count 2010.
Humpback Whale Wing on Wing
The humpback whale’s scientific name is Megaptera novaeangliae, meaning ‘Giant Wings of New England’, which refers to their large pectoral fins that can reach a length of 15 feet. These fins are used for maneuverability, stabilization, enabling the whale to stop, and swim backwards. And sometimes they are used just to show off.
Photo by Phillip Colla
