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 Fluke Up Dive
When humpbacks are about to dive they will often take a breath and then roll their body forward and dive, throwing their tail flukes into the air and exposing the ventral surface of the tail. When the tail of the humpback appears out of the water in an upward arch this is the best time to identify individual whales.
Humpback Whales Hawaii
Humpback whales, being mammals just like humans, exhibit a number of traits common to all mammals including the following: they are warm blooded, breathe air, and bear live young and nurse them with milk. Adults typically range in size from 35 to 55 feet, and weigh approximately 80,000 pounds. Their scientific name is Megaptera novaeangliae (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.
They can easily be identified by their stocky bodies with obvious humps and black dorsal colouring. The head and lower jaw are covered with knobs, which are actually hair follicles and are characteristic of the species. The tail flukes, which are lifted high in some dive sequences, have wavy trailing edges. The long black and white tail fin and the pectoral fins have unique patterns, which make individual whales identifiable.
Humpback whales don’t have teeth, but instead have baleen. The baleen is a wide plate in the whale’s mouth, made up of hundreds of long, fringed blades forming a sieve that the whale uses to filter krill, plankton, and small fish out of seawater. These blades measure 18 to 36 inches. Most baleen whales feed by taking a large mouthful of food and water, trapping the food behind the baleen, and then swishing the water out through their baleen plates.
Humpback whales are found in all of the world’s oceans, although they generally prefer habitats near shore or island for both feeding and breeding. The humpbacks of the North Pacific live in the waters off Alaska in the summer, and migrate each year to the main Hawaiian islands and stay during the winter months of November through May. The round-trip distance they travel during this annual migration is approximately 7,000 miles, one of the longest migration distances of any animal species. During their stay in Hawaii, they do not feed, but devote most of their time to mating and bearing their calves.
Humpback Whale Identification
The humpback whale fluke is very broad and flat, ranging in size from 10 to 15 feet wide and capable of propelling the whale at over 15 miles per hour for short periods of time. Flukes normally have a serrated edge and a deep notch in the center called the median notch.
Each humpback’s tail fluke has a distinct black and white pigment pattern that allows researchers to identify an individual whale. Unique visual identification allows researchers detailed information on population, growth rates, and migration. Photographic catalogs of thousands of fluke identification pictures help scientists study the behavior of this incredible mammal.
SPLASH (Structure of Populations, Levels of Abundance and Status of Humpbacks) is an international effort involving more than 50 organizations. Launched in 2004, the project determined whale migratory patterns and estimated population sizes by using a library of photographs of whale flukes to identify 8,000 individual whales. By matching whale flukes photographed in their feeding areas with those photographed in the wintering areas, researchers were able to determine the patterns of individual whale movements, as well as estimate the size of populations.
