Finback Whale
(Balaenoptera physalus)

Federally Endangered

Description

The massive finback whale (sometimes referred to as "fin" whale) is second in size only to the blue whale, making it the second largest animal on earth. It is long (up to 78 feet), sleek, and streamlined, and is the fastest great whale. A rorqual whale, it has 50-100 pleats and grooves extending from the chin to the navel that allow the throat area to expand when feeding. The finback's most unusual characteristic is the asymmetrical coloring on the lower jaw, which is whitish on the right side and mottled black on the left. Otherwise, it is light gray to brownish-black on the back and sides. Two light-colored chevrons (stripes) originate behind the blowholes and slant aft toward the flukes (tail) to form a broad V across the back. The undersides of the body, flippers, and tail flukes are white. The finback whale has a prominent curved dorsal fin located far back on the top of its body. This whale produces a distinctive, robust spout, which rises to 20 feet. When starting a dive, it arches its back, showing its dorsal fin, but rarely shows its flukes or breaches the surface. Females are slightly larger than males, and weight for both sexes is between 50-70 tons.

The finback is distinguished from the blue whale by its smaller size, unique coloration, longer, narrower head, and taller dorsal fin. The sei whale is smaller and more slender, has a uniformly colored body, and has a relatively smaller dorsal fin. Map of range and known locations of finback whale

Range and Habitat

Finbacks live in all oceans of the world in coastal and offshore waters. They are found in largest numbers 25 miles or more from shore. They tend to be nomadic and migrate to subtropical waters for mating and calving during the winter and to high latitudes and cold currents for feeding in the summer. North Atlantic finbacks are most abundant between Long Island and Labrador. They are most typically observed in 300- to 600-foot water depths over the continental shelf. New England waters represent a major feeding area for North Atlantic populations. Some individuals overwinter near Cape Cod, but in the Gulf of Maine the period of peak abundance is April through October.

Life History and Ecology

Finback whales are the most common whales in the Gulf of Maine. They travel singly, or occasionally in groups of up to 100 on feeding grounds and during migration. In the Gulf of Maine, they feed on herring, capelin, squid, and krill. They have been observed circling schools of fish at high speed, rolling on their right sides, and engulfing the dense school of fish. They can dive as deep as 755 feet in search of food. Their asymmetric color patterns may aid in capture of food. They can consume up to two tons of food a day. During feeding, large volumes of water and food are engulfed and the plated grooves in the throat expand. The mouth is closed and water is expelled through 350 baleen plates, which trap the food near the tongue to be swallowed.

Finbacks probably start to mate at 5-10 years old when they attain a length of 55-60 feet. Breeding may occur throughout the year, although the peak period occurs from November or December until March. The gestation period lasts about 12 months and the calf weighs about two tons at birth. The calf is weaned at about six months of age or when it reaches 35-40 feet in length. Females usually have one calf every third year. Potential longevity is unknown.

Threats

Populations were greatly reduced by commercial whaling. Like other large whales, finbacks are at risk of entanglement in fishing gear and collisions with ships. Marine ecosystem changes induced by global warming and pollution may affect food availability. Recreational whale watching may occasionally cause disturbance, but this is believed to be insignificant. Mortality rates from these causes are not limiting population recovery at this time.

Conservation and Management

Given their speed and preference for the open sea, finbacks were almost completely protected from early whalers. However, with the introduction of modern, fast boats and harpoon guns, finback whales became easy victims. With the depletion of blue whales, the whaling industry turned to the smaller, abundant finback whales as a replacement. As many as 30,000 were killed annually from 1935-1965. The International Whaling Commission (IWC) whaling quotas were lowered in the mid-1970s and reduced to zero in 1985. The North Atlantic population before hunting was 30,000-50,000. In 2000, the IWC estimated there were 2,200 finbacks between Virginia and the Gulf of St. Lawrence. Several thousand more likely exist off eastern Canada. Populations off eastern North America are believed to be increasing.

Finbacks were federally listed as endangered in 1970. Finbacks are protected from take and harassment by the federal Endangered Species and Marine Mammal Protection Acts. In 2000, the Atlantic Large Whale Take Reduction Team developed a Take Reduction Plan to implement specific area closures and gear restrictions and identification of Critical Habitat in Northeastern waters. Implementation policy is still changing. The Maine Department of Marine Resources has lead management authority for marine mammals, including the finback whale.

Recommendations:

The Maine Department of Marine Resources recommends that National Marine Fisheries Service Guidelines for whale protection be employed. Regulations can be found at:www.nero.nmfs.gov /whaletrp/. Current (2002) guidelines include the following:

Dedicate state education and outreach efforts to fishermen.
Close critical whale habitats to some types of fishing gear during times when whales are likely to be present.
Prohibit some fishing practices (e.g., leaving inactive gear for more than 30 days) that increase risk of entanglement.
Require some gear modifications in federal waters (e.g., knotless weak links in buoy lines for lobster traps and gillnets, no floating line at the surface) to reduce risk of entanglement.
Utilize state and federal contacts for Whale Disentanglement Networks to locate entangled whales and remove gear. If you see an entangled whale, call the Northeast Disentanglement Network at 1-800-900-3622, the Coast Guard Station nearest you on 16 VHF Radio, the Maine Whale Take Reduction Coordinator, or the Maine Marine Patrol.
Investigate and implement measures to reduce ship strikes of whales, including: 1) routing ships around observed whales, 2) restricting speed of vessels operating in whale habitats, 3) requiring mandatory shipping lanes when transiting through critical habitat areas, and 4) providing ship captains operating in critical habitats with the latest whale sighting data.
Whale watchers must employ the following guidelines: 1) No vessel should approach closer than 300 yards. When whales are nearby, move at a constant, slow, "no wake" speed. 2) Do not engage props while whales are within 100 yards and do not chase whales. 3) When watching whales, do not box them in or cut off their path to prevent them from leaving. 4) Do not attempt to approach mothers with young calves. 5) Do not operate aircraft within 300 yards of a whale.
Plan for protection of critical whale habitats in state and federal oil spill contingency planning.

For more information contact Maine's Endangered Species Program at (207) 941-4466.

DEPARTMENT INFORMATION

Finback Whale (Balaenoptera physalus)