SCIENTIFIC NAME: Balaenoptera edeni

DISCOVERED: Anderson, 1878

COMMON NAME: Bryde's Whale, Tropical Whale

GEOGRAPHICAL DISTRIBUTION:

Occurs between 40 degrees N and 40 degrees S latitude- may extend further into warmer currents
Most common in tropical and subtropical areas- between 30 degrees N and 30 degrees S
Local pockets of abundance off South Africa, Japan, Sri Lanka, Fiji and western Australia
Migration of short distances for offshore animals
No known long distance migrations

DESCRIPTION:

3 parallel longitudinal ridges on head
Prominent dorsal fin
Skin may appear mottled with circular scars- caused by parasites or Cookie-cutter Sharks
Dark upper side
Slender, short flippers
40-70 throat grooves
Pointed tips on flippers
Light purple-gray, blue-gray or creamy underside
Broad, flattened tail stock
Flukes may be dirty white on undersides

NATURAL HISTORY:

HABITAT:

Prefers water temperatures above 68 degrees F (20 degrees C)
Tropical, subtropical and some warm temperate waters

FOOD & FEEDING:

Typically makes sudden changes in direction
Feeds year-round
Euphausiids are important component of diet
Schooling fish are preferred- including pilchards, anchovies, herring and mackerel
Bonito and cephalopods also taken, as well as sharks

LIFE CYCLE:

Average length at sexual maturity= 12.5m (females), 12.2m (males)
Age at sexual maturity = 10 yrs (females), 9-13 yrs (males)
Gestation period lasts one year
Lactation lasts less than one year
Females give birth every second year
Newborn calves are 3.4m at birth

BEHAVIOR:

Not much known
Sometimes approaches boats
May breach clear of water
Averages 4-7 blows with a long dive of up to 8 minutes- may stay under for longer
Loose groups- spread over several miles
Rarely shows top of head
Often shows back and dorsal fin before a long dive
Irregular dive sequence
Hazy blow

WORLD POPULATION:

Northern Indian Ocean= no information available on status- although some sightings off Sri Lanka in 1982; total population estimated at 13,854 and exploitable pop. at 9,144
North Atlantic= not featured greatly in commercial catches, no data on abundance from sightings available
North Pacific= management of 3 stocks
Western North Pacific= 23,500 in 1986, exploitable pop. at over 17,000; total=18,000
Eastern North Pacific= 10,000 in total
East China Sea= no information available
Southern Hemisphere= new stock divisions introduced in 1980 and 1981
South Atlantic= no exact figures available
South African Inshore Stock= cumulative catch of 808 whales between 1950 and 1967
Peruvian Stock= exploitable pop. estimated at 5,723-25,550 with central value of 15,638 in 1983
Southern Indian Ocean= total pop. in 1980 estimated at 13,854
Solomon Islands Stock= 1,800 in 1982
Western South Pacific Stock- 59,400 total pop. in 1980
Eastern South Pacific= In 1980, total pop. of 13,194 and exploitable pop. of 8,708

HUMAN INFLUENCES:

Early land and pelagic operations by various countries in tropical and warm temperate waters may have caught the species
Except for Pacific and southern African populations, most stocks have not been exploited to any great extent
Interest of exploiting Bryde's more widely in the 1970s- Japan conducted research cruises, USSR also made limited investigations
Products used from Bryde's whale catch in the Indian and Pacific Oceans include oil, collagen peptide, frozen meat and blubber, and other frozen products
Average of 9.346 tons of products used for human consumption per whale- 68.4% of total body weight of the whale