Hello again from Stellwagen Bank National Marine Sanctuary:
The first two humpbacks of the season have been spotted in the Sanctuary -- one whale, which looked smaller and may be a juvenile, was observed on Tues. (April 11) and an adult was seen on Mon. (April 17). They were located at different ends of the Sanctuary (which is 638 square nautical miles in area or 842 square miles). The same research/survey boat recorded 7 right whales on Tues. of last week and none on Mon. and Tues. of this week.
A quick report from Bermuda says that they have been allowed to use the crossbow to radio-tag, however, the police keep the bow until sailing time. Inclement weather has prevented much work, but one whale has been tagged. Hopefully, more info. on this next week.
The Virginia Marine Science Museum reports that they have stopped their whale watches (the last trip was during the first weekend in April). The last whale spotted was on March 26. However, they will begin dolphin watch trips in May.
In addition to the humpbacks seen on Stellwagen Bank, the researchers are now also spotting several minke and fin whales.
A quick lesson on whale classification is provided at the end of this report. It will help you with some of the terminology I'm about to use.
Scientists believe the balaenoptera (rorquals excluding the humpbacks) may move to lower latitudes and/or offshore during the winter months; they don't seem to congregate in one location (as opposed to the humpbacks that mass in the West Indies).
Humpbacks congregate in the West Indies, but then move out to distinct summer feeding grounds with little exchange among the populations once they leave Caribbean waters. The western North Atlantic aggregations are: Gulf of Maine (including Stellwagen Bank), Gulf of St. Lawrence and eastern Canada, western Greenland, and Iceland. (Whales found in the Gulf of Maine or another location, keep coming back home.)
Whales have also been found off of Norway. Where do these whales go in the winter? (Look at a map of the Atlantic Ocean as you read this.)
Some research now underway in the Cape Verde Islands off Africa is looking at a population of whales found in the eastern Atlantic. Is this a remnant of an eastern Atlantic population totally separate from the Caribbean group? Or, are these whales wayward members of the western Atlantic population?
Fred Wenzel, a doctoral student at Northeastern University in Boston, is presently there (having a hot time -- a volcano exploded on one of the islands last week). The Center for Coastal Studies has reported to me that Fred spotted two cow-calf pairs and that he heard some singing. The Gulf of Guinea (near the Cameroons and Nigeria) is known as an important historical breeding ground for whales; a Norwegian whaling station was located in that vicinity for many years. While the West Indies (Silver Bank) was known as an active whaling ground since the time of the conquistadores, the Gulf of Guinea may have an even older history -- the route was well known prior to the New World discoveries by traders travelling around Africa on the way to the Far East.
Fred wants to find out if the whales near Africa are an eastern Atlantic population that travels up to Norway. He had been part of an international research project called YONAH (Years of the North Atlantic Humpback Whale) which collected data during 1992 and 1993 of whale populations. Photographs of whales found in waters off Norway produced no matches with whales from the West Indies lending support to the hypothesis that the two groups of whales are from separate stocks. Perhaps Fred will get some matches during this year's study.
That's all for now. Enjoy spring!
Anne Smrcina Education Coordinator Stellwagen Bank National Marine Sanctuary ********************************************************** QUICK LESSON IN WHALE CLASSIFICATION
CLASS Mammalia: have lungs and breathe air; four-chambered heart; bears live young and nurse young with milk; maintain constant body temperature independent of environment.
ORDER Cetacea: all whales; consists of three suborders.
SUBORDER Archaeoceti (now all extinct). SUBORDER Odontoceti (toothed whales): killer whales or orcas; dolphins; porpoises; beluga whales; sperm whales. SUBORDER Mysticeti (baleen whales): consists of four families-- Balaenidae, Balaenopteridae, Eschrichtiidae, Neobalaenidae.
FAMILY Balaenidae (the right whales): right whale (northern and southern populations), bowhead or Greenland right whale. These whales have no dorsal fin, no throat grooves, and have the largest baleen plates that hang in a distinct highly-arched jaw. Balaena mysticetus -- bowhead whale Eubalaena australis -- southern right whale Eubalaena glacialis -- northern right whale
FAMILY Balaenopteridae (the rorqual whales): blue, fin, sei, humpback, and minke whales. These whales have long, streamlined bodies and throat grooves (which allow expansion of the throat while feeding), a small dorsal fin, and baleen plates (shorter than right whales). Balaenoptera acutorostrata -- minke whale (three populations that may be three separate subspecies (acutorostrata -- North Atlantic, bonarensis -- southern hemisphere, davidsonii -- North Pacific) Balaenoptera borealist -- sei whale Balaenoptera edeni -- Bryde's whale
Balaenoptera musculus -- blue whale (with three subspecies - - brevicauda -- pygmy blue whale, musculus -- northern hemisphere, inermedia -- southern hemisphere)
Balaenoptera physalus -- fin whale Megatera novaeangliae -- humpback whale
FAMILY Eschrichtiidae (the gray whales). Only one living member left in this family, the gray whale found in the Pacific. This whale has few throat grooves, short baleen plates, and a small dorsal hump followed by a series of bumps (but not a fin like the rorquals). Eschrichtius robustus -- gray whale
FAMILY Neobalaenidae (a rather new classification): The pygmy right whale got its own family. This whale has a dorsal fin. Caperea marginata -- pygmy right whale
Among the toothed whales, these are the major families: Delphinidae (dolphins -- pointed teeth, generally bigger than porpoises, large curved fins; includes killer whales, pilot whales, white-sided and white beaked dolphins, bottlenose and common dolphins; 34 species in all) Phocoenidae (porpoises -- teeth are flattened laterally, small triangular fins; includes harbor porpoises) Physeteridae (includes sperm whale and dwarf sperm whale) Monodontidae (white whales -- including beluga and narwhal) Platanistidae (river dolphins) Ziphiidae (beaked whales; includes Gray's beaked whale, southern beaked whale) [V
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