Humpback Whale Migration Update: February 5, 1997

"Greetings! This is Anne Smrcina reporting from Stellwagen Bank National Marine Sanctuary. I'm glad to be back for my 3rd year as whale migration reporter for Journey North. Since the Stellwagen Bank Sanctuary is located off the end of Cape Cod under 100 feet of water, I don't have my office there. Instead I'm based in Plymouth, Massachusetts --home of that famous rock.

"It is estimated that about 6,000 humpbacks live in the North Atlantic. (There are other populations elsewhere on the globe, but the groups do not mix.) The whales we see at Stellwagen Bank are presently down in the Caribbean, around Silver Bank, for their winter calving and breeding season. Although they are most concentrated at Silver Bank, and Navidad Bank close by, humpbacks can also be found from the Bahamas to the Grenadines.

"Whales do not eat during their stay in the Caribbean, but live off their reserves of fat called blubber. In the spring they come to the waters off Cape Cod to feed on small fish, then continue up north to the Bay of Fundy. Other whales travel to the waters off Newfoundland, as well as to Greenland and Iceland.

"On humpback wintering grounds one conservation issue has arisen in recent years.The number of whale watch vessels has increased enormously. What was once an almost nonexistent business is now booming, with a substantial fleet of large vessels (about 16) and over 40 small boats bringing European and Canadian tourists out to the whales in Samana Bay and other locations. Luckily Silver Bank, where calving occurs, is too far from shore for a day's trip. The problem is greatest around Samana Bay, which is right on shoreline.

"Guidelines are needed like those we have in northern waters, where there are specific rules about approaching whales. For example, our rules don't allow people to dive with the whales or injure or harass them in any way. In contrast, the Dominican waters are one area where wildlife photographers are allowed to take underwater photographs.

"There's another reason underwater photographers like the Caribbean, and it's the same reason whales don't eat during the winter. Do you know the reason?

Challenge Question #1
"Why don't humpback whales eat during the winter in Caribbean waters?"

To respond to this question please follow the instructions at the end of this report.

"It seems not all humpbacks made the trip this year. I went out on December 12 and we spotted at least 4 whales, of which 2 were definitely humpbacks. We could tell by their very long flippers. (Unfortunately, we didn't have any of the whale watch guides on board so we couldn't identify them individually. Each whale has unique markings on its tail, and some whales watch naturalists have learned to recognize them.) The ones we saw may have been juveniles, who don't need to go south for breeding or calving purposes.

"The whales seemed to be feeding. According to local fishermen, it seems sand lance (a favorite Humpback food) came in during the summer and never left. This may explain why last season was banner year for whales. In fact, one day I saw 31 whales in less than 3 hours! Some whales probably decided the feasting was too good to leave.

"Sand lance are 5-6 inches long, and fit in palm of your hand. Their population seemed to crash a few years ago, and now may have recovered. Nobody knows much about this. Their population might be cyclical, expanding and contracting in 7-10 years cycles. We do know whale sightings were the best since the mid-80's.

"Until next week, this is Anne Smrcina signing off".

Try This!
Draw a map that shows the range of North Atlantic humpback whales Anne describes.
Include these features on your map:

• Humpback whale wintering grounds.
• The major calving areas.
• Stellwagen Bank National Marine Sanctuary
• The Humpbacks summer feeding grounds.

How to Respond to Challenge Question #1:

1. Address an E-mail message to: jn-challenge-hwhale@learner.org
2. In the Subject Line of your message write: Challenge Question #1
3. In the body of the message, answer this question:

"Why don't humpback whales eat during the winter in Caribbean waters?"

The Next Humpback Whale Migration Update Will be Posted on February 12, 1997.