Humpback Whale Migration Update: April 12, 2000 Today's Report Includes:
Greetings from the Stellwagen Bank National Marine Sanctuary Humpback whales are starting to show up in greater numbers on Stellwagen Bank, according to right whale researchers who are making regular patrols. In addition, although whale watching doesn't really start in force until May, an occasional commercial whale watch boat has been out and has reported seeing whales. Who Are These Early Arrivers? Within the next week the Sanctuary will be supporting a research cruise by the Center for Coastal Studies to determine who these early arrivers are. David Mattila, chief scientist on the project, reports that the researchers will photograph the flukes (for positive identification in the lab), take skin samples if possible (to determine family relationships based on DNA testing), and record behaviors. The researchers don't expect to see mothers and calves for quite some time yet as they tend to leave the calving grounds last. Researchers are curious, however, as to the travel patterns of the other parts of the population; the adult males, the non-pregnant females, the newly pregnant females (who will calve next winter), and the juveniles. Dominican Republic Humpbacks Come and Go Earlier Kim noticed that although the total numbers were similar to last year, this year Kim felt the peak number of whales occurred a bit earlier than last year (third week in February 2000 verses the first week in March 1999). The whales started coming in a bit later than last year. Sightings were slim in mid-January, but by mid-February the whales were there in force. Kim also believes the whales started leaving a bit earlier; by March 15th most of the whales still there were mother-calf pairs.
Whales Showing Lots of Baleen Kim saw large surface-active groups (social behaviors common to the area), and some unusual behaviors. Usually the whales keep their mouths closed in the southern grounds, but this year many whales, including the young, were coming to the surface with open mouths and baleen quite apparent (something we see all the time up at Stellwagen Bank, which is a feeding area). According to Kim, they couldn't see any food in the whales' mouths, but that is not to say that these weren't cases of opportunistic feeding (on schools of small bait fish in the bay). Objective vs. Subjective Observations There are two ways to write a description of something that happened. One way uses observations that are made objectively, or with a scientific basis. The other description uses subjective observations. These are observations described using personal feelings. Kim's two-part report today is interesting and valuable to us. It gives us a look at some whale behavior that she has observed in the Dominican Republic. She told us that it contains her personal observations and is not a scientific report. Did you notice any words in her observations that would lead you to think they were personal rather than scientific? Underline the words in her report and then answer this question.
(To respond to this question please follow
the instructions below.) Whale Safety is Top Priority Kim runs two companies, Victoria Marine and Whale Samana, and she has been playing a role in the development of the management plan for Samana Bay (an area along the northern coast of the Dominican Republic). Her vessel, Victoria II, is one of 40 officially permitted whale watching vessels (the National Park Service in the Dominican Republic has set specific criteria including safety and proper boating etiquette around whales before a permit is granted). The permitting system was put in place to cut down the number of boats that were going out to view the whales in Samana Bay and presenting potential threats to their safety. Says Kim, "Some of the late calves we saw in March were tiny pickles. They come up and down every three minutes while their mothers may stay down up to 20 minutes. It's awfully hard to see them out there when they're by themselves." Now that the numbers of boats are somewhat under control, she reports that the major issue is speed. With calves only measuring 9-12 feet long, a boat going 20-30 knots would have a hard time spotting a calf and then stopping or veering in time to avoid a collision. Try This! Use Art to Communicate! We sure don't want any of those young calves injured by a boat going 20-30 knots through the calving grounds! Imagine you are working for the National Park Service in Dominican Republic as a sign painter. Your job is to make a sign warning boaters to slow down so the small calves can safely swim and play. What will your sign look like? As a class project or for extra credit design and make your own sign to protect the baby humpbacks from speeding boats. Close Encounters May Be Too Close! I hope to have a description of the types of whales now at Stellwagen Bank for my next report. And it shouldn't be too long before we get to see some of the new calves and their moms. This is Anne Smrcina, education coordinator for the Stellwagen Bank National Marine Sanctuary, signing off. Discussion of Challenge Question #7 Last update Anne asked, "Why do you think the humpbacks prefer particular areas of the Oahu coastline?"
Then she hinted that you may want to see if you can get a topographic/bathymetric map of the area around the island. Discussion of Whale I.D.- Challenge Question #8 Last update we discussed the ID tools we use for naming humpbacks. Anne asked why researchers photograph right whales but not humpbacks from the air for identification purposes. How to Respond to Today's Challenge Question: 1. Address an e-mail message to: jn-challenge-hwhale@learner.org The Next Humpback Whale Migration Update will Be Posted on April 26, 2000 Copyright 2000 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form
|