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Right Whale Migration Update: May 13, 1998
Today's Report Includes:
- Latest Right Whale Migration Sightings
- More On Navy Objections To Right Whale Reporting
- Response To Challenge Question # 5
To: Journey
NorthFrom: Anne Smrcina
Greetings from the Stellwagen Bank National Marine Sanctuary.
It seems that April showers up here in the Northeast have taken on a longer life
-- it's been raining since May 1st. Along with the rain, we've had a bit of March-like
winds too and lots of fog, making for difficult sighting conditions. Here's a question
for you (answer at the end of my report). If April showers bring May flowers, what
do Mayflowers bring?
Latest Right Whale Migration Sightings
Very few plane patrols have been able to get out to the Great South Channel and other
areas where whales are suspected to be feeding. Some of the most recent sightings
are:
- April 29th: 41.600N, 69.583W -- six whales in the Great South Channel, and numerous humpback, fin and minke whales were also seen feeding in the area.
- April 30th: 42.550N, 69.616W -- one whale at Wildcat Knoll, an area east of Stellwagen Bank (whales were seen there last year)
- May 4th: 41.666N, 69.583W -- one whale in the Great South Channel shipping lanes
More On Navy Objections To Right Whale Reporting
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Migration Route of North Atlantic Right Whales |
One teacher asked about the Navy concerns about this program -- the Navy was quite vocal in their opposition to the plan. Military and National Security Council advisors to the President argued that the program would jeopardize US security concerns. They said that the requirement to have ships report entry into an area of US waters would set a precedent that could lead to other such reporting areas in other countries. This potential series of reporting zones could threaten the tradition of freedom of navigation on the high seas. They also said that during times of war or world tension, enemy ships could lurk outside the reporting zone and determine which ships were not signaling ahead (the navy ships -- which would then be more vulnerable to attack). The Navy preferred a voluntary system for reporting.
In answer to the Navy, environmental groups noted that there are already seven other reporting areas around the globe -- one of which is the Great Barrier Reef off the northeastern coast of Australia. An editorial in the Boston Globe noted: "If the Navy agreed to follow the system voluntarily, then no one could tell which ships were which since all would be reporting....In times of war or heightened tensions the rule could be put in abeyance."
The reporting system will increase the value of the present Early Warning Network and overflights of the critical habitats by making all ships at sea aware of the whales' whereabouts.
Response To Challenge Question # 5Here's the answer to Challenge Question # 5 from several weeks ago on the difference between satellite and radio tags.
Both types of tags are dependent on batteries and the types of packaging and attachment devices employed. Most batteries can work for several months, but the attachment devices differ. Implanted tags, using devices that hook into the blubber, can stay for weeks or months. Suction cups (like the kinds used during the tagging cruise I reported on several weeks ago) stay on for several hours.
In general, satellite tags are used for long-term studies of whale movements (such as migrations). The whale's position is relayed via satellite to a home base, usually a couple of times a day (depending on the timing when the whale surfaces and the overhead passage of the satellite). If the whale surfaces when the satellite is on the other side of the world -- no data can be transmitted. If the whale is underwater when the satellite is overhead, again no data. Timing is the key.
On some tags additional sensors can provide information on mean surface temperature or dive duration -- such as mean dive duration since last transmission and most recent dive duration.
Satellite tags are also used to track entangled whales -- a tag is attached to the debris, which allows researchers to follow the whale and attempt a disentanglement when the conditions are appropriate. A satellite tag was attached to trailing debris on the whale "Metompkin" whose story can be found on the WhaleNet home page.
In contrast, radio tags are used in more localized research. These tags have a line of sight coverage. The continuous signal can be heard by the researchers whenever the whale surfaces, allowing them to home in on the beep and track the whale. Some new tags have GPS (global positioning system) capabilities -- but these tags need a long surface time (longer than is available with right whales).
New multi-sensor VHS tags are able to collect a wide variety of data, all of which is stored in the tag package. After a certain length of time, the tag comes off the whale. Researchers then collect the tag and the data. Some of the information that can be collected includes: depth of dive, dive duration time above and below the surface, swimming speed, salinity/conductivity of the water, water temperature, body orientation (rolling, turning to side), and sounds in the water.
David Wiley, the researcher I accompanied on the right whale tagging trip several weeks ago, notes that scientists have to take into account changes in the whale's behavior that may be directly attributed to the tag. Does implantation of a tag cause the whale to speed off, leaving the others behind? Does the whale do more rolling or breaching? The less invasive the tag, the less likely for it to affect the whale's behavior. Says Wiley of his suction cup tagging effort -- "It's good science and good ethics, especially in this case where the whales are in such a critically endangered state."
So there you are -- satellite tags are ideal for long time periods and long distance data collection -- such as migrations; radio tags are ideal for localized studies, often involving packages of sensors that can be recovered by the researcher. In addition, cost is a factor -- radio tags are relatively inexpensive (up to several hundred dollars). Satellite tags run in the thousands of dollars.
And finally, the answer to the question at the top of this report: If April showers bring May flowers, what do Mayflowers bring? Pilgrims!
That's all for this report. This is Anne Smrcina, education coordinator of the Stellwagen Bank National Marine Sanctuary headquartered in Plymouth, Mass., signing off.
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The FINAL Right Whale Update will Be Posted on May 27, 1998.