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8 CHAPTER 4 MOTION

April 22, 2007—A young harp seal was found stranded on a beach inVirginia’s Chincoteague National Wildlife Refuge. He appeared slightly thinwith some superficial injuries. Park rangers, optimistic that he would healon his own, placed him under observation. Unfortunately, park visitorsdidn’t heed requests to keep a respectful distance from the seal.

For the seal’s and the public’s safety, he was captured and sent tothe Virginia Aquarium Stranding Center. Veterinarians treated himwith antibiotics, and soon he was consuming 10 pounds of herring aday. In less than a month, the seal grew from 35 to 66 pounds.

During that time, a 13-year-old girl asked her birthday party gueststo bring donations to the Aquarium’s Stranding Response Programinstead of gifts. With the money she collected, the aquariumpurchased a satellite tag to track the seal’s movements.

On May 19, 2007, the tag was attached and the healthy seal wasreleased back to the ocean.

What Is a Satellite Tag?A satellite tag is a palm-sized, salt-water-resistantdata collector with anantenna attached. It isglued to the fur of a seal’supper back, where itremains until the sealmolts and the tag falls off.

The tag records information including the time, date, dive depth,dive duration, and amount of time at the surface over the last sixhours. When the seal surfaces, the tag transmits this data tosatellites orbiting Earth. Sometimes there are no satellites overheadwhen the animal surfaces, so data isn’t received every day.

When data is received, instruments on the satellite record thelocation of the tag and relay the data to processing computers backon Earth. Organizations such as WhaleNet (� Internet keywordsearch: whalenet) make this information available online, whereit is used by marine scientists, government and conservationorganizations, and students.

The Seal’s Journey: Position, Time, and SpeedWhaleNet’s Satellite Tagging Observation Program (STOP) providedthe following information about the seal’s journey.

Date Time (GMT) Time Elapsed Latitude Longitude Distance Traveled since previous from previous point

point (h:min)

05/19/07 10:06 0 36.850 N 76.283 W 0 km ` (This is the release

location–First LandingState Park, Virginia.)

05/30/07 04:45 258:39 42.195 N 65.554 W 1096 km

06/03/07 07:27 98:42 44.317 N 63.137 W 307 km

06/05/07 19:20 59:53 45.294 N 60.812 W 214 km

06/11/07 03:11 127:51 45.749 N 59.440 W 119 km

06/16/07 20:16 137:05 47.669 N 58.009 W 240 km

06/19/07 08:11 59:55 46.594 N 56.125 W 186 km

06/25/07 13:17 149:06 48.523 N 51.069 W 437 km

06/28/07 06:25 65:08 50.412 N 51.192 W 210 km

07/03/07 08:46 122:21 54.127 N 54.070 W 458 km

07/05/07 00:40 39:54 54.889 N 55.558 W 128 km

07/09/07 19:08 114:28 56.665 N 59.970 W 340 km

This information can be used to determine the seal’s average speedon each leg of his journey. To calculate his average speed on the first leg:

1. Convert elapsed time from h:min to hours. 258 hours 39 minutes = 258 39/60 hours = 258.65 hours

2. Plug the values into the speed formula: speed = distance / time.Speed = 1096 km / 258.65 h = 4.237 km/h

With the satellite tag attached to his back, the seal movestoward the ocean.

High Tech

AnimalTrackers

Sea ice formed late and broke up earlyfor seven of the eleven years between1996 and 2007. Satellite tagging datahelps us monitor how animals respondto these changing conditions. Someseals travel further north. Others havetried to adapt to new habitats—forexample, seals have given birth onland instead of ice. There the pupsface new predators like foxes, wolves,and domestic and wild dogs—animalsthat don’t hunt on ice.

Marine scientists share informationabout seal population activity withgovernment agencies that monitor seal hunting and fishing industries. If the seal population declines, newregulations could be enacted to restricthunting and/or protect the seal’s foodsources and critical habitat areas, whileareas with abundant resources can beopened to the fishing industry. Themore we learn about how animalsinteract with their environments, thebetter decisions we can make abouthow we use the oceans.

New Insights, Improved CoexistenceKnowing the seal’s average speed atvarious points on his journey can helpus gain insight into his behavior. Forexample, between June 5 and June 11,his average speed slowed significantly.During that time, he remained in asmall area just off the coast of CapeBreton Island. The satellite datasuggests that this area may be a“critical habitat” for the harp seal. What was he doing there? Resting?Feeding? Finding answers to thesequestions can help us make betterdecisions about how and when wehumans use this coastal region.

J. Michael Williamson, WhaleNet’sfounder and director, explains, “Similardata from tagging right whales has ledto changes in shipping lanes aroundthe whale’s feeding areas and slowedshipping traffic through areas wherewhale calves are born. Satellite taggingresearch studies have led to many newlaws and guidelines governing humanactivities around endangered species.”

What’s Nice about Sea Ice?Satellite tagging data can also help us understand more about howanimals adapt to changes in their environments. For example,marine scientists are paying careful attention to how far up theDavis Strait harp seals travel. Harp seals stop their northwardjourney when they run into sea ice, rather than swimming under it,since they need to breathe air like we do.

Harp seals rest, mate, molt, and grow new coats on the sea ice. Theyalso give birth and nurse their pups on the ice. If the ice breaks upbefore the pups are weaned, the pups may drown or be crushedbetween large chunks of ice.

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9UNIT 2 MOTION, FORCE, AND ENERGY

Questions:

1. What was the seal’s average speed between June 5 and June 11, 2007?

2. Name two ways satellite tagging can help humans make better decisions about how we use the oceans.

3. Research: Using the � Internet keyword search:whalenet, find out what marine animal species are currently tagged. Use the website resources to create your own map of one animal’s journey. Compare your animal’s top speed to the harp seal’s. What questions do you have about your animal’s travels?

Satellite Tracking Map of the seal’s journey.