FINAL Gray Whale Migration Update: May 16, 2001
News from the North
Science Teacher Lance Westing from King Cove School in King Cove, Alaska has whale news to share, too. "Yes, gray whales have been traveling by our town of King Cove. The last
Moms and Calves Off British Columbia and Washington
A few whale moms and calves have finally been seen passing Tofino, BC! Whale Researcher Rod Palm writes from Strawberry Isle Research Society:
Rod is also happy about no reports of dead Grays stranded on their shores. (If you followed the gray whales'
migration in the 1999-2000 season, you'll remember near-record numbers of gray whales stranded between Washington
and Mexico. Nearly all of those strandings involved adults and juveniles, unlike the previous season's large numbers
of stranded newborns.)
Solo Travelers off California
Farther south along the whale trail, Channel Island Marine Sanctuary (near Santa Barbara, CA) reports few gray whale sightings in the past month. On May 14, Robyn wrote: "The only gray whales that are still traveling up to their feeding grounds in the Arctic waters are the mothers and their calves. The few whales that had their calves late this spring are finding themselves left behind, fending for themselves and their newborns. Many whales that we have seen lately are solo female gray whales that probably lost their calves either after birth or from predation." Robyn and other Naturalist Corp Volunteers share these recent whale tales:
"I saw two whales that primarily stayed near the surface while occasionally showing a blow," wrote Pam Eichele. "There was one adult and one juvenile approximately 2-3 years old. They were in about 116-foot-deep water and were taking 3-1/2 to 4-minute dives. A little later when we left the whale, we found approximately 2000 very playful Pacific White-sided Dolphins that swam with the boat."
C. French said, "I saw one adult gray whale that dove and stayed under about 8 minutes each time. There were good spouts, with a good show of the ridges down to the fluke, but no fluke shots. The whale was heading northwest at about 3 knots. The whale was off of Hope Ranch in Santa Barbara. The ocean was calm and visibility was clear, giving us perfect weather to spot whales.
"We saw a gray whale at about 4:45 p.m. heading west along the Santa Barbara Coastline. It was traveling at about 3.5 knots, the normal speed of a gray whale during migration. This was a juvenile that didn't have many barnacles. When it dove we got a good view of the ridges along its back all the way to the fluke." -Robyn Peverill and Cindy Wu
Lowest Calf Counts in Eight Years
Dr. Wayne Perryman of NOAA's Southwest Fisheries Science Center at Piedras Blanca has been waiting for calf counts to pick up. He writes, "The counts picked up the week of April 30 to May 6 when the survey team counted 25 calves. However, the count dropped to 12 calves the week of May 7-14, which was not encouraging news. Today (May 15) the total calves counted stands at 66--which is the lowest count by this date in the eight years of surveys from this site. We're hoping for at least a bit of a surge this week.
"The good news for gray whales this year was the reduction in the number of strandings, but clearly calf production has not recovered to the levels that we saw in 1996-1998 when total calves for the season were closer to 500. Maybe we will have better luck next year."
Indeed, we plan to catch up with Dr. Perryman this summer after his study is complete to find out more about this year's mothers and calves.
ACS Cenus Ends May 15
When the sun goes down on May 15, the ACS Gray Whale Census on Palos Verde Peninsula (33.44N,-118.24W) is officially over. Last time Alisa Schulman-Janiger, Director of the ACS Gray Whale census, said they may extend the counting if the cow/calf migration runs late. Take a look at the most recent ACS sightings, below. This year brought the lowest northbound count ever (and the fourth lowest southbound count). Which day was the peak day for calf sightings on the journey north?
Tough Questions from Mike & Winston
"The Gray whale migration is almost over and once again it has been a very poor year for sightings, with one of the lowest counts on record. Questions are being asked: What is happening to the Gray whale? Are their numbers decreasing? Have they changed their migration pattern or route? Are they migrating all the way to Baja? Has an increased number of whale watching boats driven the Gray whales farther off shore to migrate?
"These are tough questions to answer. We know that the count numbers began to fall after the last El Nino. With the heavy El Nino rain we had large amount of storm drain runoff. The runoff polluted the coastal waters off the west coast. El Nino, along with global warming, also raised the sea temperature in the Bering and Chukchi Seas, the main feeding ground for the Grays. This has caused a mass die off in their food (bottom dwelling amphipods). An increase in the exploration for gas and oil by the Russians has also taken place in that area, and the area is heavily fished.
"With the Gray whales' food supply dwindled, the migration has run later and later; the gray whales have been staying longer in their feeding grounds, trying to get enough food to sustain them on their migration. They maybe not getting enough food to make a full migration. Also in these lean food times, it is possible that the females are not getting pregnant, explaining why the calf sightings are way down.
"One in ten whales caught by the native Russian hunters has flesh so putrid (possibly contaminated) that sled dogs refuse to eat it. We know that in 1999, more than 250 Gray whales washed ashore along the West Coast of the United States. How many actually died and didn't wash up on the beaches? How accurate is the NMFS Gray whale population estimate of 26,600? Only time will tell if the gray whale is in trouble again."
Why So Few Calves?
What could account for this year's greatly decreased calf counts, especially noticeable after a few years of record high counts? Alisa Schulman-Janiger points out possible explanations, and says the answer may be due to a combination of all of these:
A Look Ahead
This year's migration has opened up a lot of questions--but researchers ALWAYS have questions! For example, researchers from Coastal Ecosystems Research Foundation (CERF) wonder what the heart rate of a free-swimming gray whale is. (What's your guess?) This Canadian non-profit organization conducts research on gray whales in British Columbia and Baja California. In February 2001 they began a long-term study of grey whales at the other end of their migration trail. "We spent a month in San Ignacio Lagoon, working in collaboration with Mexican researchers, as well as on our own projects. Our primary aim while we were there was to measure a heart rate in a free-swimming grey whale, something that has never been done before for any species of baleen whale. The project involved getting a suction-cup heart rate monitor tag onto a forty ton animal using a four-foot pole-- an experience that did wonders for our own cardiac output! We came home with several recordings, some of which may have heart rates, though we won't know for sure until we go through the data with a fine tooth comb."
CERF also helps with ongoing studies of abundance and movements being conducted by a research group from the Universidad Autonoma de Baja California Sur, in La Paz. They took 1300 photographs of approximately 200 whales, and are looking particularly for any of the whales they know from British Columbia. As CERF heads back to Mexico again next winter to continue both projects, we hope their news will be part of OUR news from the lagoons. Stay tuned!
As Far As the Ice Allows
You may remember that gray whales don't have dorsal fins, but instead have 6 to 12 knuckles or bumps along the dorsal ridge. Robyn's observation in today's report mentioned this fact. When you think about their migration route, do you think this feature of their anatomy is an adaptation? How far north is the sea free of ice? Check out a picture of the latest ice situation here:
Beast Feast: Discussion of Challenge Questions #14 and #15
Challenge Question #14 asked, "What evidence suggests that a gray whale turns onto its side while feeding?"
Reading our page "Beast Feast" gave you this answer: Scientists have noted that the baleen is often worn and there are generally fewer barnacles and skin abrasions on the right sides, indicating that the whales have a side inclination to their feeding.
Challenge Question #15 asked, "What are feeding tracks?"
Feeding tracks are the marks left in the ocean bottom by the feeding of gray whales. The food they eat dwells on the ocean bottom. With their mouth 10-20 cm above the surface of the ocean bottom, these baleen whales create a pulsating suction by depressing their tongue. The suction pulls the prey from a depth of 20-30 cm. Feeding tracks are slightly curved and measure about 3 meters long and about 1 meter wide.
Cow/Calf Pairs: Response to Challenge Question #16
We asked you to look at the data last time and answer this: "Of the 696 Northbound gray whales counted by the ACS Census so far, the percentage of cow/calf pairs is ______."
Calves, which are still nursing, travel with their mothers, so the 18 cow/calf pairs are about 2.5% of the total seen up until April 30.
Year-End Evaluation: We'd Appreciate Your Thoughts!
Please take a few minutes to share your suggestions and comments in our Year-End Evaluation Form below. The information you provide at the end of each year is the single most important tool used to guide our planning.
Have a Whale of a Summer!
This is the FINAL Gray Whale Migration Update for Spring 2001. Have a wonderful summer as you keep your eyes open for news of gray whales. We hope you'll be back with us for the gray whales' journey north in 2002!
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