March 12, 2001 Report
by Chris Slay
New England Aquarium?s Right Whale Research Group
"From 25 February through 03 March, we flew all 7 days, although 3 surveys were shortened due to morning fog.
In that one week, we had 50 sightings; 43 were mother/calf pairs. On a single flight, we had 10 different mothers
with calves, all within a few miles of each other. There's never been a week like that since the inception of surveys
in the calving ground. We may have been witnessing a pre-migration staging event. The area off of Amelia Island
appears to be where the animals "bunch-up" upon arriving in the calving ground, before stringing out
along the Florida coast. A similar massing seems to occur at the end of season, before most of the animals head
north along the eastern seaboard.
Weather kept us grounded from 04 - 06 March. Upon returning to the daily grind we have seen no more than 2 mother
calf pairs during a flight. We were skunked on the 9th, only the fifth time that's happened in almost 70 flights.
There may still be 2-3 pairs south of us based on reports from other groups down the coast but I'd say that most
of the class of 2001 is somewhere between Savannah and Cape Cod. Hopefully they'll meet with better luck than
#1160, the first confirmed vessel-struck whale of 2001.
Number #1160, or Bolo, named for the shape of her callosity pattern which resembles that primitive
South American weapon, was sighted by us on 08 December, with another female, #1509 (Rat). These two were hanging
out together during mid-December until Rat was seen alone on 27 December. Five days later she was sighted with
a calf. It would be another two weeks before we saw Bolo again. When we came across her on 16 January she had also
given birth. Her calf has solid white flukes and white-rimmed flippers, which makes the pair instantly recognizable.
So when the University of North Carolina at Wilmington reported a calf of this description, we were pretty sure
we knew the pair in question. UNCW conducted aerial surveys for whales along the coast of the Carolinas during
February. They sighted four different mother/calf pairs, including #1970, a mom not seen by the other teams. We
appreciate UNCW adding this animal to the list for 2001. During the course of their surveys, they located #1160
off of Hilton Head Island, SC and reported that a boat had struck her. This was based on the observation of gruesome
propeller cuts tracking across 10'-12' of her back. That was 16 February.
We had last seen this pair off of Amelia Island on 29 January, unscathed. She must have sustained the wounds along
the coast of Georgia during the first half of February. Backtracking, Bolo returned to the EWS survey area and
was sighted by our crew on 28 February, off Brunswick, GA. The next day, en route to their survey area, the OSS
(Offshore) team sighted Bolo and her calf off Brunswick. Lisa Conger, leader of the offshore aerial survey team
(a unit of the Florida Fish and Wildlife Conservation Commission)OSS team, located the pair by water, enlisting
the help of a GA-DNR enforcement vessel. She had a relatively good look at the cuts and reported that the injury
doesn't appear life threatening. The lacerations go into the white blubber layer but not too deeply. None of the
cuts appear deep enough to effect muscle tissue. From Conger's descriptions and from aerial photographs, it is
evident that there is series of cuts along the whale's side, parallel to the ones on her back. This suggests that
the vessel striking her was of the "twin-screw" variety. The length of this series of cuts, their size
and the distance between each cut, indicate the boat was probably between 45 and 75 feet in length and moving very
fast. It would be a reasonable guess that the vessel was a twin-diesel powered motor yacht, about 50' long. We've
seen a lot of those boats bombing around the calving ground at speeds well over 20 knots. It looks like #1160 may
have tried an evasive dive, as the forward half of her body has no outer signs of injury. The portion of her back
that would arch up upon submerging is where she took the hit. She's also missing a dinner plate-sized chunk of
tissue from the notch of her flukes. Had the calf taken this hit, it would be dead. I think the word Conger used
was "lucky".
No doubt, there's some guesswork involved in understanding boat/whale encounters. It's hard
to know how whales react to oncoming vessels. We have contacted ships from our aircraft on several occasions this
season when we perceived there was a potential for collision. While we might observe a vessel making course or
speed adjustments, it's difficult to ascertain what the whales hear beneath the surface and how they might attempt
to avoid being run over. Two incidents come to mind that give us some information about whales' responding to ships.
On 10 February, at 1101 hours local, the EWS team noticed a vessel approaching a pair of whales they had finished
photographing 2 minutes earlier. The vessel was headed toward the whales so they flew over the freighter to get
an exact location, vessel name and to radio the ship. The mother and calf were surfacing/submerging, not making
much forward progress, slowly headed south at N30 59.6 x 081 1.9. The freighter Winfield was outbound from Brunswick,
N31 01.5 x W081 13.7, heading ESE, 1.9 nautical miles (NM) from the whales.
The crew was unable to get a response from the ship on VHF. When the ship was 1 NM from the whales the pair changed
direction and began swimming NNE, across the path of the ship. Could this have been a response to detecting vessel
noise? The skipper of the dredge Lindholm, knowledgeable about right whale conservation efforts, overheard the
EWS crew's attempts to raise the Winfield. He responded and asked the EWS crew for a location and asked which way
the Winfield should alter course. He then successfully raised the Winfield, explained the situation and the ship
made the suggested course change to port (NE). No change is speed was apparent. When this course change was made,
at approx. 1111 hours, the ship was .5 NM from the whales and closing. Until the course change was made, it appeared
a collision was imminent. When the ship changed course the whales appeared to respond, possibly to a change in
the acoustic signature of the vessel that occurred with the course change? The mother and calf turned and headed
WSW. The dredge captain relayed an updated location from the EWS crew and gave the ship an "all clear"
when they had passed the whales. At 1117 hours the ship went to a course of ~150 degrees. A rough speed check was
done at this time. The ship covered 2.4 NM in 10 minutes: 14.4 knots.
Two days earlier, the EWS team began circling a mother and calf right whale for photos and noted a submarine approaching
from the southeast. They estimated the sub to be ~3.5 NM away, heading NW, directly to the whale's position (exact
times and locations are omitted). The pair was at the surface, swimming slowly to the south. The EWS crew continued
circling on the whales while calling the sub via VHF. Contact was made and the sub's crew stated that they would
post an additional lookout and reduce speed to 10 knots. The submarine was observed slowing at this time, further
reducing speed as it neared the whales. Observers estimated sub's speed at less than 10 knots. When the submarine
was approximately 200 meters from the pair, the whales dove and apparently changed direction, almost 180 degrees.
When they resurfaced, less than a minute later, they were approximately 300 meters off the starboard beam of the
submarine, heading NE. At this time submarine's crew transmitted that they would maintain a reduced speed.
Events such as these will be much less common as the season comes to a close. Halfway through today's survey and
only one mother/calf pair has been sighted. It's starting to feel like we're seeing the last of the stragglers
at the end of a party.
By the way, we now have a calf count of 26, minus the one mortality."
Copyright 2001 Journey North. All Rights Reserved. Please send all questions, comments, and
suggestions to our feedback form
|