2006 Right Whale Field Notes

                    -March

March 30.  2006 has been a hard-luck year for the PCCS habitat studies team conducting surveys and sampling aboard the R/V Shearwater.  Vessel-based right whale sightings remain very scarce (a total of 4 to date this year!) and zooplankton collections continue to reveal extremely low densities in both the surface and water column of Cape Cod Bay.  Despite reports of six right whales aggregating and feeding in the southwest quadrant on 28 March, two days later they had all apparently exited the Bay, and the zooplankton resource on which they fed had dissipated.  However, the recent calm, sunny conditions have brought about some notable changes in Bay waters.  First, on-station profiles of water temperature revealed the initiation of a vertically-stratified water column in which a slightly-warmer, less-dense layer lies on top of cooler, denser waters.  This thermal stratification typically develops and intensifies through spring until two distinct layers comprise the water column, with a strong density gradient preventing mixing between the layers during summer.  An extensive phytoplankton bloom was also observed throughout Cape Cod Bay during this cruise – a phenomenon that was exceptional in its intensity and extent, coating zooplankton nets at all but one station (in the far northwest) and making waters appear thickly brown.  Subsequent microscope analysis revealed that the phytoplankton species present are not harmful or toxic, and it is likely that this bloom will be grazed down by zooplankton in the coming weeks – hopefully generating sufficient zooplankton densities to attract right whales into the Bay to feed.

March 30.  With the forecasters predicting another perfect day out on the water, the R/V Shackleton headed out to the southern central region of the Bay. This area was searched extensively but no right whales were found. No whales were seen inside Cape Cod Bay by the aerial team either, but there was a possible sighting of a right whale from the R/V Shearwater in eastern part of Cape Cod Bay. The team on R/V Shackleton went to the whale’s location to investigate, but all that was found was a lone minke whale.

March 30.  Today the survey team decided that if the whales wouldn’t come to us, we would have to go find them.  We completed a full survey of Cape Cod Bay without finding a single right whale.  A lone fin whale surfacing off of Race Point and the quick movements of a couple of minke whales were the highlight of the survey.  Upon leaving the Bay, the survey team headed north-east of Cape Cod to complete a series of tracklines over the Boston shipping lanes.  Within minutes we found a surface active group containing five right whales to the north of the shipping lanes.  The white belly of a female right whale glowed as she lay belly-up at the surface.  The four other whales in the group swam around and under her, attempting to turn her over for a chance to mate with her.  The survey team worked quickly to obtain photographs of each whale as they surfaced and then dove beneath the female.  Continuing on, the plane was only able to survey for a couple of miles before they came upon the next group of right whales.  Baleen glowed underwater as the whales fed subsurface.  The longer we circled in this area, the more whales we found.  Within the two hours we spent with these whales, seven whales were sighted.  As the seven whales fed within a mile of each other, they merged together and moved apart continuously.  The whales fed head to tail in a line, staggered in a diagonal pattern and at one point were so close to each other that two collided.  With the sun lowering in the western sky and the light failing us, the survey team reluctantly left the whales and headed for home.

March 29. The R/V Shackelton headed out to the area where the team encountered feeding whales yesterday and searched to no avail. The team was then given the location of a right whale that had been seen from the plane. This whale was sighted briefly but spent the vast majority of time subsurface, surfacing only for a few seconds. The hydrophone was deployed and the team listened, but no vocalizations were heard from this whale. This whale proved impossible to follow due to the amount of time spent underneath the water. Although no more right whales were subsequently seen in the Bay, two harbor porpoise and several harbor seals were sighted.

March 29. This morning the team left Chatham early, eager to get an early start for they thought would be a long, whale-full day.  As the plane made its way from the southern part of Cape Cod Bay to the north, the observers found that the whales that had been here just yesterday were no where to be found.  As the observers broke away from their track line to record the position of a humpback whale, they noticed a dark shadow far beneath the surface.  The pilots circled over this spot as the observers tried to identify the shape.  As the shadow began to rise from the depths, the tell-tale white glow of a right whale’s callosity became visible.  This right whale’s open mouth indicated that it was feeding at some unknown depth.  Although this was the only right whale spotted during this survey, the fact that it was so hard to find leaves us wondering if there were a few others slinking along out of sight. 

March 28.  Today’s flight started a sequence of three great field days.  The winds were predicted to remain between 5 and 10 knots and thus the seas would be calm.  Such a weather window would allow the aerial survey team to cover Cape Cod Bay on three consecutive days, giving them a truly complete picture of how the right whales are currently using the Bay.  Although today’s flight began in the late morning, the action started quickly as right whales were spotted just five miles north of the Cape Cod Canal.  Six right whales hung underwater with their enormous mouths agape as they fed on a tightly packed line of plankton.  This highly concentrated food resource was visible from the air, appearing as a dark orange strip in the water.  The airplane circled over the whales as the observers recorded their positions and behaviors.  The photographer waited patiently until the whales surfaced for a quick breath, taking identifying photographs of the whales’ unique callosity patterns once their heads broke the water’s surface.  We stayed with these whales for over an hour, watching them feed subsurface along this slick.  Once a whale would reach the end of the slick it would make a sharp turn and travel back through it in the opposite direction.  Confident that we had identifying photographs of each whale, we continued with our survey.  No other right whales were sighted this day. 

March 28.  Sea and sighting conditions in the bay were perfect and early on the aerial team found a group of six whales for the researchers on R/V Shackleton to work with. The whales were concentrated in a relatively small area on the west side of Cape Cod Bay. As soon as the whales were sighted the team deployed the towed array and began making acoustic recordings. Many right whale vocalizations were heard and recorded and at the same time behavior was described and recorded. Several different behaviors were observed throughout the day from skim feeding and sub surface feeding, to socializing, breaching, and fluke waving. Right whale calls were also heard at the surface without the aid of the hydrophone. Vocalizations were linked to individual right whales and vocalization rates could also be tied with behavior. Photographs of individual right whales were also taken so that they could be identified and to make sure that we know which individuals were being followed throughout the day.

March 25.   The aerial survey plane taxied down the runway early this Saturday morning.  The team was excited due to yesterday’s sightings.  Would the right whales still be in the Bay?  Would we find several whales in an energetic surface active group as they had been yesterday?  The wind had picked up a little overnight and we found that our sea was no longer a glassy mirror.  Small wavelets covered Cape Cod Bay and occasional white caps forced the observers to stay diligent and as they constantly searched the water for any indication of a marine mammal.  Unfortunately the team’s efforts went unrewarded.  No marine mammals were seen during today’s survey.  Such a day proves how dynamic these whales really are.  While they do follow a general migration, traveling as far south as Florida in the winter and up to cold Canadian waters in the summer, their small scale movements can vary.  For a whale that travels at about 6 miles/hour, a trip from Cape Cod Bay to the Great South Channel would take less then a day.  If these whales are looking for a food resource, they could easily travel back and forth between these two spring feeding habitats to locate the best food.  The aerial survey team completed their survey and returned home, hopeful that the right whales will be back in Cape Cod Bay by their next day in the field.

March 24. Over a week had passed since we were able to conduct a full aerial survey of Cape Cod Bay.  As we boarded the plane everybody was hopeful that today this spell would finally be broken. The sea was very calm this beautiful sunny morning, the water’s surface resembling a mirror only disturbed by small flocks of seabirds resting at the surface. It was one of these “patches of birds”, that after careful observation turned out to actually consist of two right whales barely breaking the water’s surface. After circling over these two whales for some time we realized that one of them looked familiar. It was the juvenile whale that we had encountered twelve days ago (see field notes for March 12th). This juvenile is easy to identify, due to its white belly that wraps up around its right flank and glows underwater. Having photographed both whales we continued our survey, excited and hopeful to find more animals further north in the Bay. Soon enough we caught sight of another right whale surfacing off Race Point Beach. We quickly discovered that this whale was less cooperative than the first two in that it rarely broke the surface of the water, making photographing the whale extremely difficult.  After almost an hour of constant circling we decided to carry on. Shortly after leaving Bay and heading down the eastern shore of Cape Cod, a couple of blows caught our attention.  As we headed to the blows we found two right whales that were soon joined by a third as it surfaced after a long dive.  We watched and began to photograph the individuals as they formed a surface active group (SAG).  A SAG is a group of right whales, rolling and touching at the surface.  Researchers believe that these groups form for mating and socialization purposes.  Most SAGs consist of one female and several males that jostle for position in order to mate with the female.  While such groups can be extremely energetic and fast-paced, they are not violent.  After taking time to be sure that all the whales in the SAG had been photographed, the airplane headed back to the Chatham airport.

March 22. Cape Cod Bay had been pounded by relentless winds from the north for well over a week, creating unworkable conditions for all the Center's research teams.  By all weather predictions, a slight easing was expected for today, and the Skymaster, the R/V Shearwater, and the R/V Shackleton were prepared to take advantage of the small weather window to comprehensively survey and sample the Bay.  Anticipation soon turned to frustration, though, as the winds and seas refused to slacken.  The Skymaster flew two survey tracklines before conceding that sighting conditions were too poor to complete a meaningful right whale survey.  The crew of the R/V Shackleton made it as far as the mouth of Sesuit Harbor, where the numerous white caps and breaking waves foretold of challenging working conditions.  Difficulties in deploying the acoustic equipment and the low chances of sighting a whale in such seas would have made their efforts fruitless.  The R/V Shearwater was able to endure the churning seas for several hours – long enough to complete zooplankton sampling at all stations in the eastern half of the Bay – before they, too, were forced to head for home.  Although no right whales were sighted on this dreary day, this does not mean that the whales have left Cape Cod Bay.  The researchers would need to complete a full survey in clear and calm conditions before such a statement could be made.  For now the researchers have returned to their offices and desks to impatiently await a break in the weather.

March 13.   After hearing enthusiastic reports from the air surveillance team that they had sighted seven right whales in Cape Cod Bay on Sunday and that some of the whales were feeding just beneath the water's surface, the Center's habitat studies team scrambled to assemble gear and personnel for a Monday cruise to assess the distribution of the zooplankton resource (right whale food) in relation to the whales.  Where were the zooplankton most abundant?  What species of zooplankton were being targeted by the whales?  How dense were the "patches" of these tiny animals on which the right whales were feeding?  All of these questions were in the minds of researchers aboard the R/V Shearwater as they left the dock, anticipating a busy day of towing nets to collect zooplankton at regular stations and in the vicinity of feeding right whales, as well as coordinating with the air survey team in order to locate and photograph individual whales.  The weather, however, apparently had a different agenda, as scientists found themselves enveloped in thick fog and soaking in rain for most of the day.  The range of visibility was less than 2 km at all times, and looking out from the boat observers were met with a wall of impenetrable gray with no distinct horizon for reference - a scene which becomes a bit unsettling to look upon after six hours or so.  Despite these uncooperative sighting conditions, the seas were mercifully calm and quite conducive to the hauling of nets, and as expected zooplankton were discovered in much higher abundance near the area where the plane had reported right whales feeding subsurface than at any other location in Cape Cod Bay.  Future microscope analysis will identify the zooplankton species in the samples to elucidate the composition of these right whales’ diet.  Although no right whales were spotted during this cruise, the crew was kept alert and entertained by occasional sightings of harbor porpoises and seals near the boat, and were also bolstered by increasingly frequent sightings of northern gannets - pelagic seabirds whose return indicates the coming of Spring!

March 13. Despite the morning fog the R/V Shackleton headed out into Cape Cod Bay. Progress was slow and steady as visibility was often reduced to less than a nautical mile. The team made their way to an area where whales had been seen feeding the previous day and began survey tracks through the area. Despite the poor conditions the team managed to find their second right whale of the week, as well as several seals and a lone harbor porpoise. This was the first sighting of Slash (#1303) this season, a female right whale first seen in 1979 and a regular visitor to the Bay last year with her calf. This whale is easily identifiable by the huge scars on her fluke, believed to have been caused by a boat collision. The team managed to follow Slash for two hours but sighting conditions were hampered somewhat by the continuing fog. 

March 12.  The R/V Shackleton left Sesuit Harbor this morning for the first time this field season. The Shackleton research team of three plans to undertake focal follows of right whales in Cape Cod Bay over the next couple of months. The aim is to collect data on small-scale movements of the whales within the Bay, vocalizations, surface and dive behavior and photo-identification. The team will then use this information to assess the vulnerability of right whales to ship strike and to help provide advice for development of management measures to mitigate future ship strikes. With the wind due to rise in the afternoon the team set about testing the acoustic equipment. The passive towed array, enables the team to listen to the vocalizations of whales was streamed out behind the boat. The array consists of two hydrophones (or underwater microphones) and preamplifiers, encased in plastic tubing and filled with isopar oil.   A digital audio tape (DAT) recorder allows recordings of vocalizations to be completed for later analysis. The team is in constant radio communication with the other research platforms in Cape Cod Bay. Radio contact with the aerial survey team is particularly important as they regularly update Shackleton with locations of all of their right whale sightings. The boat team was informed of several whale sightings today and this coupled with visual observation from the boat meant that the first whale was easy to find. The weather however, was not on the team’s side and after the first glimpses of the whale we had to head for home.

March 12.   Anticipating rain this afternoon, the aerial survey team took to the air early this morning.  Starting in the southern part of Cape Cod Bay, we worked our way north throughout the day.  The tracklines went quickly, as no whales were sighted in the southern part of the Bay.  Just as the team began to wonder if the whales had left to find food elsewhere, a black flipper surrounded by turbulent white water appeared to the north.  Breaking away from our trackline to circle on the whale, the team realized that the white water was the result of two right whales interacting at the surface.  The team prepared to photograph the pair as they dove together and reappeared lying belly to belly.  The white belly of one whale gleamed underwater as it dove beneath its partner.  Photo analysis conducted back at the lab revealed that this pair consisted of a female and a male, indicating that this social interaction may have occurred for mating purposes.  As the aerial team continued to survey, more right whales were spotted in quick succession.  Slightly northeast of our first sighting, four right whales were photographed within one mile of each other.  Several of these whales, appeared from the depths with their huge mouths gaping.  The observers excitedly noted this behavior, which indicates that the right whales have found food in Cape Cod Bay!  Among the individuals seen in this area was a small right whale.  Based on its size and a few remaining red cyamids, a distinct species of whale lice commonly found on the callosities of young right whales, the observers believe this whale is a yearling.  Although yearlings are certainly old enough to fend for themselves, they occasionally travel with their mother well into their second year of life.  Once this yearling is matched to one of last year’s calves, we will be able to determine if it arrived in Cape Cod Bay with its mother or as an independent, self-sufficient whale.  The aerial survey team continued to search for whales until the rain moved in, sending them back home before completing the survey.  The team will now anxiously wait for the wind to calm down again so they can discover how many right whales are using this habitat.

March 8. The aerial team started their survey in the northern part of Cape Cod Bay today. After surveying for a couple of hours, we received a call from R/V Shearwater, who had found right whales while taking plankton samples. As we flew over to assist in photographing, we realized that there were two adult right whales here, swimming side by side. While we circled above these whales, we noticed a front line in the water, where the color of the water distinctly changed. Such front lines can be caused by the convergence of water masses as a result of winds, currents and/or tides. These areas are often found to be teeming with zooplankton. Unfortunately this was not the case today. Continuing our survey, we searched for any signs of a marine mammal. After completing a few more tracklines, two more right whales were spotted. Recognized by the broad, white scar across her back, the observers tentatively identified one of these whales as right whale #1039. #1039 is an adult female and an occasional visitor to Cape Cod Bay. Last year she was sighted by the aerial team in the Great South Channel, which lies to the south-east of Cape Cod and is a good feeding area for right whales in the late spring. Near the end of the survey, one last right whale was seen gracefully diving out of sight. Unfortunately the aerial team could not wait for the whale to surface, as the plane was getting low on fuel and the sun was getting low in the western sky. Elated by the day's sightings, the aerial team headed home anxious to review their photographs and match the whales to individuals in the Right Whale Catalog (maintained by the New England Aquarium).

March 8. The R/V Shearwater and its skeleton crew embarked on the ninth Cape Cod Bay habitat monitoring cruise of 2006, hopeful for thick plankton tows and right whale sightings. Conditions at the dock were mostly sunny and winds were low, but as the boat left Provincetown Harbor researchers were greeted by a larger-than-expected swell from the north, residual from nearly a week of north winds. Vessel-based habitat surveys involve two principal activities: collecting zooplankton samples by towing nets at predetermined locations in the Bay, and watching for whales and other marine mammals while transiting between sampling stations. Both of these activities become more difficult in choppy seas, but today the crew was roused as on-station net hauls showed that the zooplankton resource (right whale food) had apparently increased since the last cruise on 2 March. These higher numbers of zooplankton encouraged the scientists because when swarms, or "patches," of these tiny animals become sufficiently dense in the water column, right whales become attracted and come to feed. As the last station was approached, observers briefly caught sight of not one, but two right whales surfacing less than a half-mile away, the spray from their blows hanging over the increasingly rough seas. Collecting photographs of these animals from a rolling boat was not going to be an easy task, but as if on cue the survey airplane was spotted in the distance, so a call went up for assistance - much to the relief of the boat's crew! Photos were taken from both platforms in hopes that identifiable images of each right whale would be acquired. After a final plankton tow in the general vicinity of the whales, and with the plane still circling overhead, Shearwater turned and headed back to Provincetown, its science crew queasy yet satisfied by the day's work.

March 2. Taking advantage of the calm before the storm, the aerial team hurried into their Cessna Skymaster this morning. A solid cloud cover, indicative of the predicted snow, made for good sighting conditions with little to no glare over the water. Shortly into the flight one observer noticed a disturbance of the water. We broke away from our trackline to investigate, hoping that this would turn out to be the first right whale of the day. Within a few minutes the whale returned to the surface. Its dark body and glowing white callosities proved it to be a right whale. The whale headed to the north, swimming subsurface and out of sight. Eventually identifying photographs were obtained when the whale surfaced quickly to breathe. We continued to survey the Bay slowly working our way from north to south. Halfway through the survey, a second right whale was found. This whale hung at the surface a bit longer, making it easier to photograph. As we finished with this whale and turned west to begin our next trackline, we discovered that the foreasted snow was moving in quickly. Aborting the survey, the plane headed for Chatham and landed just as the first snowflakes were settling on the ground.

See field notes from earlier this season.

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