KILLER WHALES 2005 - Tiu Similä Tiu Similä
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KILLER WHALES
2005
© Tiu Similä
Tiu Similä
This is the annual report of the Norwegian Killer Whale Project (NORCA). Year 2005 was
one of the most productive and exciting years since the project started in 1987!
WINTER, SPRING AND SUMMER
During winter and spring photo-identification pictures and other data were analysed. The
main focus of the project during this time was on the four MSc and one BSc study which were
to be completed before summer. Tiu gave a talk in April at the annual conference of European
Cetacean Society on interactions between killer whales and herring. During summer we
continued our pilot survey of killer whales occurring along the coast of Tromsø and
Finnmark. This work progresses, but slowly, since there does not appear to be any seasonal
“hot spot” for killer whales in these waters. Reports of killer whales feeding on whales and
seals support the hypotheses that these coastal waters as well as much of the Barents Sea are
inhabited by killer whales preying on marine mammals. This would explain their apparently
wide range and unpredictable occurrence. We are hoping that a more intensive study will be
conducted on these whales in near future, including genetic sampling to learn about their
relatedness to the herring feeding killer whales as well as other killer whale populations in the
Northeast Atlantic. These studies should also include fatty acid and stable isotope analysis, to
learn more about their feeding ecology.
George McCallum, our main ID photographer, managed to obtain killer whale identification
pictures during summer while onboard research vessels of the Marine Research Institute.
Most of these images were from the southern Norwegian Sea and the North Sea and none of
these individuals were matched to the ones we have in our catalogue. These whales probably
belong to the population of killer whales known to feed on mackerel in the North Sea. A
newly started co-operation project between Tiu and researchers from University of Aberdeen
and the Sea Mammal Research Unit aims to study the identity and behaviour of these killer
whales. Also these whales interact with mackerel fishing vessels in a similar manner to the
Norwegian killer whales feeding around herring purse seiners.
©Tiu Similä
WHALE-WATCHING
Killer whale watching in Tysfjord started in 1992 and since then the number of passengers has
increased from hundred a year to over four thousand, just in Tysfjord. There has been a
considerable concern about the possible effects the increased tourism could have on the
behaviour of the whales. It has been a key priority of the research project to work towards
ensuring responsible whale-watching in the area.
To raise awareness around these issues, Dr Rob Williams from British Columbia, Canada
visited Norway in late October. Rob has done extensive research on how killer whales are
affected by boat traffic and is one of the worlds leading experts on these issues. Rob visited
different whale-watch operations in the area and arranged a workshop for tour operators and
guides in the end of October at the Tysfjord Tourist Centre.
©Sanna Kuningas
- NW-7 with whale-watchers-
Natural behaviour of killer whales (as well as that of other whales) can be disturbed by boat
noise. To avoid this, there are a few simple and very effective rules that should be followed by
those driving the boats; never approach killer whales from the front or from behind, keep the
speed low and direction of the boat as constant as possible. In addition, it should be avoided
that several boats follow one group of killer whales. In other areas where killer whales are
watched, this is often not possible. In Norway the large number of whales in the fjords usually
allows the whale-watch fleet to “spread out” so that the number of boats/killer whale group
can be kept low. The key issue is good communication between the skippers of different
boats.
In recent years one of the biggest problems has been so called “good weather weekends”. On
calm, cloudless Saturdays and Sundays killer whales are being watched not only by the
commercial whale-watching fleet but also by private boats. It is very positive to see the
increased local interest in killer whales, however, the drivers of these boats usually do not
know how to behave around killer whales which creates difficulties for the whales and whale-
watchers. A typical example is so called “leap-frogging”; a boat speeding up to whales every
time they surface instead of approaching slowly, parallel to the whales. It was agreed in the
workshop that one of the priorities for work in 2006 is to reach out to the general public and
inform about how to watch whales without disturbing them. This work will be done in
cooperation with WWF Arctic Programme.
Norway is the only place in the world, where tourists can go snorkelling with killer whales.
Being the only operation of its kind sets a special demand for setting a high standard.
Guidelines for snorkelling and diving with the whales will be written together with Lofoten
Opplevelser, which is the tour operator with longest experience in arranging such trips and
Anthony Mayer who has been in the water with the whales hundreds of times since 2001 and
has an extensive understanding of their behaviour with snorkellers.
Another concern has been whether the whale-watching boats are “conditioning” whales to
follow boats. There are several observations each year of killer whales following whale-
watching boats, playing in the jet stream of propellers, approaching divers, responding to
whistles and other sounds made by passengers etc. The question has been if whale-watching
teaches killer whales to follow boats, which could have negative consequences for the whales.
Malin Lundgren from the university of Gothenburg, Sweden, did her MSc thesis investigating
the “friendly whale” behaviour. One of the main aims of her work was to determine the age of
killer whales following and interacting with whale-watching boats. Her results show that it is
almost exclusively young (less than five year old) individuals that interact with whale-
watching fleet. If some individuals had learned over the years to follow boats, her sample
would have included several sub-adult and adult individuals. Although this study shows that
there is no reason to be concerned about long term effects on the behaviour of individual
whales, there is every reason to be cautious, in particular when young whales play in the jet
stream created by the propellers. Several killer whales in the photo-identification catalogue
bear evidence of too close contact with boat propellers.
Ana Catarina Alves from the University of Lisbon, Portugal, used photo-identification data
collected from the whale-watch boat “Leonora” in 2002 and 2003 to investigate if this data set
could be used to study social organisation of killer whales. Her data clearly showed that there
are stable bonds between individuals. However, there are a couple of basic problems in using
a whale-watching boat in photo-identification work. First, encounters with one group are
often too short for a proper documentation of “who was there” and more importantly, a
whale-watching boat is not driven like research vessel and therefore getting to the left side of
the whales (where identification pictures are taken from) is not a priority.
©Tiu Similä
PHOTO-IDENTIFICATION WORK
One of the problems of the photo-identification work is that there are a large number of
whales in the study area and the days are very short. Therefore the chances of getting
identification images of each individual in a group/encounter are small. In her MSc thesis,
Erika Melander from the university of Gothenburg investigated whether digital video camera
could be a useful tool in identifying individuals. Much of the material of her thesis was
collected by Anthony Mayer. Anthony has been working at the Tysfjord Tourist Centre since
2001, taking both surface and underwater video during the whale-watching trips. Erikas study
concludes that it is possible to identify well-marked killer whales from video tape. However,
the footage needs to have been taken very close (approximately less than two whale lengths)
to get good enough resolution in the images. It appears that a better option than using video
camera is to increase the amount of still cameras/encounter. However, a video camera is a
useful tool in estimating group sizes.
© Tiu Similä
- A newborn calf surfacing to breathe, tightly flanked by its family members. Documentation of births and
deaths is an important part of the photo-identification work -
As a part of her BSc thesis, Sanna Kuningas from the Sea Mammal Research Unit, started
together with Tiu to build a database containing detailed information on the photo-
identification material. In practice this means that each image where a whale can be identified
needs to be re-analysed for sharpness, contrast and angle of the image. The database also
contains information on best picture for each whale/year, presence of calves, group sizes etc.
It has taken several months to do this work, and still few months of “image gazing” remains
before the database is finished. Once all the data has been entered, the information can be
used for several purposes; trends in population size, survival and mortality rates, social
structure, group sizes etc. For her BSc thesis Sanna analysed population size using mark-
recapture method, based on data from 1991-92 and 2002-03. Her results show clearly that this
method underestimates the population size due to the fact that only part of the population is
“marked” (eg. identifiable) and that only some of the animals in each encounter are
photographed. In particular calves and juveniles very seldom have identifiable features and
even some of the adult individuals are virtually not identifiable. As part of her PhD study
Sanna will investigate the percentage of identifiable individuals in the population; this
information is vital for correct population estimates.
INTERACTIONS BETWEEN KILLER WHALES AND HERRING FISHERY
Since 2002 interactions between killer whales and herring fishery has been studied. Part of
this work was an MSc study at the University of Uppsala, Sweden, by Ylva Ericsson.
When the herring comes to winter in the fjords it is not present in small schools but as thick
(up to couple of hundred meters!) layers which can be several kilometres long. Although
millions of tons of herring are present in the wintering grounds and it can be said that the
whales are “swimming in their food”, it is not an easy task for the whales to get hold of their
meal. Much of the daily life of the killer whales in October-January is about how to get hold
of small herring schools that are easy to herd and prey on.
The whales are able to dive down to several hundred meters (at least 312 m) to start herding
herring from the wintering layer. However, this is an elaborate process and the whales do not
always succeed in isolating a school. Another option is to look for herring in areas with
underwater seamounts; in these areas herring layers are often divided into smaller patches and
in addition the seamounts help the whales in herding the fish. When the whales have
succeeded in isolating a herring school, they start herding it towards the surface. Before
feeding, they stun fish by powerful underwater tailslaps and feed on stunned herring one by
one. Detailed documentation of this feeding technique, carousel feeding, has been much of the
focus of our project.
At the same time as the stock size of Norwegian spring spawning herring has been growing
(after 1995), the fishing quotas have increased. Killer whales are inquisitive animals and
quick learners, and it did not take them long to realise that as the purse seiners and travwlers
are pumping in their catches, fish fall out of the nets. Just like fish the whales have stunned by
tailslaps, this fish is often lethargic which makes them easy for the whales to catch. The
research results show that feeding around fishing boats has become an important part of the
feeding behaviour of killer whales. There is a clear correlation between fishing activity and
observations of carousel feeding – in practice on a day with several fishing vessels out means
that we do not see whales feeding on their own. The reason why we have seen more carousel
feeding in December than in October-November is that by this time the herring quota has
been taken and fishing activity low.
©Tiu Similä
Feeding around fishing vessels, in particular purse seiners, is not entirely risk free for the
whales. Purse seiners often throw their nets close to other vessels that are in the process of
catching herring; this way whales that are feeding around a boat pumping in its catch can get
inside another boats net. The whales are capable of swimming through the nets and jumps
over the cork line have been reported, although rarely. When fishermen observe killer whales
inside the net, they usually try to lower down part of the cork line to release the whales and
avoid damage to their nets, but this is not always possible and the whales will try to swim
through on their own. Reports of killer whales getting entangled and drowning in the nets are
very rare; and all reports have been of very young calves (which are not strong enough to
swim through). Swimming through the nets can create cuts in the dorsal fin, most commonly
in the trailing edge. Analysis of killer whale photo-identification data collected in the
wintering grounds in 1991-92 and 2002-03 has revealed a significant increase in net marks in
the dorsal fins of the population, which is another indication of an increased interaction
between the herring fishing fleet and killer whales.
- Adult male NG-14 without net marks in 1992 (left) and in 2005 with net marks on his dorsal fin -
The fall 2005 was in many ways very different from the previous seasons. Only the oldest
herring wintered in Vestfjord, Tysfjord and Ofotfjord and younger herring (over 90% of the
stock) wintered in offshore waters northwest of the fjords. Luckily, the whales seem to prefer
the fat, old herring and we still saw killer whales each day. However, we did not observe
several of the family groups and it is likely that they spent their winter feeding on the younger
herring in offshore waters. In addition to there being less fish, the herring was present often in
very great depths – down to 600 meters! Although the herring migrates closer to the surface
during the night, it was still unavailable for many of the fishing boats and catching herring
must have been hard work for the whales as well. Therefore much of the fishing fleet tried to
fish in the offshore waters, and we therefore saw more carousel feeding in November than in
the previous years.
It is very probable that these recent changes in the migration pattern of herring indicate that
within the next couple of years no more herring (or killer whales!) will be found in the fjords.
Dramatic changes in the wintering migration of herring have occurred in the past and
although it is sad to realise that our time in the fjords might be over, it will be thrilling to
document how the killer whales will adapt to these changes. The deep offshore waters are a
different environment from the fjords with their varied topography, tidal currents, bays and
inlets.
RESCUE OF NP-1
On 3rd of November, Cathy Harlow, a guide on a whale-watching boat sighted a male killer
whale which had gotten entangled in fishing gear outside Skrova in Vestfjord. One of the tour
operators in the area, Orca Diving, had an experienced free diver Pierre Robert de Latour
onboard and we therefore contacted him for assistance. Luckily the boat was only three hours
from the entangled whale and could get there quickly to assess the situation.
The male, later identified as NP-1, had gotten entangled in line connecting a buoy and
flagpole, used for indicating the position of the net. The whale had got the rope twined twice
around its left flipper. This is the first report of a killer whale getting entangled in this kind of
fishing gear and it is not known how this accident happened. The most likely scenario is that
NP-1 had been chasing fish and accidentally making a “somersault” so close to the line that
he got his flipper entangled. After several hours of trying, Pierre had to give up the rescue
attempt the first evening.
©Heike Vester
- Adult male NP-1 entangled in fishing line -
The coastal guard boat “Malene Østervold” came to assist in the rescue operation and marine
mammal biologist Heike Vester from Lofoten joined the team. As soon as it got light the next
day, the rescue attempt was continued. The whale was able to swim in a circle of about 300 m
in radius, and every time Pierre entered the water the whale dove for several minutes,
surfacing hundreds of meters away. The rest of NP-1:s family group was observed in the area;
once two adult males approached NP-1 but rest of the time the family members stayed more
than 300 meters from the whale. Although no sound recordings were made, it is likely that the
whales kept acoustic communication
After several discussions of possible options of how to rescue the whale, the best choice
seemed to be to gain the whales trust and keep approaching him slowly with constant running
engine to send in the diver to cut the rope. Towards the afternoon of the 4th of November the
situation for the whale started to become critical; the rope was no longer loose but was
hanging straight down indicating that the net had moved and NP-1 had to actively drag it
towards the surface to be able to breathe. After several attempts the rescue team started to be
able to approach the whale closer and closer and in the end Pierre was able to cut the rope
about 8 meters behind the whale. He reported that just before he cut the rope, he was
swimming very closely, ca 5m next to the whale. At that time the whale did not swim away
anymore, he actually swam back towards the diver and turned, looking at him. The diver then
swam under the whales’ belly and could cut the rope. After he was cut free, the whale swam
fast out of the area, with 8 meters of rope and the flagpole still attached to his flipper.
However, it is likely that as soon as the rope no longer was connected to the net it became
loose and fell off the flipper. The NP pod was not observed later in the season, so we were
unable to report how NP-1 was doing after his rescue…
STUMPY UPDATE
Our little “celebrity whale”, Stumpy, was observed several times this season. Stumpy was
observed for the first time in 1996 as a one year old with severe damage to the left rib cage
and spine behind the dorsal fin. It was quite obvious that he had collided with a boat. Due to
his spinal deformity Stumpy is unable to dive properly (though we are still waiting for
underwater footage of his behaviour!) and therefore his ability to catch herring is limited.
Stumpy is taken care of by several family groups, which take turns in being his “family”. It
appears that he changes groups couple of times per month during fall; we have no information
of his social behaviour during spring and summer when killer whales and their prey is much
more widely spread. The total number of groups we have observed “babysitting” Stumpy is
now 11. However, it appears that some groups take care of him more frequently than others,
in particular NE5 and NE15 pods.
Unlike the past years, Stumpy was no longer just a spectator to feeding events, but appeared
to be more active. He still spends much of his time at the surface, but is no longer in the
“outskirts” of a feeding event, observing the feeding behaviour of other whales. In stead he
often coordinates his swimming behaviour with those of the other whales and is probably at
least acoustically participating in the herding and feeding events.
©Sanna Kuningas
- Stumpy in November -
D-TAGGING
The absolute highlight of this years research was cooperation with Ari Shapiro, a PhD student
from Woods Hole Oceanographic Institute, and one of his supervisors, Dr Patrick Miller from
Sea Mammal Research Unit, St Andrews Scotland.
Ari has started a 3-year PhD study on acoustic communication of killer whales in Tysfjord.
Ari has access to what might be called the “ultimate tool” in studying vocalisations in wild
cetaceans, namely the D-tag. This tag, developed by Mark Johnson, collects continuous
information on swimming speed, dive depth, body orientation and the vocalisations of the
individual. The tag is attached with four suction cups with a release mechanism, in Tysfjord
the tags were set to stay on for only a couple of hours to make sure they were not lost due to
tags being attached to the whales after dark. The tag carries also a radio transmitter, which
makes it easier to track the animal at sea and in particular to find the tag after it has been
released.
The research vessel “Iolaire” participated in D-tagging of sperm whales off Andenes,
Vesterålen, this summer and therefore the boat was already equipped with tracking gear and
several of the crew members had previous experience of tag attachment and tracking of the
whales. To get the most out of the tag data, the behaviour of the tagged animal and his
companions were observed in great detail and Filippa Samarro assisted Patrick Miller in
getting continuous sound recordings of the whole group using a towed hydrophone array. This
array also allowed for getting the bearing and position of different individuals. Needles to say,
to get all this data simultaneously was very demanding and required several skilled observers
onboard.
© Tiu Similä
- Iolaire tracking a tagged whale-
The tags were attached from a RHIB using a long pole and after tag attachment the whales
position, surface behaviour and heading as well as distance to the boat and to the whales
nearest neighbours were recorded at 5 minute intervals. The first field season was very
successful ! Eight tags were attached and a total of 24 hours of data were recorded. Even more
importantly, this data set includes two samples of two animals tagged in the same familygroup. This enables Ari to analyse vocal communication between family members during
different behaviours.
©Tiu Similä
- An adult male from NÅ-pod with a D-tag-
Filippas recordings with the towed hydrophone proved very useful in differentiating when the
whales are travelling from when they are looking for or herding herring. It is not possible to
distinguish between these behaviours just by looking at the surfacing pattern of killer whales
and a stationary hydrophone does not work particularly well for listening at moving whales.
NORWEGIAN KILLER WHALES MOST TOXIC MAMMALS IN THE ARCTIC
In 2002 biopsy samples were taken of killer whales to study their toxic load. This project is
directed by Dr Hans Wolkers from the Norwegian Polar Institute and is conducted in
cooperation with the WWF killer whale project. The results of the pilot study were published
in October-05; killer whales had record high levels of PCB:s, pesticides and brominated flame
retardants and are now classified as the most toxic mammal in the Arctic! These alarming
results have made it important to widen the sample size to have a good overview of the status
of the population; 18 new samples were taken in November -05 and the work will continue in
2006.
Killer whales in the Northeastern Pacific Ocean also have high levels of toxic chemicals.
Killer whales are long-lived mammals at the top of the food chain, which makes them
particularly vulnerable for accumulating toxic chemicals. The record high levels of pollutants
in Norwegian killer whales are alarming and indicate that their environment, the Norwegian
Sea, is not healthy and that chemicals in everyday products are contaminating arctic wildlife.
The appearance of a potentially dangerous brominated flame retardant in the killer whales is
of particular concern, because most of these are not substances which are not currently
banned. Brominated flame retardants can affect neurological functions, behaviour and
reproduction.Whether or not these high levels are a serious threat to the health and survival of killer whales
is not known. When the database on photo-identification data has been completed it will be
possible to start analysing trends in population size and also look into survival of calves and
adult mortality rates.
DEAD KILLER WHALES FOUND IN OFOTFJORD
Since the long-term study on killer whales started in 1986, a total of nine dead killer whales
have been recorded. It was therefore quite unusual that two dead individuals, an adult male
and an adult female, were found in Ofotfjord in late November (the male found first, the
female five days later). Usually, when a killer whale dies, the carcass sinks. It is very likely
that only bodies of individuals which are ill and strand in shallow water are found. The two
dead animals were found short time after the news of toxic loads in killer whales had made
the media headlines; therefore there was concern about possible connection between these
findings and the two dead whales. Both animals were obducted and their stomach contents
showed that they had not been feeding for some time before death, which indicates that they
were both ill. However, it was not possible to investigate what kind of illness… At the time
when the adult male was found and towed to Tysfjord, the killer whale project was visited by
Luis Freitas from Madeira. Luis is responsible for work on stranded cetaceans in Madeira and
therefore has extensive expertise in dissecting a dead whale; his expertise was vital for correct
handling and sampling of the whale.
©Tiu Similä
- The adult mal towed to a beach in Tysfjord -
The adult male remains unidentified, but both its length (6,95 m) and the wear in its teeth
indicate that it was an old individual. Bruises on its right side indicate that it had been hit by
an object (a boat?) before death. The animal had probably been very ill and floating at the
surface, unable to avoid collision with a boat. The female was identified as NU-8, an
individual we used to see very often in the early 1990`s, but more seldom the last 10 years.
Samples for genetic and toxic chemical analyses were taken of both individuals, and both
skeletons have been cleaned and will be prepared for display. The skeleton of the male will be
displayed at the Tysfjord Tourist Center.ACKNOWLEDGEMENTS
Funding for the project was provided by WWF Sweden, Tampereen Särkänniemi, Discovery
Initiatives, Orca Tysfjord, Canon and Dell Computers. Thank you!!
Coastal Guard boat “Malene Østervold” and M/S “Langoysung” are thanked for assistance in
the rescue of NP-1 from fishing gear.
Geoff McGee was an excellent and entertaining skipper of Iolaire, Mads Christophersen,
Andy Foote, Luis Freitas, Jesper Jensen, Petter Kvadsheim, Sanna Kuningas, Jenny Matteson,
Patrick Miller, Sari Oksanen, Filippa Samarro, Ari Shapiro, Jennifer Snowball, Jonatan
Svensson, Anders Svensson and Nick Trengenza all contributed to a memorable field season
in Tysfjord!
George Mc Callum and John Stenersen supplied the project with many valuable identification
pictures.
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