Anthrax in Africa, in Britain and in the lab

Two interesting recent papers reminded me of being woken in the night by a clattering on the door, people being roused and muffled voices. The next morning my bleary-eyed mother and grandmother told me it was the police who came knocking. An animal had died of anthrax on a local farm occupied by a cattle dealer and they had come to requisition coal, then strictly rationed, in order for the carcass to be incinerated without delay. They had to burn it, my grandmother told me, as I probably asked too many ‘why’ questions, because anthrax got into the soil and could infect and kill animals and farm workers years later. That would be in the late 1940s when I see from DEFRA that there were 119-344 outbreaks per year between 1945 and 1950 (anthrax is almost unknown on British farms now; the last, isolated, outbreak was in 2006).

The first paper† I read was on how some hoofed herbivores are attracted to anthrax-infected carcass sites in Etosha National Park in Namibia, thereby enabling anthrax to infect new victims. Despite the rapid removal of soft tissues by scavenging birds and mammals, a carcass was found to improve the soil and vegetation around it. The overall finding was that, initially, herbivores avoided carcass sites, then were attracted to them and finally showed no preference. Bacillus anthracis spores were found in the grass from these sites for up to two years after the animal’s death.

In the authors’ words:

The results suggest that for zebra, springbok or wildebeest encountering a site where a zebra has died within the last year, an animal is up to four times more likely to graze at the potentially infectious carcass patch than at a random grassland patch nearby…Carcass and control patches seemingly became indistinguishable again for grazers from 1.5 to 2.5 years after death of the focal animal. This seems to match the time scale of carcass effects detected in grass biomass and nitrogen, and early preference for grazing at carcass sites would significantly increase the odds of anthrax transmission from grazing in the first year after death.

There were, however, interesting differences between the herbivore species that are found in Etosha. Gemsbok showed no clear foraging preferences; this species also had a low incidence of confirmed anthrax cases (1.3% of cases between 1968 and 2011) while constituting 13.5% of the herbivore population as estimated by aerial survey in 2012.

A paper* from the same stable adds another level of operation of anthrax. When the grass preferred as forage by the zebra was grown from seed in an experimental plot, the addition of anthrax spores enhanced the establishment of grass seedlings by about 50%. When very small amounts of blood were added, the height of the grass was increased. Anthrax had no effect on height and blood had no effect on the establishment of seedlings. (No other carcass constituent was tested and it is possible, of course, that body fluids in general seeping into the soil could contain the constituent(s) responsible for the effect of blood.) Therefore it seems that anthrax in the soil acts to secure the rapid regeneration of grasses and the attraction of herbivores to carcass sites. Some constituent of blood then makes the grass crop more luxuriant and even more attractive to grazing herbivores. Natural selection has really equipped B. anthracis to exploit its hosts.

The other paper I read was the Biographical Memoir on Harry Smith FRS (1921-2011) by Alan Rickinson FRS‡. Harry Smith was always direct, to the point, of rapid judgement and, therefore, a delight to sit with at dinners. The last conversation I had with him, as he headed off to Birmingham, was about a scientific institution. ‘That place has gone down hill badly’, he said as he shot off into the night. However, I digress. Harry solved how anthrax kills. No lethal toxin had been identified in vitro. Only by working in vivo was he and his colleagues able to determine the mechanisms. Even then the toxin was not simple. There were three components, all non-toxic when tested separately, but together responsible for the devastating effects of anthrax on the body. Rickinson writes:

The discovery of the anthrax toxin was a significant advance that, with the benefit of hindsight, marked a turning point in the field of microbial pathogenesis.

And all that has been done since I was awoken during the night and introduced to the lethal world of anthrax.

Bacillus anthracis
https://phil.cdc.gov/phil/home.asp

These Plains or Burchell's Zebra (Equus quagga) are in the shade, not long before sunset, in Botswana in 2001

† Turner WC, Kausrud, KL, Krishnappa YS, Cromsigt JPGM, Ganz HH, Mapaure I, Cloete CC, Havarua Z, Küsters, M, Getz WM, Stenseth NC. 2014. Fatal attraction: vegetation responses to nutrient inputs attract herbivores to infectious anthrax carcass sites. Proceedings of the Royal Society B 281: 20141785. http://dx.doi.org/10.1098/rspb.2014.1785 

*Ganz HH, Turner WC, Brodie EL, Kusters M, Shi Y, Sibanda H, Torok T, Getz WM. 2014. Interactions between Bacillus anthracis and plants may promote anthrax transmission. PLoS Neglected Tropical Diseases Jun 2014; 8(6): e2903. Published online Jun 5, 2014. doi:  10.1371/journal.pntd.0002903

‡Rickinson, A. Harry Smith CBE. 7 August 1921-10 December 2011. 2014. Biographical Memoirs of Fellows of the Royal Society 60, 399-411

Newts in Britain: This is What Happened

I wrote the other week of protection of the Great-crested Newt (Triturus cristatus) in Britain as a result of habitat loss, and, for habitat loss, read the filling-in and building-over of suitable ponds. The local Common or Smooth Newts (now Lissotriton vulgaris, then Triturus vulgaris which in the breeding season were abundant in local ponds, slow-moving streams and ditches, got me interested in zoology. To illustrate what has happened to those habitats since 1960, I show the following two images from Google Earth of places I used to find newts. In one, the slow-moving stream has been culverted and, in places, built over. In the second, the pond has disappeared and the area is covered in football pitches. Local authorities just loved to 'tidy' remaining wild places, even if a habitat was not actually built over, and as a result ponds, streams and ditches which were ideal for children to explore have gone.

A small stream ran from right to left across this land in the 1950s

The pond that was here is now part of a football pitch

I never found a Great-crested Newt in this same area. However, I was intrigued to find the result of a survey for some building scheme that showed such an animal had been found in the past few years in the garden of a house. A note on the survey said that the site had been cleared in 1991 and the newts moved elsewhere. In other words, the pond had been filled in as houses were built. I never found this pond with its Great-crested Newt when I was looking in the 1950s and early 1960s. It must have been on an area of land that was allotments, nurseries and orchards (and described as such on the 1935 land-use map). I can see the land in my mind's eye now but I can only think it was at behind one of the large houses that stood back from the road and surrounded by orchards. Sadly, my friend at primary school who scrumped apples from these orchards (when not playing cowboys and indians with cap pistols and home-made tomahawks) and who might have been able to remember a pond there died many years ago.

However, moving on from my annoyance at not having found a pond that held Great-crested Newts in the 1950s, I do have a question: Is there any evidence that catching and moving Great-crested Newts from areas chosen for building 'development' have any effect on the size of the population? Or is translocation just 'greenwash', in other words, a load of eyewash that obfuscates conservation and protection and thereby permits builders and public bodies to pay lip service to conservation while filling in another pond?

Antarctic Zoology Loses Two Stalwarts: Dick Laws and Bernard Stonehouse

Closely following the news of the death of Dick Laws on 7 October, I saw the notice in The Times this week that Barnard Stonehouse had died on 12 November. Both started out with the Falkland Islands Dependencies Survey in the late 1940s and Dick later became Director of the successor body, the British Antarctic Survey. Both were born in 1926.

For followers of this blog, Bernard Stonehouse collected a series of Emperor Penguin embryos in 1949, as I described in In Search of a Penguin’s Egg. Why?...What happened to Nelson Norman's 1959 embryos? on 3 July this year.

FIDS and BAS, to my certain knowledge, exemplifies spirit of scientific collaboration that I hope continues. Workers in Antarctica could not have been more helpful in collecting, storing and bringing back material.

Dick told me that I must go to the Antarctic. I did. He was right.

Heading south to the Lemaire Channel. 30 January 2005

Salt Glands in Iguana iguana. Somebody got there first

After Knut Schmidt-Nielsen described his discovery of salt glands in marine birds in 1957, other scientists and naturalists realised that they had seen the phenomenon earlier but had no appreciated what they were seeing. In the early 1960s, salt glands were discovered in terrestrial lizards (the salt gland in the Galapagos Marine Iguana was described by Schmidt-Nielsen and his friend Ragnar Fänge in 1958).

In 1963 Knut, with Arieh Borut, Ping Lee and Eugene Crawford in a paper in Science (142, 1300) reported:

A specimen of the tropical lizard Iguana iguana which was kept in the laboratory was occasionally found with white incrustations around the nostrils. The material was water soluble and preliminary analysis showed large amounts of potassium as well as sodium. Closer observation of the lizard while kept in a glass-walled terrarium revealed that the animal had the habit of pushing its nose against the wall thereby leaving a salt deposit on the glass.

A few weeks ago I was looking for information on Mrs Kathleen Pickard Smith for my other blog on the history of keeping reptiles and amphibians. She wrote a popular book on her experiences during the 1950s, Living with Reptiles, which was published by Thomas Nelson & Sons of Edinburgh in 1961. I read the book in 1962 and eventually gave it to the Zoo library. On reading bits again while I was scanning it,  I find she noted the following about her iguana, 'Ig':

Never a fast or a hunger strike to alarm us—true, he sneezes quite a bit in cooler weather, which leaves a chalky deposit on his nostrils and on the glass of his cage, but this is quite natural.

So, again we have an observation of salt glands in action, this time in a terrestrial lizard, before the observer could appreciate what had been observed.

#180977731 / gettyimages.com

Chinchillas in Zoos, and early import

AJP Photograph

Long-tailed Chinchillas (Chinchilla laniger) appear to be in deep trouble in the wild. However, I have not been able to find any definitive evidence on their status that is not nearly 20 years old. There are, of course, lots of domesticated chinchillas which have their origins in this species (see my earlier post). The few zoos I have visited in recent years seem to show them as domesticated ‘educational’ animals rather than in a nocturnal house setting of naturalistic habitat or in the size of colony that might occur in the wild—in other words, an exhibit that would really play an ambassadorial role in drawing attention to the parlous state of this species in the wild. I thought I had read somewhere that a British Zoo once had such a colony of chinchillas. Then the Bartlett Society Journal dropped on my desk. Russell Tofts in his article on the history of Jersey Zoo (now called, euphemistically in what must be another example of political correctness and focus-group inspired marketing strategy, Wildlife Park) provided what I had been trying to remember, under the year heading 1966:

In Jersey, an airy block building measuring 10 feet by 12 feet, well-lit by natural light, was constructed for an initial colony of twenty-five animals. By the end of a successful breeding season, the colony had risen to thirty-one (including seven animals that had had to be removed).

I would not think the Jersey effort would have been successful as an exhibit. Chinchillas really do sleep all day and a reversed daylight system would be needed to see them on the move. Nor do I underestimate the difficulty of setting up a colony in the first place. Adult chinchillas take very unkindly to being introduced to new potential cagemates; very unkindly is an underestimate.

In the 1950s chinchilla bubble in UK, when gullible individuals thought they were would be able to make their fortunes by breeding chinchillas for fur, and prices of live chinchillas rocketed, pairs of chinchillas were advertised at from £50 in 1957, the equivalent of £875 today. I think these chinchillas were from imported stock that was probably derived from the Chapman collection which was taken to California in 1923.

Advertisement: Cage Birds 21 February 1957

However, Britain had seen chinchillas before then, both in zoos and private collections. I came across this mention in an article by HD Astley in the September 1913 issue of Avicultural Magazine

Mr Goodfellow [Walter Goodfellow, 1866-1953, the renowned collector] brought home from Chili [sic], landing in the first week of July, some birds which were a puzzle to those who had never before seen them. Mrs. Johnston very kindly invited me to go to Burrswood on the day after their arrival. Incidentally, the principal interest was not birds, but Chlnchillas; which I preferred infinitely to see in their skins, rather than the latter made into muffs and boas, etc. As however, they are not birds, I must refrain from studying them too closely, at any rate in the Magazine suffice it to say, they are most fascinating, and a pearly-grey coated Chinchilla, when tame, would make a charming pet. 

I do not know whether any of the chinchillas imported into Britain survived until after the Second World War. It is possible that they did because the super-rich of the day kept extensive collections, particularly of birds, and it is doubtful if records of what many of them had and bred were kept or preserved.

Worst scientific article title of the year?

It used to be an unwritten rule that the title of a scientific paper should inform the reader what the work described and the species or group of animals from which data had been obtained. For some journals, the editorial policy was to insist on the latter. But in these smart-arse title days, I am left wondering what a paper is about. Looking through the contents of Proceedings of the Royal Society B, as I do with each issue, I often find the title actually obscures rather than informs the reader of the content. But this one really takes the biscuit: Parental risk management in relation to offspring defence: bad news for kids. No, it is not about young goats; it is not even about young children. It is about a study of nest defence behaviour in Blue Tits.

I presume the authors, judging by the last sentence of their abstract, are trying to draw attention to possible extrapolation of their findings to ‘living beings, including humans’  but for that claim to form the title through a slang word for human children is a travesty. The work is about the behavioural strategies employed by Blue Tits against threats by predators to them and their offspring. So why not say so? It makes the work no less and no more important.

Bryde's Whale

We have seen Bryde’s Whale in several parts of the world. When one is seen, the Brits shout ‘brides’ across the deck while the hispanophones (in the Galapagos, for example) shout ‘bridies’, pronounced as the Scottish pasty. I now find we are all wrong.

Bryde’s whale is named after the Norwegian, Johan Bryde (1858-1925) who founded the whaling industry in South Africa. The pronunciation is something like ‘brude’s’ or 'brudess' (I can never get my tongue round Scandinavian pronunciation or its rules, despite being born in the old Danelaw part of England where streets are still ‘gates’. So next time you are whale-watching you can smugly shout ‘Brude’s’ across the deck, while the rest of the crowd wonder what on earth you are talking about.

I also had not know, until I started looking it up, how much uncertainty there is on the taxonomy of Bryde’s Whale and how much more needs to be known before more definitive pronouncements can be made. The IUCN Red List has the details of the various forms that go under the heading of Bryde’s.

Balaenoptera edeni (Anderson, 1879) is the scientific name in use because Bryde’s Whale, described from specimens killed off South Africa by Olsen in 1913 and named B. brydei, was considered to be synonymous with the form described by Anderson which was collected just off the shore of Burma. The original edeni (Eden’s Whale) is thought to be smaller at maturity than ‘ordinary’ Bryde’s whale and has been called the ‘pygmy’ version; some have now separated the two into the original two species; some consider them subspecies.

Bryde's Whales off Mirissa, Sri Lanka, 26 November 2013                                                           AJP Photograph

There have been other findings of similar whales that further confuse the issue but the point of mentioning the two forms in the current context is that in the northern Indian Ocean, off the southern tip of Sri Lanka, we saw Bryde’s Whales on both days we were there in November 2013, along with the Blue Whales, Orcas and Spinner Dolphins. I now see that there is a claim, with a video on Youtube and articles in the Sri Lankan press, of a possible sighting of Eden’s Whale, the dwarf or pygmy form or separate species, off Sri Lanka. I saw a number of critical comments as to this identification but they seem to have disappeared when I looked for them again. But this observation illustrates how much there is still to find out about marine mammals and how difficult research is in this field.

But a better week for this newt

Number one son, who lives in England, was walking to his garage last week and nearly trod on this beast on the gravel drive used by a number of residents.

It is, of course, the Great-crested or Warty Newt (Triturus cristatus), a protected species in Britain with habitat loss the major, perhaps sole, cause of its decline in the middle decades of the 20th Century. Ponds were filled in for housing developments and agricultural 'improvements'.

This one was moved from the drive to the adjacent countryside and told to be more careful in future.

A bad week for newts—and the amphibian trade. Time to panic—or not?

Science last week had the latest on the new chytrid fungus, Batrachochytrium salamandrivorans. This fungus was discovered after it wiped out Fire Salamanders (Salamandra salamandra) on a Dutch nature reserve in 2010. It is distinct from B. dendrobatidis, the species that is devastating frogs and toad populations throughout the world. A multinational team reported in Science the results of their exposing specimens of 35 captive-bred or wild caught amphibian species to the new fungus. The results were clear. The anurans, or, if you prefer, salientians, in other words the frogs and toads, were not affected nor was the one gymnophionan or caecilian tested. But nearly all the urodeles, or caudates, were, and died rapidly after infection. These results were confirmed by looking for the organism’s DNA in the skin of 5391 wild amphibians. It was found only in urodeles and only in ‘East’ Asia (Thailand, Vietnam and Japan) and in those European countries (Netherlands and Belgium) where the severe disease outbreaks were observed.

Salamandra salamandra - this one is in Hungary

The infection experiments indicated that three Asian urodeles tested could act as reservoirs of the disease: Cynops pyrrhogaster, Cynops cyanurus and Paramesotriton deloustali. Seven specimens either limited the effect of the clinical disease or completely eliminated the infection. The authors calculate that the two chytrids diverged about 67 (mean) million years ago and that the potential of the ancestors of modern Asian newts to be a disease reservoir evolved between 55 and 34 million years ago. B. salamandrivorans was also found in a museum specimen of Cynops ensicauda at least 150 years old, supporting the view that the Asian species have greater tolerance to infection and constitute a reservoir through which species in other parts of the world could be fatally infected.

In a survey of wild amphibians, the organism was found only in East Asian urodeles—4% of the specimens of the latter species.

Because of the organisms apparent presence only in Asia, movement of amphibians in trade or for research appears to be responsible for the outbreaks in Europe. However, surveys done of urodeles at exporters, going through Heathrow airport or in pet shops found no infected individuals in the 542 tested. Another survey, this time of individuals established in captivity, found 3 specimens out of 408 infected; all were Tylotriton vietnamensis while 15 of the same species were uninfected. 

These figures suggest to me that the importation of infected animals into Europe or the USA has been relatively uncommon. If the number of infected animals arriving had been greater then might we not have seen an outbreak in Europe earlier than the 21st Century? Vast numbers of East Asian urodeles have entered Europe from at least the early decades of the 20th Century, particularly Cynops pyrrhogaster and, more recently, Cynops orientalis. One out of 116 wild C. pyrrhogaster was found to be infected. Unfortunately no wild specimens of Cynops orientalis, probably the commonest urodele now in the aquarium trade, were tested. Of those in sampled at exporters, at Heathrow or in pet shops (including 11 C. pyrrhogaster and 145 C. orientalis) no infected individuals were found.

In the 1920s to the 1970s at least, C. pyrrhogaster was often kept by amateur herpetologists with native newts in indoor and outdoor vivaria. The opportunities for an infection of B. salamandrivorans to escape into wild newt and salamander populations must have been very great especially since surplus native species were often released into the wild. The authors of the paper in Science state that 2.3 million Cynops orientalis were imported into the USA between 2001 and 2009. Is it not likely that if this species were a common reservoir for B. salamandrivorans that the odds are that there would already have been an outbreak of the disease in the USA? But, however common or uncommon the infective agent is in the wild, in trade, or in specimens established in captivity, it is the fact that it is there at all, with its potential to devastate urodele populations in other parts of the world, that has given rise to great concern.

Given that the Netherlands has always been an epicentre of the amphibian and reptile trade and of expertise in keeping and breeding these animals, could it perhaps be the case that some of the species that became more common in captivity since the 1980s have a higher proportion of carriers than C. pyrrhogaster, for example? The detected occurrence in a species of Tylotriton would support this argument. Therefore, we may have the scenario in which a Dutch urodele enthusiast, passed infection to his or her captive European salamanders, which he then released into the wild. Or, he may have handled his infected individuals and then handled salamanders in the wild. Whatever the scenario, herpetologists, or somebody keeping urodeles as pets, have again unwittingly caused devastation to a wild population that could lead to extinction. Nobody anywhere predicted the presence of pathogenic chytrids.

It is not surprising, given the devastating effects of infection on non-Asian urodeles, that there have been calls to ban the movement of urodeles (as well as anurans because of the effects of mixing strains of B. dendrobatidis) between continents, although it has to be said that the movement of herpetologists and tourists between continents is also hazardous. The authors of the papers in Science conclude:

Our study demonstrates that the process of globalization with its associated human and animal traffic can rapidly erode ancient barriers to pathogen transmission, allowing the infection of hosts that have not had the opportunity to establish resistance. Thus, pathogens, such as those we describe here, have the potential to rapidly pose a threat of extinction.

In a separate commentary in Science this point is stressed in relation to a potential outbreak in the susceptible species of the USA where there is a war of words between the conservation lobby which evokes the precautionary principle to advocate a complete ban on imports and the pet trade (Cynops orientalis is very much part of the aquarium novelty trade). It is also pointed out that the US has no mechanism to control the import or sale of infected amphibians.

Will we continue to see amphibians included in the fancy aquarium fish trade? Will pre-shipment testing, quarantine and prophylactic treatment be sufficient? Eventually, I suspect, the trade in wild, ranched or captive-bred amphibians will be further restricted and very tightly controlled; the risk of doing nothing will be deemed too high. Time will tell if eventually is too late, or if the horse has already bolted.

Here is a very short video of Salamandra salamandra in the wild in Hungary in 2010:

Blue Whales off Sri Lanka: Orcas attacking a beaked whale as a bonus

On 25 November 2013 we headed off from Mirissa hoping to see Blue Whales but in the GPS position some had been seen the day before there were two Orcas, or in old money, Killer Whales. You can see them on the video footage I took (below or directly on YouTube) along with the Blue Whales.

In looking for further information on orcas in Sri Lankan waters, I came across the brilliant Orca Project Sri Lanka (OPSL) which, to quote: is the first citizen-science project centred on studying orcas (Killer Whales) sighted off Sri Lanka. On scrolling down the posts I found that our two orcas were known to them. They were OM001 ‘King’ and OK008 ‘Arya’ and have been seen off Mirissa in 2008, 2010, 2011, 2012, 2013 and 2014. After we saw them on 25 November 2013, they appeared again on 7 January, 12 April and 7 June 2014.

The two orcas.    AJP Photograph

Then things got even more interesting. A fellow traveller on the Naturetrek tour whale-watching extension sent us a still photograph which showed the orcas pushing what appeared to be some sort of dolphin with a brownish coloration around the base of a beak. I had missed it on video as I changed positions but could just see the end of the action as I began to film again. Other photographers had sent stills to OPSL and they in turn asked experts on marine mammals. Here is an extract from OPSL’s post of 19 December 2013 (the photographs are shown there):

…OPSL in collaboration with Josh McInnes of the The Transient Killer Whale Research Project are currently writing a small paper on a very exciting finding. When OM001 and OK008 visited Mirissa on the 25th of November, they decided to chow down on the local marine-life...so what's on their menu? Turns out they like Beaked whale, deep diving and little-understood cetaceans of the Ziphiidae family…Observation details include the orcas feeding on an unidentified object. In two of the images, a beak or rostrum can be seen with a patchy brown/green colouration to the surrounding skin. OPSL contacted Josh McInnes, who specializes in the study of mammal-eating (transient) killer whales of the Pacific Northwest, to offer his opinion on the ID. After looking at the photos, Josh concluded that the beak shape and brown/green colouration (caused by diatoms) appears to be consistent with that of a Blainville’s beaked whale Mesoplodon densirostris.

I had seen a report from the BBC which described research on the stealth mode Blainville’s Beaked Whale adopts when it is comparatively near the surface. In the depths the beaked whales are rather vociferous but on rising towards the surface for air sonar silence reigns. With orcas around I can see why that is a good strategy.

Links to this and other work on the fascinating world of ziphid cetaceans, written by the lead worker, Natacha Aguilar Soto, of La Laguna University in the Canary Islands, are here. A video showing their work on beaked whales is here.

The Smithsonian Institution has a Beaked Whale Identification Guide showing photographs of dead specimens. Another possibility, purely on the basis of one specimen stranded on Sri Lanka is Mesoplodon ginkgodens, a species known only from a few dozen specimens. It would be interesting to hear whether the marine mammal experts can eliminate this one. From a size comparison with the orcas, my impression, and it is only an impression, is that the beaked whale killed must have been not fully grown (and female?) when some of the clearer differences between the two species might not be evident. However, looking at the photographs in the Smithsonian collection, I do see where the experts are coming from. Whatever, the time must be ripe for some hydrophonics in the deep waters of Dondra Head even though the sound of ships’ engines will be a constant feature. Has anybody tried to pick up the sounds of beaked whales there yet?

NOTE ADDED 12 APRIL 2022

Well we did have a photograph of the orca battering the beaked whale. I was looking through AJP's still photographs and noticed it, taken what must have been seconds from the ones taken by a member of our party. The rostrum is clearly recognisable:

Blue Whales and Ships off Sri Lanka

Nearly a year ago we were off the southern tip of Sri Lanka to see Blue Whales. The chance of seeing the largest living animal that has ever lived was too good to be missed and the reliability of a sighting in the right season from the boats that are based at Mirissa was said to be extremely high. I am pleased to say that report was correct and if sea conditions are good then whales, as the photographs show, will be seen.

                                     AJP Photographs

Heading out from Mirissa to the sea of Dondra Head to the east where the continental shelf ends, one is not slow to realise that as well as spotting whales one is also spotting ships heading west—a steady stream of very large container ships. It also does not take long to realise that the Blue Whales are living in that shipping channel. The odd traumatic meeting of very large mammal and very large ship seemed inevitable. Indeed, I find there are reports of an increased number of blue whale strandings in recent years with some carcasses showing blunt force trauma. However, strandings in Sri Lanka would be an underestimate of any fatalities since during the north-east monsoon bodies would be carried away from that coast. The key question, of course, is whether fatalities or injuries from collisions with ships are having an effect on the size of the population and its ability to recover from exploitation in the past.

The whales really are in the shipping lanes                                                                                 AJP Photographs

Recently, I came across a new paper presented at the International Whaling Commission’s Annual Meeting of the Scientific Committee, held in May 2014, that set out to investigate this problem. The survey work was done between February and April 2014 (the report for the meeting must have been prepared with commendable despatch).  The abstract of the paper, Preliminary results of surveys to investigate overlap between shipping and Blue Whale distribution off southern Sri Lanka, says it all:

Surveys were conducted off the southern coast of Sri Lanka during February to April 2014 in order to investigate the distribution patterns of blue whales (Balaenoptera musculus) in relation to current shipping lanes and further offshore. There have been several reported ship strikes of blue whales in this area and the IWC Scientific Committee has recognised the potential for ship strikes to have population level impacts on blue whales in the northern Indian Ocean. A total of 1413km of visual survey effort was conducted on 16 survey days along north south transects between 5° 28’ N and 5° 53’ N. The highest densities of blue whales were observed in the current shipping lanes, peaking at an average of 0.12 individuals km-2 in the westbound shipping lane. These high densities of whales combined with one of the busiest shipping routes in the world suggest a severe risk of ship strikes. Previous data on blue whale distribution and coastal upwellings indicate consistent and predictable patterns of whale distribution, suggesting there is considerable potential for effective measures to keep ships and whales apart. 

This is one of the figures from the report showing the sightings along the transects as well as the shipping lanes (westbound to the north and eastbound to the south).

The next map shows a cut-down Figure 8 of the report. It plots the sightings of Blue Whales by the whale-watching boat Raja & The Whales (used for the survey; the Captain is a co-author) in 2013 and 2014. On that I have superimposed my camera GPS data for our sightings on two days in November 2013. No wonder we seemed close to the westbound shipping.

The question then arises of course as to whether the data showing a clear coincidence of whales, ships and whale-watching boats will have any effect in either moving the channels to the south or in introducing speed restrictions which appear to be effective in preventing collisions with whales. A related but pertinent question is will development of the new Chinese-funded port at Hambantota, along the coast to the east from Dondra Head, have any effect on the density and route of traffic through the water frequented by the whales?

AJP Photographs

The following is the video footage of Blue Whales, Orcas, Bryde's Whales and Spinner Dolphins I took on 25 and 26 November 2013. It can also be seen directly on YouTube here and here.