Frances C. Robertson
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Sunday Science Somethings. Installment #1

2/16/2014

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PictureNenyaki ©2008
It has been an age and a day since I wrote on this blog. I could blame trying to get my thesis finished up (it is on track by the way) or numerous other things. OK, so I am going to blame my thesis after-all because it has been all engrossing and I haven’t really left my computer or thought about much else during this time! 

But I have decided that it is time for me to escape the thesis induced black-hole and re-enter the world of my blog. I do happen to have a plethora of ideas to write on –the issues surrounding self-promotion in science or last month’s Alaska Marine Science Symposium, and minke whales could always do with more attention. But instead I have decided to start a series of blog posts entitled “Sunday Science Somethings”. I have adapted and borrowed the Sunday Something idea from my sister, who wrote a fun blog about all things pretty and beautiful. My adaptation will also talk about beautiful things, however, you will have to expand your definition of beautiful because I plan to share amazing, exciting, and fun science stories –most of which I suspect will be marine focused as that is my thing. But science itself is a beautiful thing so borrowing the title from my sister’s blog on beautiful things seemed appropriate –and as an added bonus she is happy to let me use it!

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This week has been full of fun, fascinating and significant science. Many scientists, science communicators and journalists converged on Chicago for the Annual American Association for the Advancement of Science (AAAS ) this week. My twitter feed has been filled with all sorts of interesting snippets’ –you can check some of these out by looking up #aaasmtg. But for me the most exciting science story to come up this week was that of study that has shown how it is possible to count whales from space. Yes, I did just write “count whales from space”.  In fact the paper, published in PLoS One this week is entitled just that: Whales from Space: Counting  southern right whales by satellite. 

This might seem like a completely outlandish exercise to many, who on earth thought one could count whales from space? But as I saw links to the article appear in my twitter and facebook feeds and the story highlighted by the likes of the BBC, I remembered the time I was checking out the Beaufort Sea with Google Earth –I had a short lived moment of over excitement as I discovered what I thought was a whale’s tail fluke.... on a closer inspection in turned out to be boat.  Needless to say the fact that scientists have now been able to show that high resolution satellite imagery (obviously Google Earth is not quite high tech enough. Yet.) can be used to count whales is utterly cool and I feel just a little bit vindicated for my Google Earth “discovery”. 

So how is it possible to count whales from space? And what are the practical uses for such methods? Or is it all just a bit of a news grabbing gimmick? First off, this is far from a gimmick. The implications for such a tool are widespread for both management and conservation of large whales. The methods presented in the paper provide the first successful attempt to use satellite imagery to count whales at and near the sea surface. Additionally, the authors attempts at automation means that whale counts can be made relatively efficiently and, importantly more quickly. The ability of this tool to help assess large areas for the presence of whales will provide an attractive alternative to the costly and risky aerial or vessel based surveys that are currently used for this purpose.
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Figure 2 from Fretwell et al. 2014. A selection probable whales found by automated analysis.
One of the reasons that I am so excited about this paper is because I can see the potential for using satellite imagery to count whales in areas that are subject to human activities –such as oil and gas activities or commercial shipping. While this approach would not be an effective tool for real-time mitigation it could provide useful for baseline data on the presence of large whales in coastal areas subject to these human activities. 

As with aerial surveys the methods presented in this paper can only count whales that are at or near the surface and so will always be subject to a bias –because whales only spend a small proportion of their at the surface. But with an understanding of how much time whales spend at the surface and how long they dive for we can try to overcome this bias. For aerial and ship based sightings this is achieved by calculating correction factors –essentially these are the probability that a whale will be at the surface when that patch of sea surface is in view of an observer. The number of whales detected in the survey –or image is then multiplied by this correction factor to give a better estimate of how many whales are actually present in the area.    My thesis work has developed availability correction factors for aerial surveys that are recording bowhead whales in the Beaufort Sea and these methods could also be adapted to help correct the counts of whales achieved through the use satellite imagery. Essentially this idea of counting whales from space is advancing aerial survey techniques into the next sphere... the exosphere and even beyond that into space. 
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Bowhead whale in the Beaufort Sea. NOAA Marine mammal surveys 2012
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Searching for the big blue.

8/1/2013

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This summer I finally got the opportunity to spend a week with a group of researchers in San Diego. Mari Smultea and Bernd Würsig have been bringing a small team to San Diego since 2009 to fly aerial surveys off the coast of San Diego in order to collect baseline data on the distribution, density and behaviour of marine mammals.  
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Project lead, Mari Smultea

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Cloudy skies
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me, happy to be observing
Mari invited me to join them for their final survey of 2013 so that I could have the opportunity to learn about how cetacean behaviour data are collected from aircraft.  Mari and I are both working with these types of data for our doctoral research, but unlike Mari I have not yet had the opportunity to see first-hand how behaviour data are collected from the air because my data mostly collected in the 1980s. So when Mari emailed to see if I wanted to join her and the team this July I jumped at the chance. Not only would I get to fly with Bernd Würsig –a leading expert in the study of cetacean behaviour and who was the first to define the different bowhead whale behaviours and collected the bowhead behavioural data that I have been using in my research, but this was my second chance this year to see the blue whale. The largest animal to have ever lived on this planet.

If you have read my earlier posts you may remember that my first real attempt to see a blue whale was back in April when I went out on a whale watch trip in Monterrey Bay. This quest was scuppered by killer whales. But this time round in San Diego my chances were better, or so Mari assured me. I was optimistic, especially after the team returned from their first flight of the survey to report that the blue whales were around just off the coast of San Diego. They came back that first afternoon having seen a number of blues that meant they were able to conduct focal follows on at least 2 whales.  
Dr. Bernd WürsigDr. Bernd Würsig observing from the plane
To conduct a focal the team will circle the whale from an altitude of 1500 ft if cloud conditions allow. They record the behaviour of the whale including the time it blows, when the tail is seen to rise out of the water –known as fluking, the time the whale dives and how long it dives out of sight for, which direction the whale is headed in, how fast it is moving and the general activity state of the whale (e.g., travelling , foraging or resting). All these data are recorded onto audio and video recorders and the whale is photographed as well. Later, these data are transcribed and scrutinized to ensure that everything is entered into the survey database.

For the first part of the survey I was able to help the team with various data tasks including examining sets of photographs collected during focal follows on the blue whales seen.  Mari and Bernd were keen to confirm that a whale observed during an hour long observation session was indeed the same whale.  I poured through photo after photo from three photo sessions that had been taken during the focal follow looking for a scratch or scar that would make matching the photos possible.  Then there it was a ding on the left shoulder of the whale –a scar likely resulting from a cookie cutter shark. I was able to match photos from each of the photo sessions confirming that they had indeed been circling over the same whale. By the end of the second day of the survey I had performed photo-ID on a blue whale from photos taken at more than 1000 ft but I still had not seen a blue whale in person.

The next day I got to fly. It was a short training flight and though I was optimistic we did not find any blue whales. We flew again the next day and saw many mola mola, common dolphins and even a group of bottlenose dolphins, but still no blue. The fifth day of the survey dawned, again the weather was not promising, but there was less cloud that the day before. We set off  to search for blue whales along the coast. Again we saw lots of mola mola and common dolphin but no blues. Heading south towards the border with Mexico we saw more common dolphins, circling groups to confirm species, estimate school sizes and document behaviours. We observed interesting behaviours such as synchronized upside down swimming followed by rapid darting manoeuvres in different directions.  We saw groups of three to six dolphins do this at a time while in front of the main school.  This behaviour was indicative of foraging –the dolphins appeared to corralling and chasing fish.

As we continued on we saw a group of Risso’s dolphins; Mari is studying the behaviour of these dolphins for her PhD and has observed Risso’s with other dolphin and whale species.  This time we saw them alone but were able to observe apparent social behaviours and surface active behaviours. These dolphins are much larger than common dolphins and very light in color due to the scaring that covers their bodies, not much is known about them in the Pacific so these surveys provide a unique opportunity to study them.  
We continued on our search for blue whales, following the edges of undersea canyons. We slowly made our way out to San Clemente Island and picked up more dolphins. Suddenly Bernd called out “whale”! Was this going to be my first blue? I saw the large rostrum of a baleen whale disappear beneath the surface –we circled back to pick it up as it surfaced but 12 minutes later there was still no sign of the whale. We continued on our way left wondering whether the whale had been a fin, sei or Bryde's whale. There was only one more day left on the survey and I was beginning to wonder if I really was going see to blue whale. Had I been slunk again?

We turned back for San Diego. Then there it was. A blue whale hanging there, seemingly suspended just below the surface. The whale glowed a beautiful turquoise blue color in the water. As we circled to document the sighting, my eyes were glued to the whale, watching and waiting for it to rise to the surface and blow. It hung there still, barley moving, then as the pilots turned back towards our track-line the whale rose majestically to the surface and blew. I watched the blue whale disappear out of view behind the plane. I had finally seen a blue whale and the image of this magnificent great whale hanging so gently below the surface was burned into my memory. 
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The final day of the survey resulted in 155 sighting in 4 hours, common dolphins, California sea lions chasing bait balls, mola mola, and more Risso’s dolphins, we didn't see any more whales despite almost perfect sighting conditions but I was happy, I had seen and learnt so much, worked with a great team of people and above all I had finally seen a blue whale. 
Blue whale fluke
Blue whale fluke breaking the surface
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    I am a wildlife biologist and I have a fascination with the marine environment and particularly whales.  I work to understand our impacts on the marine environment and how our work as scientists can facilitate better management that aims to reduce the effects of human activities on marine species and their environment. 

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