Tuesday, October 27, 2009

Of whale sharks and lasers....

A contribution from intern Gareth Jeffreys, known on the team as 'Lazer Boy', who has agreed to share with our readers some of the hi-tec work he has been battling with for the last nine weeks...

We are now fast approaching the very end of the 2009 whale shark programme, and with the onset of some very turbulent weather it looks like the last remaining sharks may be spared having laser beams fired at them... these laser beams are in fact green laser pointers mounted 50cm apart parallel to each other on an underwater camera, also known to very few people as laser photogrammetry.

Why? Well, as an in water method of measuring whale sharks it has a certain more elegance to it than two willing volunteers trying to swim to the front and back of a shark with a tape measure in tow!
Gareth on a 'dry run' lasering the whale shark mural at Dive Seychelles

How it works is by fixing two laser dots at exactly 50cm apart on to the side of a shark (when at a right angle to it) and taking a photo, and another and another as the shark moves past you. The resulting images are then fed through Photoshop, the pixels counted, and lo and behold you have an accurate measurement of the total length of a whale shark! Sounds simple enough... However, after three incarnations of the laser set up, days searching for that elusive extra millimetre of accuracy and a number of laser failures later, I can safely say that simple ideas don't necessarily make for simple projects.

Gareth making sure his lasers are millimetre perfect...

So with the lasers finally set up, it was time to persuade the sharks to start posing nicely for the cameras. Which surprisingly they did, until you reach their tails that is…. To get an accurate length of any shark you need it to be straight, but if a shark is going to swim it is going to bend it's tail, quite considerably in fact. Even worse, you may have an inquisitive shark that is going to keep swimming in circles trying to follow you. Where in lies the trickiest in water technique for a laserer to master, the 'Straight Tail Shot'.

Fortunately for me, and my results, it was soon apparent that whale sharks do not swim continuously, but have periods where they 'glide' through the water with what turns out to be a straight tail! But again life was never going to be that simple. It turns out a great time to catch the shark gliding is when it drops it's nose and begins to slowly dive. So the end of many an encounter was accompanied by a lonely snorkeller furiously trying to out dive the whale shark (14 metres is the current record) and get the holy grail of laser shots, the head, body and tail in three sequenced photos.

How deep was that Gareth... you look really small!

All this work was obviously done for a reason, and a season's worth of data has come up with some interesting results. Most notably being that team leader Luke Riley has won the coveted contest for closest size estimation of the year at just 1mm out, but before he accepts this most prized award it should also be noted that he also takes home the 'not even close' award for an almighty 2.15 metres difference on a single estimate!... Sorry Luke!

And so for some results for the season:

Largest shark measured: 9.54m (a beautiful female encountered on a day with at least three sharks over 8 metres in the near vicinity)

Smallest shark measured: 4.00m (last shark to be measured, and Luke's saviour for the closest estimate of the year award)

Number of different individuals measured: 32

Monday, October 26, 2009

Chunky gets tagged!

Chunky (sey.2009.035) is the proud wearer in the latest in power accessories… a MK10 Pop-up satellite tag….

Originally the tag had been allocated to Umberto (UT05-067), who had been seen in Seychelles several times since 2005, but since having the tag prepared for him Umberto seems to have become very elusive… can’t think why!

After having had the tag on stand-by in the boat for a week David decided to deploy it on the next shark of a greater length than five meters and who should appear to say hi but Chunky, who at over 7.5 meters was more than big enough for the tag! In fact Chunky has now been measured with the lasers by Gareth at 7.8 metres.

Chunky being tagged by David with the MK10 PAT tag, Photo Ciara McCarten

Actually David was a bit concerned with tagging Chunky as big sharks tend to have very tough skin, as biopsying several big sharks last week had shown… so a double band sling was loaded to make sure that the anchor plate would penetrate Chunky’s thick skin.

No sooner said than done and David quickly fired up the tag and had it safely attached to the base on the right side of Chunky’s dorsal fin. Chunky wasn’t overly impressed at all the attention and was already heading for deeper water when David tagged him.

Chunky was not impressed and headed off to deeper water, Photo Ciara McCarten

This tag is set to release in four months time and so we hope to find out more about where the larger sharks that visit Seychelles go to when they leave this area…

Friday, October 23, 2009

Abi and the sand shark….

Changeable weather over the last week has been somewhat problematic resulting in more than one monitoring trip being cancelled and on one afternoon we had people and boats in place but we couldn’t get the aircraft off the runway and so cancelled one boat at the last minute….

This left intern Abi on the beach to look after the bus and people’s belongings, but Abi is not one to just lounge about sunbathing and finding that she was missing being out with her favourite spotted sharks, she made her own while she was waiting!

While her beach art was well appreciated by all it was no surprise that her dream sand-shark had a distinct ‘U’ on its side… maybe Abi’s affair with Umberto isn’t dwindling after all!

Wednesday, October 21, 2009

The big sharks come to town!!!

Well the last week has been rather interesting with the South East wind stopping entirely only to be replaced two days later by a strong North Westerly accompanied by lots of rain and a change in currents which seems to have confused the resident whale sharks no end as they have moved off all over the place! Interestingly we also had sightings of the biggest sharks of the season so far, all of which were almost certainly adults….

The big sharks certainly impressed everyone! Photo Abi March

On the 15th of October we first had a sighting of a 9-10m whale shark that was joined six minutes later by an even larger male of around 10.5 m with very large claspers. David biopsied the female shortly afterwards with no reaction and both sharks were photo identified as being new to the Seychelles database (Female: sey.2009.041. Male: sey.2009.045).

On October 16th we had another pair of big boys… first was Chunky (sey.2009.035) a 7.8m male we had seen before and named Chunky due to his immense girth and the fact he has lost a great chunk of his 5th gill cover on his left side (so Chunky x 2?).

Here's Chunky! As well as a school of several hundred fusiliers! Photo Abi March

Chunky stayed with us for quite a while when he was joined by another 9m male shark (UT05-111). They circled each other for about 15 minutes then both sharks went off in opposite directions. During this encounter UT05-111 was biopsied which he disliked and quickly swam away. It is unusual for us to find adult sized sharks and all the interns were duly impressed by the scale of the differences between the usual 5-6 metre sharks and these ‘real sharks’….

Two 9+ m sharks circle each other for a few minutes to everyone's surprise!

What more surprises does the last few weeks of the 2009 season hold?

Friday, October 16, 2009

Umberto.... love at first sight?

A rather different post from intern Abi March... getting attached to cats and dogs is common so I guess we shouldn't be too surprised when an intern falls for a shark!

From my first sighting of a big spotty grey fish over 6 years ago on the Ningaloo Reef in Western Australia, I fell in love with whale sharks. I put my head in the water and a big mouth about a metre wide was coming towards me. It was a huge, beautiful, gentle fish, it was love! Even seeing pictures in magazines, my tummy gives a little flutter. Two years ago I saw them in Holbox in Mexico, lots of them cruising around in a bay, swimming under the boat, hanging around for ages, I didn’t think whale shark experiences could get much better… until I came to the Seychelles!

Over the last 7 weeks I have seen more whale sharks than I could have dreamed of, but it doesn’t matter how many I see, I still get the same excited, in awe feeling whenever I get in the water. I’ve had so many memorable encounters and have met many lovely sharks, my favourite being Umberto, closely followed by Yogi and it’s always a thrill to be in the water and recognise them.

A couple of weeks ago, we were on the boat in the south, we’d been told the sea would be quite rough that day. It was, the boat was crashing up and down, and as a big wave broke into the boat I wasn’t holding out hope that this would be the best sharking day. However, we had some good encounters, the choppy waters doesn’t effect the sharks, but some clients were feeling a little worse for wear so David decided to go into the bay. Johan found us a shark there and as I was on radio, I directed our skipper to it. The shark was swimming right on the surface and seemed very pleased to see us. Tori and David got into the water followed by the clients, he was very intrigued by these strange creatures that had joined him and kept coming closer to them to have a good look. Then the shark wanted to check the boat out, I was sat on the edge watching him and he came right up to me, head jutting out of the water and just stared at me. We had made eye contact and it was the most incredible thing, I‘d loved to have known what he was thinking! I was still on the radio to Johan telling him in high pitch squeals what was happening.

Umberto (UT05.067) showing us his famous U shaped mark that makes him easily recognisable

Then Tori came back on board, gave me her mask and snorkel and said “Abi, give me the radio, you’ve gotta go in and see this”. Despite us observing our whale shark code of conduct where you stay 3 metres away, this shark had other ideas. At one point, David, Gareth and myself were next to the boat, the shark eyed us and came closer, then closer still, and soon enough we were all the fill in a whale shark/boat sandwich. I put my hands to my face to stop getting squashed and he squidged alongside, his pectoral fin folding across me. His skin was so smooth and soft, it was amazing. I got back on board and declared to David that this was my new favourite shark! When IRISing the next morning it turned out that this was a totally new shark in our database, sey.2009.027. I found that really interesting, we were probably the first boat and people he’d ever seen, no wonder he was so curious.

Last week, with the weather not its greatest, Johan could only fly the north of the island. So out we went on the boat, our first time in the north this season. The sharks here were very fast, and as the spotter it was a job to keep up and get the ID shots. After a few short encounters we found a great spectacle with loads of birds above the surface of the water and a huge shoal of fusiliers underneath, all busy feeding on the plankton. Then in the chaos we saw two whale sharks, swimming along, gulping the plankton rich sea. David said that it probably wasn’t best to go in as they’d be very quick. Seeing this fantastic sight I was itching to get in, “shall I just go and get you the ID shots?” I said. David looked dubious, but after a moment relented and soon I was jumping in. I hit the water and looked down and could just see fish everywhere, then to my left appeared a whale shark. Before I could take a photo I heard my name shouted from the boat, a quick look to my right and the other whale shark was skimming past underneath me! It was an incredible, breathtaking experience. Though David was right, after tiring myself out I couldn’t keep up any longer, and it was also very difficult to get the ID shots!

The feeding frenzy.... sharks fusiliers and lots of fish poo!

Back on the boat we again moved nearer to the scene, I said to David “If I asked to go in again you’d say no wouldn’t you?” to my surprise he simply said “Go on then!”. It was the most frantic but brilliant encounter and soon John, Tori and the clients were soon experiencing it too. On getting back on to the boat the last time, I hugged David and once again declared that these were my most favourite sharks!

Abi and Umberto, love at first sight?

After my declarations of favourite sharks to David, I have to point out that I’m not that fickle, it’s just that all the experiences and the whale sharks are amazing! However, I do take back my comments, as after a wonderful long encounter with him today, my heart belongs to Umberto!

Tuesday, October 13, 2009

My own private shark encounter.....

Intern Dominique Rhoades gives us her insight to a special day...

It’s amazing to think that 7 weeks into a 10 week program, and having had about 40 in water encounters with various sharks I am still having completely mind blowing experiences… One might think that once you’ve swam with a whale shark, that was it done and you could tick it off your list, but the experience never fails to be spectacular! With so many different personality traits you soon get your favourite sharks but they are all amazing in their own completely individual ways…. I just had to tell you about this shark I had the pleasure of meeting the other day………
We went out with the boats from the south of the island, as we had been doing for the past 7 weeks now, it was my turn to be spotter again today as I had been recording for the past few days, so I was of course excited to be in the water with the sharks, but I didn’t realise how amazing my day would turn out to be….

After a slow start with no sharks clearly visible to Johan, our micro-light pilot, we played the waiting game… the other boat had just been sent to a shark and we were giving them time with it and then would head over if nothing else appeared for us…

Just then the call came from Johan, turn right 40 degrees for 200 meters. We followed instructions where Johan lead us straight to our first shark of the day. I jumped straight in with Luke, our team leader and our group 1. I was spotting so kept on the shark with my hand in the air so all the clients knew where to swim to. While I did this Luke got ID pictures and sexed the shark. Luke asked me to sex her too, which I did and consequently ended up on the opposite side of her to everyone else, so when Luke dived to get more pictures she banked towards him and the clients, leaving her belly completely exposed to me, which was pretty special, and she (the shark) was a female! A rare treat!

She seemed to be happy swimming with us and after a few minutes Luke took the clients back to the boat and we got group 2 in. After a really long encounter, with her swimming mostly around us in big circles, Luke took the 2nd group back to the boat as they had a call for another shark, and after all our aim is to encounter as many different sharks as possible…

Completely mesmerised by this beautiful, unscarred, 5m female shark I suddenly realised I was alone in the water, as I looked back at the boat to see the last getting on Luke shouted “Dom stay on that shark!” I gave him the thumbs up and kept swimming with her, now in a straight line, my hand in the air all the time so everyone could see me…

After a few more mesmerising minutes I was getting tired now, after all I had been non stop swimming in fairly rough conditions for at least 25 minutes. As if she knew this my shark suddenly started circling me again, as I realised this I slowed until she came closer and closer, I stopped completely, just staying afloat I looked back up for the boat, to see they had left me for the other shark. I could see a tiny dot on the horizon which I took to be one of our boats but nothing else for miles! This wasn’t a massive deal as Johan was still in the air to guide them back to me and I knew at least one of the team on the boats would also be keeping an eye on me, all the same to suddenly realise you are completely alone in the middle of the sea is a bit nerve racking… But I wasn’t alone…

As if she knew I was feeling vulnerable my beautiful shark came so close I could have put my hand out to touch her, I could even see her blinking! (the sharks don’t always follow the encounter code and I let her do what ever she wanted while I stayed still).

Annoyingly I could also see hundreds of copepods on her bottom lip which were definitely in grabbing reach, but not wanting to risk scaring away my only friend I let her be.

A few more minutes passed when I heard the rumble of David’s boat coming near, ready to put their groups in on this shark I had kept for them… I was completely exhausted by this point so after Tory was in and spotting for her group I returned to David’s boat for a rest.

David soon was questioning whether to put a satellite tag on her or not, as he thought she might be a bit small, but I really wanted to find out where this girl was going so I encouraged him to do it, hoping it wouldn’t hurt her or scare her away.

Once everyone had had a good look David got in with the PAT tag and as I watched nervously from the boat he tagged her on her right side just below her dorsal fin, she didn’t even flinch! She stuck around afterwards too, long enough for David to get back on the boat and say “Don’t you want to get back in and look at your girl’s new jewellery?” YES! I said and I was away before he could blink with the camera in hand.

After 10 more minutes and a good few photos of her with her new ‘jewellery’ David started beckoning us back to the boat – I couldn’t believe it was time to go back already and I had been with this one shark all day! It felt like minutes, not hours that had passed while I was with her.

It turned out David also grabbed a copepod off her dorsal fin while he was in so we should be able to find out where she came from in the last few months by identifying the stable isotopes in the copepods.

As we headed back to shore with the boat I couldn’t help but reflect on the amazing day I had had… I’m sure this is a day I will remember forever.

When we got back to the office to ‘Iris’ our tagged shark, we found she was a new one, never seen here before, so I have named her Anomie, officially known as sey.2009.042.

Now I have to play the waiting game… Firstly to see if I can see her again before I leave the Seychelles in 3 weeks and then 90 days from tagging her, the pat-tag, or ‘pop off tag’ will ‘pop off’ her and start transmitting to the satellite to tell us where she has been once she left Seychelles waters….. If all goes well, she will keep the tag for the full 90 days and we will get back some vital information on migratory paths of these sharks… Wherever she goes, I just hope she stays safe and returns to the Seychelles again so I can keep up to date with how she is doing through David and MCSS…

Thank you David, Glynis, Luke and Katie, for the chance to have this utterly amazing, once in a lifetime experience I will never forget.

It’s almost enough to make a girl forget her Giraffes!

Dominique x

P.s. I think she may be renamed as Poppy as she did get the first Pop-off Satellite tag..

Sunday, October 11, 2009

This season’s first satellite tag goes on…

Well the season has certainly started to gather some pace now and the first of the Aquafirma groups seem to have had a positive influence on the sharks if not the weather!

David had taken a satellite tag out for the 8th of October but the encounters did not provide a shark of a suitable size, he wanted one of over five metres; however on the 9th he was in luck. Sea conditions were again rough but two sharks had been spotted by Johan the micro-light aircraft pilot and with a boat on each it was apparent that both were very curious, giving long encounters, and both were females…. A very rare occurrence!

The shark that David’s team had was around 4.5 m and David was reluctant to tag it as the tether was set up for a larger shark; however, the other team’s shark was around 5.5m and so would be ideal… so leaving a spotter with each shark, the two boats swapped over.

Both Dominique and Ciara said it felt a little strange to be left all alone with ‘their’ sharks and there was definitely some sort of female bonding thing going on, but all four of the girls did well and the groups swapped over without any hiccups.

The ‘target’ shark was a very cooperative shark with an entourage of around 20+ yellow pilot fish and around the same number of slender remoras.

Once all the visitors had seen this shark it was time for David to go into action and this young lady didn’t even flinch as he attached the Wildlife Computers PAT tag to her right hand flank next to the dorsal fin.
In fact the shark continued to swim around the group with occasional visits back to the boat and showed no effects from the tagging… in fact David even got to dislodge a Copepod from her dorsal fin which Tori collected and labeled up for analysis.

The PAT tag safely deployed on the shark.

The team had the photo IDs processed by the following morning and the proud bearer of the satellite tag was in fact a new shark to Seychelles and registered as sey.2009.042 the 42 new shark of 2009.

It is planned to put on the second satellite tag during the coming week so let’s hope that the weather is as cooperative as the sharks!

Monday, October 5, 2009

Collecting copepods and almost riding a whale shark ....

The past couple of days on the water have been fantastic shark wise, and although we have had a bit of bad weather apparently the rough seas are attracting super friendly whale sharks.

I didn’t think I could top whale sharks after yesterday’s day of long encounters with very friendly and inquisitive sharks. We had sharks that just didn’t want to leave us alone. And although the seas were rough and the passengers were feeling a little ropey, to say the least, everyone was smiling all the way home as we had some of our longest encounters of this season... even as recorder I managed to get a good look and even got in on a shark for a while. It just keeps on getting better for us at the moment with today being possible the best day of whale sharking I myself have had to date!

Today was my day to spot with David on the boat, which put me in a fantastic mood right from the get-go as this means that I get to be in the water with all the sharks. So after two sharks that were polite enough to hang about to have their photos taken and give the clients a bit of a show, we were ready for our third shark of the day.

What a beautiful shark this was, a juvenile male at around 4metres, which had quite an affiliation with the bubbles created from almost everyone’s fins. And as I fell in love with this shark it was apparent that this shark fell in love with the boat, particularly the props which it just kept going up to kiss.

So now it was time to do some science and David got ready with his biopsy pole, I was worried for a second that this might scare away our friendly shark. The shark however didn’t even flinch for a second and was straight up gaping at bubbles and circling the boat as if nothing had happened.

That’s when I heard David shout, "Come on Ciara enough photos now, get me a copepod!" and I’m not going to lie I was a little worried having never collected a copepod, and not having anything but my fingers to get it with I took on this challenge. So here I am swimming next to this friendly shark trying to work out the quickest easiest way to go about this when I realize the only place I can see any copepods is in the centre of this sharks bottom lip.

So I swam next to this shark's head for a while trying to work out how to-do it, while trying to avoid becoming the filling of a whale shark / boat sandwich.

Ciara looks for an easy way to get to the copepods.... there wasn't one!

So then I realized I just had to do it then and there and so I swam right up next to its head reached over the top and plucked not one, not two but three copepods off its bottom lip, and as I reached my arm out and shouted that I had got them, amidst the cheers from the boat, I realized I was now almost riding this beautiful shark and so backed off and swam quickly to the boat to hand the guys my gains!

Now overflowing with glee, David asked quite matter of factly if I could lead this shark over to the other boat so we could do a plankton tow. Without even really thinking about how I was going to do this I just said "yeah sure", and as if this shark had known what I’d wanted all along it followed the bubbles from my fins all the way across to the other boat!

David and Abi examine Ciara's copepod haul, not one but three specimens!

And I didn't think the day could have got any better, so still on a high from my fantastic day sharking I stayed on the boat to travel back to the north of the island with Lillian our skipper. So after a bit of a bumpy ride back we were just getting into calmer water near Beau Vallon bay, when we spotted a big dorsal fin come up out of the water, and I new straight away I needed to get in and was shouting at Lillian to pass my camera, and I hopped straight in.... just me and this shark in what looked like plankton soup. As I lifted my head out of the water Lillian was pointing at another shark coming towards me, two beautiful sharks ram feeding at the surface with just me in the water to enjoy them!

What a wonderful end to a very special day!

........Ciara McCarten, MCSS Intern

Saturday, October 3, 2009

October Arrives…

September bowled along right into October with reasonable flying conditions if rough seas, but despite that there was no shortage of guests for the encounter programme and also no shortage of sharks!

We finish the first day of October with 127 encounters and 62 sharks identified using I3S photo ID… of which equal numbers are new sharks compared to those that have been seen in previous years. Sex ratio wise the boys are winning hands down with 52 males compared to only 3 females so far this season.

The team of interns are doing famously obviously Katie’s training and Luke’s supervision have been paying dividends. Even Dr. David was surprised to learn they are staying in the office until 9.00 at night some evenings just so they can finish all the data entry so no-one needs to work in the office the following afternoon because they all want to be out on the boats, so days-off are a thing of the past!

The coveted Copepod Crown now has a new contender with Ciara putting in an amazing pitch with 3 copepods collected in a single snatch…. Tori is going to have her work cut out to equal this!

The first of our UK groups from Aquafirma arrive today being led by ‘veteran’ whale shark watcher Charlotte Caffrey; the participants in these groups will be out with us for five days learning what we are doing and assisting the interns with data collection, as well as having a great time! So the next two weeks looks like they are going to be very busy!

Johan our micro-light pilot and tame meteorological expert has been keeping an eye on the rather odd weather system for us and is predicting 3-4 days of great conditions, so I hope that the sharks are appreciative!