especially the around the claddagh duff connemara region where subsistence farmers used to sail out on their hookers and open boats sometimes way off shore sometimes to a place called the sunfish bank which is about thirty miles west of achill island to kill
the basking sharks this is an old woodcut from the seventeen one thousand eight hundred s so they were very important and they were important for the oil out of their liver a third of the size of the basking shark is their liver and it 's full of oil you get gallons of oil from their liver
and that oil was used especially for lighting but also for dressing wounds and other things in fact the streetlights in one thousand seven hundred and forty two of galway dublin and waterford were linked with sunfish oil and sunfish is one of the words for basking sharks so they were incredibly important animals they 've been around a long time have been very important to coast communities probably the best
and as the shark came round it would hit the net the net would collapse on it it would often drown and suffocate or at times they would row out in their small currachs and kill it with a lance through the back of the neck and then they 'd tow the sharks back to purteen harbor boil them up
use the oil they used to use the
we 're often all frightened of sharks thanks to jaws maybe five or six people get killed by sharks every year there was someone recently wasn 't there just a couple weeks ago we kill about one hundred million sharks a year so
sharks were still killed up into the mid eighty s especially after places like dunmore east in county waterford and about two and a half three thousand sharks were killed up till eighty five many by norwegian vessels the black you can 't really see this but these are norwegian basking shark hunting vessels and the black line in the crow 's nest signifies this is a shark vessel rather than a whaling vessel
the importance of basking sharks to the coast communities is recognized through the language now i don 't pretend to have any irish but in kerry they were often known as ainmhide na seolta the monster with the sails
and another title would be liop an da lapa the unwieldy beast
there 's great concern that basking sharks are depleted all throughout the world
some people say it 's not population decline it might be a change in the distribution of plankton and it 's been suggested that basking sharks would make fantastic indicators of climate change because they 're basically continuous plankton recorders swimming around with their mouth open
they 're now listed as vulnerable under the iucn there 's also moves in europe to try and stop catching them there 's now a ban on catching them and even landing them and even landing ones that are caught accidentally
we know very little about them
and most of what we do know is based on their habit of coming to the surface and we try to guess what they 're doing from their behavior on the surface i only found out last year at a conference on the isle of man just how unusual it is to live somewhere where basking sharks regularly frequently and predictably come to the surface to bask
so what we 've been doing a couple of years but last year was a big year is we started tagging sharks so we could try to get some idea of sight fidelity and movements and things like that
so we concentrated mainly in north donegal and west kerry as the two areas where i was mainly active
with a big long pole this is a beachcaster rod with a tag on the end
so what they do is they store the data a satellite tag only works when the air is clear of the water and can send a signal to the satellite and of course sharks fish are underwater most of the time so this tag actually works out the locations of shark depending on the timing and the setting of the sun plus water temperature and depth and you have to kind of reconstruct the path
what happens is that you set the tag to detach from the shark after a fixed period in this case it was eight months and literally to the day the tag popped off drifted up said hello to the satellite and sent not all the data but enough data for us to use and this is the only way to really work out the behavior and the movements when they 're under water
and here 's a couple of maps that we 've done that one you can see that we tagged both off kerry and basically it spent all its time the last eight months
in irish waters christmas day it was out on the shelf edge and here 's one that we haven 't ground truthed it yet with sea surface temperature and water depth but again the second shark kind of spent most of its time in and around the irish sea colleagues from the isle of man last year actually tagged one shark that went from the isle of man all the way out to nova scotia in about ninety days that 's nine and a half thousand kilometers we never thought that happened
another colleague in the states tagged about twenty sharks off massachusetts and his tags didn 't really work all he knows is where he tagged them and he knows where they popped off and his tags popped off in the caribbean
one thing that i think is a very surprising and strange thing is just how low the genetic diversity of sharks are now i 'm not a geneticist so i 'm not going to pretend to understand the genetics and that 's why it 's great to have collaboration whereas i 'm a field person i get panic attacks if i have to spend too many hours in a lab with a white coat on
take me away so we can work with geneticists who understand that
if you look at nucleotide diversity which is more genetics that are passed on through parents you can see that basking sharks if you look at the first study was an order of magnitude less diversity than other shark species and you see that this work was done in two thousand and six before two thousand and six we had no idea of the genetic variability of basking sharks we had no idea
did they distinguish into different populations were there subpopulations and of course that 's very important if you want to know what the population size is and the status of the animals
so it does seem to be that basking sharks for some reason have incredibly low diversity and it 's thought maybe it was a bottleneck a genetic bottleneck
or from ireland south africa they all basically seem the same but again it 's kind of surprising you wouldn 't really expect that
i don 't understand this i don 't pretend to understand this and i suspect most geneticists don 't understand it either but they produce the numbers so you can actuallyestimate the population size based on the diversity of the genetics
and using different microsatellites gave the different results but the average of all these studies came out the mean is about five thousand
there 's actually a risk of extinction of this species because its population is so small in fact of those twenty thousand eight thousand were thought to be females there 's only eight thousand basking shark females in the world i don 't know i don 't believe it
so where do you get
samples from for your genetic analysis
well one obvious source is dead sharks dead sharks washed up we might get two or three dead sharks washed up in ireland a year if we 're kind of lucky
just before christmas illegally because you 're not allowed to do that under e u law and was actually sold for eight euros a kilo as shark steak they even put a recipe up on the wall until they were told this was illegal and they actually did get a fine for that so if you look at all those studies i showed you the total number of samples worldwide is eighty six at present
now when we were out tagging our sharks this is how we tagged them on the front of a rib get in there fast occasionally the sharks do react
so i was thinking that must have come from the shark now we had an interest in getting tissue samples for genetics because we knew they were very valuable and we would use conventional methods i have a crossbow you see the crossbow in my hand there which we use to sample whales and dolphins for genetic studies as well so i tried that i tried many techniques all it was doing was breaking my arrows
because the shark skin is just so strong there was no way we were going to get a sample from that so that wasn 't going to work so when i saw the black slime on the bow of the boat i thought if you take what you 're given in this world
and i said you might try that
and so he was all very excited it became known as simon 's shark slime
we managed to collect slime and here it is look at that lovely black shark slime and in about half an hour we got five samples five individual sharks were sampled using simon 's shark slime sampling system
and you always think you might have some legacy you can leave the world behind and i was thinking of humpback whales breaching and dolphins but hey sometimes these things are sent to you and you just have to take them when they come so this is possibly going to be my legacy simon 's shark slime so we got more money this year to carry on collecting more and more samples
and one thing that is kind of very useful is that we use a pole cameras this is my colleague joanne with a pole camera
where you can actually look underneath the shark
the back of the shark so you can quite easily tell the gender of the shark so if we can tell the gender of the shark before we sample it we can tell the geneticist this was taken from a male or a female because at the moment they actually have no way genetically of telling the difference between a male and a female which i found absolutely staggering because they don 't know what primers to look for
so as a field biologist you just want to get encounters with these animals you want to learn as much as you can they 're often quite brief they 're often very seasonally constrained and you just want to learn as much as you can as soon as you can
but isn 't it fantastic that you can then offer these samples and opportunities to other disciplines such as geneticists who can gain so much more from that
so as i said these things are sent to you in strange ways grab them while you can i 'll take that as my scientificlegacyhopefully i might get something a bit more dramatic and romantic before i die but for the time being thank you for that
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