Archive for ‘in English’

16 ottobre 2012

our new exciting research!

MedSharks – the Italian research and conservation association – is getting ready for the European Elasmobranch Association meeting in Milan in november with exciting updates on its work on Mediterranean basking sharks: we’ve involved oceanographers and even the Navy to learn why baskers like some specific spots in Sardinia (the big island in the middle of the Med which we discovered is a seasonal stop-over in their migrations). We also tried to assess the impact of pollution (really exciting and worrying news). This project, called Operazione Squalo Elefante, is supported by the Italian branch of the Fondation Prince Albert II de Monaco. We’re also presenting official stats on shark landings in Italy in the last seven years, and a fun citizen-science project called Mermaid’s Purse, supported by the Save Ours Seas Foundation, that involved divers to sketch a map of breeding grounds in Italy of the nursehound shark. Our websites badly need update and mantaining, so you might not find all informaton there yet… but it will be soon!

Annunci
3 giugno 2005

bingo! questa è davvero grossa

Ci sono squali che sembrano razze e razze che assomigliano a squali, uno di questi è la ?strepitosa scoperta? di quest?anno. Alla foce di un fiume, in acque non troppo invitanti per noi, abbiamo incontrato questi grandi pesci chiamati pesci chitarra. E? una scoperta veramente importante perchè di questi animali, difficilmente sono stati osservati nel loro ambiente naturale, si hanno pochissime segnalazioni ? e tutte ovviamente si riferiscono ad animali pescati. Una volta presenti in tutti i mari, queste razze sono considerate oramai scomparse nelle acque italiane e in genere sono altamente minacciate. Pensate che nel giro di cinque minuti ne abbiamo contati più di dieci esemplari (della lunghezza di circa 180 cm). Ma con l?acqua torbida e la loro prontezza a scappare creando nuovoloni di sabbia, è molto difficile stimare un numero preciso di animali presenti.
Questi pesci hanno la forma di squalo, ma in realtà sono delle razze. La differenza principale sta nel fatto che le razze hanno la testa fusa assieme alle pinne pettorali e le branchie sono in posizione ventrale; mentre gli squali hanno la testa, anche se appiattita, sempre chiaramente separata dalle pinne pettorali e le branchie sono nella porzione superiore del corpo.
Come avrete già capito, per Medsharks si apre un nuovo capitolo; il prossimo anno il lavoro raddoppierà e io ed Eleonora dovremo dividerci fra squali grigi e pesci violino.
A proposito, se le informazioni che vi abbiamo dato in questi giorni sul blog vi hanno incuriosito, volevo ricordarvi che stiamo organizzando dei corsi di biologia degli squali. Il primo si terrà a Talamone dal 17 al 19 giugno, poi dal 22 giugno inizieranno quelli organizzati a Roma. E ancora: MedSharks è un?associazione: diventare soci è facile e, oltre alla soddisfazione di darci una mano concreta per la realizzazione della ricerca, potrete usufruire di una marea di sconti assicurati ai soci da molte aziende che hanno a cuore la nostra causa. Tutte le informazioni sul nostro sito http://www.medsharks.org

 

3 commenti ↓

#1   piergiorgio on 06.06.05 at 00:27
URKA! GASP! GULP!
Ero certo che la baia misteriosa avrebbe tirato fuori qualche altra sorpresa.Questi strani pesci a triangolo (ma si chiamano chitarra o violino?)sono davvero una chicca inedita,”suonateli” a dovere.Brave.SMACK!

#2   milena on 09.06.05 at 00:57
….non finite mai di stupirmi, siete veramente strepitose!!! baci a presto
Mile

#3   Giorgio e Laura on 11.06.05 at 21:22
Siamo a cala di Luna e ti pensiamo tanto…Quando torni? Baci.

2 giugno 2005

hurray! still no sharks, but…

 

Thursday, June 2nd
Jimmy, our tagger, has left without tagging one single shark, nor having collected any DNA sample. He did his best, and more: he spent long hours in the sea, trying to get close to a shark. We often left him alone, to minimize the disturbance in the water and maximize his chances of tagging at least one shark. But to no avail: it is not enought to see a shark in order to tag it – it really has to come, quite literally, within his reach – or that of his gun.
Why the sharks have deserted the bay is still a mystery, but it’s a fact. It happens: we are dealing with wild animals, not with machines; and the sea has no cages or borders, it is not a zoo: animals come and go as they please, following rules we have not yet disclosed. After all it is precisely for its unpredictability that we love the sea…
The reason behind this very philosophic attitude is that we have made an incredible new discovery. We have collected photos and information on the catputre of two “big-eye” thresher shark, an extremely rare species in the Mediterranean. This species – which is obviously quite well recognizable by its two giant eyes – has only been seen a handful of times in our sea. The first sighting dates back to 1981; since then only 5 other animals have been reported, and only in the Sicilian Channel and in Sardinia.
I have a particular interest in this sharks, as a few years ago I’ve been fortunate enough to see some pictures taken by Egidio Trainito and Mario Romor of a 4-metre shark beached on the island of Tavolara, Sardinia. Within the “Mediterranean Observatory” project (http://www.sea-stories.net/osservatorio.html) But it was not all: it was a pregnant female and it was bearing two embrios and 5-6 eggs. And imagine the surprise as a mortal wound was found on the shark’s head, where a 15cm-piece of the sword of a swordfish was stuck! I collected these photos and delivered to the researchers at Icram, Italy’s Marine Research Insitute. It turned out it was a “big-eye”, specimen n.6 in the mediterranean.
Back to us. Our new Turkish friends told us about a large shark caught a few months back. Given our interest in “everything shark” in the area, they offered to show us the tail of the animal. Now, it’s very difficult to tell shark species apart just by looking at a tail… unless you are facing the extremely long tail of the thresher shark, almost as long as its owner’s body. Ever since the Tavolara episode, every time I hear about the capture of a threseher I immediately ask wether it had normal or very large eyes. The answer has always been the same: normal. Until now! We now also have a photo, taken right after landing, to prove beyond doubt it was a big-eye (and a little piece in its tail that sets it apart from the other two species of threshers)

 

30 maggio 2005

pop-up satellite tags

The most loyal among our public will surely remember how desperate we were last year, when we had to leave without our precious (in every sense of the word) satellite tags, which were malfunctioning. Luckily this year the tags work, and were the first items we stored in the bag on the eve of our departure.
The tags we use are Pop-Up satellite tags, a.k.a PAT tags, which stay attached to the animals up to a year and automatically detach on a set date. Once they reach the surface, thanks to an in-built float, they start transmitting the data to the Argos satellite system, which will email the results back to us.
During the time they are attached to the animal, the tags will record several information like water temperature and the depth at which the shark swims. They also record the light levels and from this, through a complicated calculation, we shall be able to pinpoint the position of the animal on the map every single day. The position is not extremely accurate, but since there are no alternatives (the GPS positioning system obviously does not work underwater!), that will do.
These tags are hi-tech and equally hi-priced. Why did we invest so much money (we have three, at 3.500 USD each plus taxes) in them? First of all because we can watch our sharks for a very limited time (21 out of 265 days); and only when they are within our visual range and, in any case, after the sun sets we can no longer follow them. All the info we gather during our stay are limited to the days we can spend in this fabulous bay, and to the hours that we spend in the water.
We do not know what they do after the sunset or where they spend the rest of the year ? that?s where the PAT tags play their role. The other reason why we decided to invest that much money in these three PAT tags, is that results obtained from similar instruments have radically changed the existing knowledge on some species of sharks. As an example, it was always believed that the basking shark hibernated and stopped feeding during the winter time: but British scientists demonstrated, thanks to PAT tags, that that is not the case. Basking sharks are constantly on the move and search for maximum concentration of their food, the plankton. Information gathered via PAT tags on great white sharks were equally important: conventional knowledge had it that this predator never ventured much farther from the coast. It turned out that they travel thousands of miles off-shore and even spends months at a time in the open ocean, away from any land.
What do ?our? sharks do? We know for sure they are capable of very long migrations: the record for a sandbar shark was 3700 km! But if you want to know, keep following our study during this wintertime, when all PAT tags will finally come off the sharls. We will be anxiously waiting for the messages relayed by the Argos satellite systems. But for the moment, we are waiting for the return of our sharks, and the arrival of Jimmy, our ?tagger?.

28 maggio 2005

how we spend our afternoons

Are you curious to know how we spend our afternoons between the dives? We analyze the pictures and catalogue the animals we?ve seen during the days? dive, so as to create a photo-ID archive.
The photoID technique has widely been used in cetaceans population studies. The advantage of this method is that it is a non-invasive technique, and it is ideal to use with shy animals as these sharks. As opposed to colleagues who study cetaceans, we have the advantage of being able to take pitures not only of the dorsal fin, but of the whole animal at a very close range ? thanks to the many hours spent underwater with them, which have taught us the way to get close without disturbing them too much.
Recognizing each individual allows us:
– get information of the size of the population
– keep track of who is in the bay every day
– keep track of who comes back to the bay, year after year
– see if these animals move to other areas (if we can collect other sandbar sharks photos elsewhere)
– if we take pictures of the animals from a known distance, we can compare the size of the animal and get a pretty accurate estimate of the size of the individual shark.

During this year?s expedition we have already photo-ID 26 sharks bearing markings, spots and scars on their bodies. But the signs we are eager to see on the body of our lady sharks are the famous ?love bites?. We?ll let you know when we see them!

27 maggio 2005

talking to Turkish people…

One of the main objectives of the 2005 expedition besides tagging sharks with satellite tags, recognize the animals one by one through photoID, collecting samples of DNA is to get new information to ascertain if “our bay” can be defined, beyond any doubt, as a nursery area for sandbar sharks. There are many things that point in this direction: the sharks seen here are mostly females; many of them seem pregnant; the bay is shallow, there is plenty of fishes but no big predators. The birth of the baby sharks last year seemed to have sealed the subject, but we want other proofs. This is the reason why we never stop asking information to the locals. We struck gold the other day: we met a guy who runs a diving center and whose father was a fisherman. We met them both last night, and he shared his knowledge of sharks in Turkey gathered in a lifetime of fishing mainly for swordfish. His information is extremely precise and important to us: he too affirms that captures and sightings of sharks in Turkey have declined drastically over the past 20 years. This is a global trend and evidently the Mediterranean sea is no exception, but the problem here is that data is even scarcer than in many other places in the world. Information gathered from reliable fishermen can give us important data of how things were in the past, and how they are now. These information are then funnelled into the “Global Shark Assessment”, an international project which MedSharks works for. Besides collecting lots of precious information, we have had once more a display of the hospitality and friendliness of the Turkish people.

26 maggio 2005

we need your help – in many ways

We really need your help these days! It?s been 2 days since we have last seen a shark! Sea people know that these things can happen but? it had never happened in our 5 years in this bay. We obviously don?t know why the sharks have disappeared: they may have moved somewhere else, or may simply swim in the deeper part of the bay where we can?t see them. This fact should not worry us too much, ?surely? the sharks will be back tomorrow; but this gives us opportunity to talk about a fact that emerges talking to the fishermen or to those who live on or by the sea: sightings and captures of sharks have dramatically declined everywhere in the world.
Every one of us should take some action: this is why we would like to invite you to sign the petition promoted by PADI?s Project AWARE for the protection of sharks (www.projectaware.org). It is very important to raise the awareness on the fact that sharks are disappearing ? it is important that people in the tops positions realize this situation, and implement managing and protection measures for sharks. Some things have already been done: both the white sharks (Carcharodon carcharias) and the basking shark (Cetorhinus maximus) have been listed in the Appendix appendice II of CITES. CITES is the international convention on trade in endangered species of flora and fauna, signed in Washington in 1973. It aims to regulate the trade in a way that balances commerce and the environmental needs, so a sto prevent the extinction of several species
In the mediterranean sea we also have the Protocol for the Specially Protected Areas in the Barcellona Convention that protects 90 marine species, includine the white shark, the basking shark and the manta Mobula mobular.
Another small thing that all of us can do to help saveing sharks is NOT to buy teeth, jaws and/or other sharks parts (and also other animals, like shells): buying such things promotes the killing of these animals.

16 maggio 2005

a first report from the bay…

We arrived last night really tired at 1am. The camp site was closed, so we had to sleep in the car. But at last today we were in the water: after half an hour of swimming and yet no shark, but lots of other fishes. Then we started to get a bit nervous: our visiting scientist, Ramon, arrives tomorrow. How can we tell him the sharks are not here? And what shall we tell you guys, who have been showering us with messages and good wishes?

…and then.. sharks! There were 5 or six, “as usual” they were all females, most of them with very big bellies. Three were swimming together, we think we recognized two of them. Tonight, before a good night rest in a decent bed, we’ll have or first session of video analysis and identification of the animals.
This is the 5th year in a row that I come back in this very bay at this time of the year. There have always been sharks, so I should bot be surprised, really. And I am not, but every year it’s a gamble: the sharks numbers have crashed everywhere. Simona was telling me during the flight that ten years ago it was normal for sport fishermen to catch sharks during every tournament. Last year they did not catch any – not a single one in any of the tournaments.