Seaquest South-west



Mass Basking Shark sighting off Cornwall, May 1998
Basking Sharks

Information from Colin Speedie (Cornish Wildlife Trust)
 

Mass Basking Shark sighting off Cornwall, May 1998

by Colin Speedie
(Seaquest South West)

A huge shoal of basking sharks was sighted in Kennack Bay on the Eastern side of the Lizard peninsula. As this event attracted media attention from all over the world, and coincided with the only spell of hot dry weather in the first part of 1998, the cliffs between Black Head and the Lizard were soon thronged with would-be shark spotters. Most of whom were rewarded with a sighting of at least one Basking Shark.

Seaquest South West

Basking sharks have for many years been recorded as regular visitors to the south coasts of Devon and Cornwall. In recent years all sightings have been reported to a local initiative run by myself for the Cornwall Wildlife Trust (CWT), who have then shared this information with the Marine Conservation Society, as part of their National sightings scheme. In 1996 a review of Basking Shark sightings was produced by the CWT, covering the years 1995-96, including some basic conclusions drawn from the project. This information has been shared with Dr David Sims and his team at Plymouth University, as simple background for his far more detailed studies of shark foraging behaviour. Since April 1998, the CWT study has become part of a larger marine life initiative, launched as a joint venture between Cornwall and Devon Wildlife Trusts, called Seaquest South West. It is hoped that the scope and aims of the basking shark research will be expanded in the coming years.

Normal Basking Shark Sightings

So what do we know so far? Basking sharks are regularly present along the South coast particularly in the peak months of May (Cornwall) and June Devon). Early in the season we tend to see a greater number of groups of larger sharks, with the group numbers and size profile diminishing throughout the season, until mid July onwards, when mainly small sharks up to 3 metres long are seen, with the occasional larger shark (or two) turning up until October. Group sizes are usually in the order of between 6 and 12, and average sizes vary, depending on the time of year, between 4 and 7 metres. Now and again, a really large shark is sighted (up to 9.5 metres), usually early in the season. The really large sharks are easily distinguished at a distance by their dorsal fin, which has a very rounded tip, and which flops around very obviously, sometimes taking an almost  permanent list to one side or the other. The younger sharks have a much more pointed tip, and the fin remains upright.

Key Sites

I has also been possible to identify a number of key sites, much frequented by Basking Sharks. The sharks tend to be seen most regularly in areas of highest plankton density for obvious reasons, and when close to shore this often means in the region of strong tidal streams, tidal fronts or tidal upwellings. These are often easily recognised by surface debris, floating in long lines in the vicinity of headlands such as the Lizard or Start Point. When I was first tracking sharks in the 1980s, we used to first locate one of these fronts, and then sail up it until we ran into the animals feeding at the surface. We nicknamed the fronts "shark motorways".

Special Areas

Other areas of high probability are indented bays close to headlands where tidal streams are much slacker, where patches of plankton can circulate for some time. These are often the ideal places for the shore-based observer to watch from, with sharks regularly being seen. Just such a place is Kennack Bay, where the sharks gathered this summer.
 

 


Mass Sighting

The first inkling we had that something unusual was happening this year was on the 12th of May, when a report was passed to me of a sighting of between 25 and 30 sharks off Cadgwith, close to the Lizard. This is a substantial number by any standards (our previous highest number recorded was 50 in 1994) and we were hopeful that we might see this group again. In the meantime we had reports from much of the South Cornish coast of sightings, indicating that this might not be a one off, and that there were considerable numbers of sharks in many locations. We also had reports of sharks breaching close to shore both on this day and the following.

The major sighting came on the 14th, in the evening. I had been speaking to one of our volunteer observers who reported 20 sharks the previous evening, off Cadgwith. As a part time fisherman, he was used to going out into the bay in the evening, particularly when the weather was so calm, and there were plenty of Mackerel about. He had a shark breach around 5 metres ahead of his boat as he was making his way back to the beach, much to the delight of his friends ashore. On the 14th he had left Cadgwith to go fishing and had set off in the direction of Kennack Bay, where he soon ran into a huge shoal of sharks. When he rang me later that evening, he explained that the sharks were everywhere in the bay, and that he had tried to count them, but had given up at 100, although he was aware there were considerably more sharks further offshore. A fellow fisherman, who had been further out, came across to him in his boat and told him that there were hundreds more sharks offshore, stretching as far as Black Head. He had decided to return to the shore as he was more than a little concerned by the numbers, and his boat was small. His estimate was that there were around 500 sharks in all. A number of people on the shore were treated to the sight of a lifetime before the light faded, and the word was soon out.

The Day After

The following morning at first light I was on the cliffs overlooking the bay, scanning for sharks. After two hours, I had to leave, having seen not one single shark. Disgusted, I reflected that this can happen. The sharks essentially follow their food. By and large, they do not hang around waiting for the plankton to come to them, if the plankton drifts away in the tide, then they follow it.

The following days saw more sightings of 10, 12 and 20 sharks up and down the Eastern side of the Lizard, so it appeared that the front was breaking up and dispersing. Certainly the water was now becoming very clear, and so it appeared that the excitement was over. However, on the 17th May, two experienced observers sighted a shoal of 100+ off Poltesco, just to the South of Kennack Bay. Using a telescope, they were very careful in their count, and made a special effort to separate dorsal and caudal fins to avoid double counting. After this date the sharks did disperse, and over the next week sightings of groups of 20, 25 and 50 were made (amongst others) over a wide geographical area.

So was this a unique occurrence? For us in Cornwall, almost certainly yes.
In Britain probably not, as most of the post war shark hunters in the Hebrides claimed that they saw shoals running into hundreds, although probably not condensed in such a small area, or as close inshore.

Killer Whales

One factor which might point to this being an unusual event was the presence in the area of a group of three Killer Whales, Orcinus orca, which appeared to be following the sharks. Of the 13 sightings that were made during their visit, 6 sightings were within sight of Basking Sharks, and two more were in bays where sharks were sighted the same day. We have a historic eyewitness report of two Orcas attacking and killing a Basking Shark at Porthcurno in the past, and certainly there would appear to be no reason why they should shadow the sharks except predation. Orca sightings are rare in Cornwall, and especially so in the summer, or for an extended period, which might suggest that number of sharks present was unusually high, and had drawn the Orcas into the area.

So what caused this sighting? Almost certainly a very abundant patch of zooplankton, drifting into an ideal location for a sighting. If this event had taken place 10 miles offshore for example, who would have known? Long term oceanographic conditions can alter plankton abundance, and it may be that this is an advance sign of some climatically driven change. Time will tell.

Should this sighting alter the perception of the shark as an endangered species. Hard to know, although it certainly raises questions about the commonly held perceptions of shark numbers. So far, however, it remains a one-off. Should it alter the need to protect the sharks? My view is almost certainly no. After all, we are still only talking in terms of hundreds of fish. In addition, it could be argued that the sharks presence in South Western waters in reasonable abundance is a positive reason to protect them. Then again, there is their potential for the eco-tourist industry, as yet largely ignored. However, hundreds of people who travelled from all over Britain to see the sharks will testify to their drawing power; they are magnificent, primeval creatures which fully deserve their protected status in my view.

An alternative view of the mass sighting runs as follows: Now that the Basking Shark has achieved protection in British waters, it has decided that it is safe to come to the surface once more?



Basking Sharks off Lundy

11 August 1999
Dr. David Hicks and the rest of the crew on a short voyage from Lundy to Tintagel spotted  30 to 40 Basking Sharks over a small area approximately 12 miles NNE of Tintagel (NW Cornwall). There were also isolated pairs 4 miles south west of Lundy.

We saw the first pair at 08:20 at  51° 08.00' N, 04° 28' W, which is a few miles south of Lundy. The second pair was spotted an hour later about two miles off Bude.

The largest siting was at 12:15. The sharks were on the surface and the fins and some of the back was visible. One shark approximately 5 metres long was in full view (head and back) for a very short time on the crest of a wave. The sharks varied from around 3 metres to 6 metres in length (estimated and very approximate).

The sea state was force 4, the sky was overcast and the sea grey. There were patches of brown 'scum' in the water, some of which was still on the hull when we got back to Saundersfoot. There were no other animals in attendance, not even sea birds, which was strange because on all other parts of the journey we were followed by several gulls.

The sharks came close to the boat, or at least they did not move when we came close to them. We had two close encounters, one about 4 metres in length almost brushed the boat and we were almost in a head-on collision with one fish. Fortunately it appeared to know the rules of the sea and we both turned away in opposite directions.

Our estimate of 30 - 40 is probably conservative, one of the crew thinks it was more like 100 sharks but it is very hard to judge.

Yes we did get a good view of the eclipse but it was immediately eclipsed by the sharks.


Basking Sharks off south Cornwall 1999

Cornish Basking Shark Reports 1999

9 March 1999
The first Basking Shark, Cetorhinus maximus, of the year is observed 100 miles east of Longships light (Land's End) by Ken Carson, a skipper of an angling boat. The shark was 4 metres long.

Colin Speedie forecasted the return of the large numbers of Basking Sharks and he proved correct. Towards the end of May, Basking Sharks appeared in their ones and two's off the south coast of Cornwall. On 16 June 1999, Colin Speedie spotted a school of 16 sharks in Kennack Bay. The numbers seen increased towards the end of June and throughout the month of July. At the beginning of August large numbers (between 30 and 100) were seen by many people out in boats between the Isles of Scilly and Land's End. Porthgwarra Bay, south of Land's End was particularly favoured this year with as many as 63 counted by Dave Flumm on 1 August 1999.

The last Basking Shark of 1999 was seen about 28 October 1999 (Colin Speedie).

Information from the Seaquest SW Cornish Wildlife Trust pages:

http://www.wildlifetrust.org.uk/cornwall/


7 July 1999
A report during the first week of July from a Cornish Fish Producers Organisation vessel said  that they counted 126 Basking Sharks, Cetorhinus maximus, (but there were hundreds present) 2 miles north of the  Longships Lighthouse, also in the area was a 15 metre (50 ft) baleen whale with a juvenile, and a Killer Whale, Orcinus orca.

17 July 1999
A member of the crew of ‘The Jubilee Queen’, reported 150 Basking Sharks off Newland  Island at the mouth of the River Camel. The Sharks had been in the area for the past two days.

30 to 40 Basking Sharks were seen ¾ mile off Stepper Point SW97 according to a report to  Falmouth Coastguards by the trawler ‘Susie’

Cornish Marine Wildlife Reports 1999 (by Ray Dennis)



Basking Sharks off Wexford
by  ********* (Dublin), 1999

I live in Dublin and really love the sea, I regularly go snorkelling in the south-east in Wexford where one calm summer's evening I had quite an experience with a Basking Shark. I was around fourteen at the time and my brother and I were snorkelling in Baginbun Bay on the eastern side of the Hook Peninsula. It was at slack tide and the water was very still. I was just practising clearing the water out of my mask underwater and when I surfaced I noticed a disturbance in the water and thought it might be a porpoise or something. I signalled to my older brother to come over and that there could be something over there. We swam over but couldn't see anything. I dived down thinking I might spot it. To my suprise I was confronted with the open jaws of a 6 metres (20 ft) long Basking Shark. My initial response was terror as it hadn't registered to me what kind of shark it was, when I reached the surface it dawned on me and my brother and I swam with it for a few minutes before we went out to sea. It was quite amazing and its an experience. I have only encountered once since (in roughly the same area). I have been going there every summer since I was born (I am 19 now) and have seen Basking Sharks four times. Once there were about twenty of us out canoeing when we came across two. They swam right through our group capsizing two boats to the terror of the people who were in them and who also didn't know much about Basking Sarks. Another time when I was out on a friends boat we came across four who seemed very playful swimming back and forth under the boat and breaching * very close to us, I feel this is unusual from what I've read of Basking Shark behaviour?

* breaching usually refers to whales and other cetaceans. Basking Sharks breath through their gills, but still break (breach) the surface, and they probably got there name for 'basking' out of the water. The first time I saw a Basking Shark, more than half its body was out of the water. AH.


Length of Basking Sharks

Opinions differ on the length to which the Basking Shark can attain. There have been reports from the North Atlantic Ocean of monster sharks of over 12 metres long and this size seems to be theoretically possible. In 1999, when I have seen over 350 sharks, I saw plenty of sharks of over 8 metres, but only one at 9 metres long, only the fourth one of this size I have seen. In 1998, I saw two sharks that were about 10 metres long. These biggies are really different, and the excess size is striking. In April 1993 I saw a shark which I estimated at 11 metres off the Manacles in South Cornwall. Gavin Maxwell who hunted them and gave Dr Matthews access to his sharks was adamnant that he had seen the occasional "monster", and had even harpooned the odd one, but always lost them as they were too powerful for their gear.                                              Colin Speedie


American Report (Good for the description)

National Seashore
Welfleet Bay Wildlife Sanctuary
The Cape Codder
The National Basking Shark Society

Basking Shark Sighting, October 28, 1999

One, 5.5 metre (18 ft) long Basking Shark in Cape Cod Bay, one mile South of Pamet Harbor, Truo MA, was sighted about one mile off shore in 12 metres (40 ft) of water, at 3:30 pm after a 1:59 high tide, on a intermittently overcast day with temperatures in the low seventies, no wind and an extremely flat Bay.

A large flopping dorsal fin was first seen about 40 metres off our starboard bowl while trolling in a northerly direction for bass and bluefish.  Upon approaching the shark, just a few feet off our boat's starboard side, our fishing lines snagged a lobster pot line and we reversed our engine to recover our tackle.  Now some 50 metres away, this Basking Shark continued to roll about exposing his dorsal fin and tail.  At times it appeared he would roll from side to side.

On our second approach, the shark seemed totally oblivious to our presents. At an extremely slow speed we approached, cutting our engine with the shark just a few feet off our starboard bow.  We observed a small, half inch whole in the dorsal fin.  Now with the boat still in the water our 5.5 metre (18 ft) skiff just "Barley" shadowed the entire body length.  The shark then rolled left slowly under the boat giving us a chance to observe the shape of the body and tail.  The body color seemed a rutty light brown to tan, and the dorsal fin black.  Interestingly enough, all three observers failed to see clearly, the head, eyes, or mouth.

After extensive review of information about sharks on the WWW we have reported this sighting to the above organizations.
Bob Smith



NEWS REPORTS:

17 August 2006
A Basking Shark, Cetorhinus maximus, was seen in Brixham Harbour, Devon, near the Lifeboat station. It was about 2.5 metres in length.

Report by Nigel Smallbones on the Seaquest South-West Yahoo Group
During a routine aerial survey for marine wildlife off the southwestern tip of Cornwall this morning, researchers from the the University of Exeter School of Biosciences, the Marine Conservation Society (MCS) and Cornwall Wildlife Trust counted 18 Basking Sharks. They were concentrated on the north coast and spotted during the two-hour aerial survey.

17 June 2004
Five Basking Sharks, Cetorhinus maximus, were found washed up dead on the Cornish coast in the space of a week, with the latest discovered at Perranporth, North Cornwall. Others have been washed up dead, at Gerran Bay, Coverack, Roseland Bay and the Fal estuary.
News Report
 

31 December 2001
A 15-18 foot male basking shark was accidentally caught in a gill net set for sea bass off the south-west coast of Guernsey on December 31, 2001. The gillnetter took a couple of photos of the basking shark with a disposable camera.

Report from Richard Lord (Guernsey)

UK Basking Shark Proposal for protection under CITES

http://www.wildlife-countryside.detr.gov.uk/gwd/shark/Index.htm


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