Cornwall Porbeagle Expedition

2007 Porbeagle Shark Expedition - Cornwall July 14 - 19 2007

Personnel And Acknowledgements

Organisers - Richard and Jacqui Peirce

Expedition leader - Richard Peirce

Skipper of Mantis - Karl Bennett

Expedition members / volunteer researchers - Rob Allen, Mark Boothman, David Green, Stuart Patterson, Mike Sharland, Tom Sharland

Videographer / Documentary film maker - Simon Spear

PhD student - Nick Pade (Aberdeen University)

We would like to express: -

• Our thanks to all those who took part
• Our thanks to God for giving us sharks
• Our annoyance and disgust at mans greed in killing them in unsustainable numbers
• Our hope that our findings will not result in the sharks we found being targeted
• Our apologies to the sharks that had to be caught to be satellite tagged for any pain and discomfort caused

Objectives

The equal joint objectives were research (tagging, abundance assessments, DNA sampling) and movie and still photography.

Underwater still and movie images of Porbeagles are rare to non-existent. The aim is to sell any footage and/or stills attained to fund a further four years of this project. It is hoped that five years of research will provide ammunition which can then be used to lobby for local protection of Porbeagle sharks with Cornwall Sea Fisheries.

Sites

The expedition decided not to release detailed information relating to capture sites and areas worked. The reason for this is that we do not want to provide a map which will enable commercial fishermen or anglers to accurately target these animals.

One day was lost due to bad weather but the other five days were worked successfully and the sites covered were a large section of Bude Bay between Cambeak Head / Crackington Haven and Knapp's Longpeak.

Chumming

Fresh mackerel chopped up mixed with bran were the chum materials used which were deployed in two chum bags beside the boat (Mantis), and in chum tubes floating on lines up to 12 metres off the stern of the boat.

Personnel / Timings

Richard was joined by seven paying volunteers who are all effectively stakeholders in the expedition and will have shares in any funds received from still and movie image sales. Some members and Richard and Jacqui, will be putting their shares towards the costs of the next four years of running this project.

Nick Pade, a PhD student supervised by Dr. David Simms and Dr. Les Noble provided four satellite tags and Richard Peirce provided a fifth tag. All the data gathered on the expedition was made available to Nick Pade for use in his doctorate thesis.

Boats

Mantis (8m) skippered by Karl Bennett and supported by RP's RIB Glauca were the two vessels used.

Daily Report

Saturday July 14

Day lost due to adverse weather

Sunday July 15

General area Cambeak Head to Widemouth Bay and off Morwenstow. Size, gender observations, and markings enabled us to positively identify five specimens in the water around both Mantis and the RIB. Good footage using a polecam was obtained of at least four of the sharks and Rob Allen obtained a reasonable still image. No specimens were tagged or fin tipped (DNA) because we were concentrating on filming, and only once did a shark take the bait which was dropped after a short run.

I had expected that free swimming underwater footage would be the most difficult task to accomplish, and so we were all delighted to have perhaps a minute of good footage in the can on the first day.

The mirrored bait tube proved a hugely successful device with all the sharks taking close interest.

In all a total of nine hours chumming were achieved.

Monday July 16

Same general Bude Bay areas as on July 15th. One specimen sighted, a juvenile female caught on mackerel feathers. This animal was tagged with an SAC GB return tag and a tissue sample was taken from the upper caudal.

Tuesday July 17

Day lost due to adverse weather.

Wednesday July 18

Same general Bude Bay area as previous days. Four separate specimens identified, one specimen tagged (PAT) and fin tipped (DNA). The tag was the first satellite tag deployed on the eastern side of the Atlantic on a Porbeagle. The tag was set to pop off in 60 days. The DNA taken was sent to Dr. Mahmood Shivji (USA) and Nick Pade.

Thursday July 19

Same areas worked. Two specimens definitely encountered. One male was return tagged and fin tipped (DNA), the other larger specimen was lost at the side of the boat when the hook came out, the shark swam off strongly and quickly. Interest in baits indicated the presence of more sharks but no further positive identifications could be made.

Friday July 20

Same areas worked. This extra day was added to make up for one of the days lost to weather.

Several sharks were encountered and five were able to be positively identified, a further three satellite tags were deployed set as follows: -

• Female - 90 lb (estimated) - tag set for a 30 day deployment
• Male - 160 lb (estimated) - tag set for a 60 day deployment
• Male - 170 lb (estimated) - tag set for a 90 day deployment.

DNA (fin tip) samples were taken from all the above (all upper caudal).

Conclusions / Notes

Nick Pade will inform us of the data gathered when the tags pop off and this information will be posted as an update to this report.

It is impossible to accurately be sure of numbers of individuals encountered however I feel it is safe to say that at least twelve separate specimens were encountered in five days and that number could be as high as eighteen or twenty. It was not always possible to sex sharks in the water or to estimate size or weight with reasonable accuracy so we have not attempted to do this.

This was a ground breaking trip which for the first time on this side of the Atlantic deployed satellite tags and obtained good quality footage and still images. We also deployed return tags and attained tissue samples. Thus even with the lost day the objectives of the expedition were met.

Pop Off Tag Results

• The first (30 day) tag popped up off Towan Head Newquay, 42 miles from the release site.
• The second (60 day) tag popped off 10km WNW of Lundy Island.
• The third (60 day) tag popped off slightly late 170kms SW of Lands End.
• The fourth (90 day) tag popped off on time 200 kms W of Ireland.

Once the tracks have been established and other data processed a further report will appear on this website.