How, Where and When to Watch Basking Sharks on the Isle of Man.
When watching for basking sharks you need to know when and where to look for the best chances of success. The short answer is- in calm weather, in June, from a boat, off the southwest coast of the Isle of Man in a year when plenty of sharks visit the Island! Of course there is much more to it than that so read this section.
There are two ways to get the latest information about basking shark sightings-
- Click on 'recent sightings' on this website.
- Ring THE MANX BASKING SHARK WATCH INFORMATION LINE on 01624-801345 to hear about the latest sightings and/or to report a sighting. Your information will be put on the website and reported to the MCS Basking Shark Watch.
Where to look?
Around the Isle of Man! It is a basking shark 'hotspot'.
Map of the Basking Shark Sightings 1987-2003 for UK, Isle of Man and Ireland.
Data from the Marine Conservation Society Basking Shark Watch [8].
The Basking Shark Watch Project found that basking shark sightings were very high on the Isle of Man, compared to the rest of British waters, especially considering the relatively small length of the coastline [23]. They also found that shoal sizes were larger on the Island than elsewhere. Their scientific paper, which will be published by the end of 2005, concentrates on analysing the information from the Isle of Man basking sharks [8]. The team who wrote this paper has been kind enough to let us have a preview and to use some of their findings, maps and histograms in this website. These should help you to identify the best times and places to see basking sharks.
Map of Basking Shark Sightings 1987-2003 for Isle of Man [8].
Where to look on the Isle of Man? The map of the Isle of Man shows that although basking shark sightings occur Island-wide they are more common on the Southwest and West coast starting from from Castletown and working clockwise around the Island, off the Chasms and Spanish Head, around the Calf of Man, Bradda Head, Port Erin, Fleshwick Bay and Northwards up the west coast towards Peel. The coast from Niarbyl Bay past Dalby, Glen Maye, behind Peel Hill and off Peel Castle, Peel breakwater and Peel headlands can be excellent areas to see basking sharks when they are here in any numbers. These places are areas of high plankton concentration so basking sharks congregate there.
This shark was off Fleshwick Bay, the Isle of Man.
Picture: Pauline Oliver
High plankton concentrations occur where ocean fronts are close inshore off headlands and islands, and in bays where tidal slacks occur. Local scuba divers say that one of the best times to see basking sharks is on the flood tide at Niarbyl where the tidal flow streaming from the south meets the calm water of Niarbyl Bay [38]. It is possible to see basking sharks from most of these sites whether you are on the cliffs or in a boat.
A close encounter from a boat off Niarbyl, the Isle of Man. Please observe the Basking Shark Code, the engine must be in neutral or preferably switched off. The engine might disturb the sharks and there is a danger that the shark might get hurt by the propeller!
Picture: Shane Stigant.
The Marine Conservation Society Basking Shark Watch Project has shown that shoal sizes were largest in the Northwest. This is not evident from the map. The biggest shoal was 100 sharks off Jurby head in July 1991.
It is not possible to guarantee a basking shark sighting at any time of year but you can certainly improve your chances by reading this section carefully. If you are lucky you may see a shark basking or feeding with its enormous mouth agape. If you are really lucky you may see a group of shark engaged in courtship behaviour such as following one another closely, circling or breaching. Even if you don't see a single shark you will definitely have seen seals, sea birds and some of the most beautiful coastline in the world, so it will be good fun trying!
Is it a bird, a seal or a basking shark?
It is a common occurrence to hear keen observers pointing excitedly at birds, seals, scuba divers, lobster pots, dolphins, whales or boats and shouting that they have spotted a basking shark. A characteristic cry is "It's a sha-----ag". This normally causes amusement but it can be rather frustrating!
The first sign of a shark is its large dorsal fin showing above the surface of the water. If the water is clear and it is a calm day, you might see the white mouth as it feeds just under the surface of the water. This is particulary likely if you are seeing the animal from above, from a boat or a cliff-top.
The first sign of a basking shark is normally its dorsal fin. You can also the the white mouth in this picture.
Picture: Pauline Oliver
Once you have seen the dorsal fin this is usually followed by the tail fin, as it is in this picture. If you can estimate the distance between these two fins, double it for an estimate of the whole animal's length.
Picture: Pauline Oliver.
This basking shark is moving on the surface in the sinuous, snake-like movement that is so characteristic of the species.
Picture: Pauline Oliver.
This basking shark is feeding well inshore. All three 'points' of the basking shark are visible above the water surface, the tip of its long bulbous snout, its large dorsal (back) fin and the tip of its caudal (tail) fin. Estimate this for the total length of the shark.
Picture: Pauline Oliver.
Sometimes the sun reflects off the wet dorsal fin and it will flash like a mirror. Some days the sharks stay on top of the water feeding for long periods, but other days they may be seen only for a few minutes and then they disappear under the water. This is known as 'sounding'. They may reappear in another place and may swim away surprisingly quickly. Juvenile sharks of 1.5-3m in length can be nervous. They usually show their noses above water and move erratically. Older sharks have huge fins, up to 2m tall. Sometimes these very large fins are floppy.
This large shark has a floppy dorsal fin. This is characteristic of large sharks.
Picture: Pauline Oliver.
It is possible to identify the dorsal fins of individual basking sharks by recognising different fin shapes, natural markings or injuries. Dr Colin Speedie and other scientists at the European Basking Shark Photo-identification Project (EBSPiP) are trying to compile a 'library' of photographs of basking shark fins so that individual sharks movements can be traced from year to year. If you take photographs of basking shark fins it would be much appreciated if you could contribute them, along with date, time and place seen, to this library at EBSPiP. Their web address is to be found at the end of this website.
A large basking shark feeding just under the water surface, east of the Calf of Man. If you were on a boat you would probably only see the tip of the dorsal fin, as is the case in the next photograph.
Picture: Maura Mitchell.
From the Shore or from a Boat?
So, should you search for basking sharks from the shore or from a boat? Good question! Basking sharks tend to appear when you least expect them. Never forget that these are wild animals and this is not a zoo. If you are only visiting the Island for a short period you can certainly improve your chances by joining a boat trip in one of the areas most likely to have basking sharks. Boat trips are advertised on the harbour sides in Peel, Port Erin and Port St Mary or you can enquire at the Isle of Man Tourist Information Board. Their contact details can be found in the contacts section of this website. We hope to collaborate with them soon. We aim to compile a picture gallery of basking shark fins which have been seen off the Isle of Man. If you would like to contribute please send us your fin pictures and tell us where and when you saw the shark.
A basking shark and snorkeller at Spanish Head with the Calf of Man and Buroo Rock behind.
Picture: Mike Glover.
Water users such as sailors and scuba divers may overhear other vessels reporting basking shark sighting on the marine radio. Please observe the nbsp;
Spotting fins gets harder once the water has even the smallest 'chop' to it.
Picture: Pauline Oliver.
Basking sharks congregate around tidal 'fronts' where the concentration of plankton, their food, is highest. Tidal fronts occur where one well mixed, cold water body that is full of nutrients meets a warmer, calm stratified (layered) body of water. The conditions at a tidal front promote the growth of high concentrations of plankton. The water may even turn green with all the plant plankton (phytoplankton) that grows under these conditions. This is known as a tidal 'bloom'. You can identify a tidal front by looking for areas where two water bodies abut one another.
Look at the seaweed floating on top of the water above this feeding basking shark.
This 'in-the-water strandline' is indicative of a tidal front, where basking sharks and diving gannets gather to feed.
Picture: Marine Conservation Society.
Typically one water body is flat and the other is choppy and rough. Local divers describe the cooler water as looking 'lively'. There may be an oily looking slick on the calmer water surface. This is not pollution but a rich soup of fish eggs, seaweed, jellyfish, plankton and marine debris. It looks rather like an in-the-water strandline. These tidal fronts attract other predators; seabirds feeding off the shoals of small fish which also congregate to feed off the plankton. You can use congregations of feeding seabirds, especially diving gannets, as indicators to lead you to a tidal front from as far as a mile away on a clear still day. Sometimes cruising basking sharks disturb shoals of small fish, which are forced to the surface from where the diving seabirds pick them off. The arrival of large numbers of jellyfish tends to herald the arrival of basking sharks as the jellyfish arrive with the same warm waters that contain the basking sharks food, plankton.
When to Look for Basking Sharks.
Basking sharks appear off Cornwall in early spring. As the seawater warms up the plankton grows much faster. This is called a plankton 'bloom'. The plankton-eating basking sharks follow the plankton bloom northwards into the Irish Sea. Typically the first solitary shark is seen off the Isle of Man in April. The highest number of basking shark sightings off the Isle of Man is from May to August, with the peak being in June. If you look at the histogram of the Basking Shark Watch data for average monthly basking shark sightings June, July and August are the best months to see basking sharks, however it is possible to see them at other times. There has already been one sighting north of Niarbyl in February 2005 so look at ANY time of year. If you don't look you CERTAINLY won't see one! Remember, the number of sharks and the timing of their arrival is completely variable and unpredictable from year to year so please don't be too disappointed if you don't see any.
The total number of Basking Sharks sighted and shoal size (mean number of basking sharks per report) in the Isle of Man between 1987 and 2003 [8].
Now to the question of the extreme variability of basking shark numbers from one year to another. This huge variation occurs because basking sharks follow the highest concentrations of plankton and the position of these will vary. If you are planning to come to the Isle of Man specifically to look for basking sharks you might be well advised to look at the notice board section of this website or phone 01624-801345 to see how good the current shark sightings are.