The North Sea is populated by around 150,000 Harbour Porpoises making it the most common cetacean in UK waters. It is currently classed as a highly mobile species and data deficient; basically so it doesn’t have to be protected! There are currently no Special Areas of Conservation (SACS) for them. Current research on Harbour porpoises is looking at their habitat use conflicting with the positioning of new off-shore wind farms.
Hotspots for Harbour porpoise on our route (see blue stickers on map opposite) are between the 2 wind farms on the outer route from IJmuiden harbour (pm route); and the approach to and from the Tyne river and up to 10 nm out to sea. Some interesting sightings include; an adult and calve at the opening of Ijmuiden harbour, a group feeding on mouth of the Tyne river and the pods seen feeding in association with Minke whales and Manx shearwaters off Scarborough Head. Then of course how could we forget “Petre” an (unusual) breaching porpoise near the windfarms! Interesting current research work by IMERS based in Imujiden is looking at porpoises ability to become habituated to the constant noise of the offshore wind turbines. It could find they can more readily adapt to this constant level of disturbance and atually change their use of sound; very similar to urban bird song adaptions. It has been suggested there may be some positive benefits to offshore windfarm creation such as an alternative substrate for colonisation by marine organisms on the bases of the turbines like a mini reef. Also the possibility of a small area of protection from fisheries IF a large buffer zone is in place and managed!
What we saw just from our regular watches on board the King is that the porpoises seem to move out of coastal areas for periods of time. This may be governed by seasonal habitat use and prey abundance. We spotted them in both coastal areas in April but by May they were spotted further out to sea throughout the route. We also had 1 high count of 20 Harbour porpoises approaching Tynemouth in July. Big numbers in July could be due to the easier spotting conditions; but this is also suggested as the main breeding time for Harbour porpoises when they can be seen socialising in larger groups. In IJmuiden sightings dropped off in May so the Harbour porpoises may be further out to sea. But juveniles were seen there between June 6th and 24th July. It has been stated that the juveniles are pushed into the Southern North Sea as numbers increase in the North. Very sadly the Southern North Sea had lost their harbour porpoise populations when large areas of the coast of the Nethelands were enclosed and built on. Some of them froze in enclosed areas one harsh winter! So its great to see a healthy population there in more recent years.
These observered patterns would have to be studied using longterm, effort-based data collected by the ORCA Science Team to have validation. Then the data can be shared with ARC (Atlantic research coalition) and hopefully used for these animals conservation in the future.
Our second most commonly spotted cetacean, White beaked dolphins- Lagenorhynchus albirostris, were regularly sited off Newcastle in April and June. … Then it went quiet! These cool water dolphins use to favour waters to the North West of Scotland, but as these waters warm up, the population has been moving south into the North Sea. We had good sightings throughout June, with a regular group seen between Seaham and Middlesborough. As they disappeared in July big schools were seen up North around Eyemouth. They did make a big splashing display once in August and I predicted they would return again in the cooler months to their southern range. Groups of around 5 white beaks were the number usually recorded but 10 were seen out to sea at the end of June. The semi-resident pod of white beaks off Newcastle is predicted to be of up to 40 individuals.
Bottlenose dolphins –Tursiops truncatus were seen between June 4th- (21st) -20th August. We last recorded them on the 21st June. The day before a pod of 18 including 1 calf were seen headed down coast to Tynemouth. These dolphins could be visitors from the Moray Firth. There are between 500 and 600 Bottlenose Dolphins in British waters, with resident populations of around 250 in the Moray Firth and Cardigan Bay. The Netherlands lost their dolphin population in the 1950’s which is a stark warning for us to protect ours.
We were lucky early on in May to see Common dolphins – Delphinus delphis 6th May. Common dolphins are seen mainly offshore in the Summer and are sometimes recorded in super-pods of up to 5000 animals…basically dolphin soup! We only saw a small group of 5 this year!!!
Another exciting sighting was that of a pod of Rissos- Grampus griseus. They were recorded early in June logging at the water’s surface. Logging is a resting behaviour, and as these dolphins mainly hunt squid at night in deeper waters perhaps they needed a rest! Risso dolphins are usually seen further North.
A very memorable encounter for me was that with White sided dolphins- Lagenorrynchus actus on the 11th June. This was a first sighting of this species for me and an unusual one also as they bow-road our ship.
The best sightings had to be of the enigmatic Orca (Killer whale) – Orcinus orca. These were recorded on the June 6th, 29th, and Sept 15th with varying degrees of certainty. But when a male was seen in the 3rd pod of 8 there was no denying they are found in this area. At other times distance pods and a passenger sighting could not be confirmed.
June and July was good for Minkes! First 1, then 2, then 4, then 6 were seen feeding at close range at Scarbourgh Head. Minke whale behaviours seen (and filmed) included feeding, lunge feeding, porpoising and breaching x3 times in a row fantastic!!!
So 2010 was a fantastic season on board The King of Scandinavia for ORCA Wildlife Officers and the wildlife watching passengers. Watch this space to find out whats seen in 2011…or join us for some great encounters out in the North Sea; on the Newcastle Amsterdam route with DFDS Seaways. Thanks everyone for your support!
Happy New Year!!
Kathryn Driscoll Senior Wildlife Officer
For more information about ORCA visit: http://www.orcaweb.org.uk/