Trip report from the 8th-10th September I-Spy

22nd Sep 2015

- Striped dolphins (Brian Clasper)

ORCA Team: Stephen Marsh, Brian Clasper, Trudy Russell, Jayne Dobner, Mike Williams, Cassie Auld

With good weather forecast for the trip, the ORCA team greeted our guests at the Portsmouth terminal.   Having set off in high and hopeful spirits, we met up again for introductions and a short safety briefing at 5.30 pm on Deck 10, our home for the next couple of days.

After dinner, the evening talk to our group drew a lot of attention from other ferry passengers as well, inspiring some to join us the following day, take out membership, buy the t-shirt and even book on an ORCA Marine Mammal Surveyor course!

Happy that we had a great team and responsive and fun guests to share the wildlife with, combined with what we hoped would be a good sea for sightings the following day, we retired to our respective cabins.

With sunrise at 06.45, we were on deck by 06.30 with a good number of our guests already keen to start the day in the Northern Bay, about three hours south of Ushant (Ouessant in French).  As is often the case in this area, we experienced great sightings of common dolphins very early on – always a fantastic way to start any day!

- Common dolphin (Brian Clasper)

Some were attracted to the ship but many of the common dolphins were intent on feeding and for the next hour or so everyone in our group had a smile on their face.  The sea state varied between 2 and 3, but there was a keen and cold wind to fight against.

As we got closer to the top of the shelf edge, where the 140 metre depth starts to increase, sightings just stopped!  For around 90 minutes we had no sightings at all and we began to worry. Could this turn into a disaster trip despite the low sea state?

The only sighting we had during this period was of a submarine’s antennae buoy close to the ship and giving away the location of its host some metres below the surface.  Could this be affecting the dolphins or not?  Possibly, but then again today’s submarine’s run fairly silently and active sonar is used sparingly by them as it gives away their whereabouts. Active sonar would normally be used by others trying to find them.

Thankfully, at the top of the shelf edge where it begins to slope to greater depths, sightings picked up again, with a half-hour period bringing more common dolphins, a couple of minke whales, pilot whales, fin whales and tuna all making the most of a productive feeding ground as the depth dropped steadily to 2,000 metres.

- Fin whale (Brian Clasper)

A bit further south where the shelf edge began to bottom out at 3,000 metres and into the abyssal plain at 4,000 metres depth, the by now excited and even more enthusiastic whale-watchers spied more whale blows (unidentified) as well as common dolphins and our first bottlenose dolphins of the day.

We would expect to see striped dolphins taking over here as they favour the deeper waters and their arrival after more bottlenose dolphins was not really a surprise.  Very active, hurling themselves out of the water in high spins, they were a joy to see.  We also had a group of dolphins that caused some discussion. At distance it was difficult to identify them positively but they may have been white-beaked dolphins, out of their usual territory.  Photographs however seem to show Risso’s, so there may have been a mixed group feeding on cephalopods – the debate continues.

- Striped and Rissos Dolphins (Brian Clasper)

We thought things had been pretty busy, but from 12.30 shouts of “Dolphins”, “Blow” and “Whale” increased and kept us all busy for at least the next four hours.

As we got close to the seaward end of the Torrelavega canyon, a deep sea canyon that extends from the abyssal plain to run in close to the North Spanish coast, Cuvier’s beaked whales popped up almost on cue, just where we would expect.  More fin whales were seen as well as good numbers of striped dolphins and a few common dolphins once the water become a bit more shallow again.

After our stay in Santander (for some ice cream research as usual!) we departed in the dark and so there was no further watching in the southern bay.

The following morning heading northwards we awoke to a slightly higher sea state 4, practically where had started watching on our southerly trip.  Again, common dolphins showed well along with bottlenose dolphin south of Ouessant.  Visibility had dropped to 16km and then 10km from the ideal 18, but then things improved as the sun got higher, back to 16km with the sea improving to a sea state 2.

- Common dolphins (Brian Clasper)

Harbour porpoises put in an early show as well, taking our species list into double figures.

We were hoping for good sightings as we went through the islands between the Brittany mainland and Ouessant, but there were no cetaceans to be seen.  We were all used to going through this area on a lowish tide when the rough, oxygen-rich water attracts fish and therefore dolphins, but this time we were on a high tide and we just enjoyed the stunning scenery and historical lighthouses instead.

Coming into the channel, the sea state remained kind to us but we were still experiencing that stiff wind.  Sadly, we encountered a large dead whale off well off the port side, with scavenging gulls surrounding it.  The carcase was large enough to be either a fin or humpback whale and although we couldn’t see any evidence of damage, it was a stark reminder of the perils these large whales encounter in busy shipping lanes and the importance of ORCA’s ship-strike mitigation project.

Happier sightings in the channel included more porpoise, common dolphins and a minke whale.

Bird sightings for the whole of the trip had been disappointing in numbers, but we encountered 20 species including a small flock of mute swan that caused a bit of a stir out at sea!

We would like to thank all of the ORCA guides for their vigilance and knowledge, but more importantly all of the guests who made it such an enjoyable trip.

 

Sightings list
 

Species                                   Portsmouth-Santander   Santander-Plymouth       Total

Harbour porpoise                            0                                         10                             10
Risso’s dolphin                                 8                                          5                               13
(White beaked or
Risso’s dolphin)                                10                                       0                               10
Bottlenose dolphin                           46                                      9                               55
Common dolphin                             269                                    44                             313
Striped dolphin                                318                                     0                               318
Pilot whale                                       20                                        0                               20
Minke whale                                    2                                          2                               4
Fin whale                                          6                                          0                               6
Cuvier’s beaked whale                    6                                         0                               6
Unidentified dolphin                        242                                    16                             258
Unidentified whale/blow                 9                                         1                               10
Unidentified beaked whale             1                                         0                               1
Total estimated cetaceans            937                                     87                             1024
Total cetacean species                   9                                         5                               10

 

Tuna                                                 3 schools                            0                               3 schools
Ocean sunfish                                  1                                         0                               1
Blue shark                                        1                                         0                               1

Balearic shearwater
Cory’s shearwater
Great shearwater
Sooty shearwater
Manx shearwater
Storm Petrel
Fulmar
Herring gull
Yellow-legged gull
Sabine’s gull
Great black-backed gull
Lesser black-backed gull
Kittiwake
Black tern
Common tern
Little tern
Arctic skua
Great skua
Gannet
Mute swan