Survey Reports

2018-09-08 - Penzance-St Marys

Survey details

Survey route: Penzance-St Marys

Company: Isles of Scilly Travel

Sea region: Celtic Seas

Survey start date: 2018-09-08

Number of nights: Day sailing

^ Surveying for whales and dolphins on the Scillonian III

We arrived in Penzance on an overcast but calm day in Cornwall. The friendly Isles of Scilly Travel staff welcomed us on board and informed us that they had seen many dolphins and tuna over the last few days, this making us even more excited for our survey.

We were up on the bridge for departure, and as we headed into Mount’s Bay, it was a calm sea state 3 with no precipitation and a light swell. After only 10 minutes, some shouts out on the deck behind us altered us to a pod of 4 common dolphins playing in the wake – which went down as an incidental sighting.

The sea state increased to a 4, but it was still good surveying conditions as the visibility was excellent, apart from a few minutes with dense fog on the port side. Our first official sighting was a pod of 8 common dolphins as we got closer to Land’s End, but they hardly broke the surface and we only got a brief glimpse of the flanks to be able to identify this dolphin pod. We recorded three more sightings until we arrived into St. Mary’s – one of a pod of 4 unidentified dolphins and two further pods of common dolphins. Diving gannets alerted us to a pod of 7 common dolphins, which was our last sighting on the first transect.  Passengers on the back deck also got a good sight of this feeding pod.

Seabird highlights on our first leg included great views of gannets, many Manx shearwaters, sooty shearwaters and a handful of guillemots. 

After a quick bite to eat and a rest in the beautiful town of St. Mary’s, we eagerly boarded the Scillonian III ready for the return leg. With the wind and swell behind us, conditions were favorable for our return – a sea state 2 and very light swell and extremely good visibility – and the sightings did not disappoint!  As we neared to a mixing in tides just as we left St. Mary’s, the shout of ‘Sighting!’ on both sides of the ship were called.  A harbour porpoise on the port side and a pod of 5 unidentified dolphins on the starboard side.

Sightings kept us busy this afternoon, with small pods of harbour porpoise, common dolphins, a possible Risso’s dolphin, a female grey seal and more unidentified dolphins being seen. Again, the dolphins were not cooperating with us and not showing themselves very well – a good sign as most of these pods were feeding, meaning there was lots of fish in the water for them to feed on. Very frustrating for us trying to identify them though!!

An animal breached in front of the ship, and this turned out to be a shark, possibly a thresher shark as it had a long tail. A sighting of a medium cetacean confused us – a brown animal with a small dorsal fin appeared on the starboard side but none of us got a good enough view to identify this mysterious mammal.

The last couple of sightings from this survey were memorable – some splashes in the water dead ahead turned out to be common dolphins and huge tuna, either cooperatively feeding or dolphins feeding on the tuna, it was hard to tell. We observed one common dolphin turn on its belly and breach out of the water on top of a tuna fish!

And the last sighting was altered to us again by lots of circling and diving gannets, with four harbour porpoises feeding below. We had a fantastic view of these harbour porpoises feeding and surfacing.

Overall, it was a fantastic day with a great team. Thank you to the friendly and engaging bridge crew and staff from Isles of Scilly travel for an extremely enjoyable survey.

Total sightings:  20 sightings consisting of 57 individual animals.

Harbour porpoise x 7 (3 sightings)

Common dolphin x 24 (6 sightings)

Unidentified dolphin x 19 (7 sightings)

Medium cetacean x 1

Grey seal x 1

Shark (possibly thresher shark) x 1

Tuna spp. x 4 (1 sighting)

Bird species seen:

Manx shearwater, sooty shearwater, gannet (adults and juveniles), guillemots, cormorant, herring gull, great black-backed gull, kittiwake (adults and juveniles), tern spp.

Survey team members

Anna Bunney, Trudy Russell, Liz Bunney