Archive for the ‘dive trips’ Category

Roa Island Beach Walk and Dive

Monday, August 10th, 2015

The evening of Saturday 1st August was overcast, with a cold wind, but dry. A small band of us worked down the beach by the new ferry jetty at Roa, following the tide out. The access way used in the construction of the new pier is still comparatively free of marine life, as are the scour pits around the jetty supports, it will be interesting to see how quickly this area gets re-colonised!

Male edible crab (Cancer pagarus) with parasitic barnacle.
Above: One of the interesting finds form the shore walk was this edible crab (Cancer pagurus) carrying a parasitic barnacle.

Peering in rock-pools and under stones we found a range of plants and animals, including the small male edible crab shown above. Despite being male (indicated by the narrow abdomen tucked up under the carapace) he appears to bearing eggs, but the abdomen is actually tucked around the reproductive organs of a parasitic barnacle (Sacculina triangularis). She will have infected the crab by burrowing into his shell shortly after he moulted. Over a period of time she invades the host’s tissues, and re-programs him, castrating him, dictating future moults (despite his small size, this crab may be quite old!) and re-directing much of his energy to the developing barnacle young.

The young barnacles will be released in the nauplius stage of development, when the females will go on to infect future generations of crabs, whilst the males will develop only as far as cyprids, in which stage they will impregnate established females. Parasitic barnacles are common on crabs, and some crab species have infection rates of up to 50% of the adult population. As a consequence parasites are an important factor in limiting crab populations.

Spider crab camoflaged in sponges.
Above: Spider crab (Macropodia sp.) wearing sponge camouflage.

On Saturday 8th August we made the most of a narrow weather window to get a dive at Roa, effectively taking the shore walk out into the permanently submerged part of the channel. Diving conditions were very good for the area, with underwater visibility between 0.5 and 1m. I was paying a bit more attention to seaweeds on this occasion, to try and make up for years of neglect in our usual species hunt, and they were a good range of species between sea level (ca. 2m tide) and about 5m depth. The water in the Bay is generally quite murky, largely as a consequence of the amounts of phytoplankton in the water. These phytoplankton blooms make the Bay one of the most productive ecosystems on the planet, but paradoxically they make life difficult for permanently attached seaweeds, which tend to be stunted, and restricted to comparatively shallow water. Otherwise we saw lots of anemones, crabs, sponges and butterfish. The numbers of peacock worms may be down on previous years, but the general impression is one of a thriving ecosystem.

The butterfish, Pholis gunnellus, a common sighting at Roa.
Above: The butterfish Pholis gunnellus is a common sight at Roa. It gets its name from its slippery, slime-covered body. In previous years we have seen young butterfish taking refuge within the tentacles of the larger anemones (Urticina spp.), where their slime may protect them from being stung and eaten by the anemone, whilst the anemone protects them from other predators.

Oban in Autumn

Monday, October 6th, 2014

The group had another visit to the Oban area in September, the weather was overcast, but mostly dry. The underwater visibility was poor for the West Coast of Scotland, but the diving otherwise good, with a couple of interesting drift dives through the Creran Narrows, and other dives in the surrounding area.
Dramatically lit tunicate
Above: Using dramatic lighting to overcome some of the problems with poor visibility (Photo by Barry – thanks to Lewis for the lighting!)

Many thanks to Gordon for organising this visit. Note: There are still places free on our return visit to Oban on the 10th October (see our diary for more information)

Possible Roa Island dive dates 2013-14

Wednesday, October 23rd, 2013

Following on from the talk on diving conditions at Roa Island, here is a provisional list of dive dates and times over Winter 2013 – Spring 2014, based on tidal information. These have not been checked yet, and are not in our calendar – so use them at your own risk.


Sun Nov. 11 LT 10:40 (meet @ 9:00)

Sat Dec. 12 LT 15:40 (meet @ 14:00) NOTE diving close to dusk
Sat Dec. 28 LT 13:43
Sun Dec. 29 LT 14:50


Sat Jan. 11th LT 14:12
Sat Jan. 25th LT 11:46
Sun Jan. 26th LT 13:04

Sat Feb. 8th LT 12:13
Sun Feb. 9th LT 13:30
Sun Feb. 23rd LT 11:17

Sun Mar. 9th LT 11:25
Sat Mar. 22nd HT 14:59

Sun Apr. 6th LT 10:52
Sat Apr. 19th HT 14:59

Sat May 3rd HT 14:54 Bank Holiday weekend
Sun May 5th HT 15:36
Sat May 10th LT 15:27
Sun May 11th LT 16:18
Sat May 24th LT 15:14 Bank holiday weekend
Sun May 25th LT 16:12
Sat May 31st HT 13:54

You can track diving conditions in Morecambe Bay here.

Thanks to Lewis for compiling these dates.

Estimating diving conditions in Morecambe Bay

Monday, October 14th, 2013

By Barry Kaye, Local MCS, 9th October 2013

The talk reviewed a web project that brings together physical information about the Bay from a range of sources, including weather, sea state and river inputs. This data informs our current understanding of physical processes in the Bay. Data are interpreted in a map that shows sea states, wind directions and the levels of principle rivers over the last five days. In addition, graphical displays review sea-sate (wave height and period) and river levels over the last fifteen days.

Graph showing river levels into Morecambe Bay

Graph showing river levels into Morecambe Bay over the last fifteen days (archival data)

The talk went on to look at how physical conditions might interact with the geography of the Bay to influence diving conditions. There is no formal model of the Bay’s ‘underwater weather’, but a number of approaches to developing such a model were proposed.

A link to the observatory is given below, users are advised, however, that this is a ‘work in progress’, there are a few rough edges, and information is provided without warranty of any kind:

Diving Roa Island: Estimating diving conditions in Morecambe Bay

Roa Island dive 19th June 2013

Thursday, June 20th, 2013

Roa lifeboat station and Piel Island at sunset just after HW

Above: Photograph of the Roa Island lifeboat station at sunset, with Piel Castle in the background, taken Wednesday 19 June 2013

Our next monthly meeting will take place at Roa Island, a site which has been visited and surveyed by our group for at least twenty years! The meeting, fromĀ 18:30 on Wednesday 24 July, is an informal shore walk to coincide with an exceptionally low tide, so we hope to see a lot of sea life exposed on the beach and in small pools that we would normally have to dive so see.

Just so the divers aren’t left out, we have a small number of high water dives planned in the run up to the shore walk*. The first of these was on the 19th June in near perfect conditions. Diving close by the pier and lifeboat station we saw a number of the same creatures underwater, that we will get to see exposed in a few weeks time.

At our August meeting (back at Capernwray Dive Centre) we hope to bring together the shore walk and dives (and maybe earlier survey work) to get a ‘hands on’ picture of life above and below the tide at this very interesting local site.

Please note: The walk in July is suitable for (accompanied) children, but be aware that the beach is very muddy, and you should wear shoes or boots that you are happy to get wet and dirty. If you bring a camera – best to have an underwater housing for it in case… You are free to explore, but most people stay within site of the pier, so it is not important if you arrive late.

Journey time from Lancaster – about one and a half hours, all welcome!

* Please note that dives at Roa Island are very dependent upon the weather, so there are a number of possible dates in the diary that we shall ‘cherry pick’ from…

Oban dive trip May 2013

Wednesday, May 22nd, 2013

Our latest visit to Oban on the 10th May was wet in every sense of the word – with almost continuous rain, but also some exceptionally good diving. Dives centred on Loch Creran, with the wormery and the inner basin being popular with all of the group.

Following from the talk about surveys in the area on the 8th, we can confirm that there are quite a lot of orange coloured worms (Serpula vermicularis) – these being seen by several divers, and possibly accounting for several percent of the individuals seen. While none were as clearly yellow as the single specimen photo’d back in 2007, this is a pretty strong indication that yellow is at least possible for this species (see gallery).

Less good news on the sea-pen front, however. A dive at Loch Feochan turned out a large number of common sea-pens (Virgularia mirabilis) in very shallow water (3-5m). Amongst these were a large number of juveniles that looked a lot like the specimen photographed at Gallanach over Easter (see gallery). After a discussion with Ron I am forced to concede that there is no current evidence for Funiculina quadrangularis at Gallanach, though Ron has seen this species there on previous occasions… (We’ll have to look again!).

Otherwise a great spectacle was put on by sea-cucumbers, with very large numbers of Psolus to be seen below about 10m in the inner basin of Loch Creran – densities reaching several individuals per square metre. There were some sea cucumbers in the outer basin as well, but in slightly deeper water (ca 18m+). There appears to be at least one other species present – but I’m not sure of its identity (photo in the gallery). Other high spots of the weekend included a thornbacked ray and a couple of dogfish.

Non divers enjoyed the Falls of Lora, and an excellent trip to the Oban Sea Life Centre (where thornbacked rays and dogfish were demanding petting!), but it was a bit damp for cycling or kayaking…

Thanks to Tralee Bay for accommodation and Gordon for organising the trip.

(by Barry 22nd May 2013)

Oban trip Easter 2013

Saturday, April 6th, 2013

Sperm whale in Oban Bay, Easter 2013. Photo Chrissy Fletcher

This Easter was one of the coldest we’ve had in several decades, but the weather was clear and sunny on the West Coast of Scotland, indeed, it was the driest I’ve ever seen it there! The cold snap made for very cold diving conditions – coldest at 5°C in the Inner Basin of Loch Creran, with most dives being 6°C and only a couple of degrees warmer on the surface. This kept even the keenest of us down to one dive a day – the rest of the day being spent warming up again! The planned diving surveys were at least in part successful despite being frozen out, and I hope to talk about those at our meeting in May.

In addition to the diving there were kayak trips around the coast, and cycling and walking explorations of Kerrera and diverse places around Oban. Without doubt the best wildlife was to be seen from a hotel on the Oban water-front, however, as Chrissy’s photo above attests – a sperm whale… That was rather unexpected!

More information about the sperm whale sighting linked below:

BBC Scotland – sperm whale sighting in Oban Bay

Hebridean Whale and Dolphin Trust – Whale and dolphin sightings


Oban survey planning for 2013

Sunday, February 24th, 2013

We have two planned trips to the Oban area later in 2013; on the 28th March and 10th May. At our meeting on Wednesday 13th February the trip organisers (Barry and Gordon) spoke about some possible survey activities that could be undertaken on these visits.

Barry focused on Gallanach, to confirm the presence of Funiculina quadrangularis, and the Wormery in Loch Creran, to confirm the identity of the blue worms photo’d in 2012 (MCS dive trip to Oban (Sept 2012))

Gordon looked to explore new areas around Loch Creran. He also noted that the tides during our trip in March might give us some very good drifts through the Creran Narrows.

Thanks to everyone to turned out for this meeting – in pretty horrid weather!

MCS dive trip to Oban (Sept 2012)

Tuesday, October 2nd, 2012

Curled octopus seen at Gallanach September 2012.

Gallanach, near Oban, is an old favourite of the group, with an interesting dive from the camping field on the shore. This year we carried out some preliminary survey work here, and at the inner basin in Loch Creran, with the option of extending it into a broader project next year for everyone to get their teeth into. We also had one dive on the wormery in Loch Creran – where we spotted a number of blue variants of the reef building worm Serpula vermicularis (previously we have reported a colour range between white and brick red).

One of the nice surprises at Gallanach was a cooperative curled octopus (Eledone cirrhosa, shown above), who hung about for a few photographs.

We are currently working up the dive notes for a first stab at a survey for our survey pages.

MCS display at the Mull visitor centre, Tobermory

Tuesday, October 2nd, 2012

Marine life around Calve Island, Tobermory, by MCS Lancashire
Images and sea-life survey information from the Lancashire MCS group’s dives around Calve Island, Tobermory Bay have been converted into a display at the Mull Visitor Centre. We hope this will encourage people to take more interest in the (usually) unseen wildlife around our coasts, and recognise it as forming unique and precious ecosystems.

Visit Mull visitor centre, Tobermory for opening times and other information.