Seven members of the group spent an interesting long weekend at the end of June in the very popular area around Oban. Weather conditions were quite mixed, but we did manage to avoid the showers.  A number of dives took place including one on a rocky reef in the inner basin of Loch Creran, then north to the spectacular submarine wall in Loch Linnhe near Kentallon.  We also made a visit to the littledived Loch Feochan just a few miles few miles south of Oban. The chart indicated that we could expect to see a lot of mud.   The mud was part of the attraction, would we find sea pens and large anemones.  From the easy access point, a lay-by right alongside the loch we swam over stones and pebbles covered with various green and brown seaweeds, then onto the gently sloping mud. There were occasional boulders covered with mussels, then at about four metres deep were dozens of the sea slug Philine aperta and the small almost transparent sacks of their eggs.  Continuing down the slope to about six and a half metres below the surface where hundreds of sea pens Virgularia mirabilis covered the sea bed.  This was only a quick look at a loch that I feel has much more to offer.  Many thanks to Jo and Barry Kaye for organising a very enjoyable weekend.

This issue we see that tides keep species apart – or at least prevent the different strains of the ubiquitous seaweed Fucus spp. from all merging into one species! We also see that iron rich waters result in changes to benthic communities and get an insight into how sponges form glass skeletons – a feat of materials engineering that has always amazed me. The tone is decidedly more serious in our Fisheries section, with a link to graphics showing just how much our fish stocks have declined over the last century. Actually ‘declined’ is not nearly a strong enough word for it. ‘Wiped out’ would be a little closer to the mark.

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It has been a while, and there is a lot to go through – so best start with some light browsing! – In Science we’ve got links to a super set of marine life photos, plus an amusing look at cnidaria from the guys at Deep Sea News. The section ends with new takes from molecular biology on the flagella and the mitochondrion – fundamental building blocks of cells.

In conservation we look at attempts to model population dynamics across a patchwork of marine reserves. This kind of understanding is essential for planning effective reserves, as if reserves are too small, or the gaps between them are too large, then they will not protect all of the species within them from over exploitation. This section ends with a look at how well displaced populations survive – as aliens in the Med or the Caribbean, or displaced benthic faunal communities.

Fisheries has an interesting couple of articles on cod fishing in the Baltic – I had full access to the PLoS 1 journal article, and that appeared to say that fisheries, seals and cod could co-habit, though there would be problems. The ScienceDaily headline is a lot more strident, in saying that seals will be the financial ruin of small fishermen. Otherwise there is a paper drawing our attention to the possibility that fisheries and climate may not be independent variables. If this is that case it will make modelling fish stock that bit more challenging…

In fact there is a second link between fisheries and climate change this issue, with news that slow growing fish in the Tasman Sea are being adversely effected by temperature rise – the Tasman Sea has increased in temperature by 2°C in the last 60 years. Thankfully the Weddel Sea has only warmed by 0.6°C, but this still represents an enormous amount of heat entering the Southern Oceans from our warming climate. To ensure there is no silver lining in this issue, we learn that bacteria are the true rain makers.

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Thanks to Gordon for organising an excellent dive weekend based at Tralee Bay (see map) near Oban last weekend (6th-9th May 2011). Eleven of us from the MCS and Preston Sub-Aqua Club enjoyed some spectacular dives.

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These including a fast run through the Creran Narrows, which Jo and I followed with a linked dive into an eddy pool by the North West shore, to get some better photos of the brittle star beds there, (it never ceases to amaze me how much colour there is in these beds, which appear from a distance to be rather unpleasant grey cob-webby places) before a rather hard swim back on the surface.

We also visited the wormery – where the serpulid reefs seem more substantial than ever – less substantial reefs are also to be found in the inner basin of Loch Creran.

Our final dive though was at Galanach, where I wanted to visit the sea-pen beds, with the intention of getting some better photos. As a rather nice bonus, however, I saw a large thorn-backed ray, which hung about long enough for me to get his mug-shot!

We also managed a small amount of microscopy, looking at a single plankton sample from Galanach. Unfortunately the phytoplankton have now disappeared (they formed a substantial component of the samples at Lochaline last month), though there is a large amount of zoo-plankton, with copepods and barnacle larvae (cyprids) as the major component.

Usually we start the science section with stories from the vertebrates, and work ‘down’, in a blatant piece of species-ism. This time the anemones float to the top, however, with reports of how the corals might have evolved, and the id of one of the chemicals that induces their free-floating larvae to settle down. We end the section with a series of parties with the world’s largest vertebrates.

Fisheries and exploitation has a report about fishermen being paid to collect plastic. Sounds environmentally beneficial? We’re not sure how the collection will work, as while there is a vast amount of plastic waste at sea, is is usually in small fragments and not very concentrated, making for a very energy intensive clean-up. A skimming exercise that would remove small fragments will also remove many of the small invertebrates and plankton that form an essential part of the food chain… It will be interesting to see if there are any benefits from this bit of horse-trading.

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A life and death issue, with a look at the short lives of copepods in our science sections, followed in exploitation by a look at how tunicates may hold the secret of a prolonged life for all of us. In conservation we ask if traditional conservation practice is the best way of protecting the marine ecosystem, and see that anoxic waters don’t stay buried!

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A very successful trip to Lochaline on the West coast of Scotland was enjoyed by ten members of our group. General weather and sea conditions over the four days was on the whole very good.  Based at the Old Post Office in Lochaline we were only a couple of  hundred yards from the access point to a spectacular dive location, the  Hotel Beach Wall. The dive starts off swimming down a very gentle slope of mainly white silica sand with occasional large boulders covered with kelp and sheltering shore crabs and sea stars etc. as the slope gets steeper tube anemones, Cerianthus lloydii  in a variety of colours are very common.  The sandy slope ends quite abruptly as we reach the top of the almost vertical wall which plunges down to a depth of more than one hundred metres.  Just a few of the very common inhabitants on the wall are Tubularia with numerous nudibranchs,  football sea squirts, squat lobsters, feather stars and sponges etc. We  are also able to add a further two animals to our Group’s list of recordings for this dive site, a lumpsucker, Cyclopterus lumpus spotted on a couple of dives and a number of Brachiopods, (lamp shells)  Terebratulina retusa.  Dives also took place at Fiunary Rocks, a typical sea loch slope  further West along the Sound of Mull and on the sea grass beds at Rubha-nan-So’rnagon  in Loch Linnhe. 

Most members of the party spent some time walking in the area, on the shores of Lochaline, to see the carved stones at Kiel and to the East side of the loch to the fossil burn where we were very lucky to see otters.

Many thanks to Jo and Barry for such a well organised trip.

Our diary has just been updated with events for this summer. This includes a series of talks on common marine ecosystems around the UK coastline, plus dive trips and walks.

Lancashire MCS summer diary

No limit to growth? – This is the surprising conclusion from studies on reef ecosystems, where it is found that total productivity continues increasing as the biological diversity on the reef increases. The broader implication for marine conservation management is that it is important to maintain balance across the widest possible diversity of life in the ecosystem.

Otherwise in this issue we see reasons not to be popular – if your a Weddell seal, and your popularity is as a snack for orcas. Also we get a glimpse of the slow lives of deep corals – which have led blameless, if rather uneventful, lives since the times of the Roman emperors, only to be killed by the recent oil spill in the Gulf of Mexico. There are no places left on the planet that can claim to being untouched by human activity. We must understand our impact better, and take responsibility for our actions – our ancestors will be able to read the records of our crimes in the sediments of the deep seas…
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This issue’s worrying news is of an oil spill that has devastated two islands in the Tristan da Cunha archipelago. Otherwise we have cutbacks, and separated populations, watching sharks get spruced up, and an indication that water fleas do have a history…

In our final article you are warned to slap on sun block now if you live in the Northern Hemisphere, due to a hole in the ozone layer. This problem is set to disappear by the end of the century, however, so it is one climatic problem we won’t be handing over to our grandchildren to solve.
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