Contributing to the festive season, we have an illustrated talk on ‘Marine Jellies’ by Gordon Fletcher on the 13th December. Gordon is a good story teller, and an excellent marine life photographer. I cannot think of a more able person to bring some of the strangest and most beautiful creatures in our seas to life for us!

Wed. 13th December 1t 19:30 ‘Marine Jellies’ by Gordon Fletcher (Lancashire MCS)
Meeting in the cinema upstairs at the Gregson Community Centre, Lancaster, LA1 3PY. Admission £2 – all are welcome!

On Wednesday 14th December we have our last public meeting of the year, with two talks from the local group looking at how some marine organisms have adapted to the ‘built environment’. Lewis Bambury will look at static objects, under the title Piers and Jetties, whilst Barry Kaye will take a look at Bilges and Bottoms…

The meeting is at 19:30 in the Cinema, upstairs at the Gregson (click for website with address and venue details).
Admission is £2. Everyone is welcome.

You can download a copy of the poster below:

Man made habitats poster (116kB PDF)

Photo: Blackpool pier by Lewis Bambury.

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!

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.

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.

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.

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Cuttlebone – provides lift for the Cuttlefish, allowing it to hover in the water without expending energy swimming.

A few interesting natural history finds amidst the litter on the the July Beach Clean at Half Moon Bay, Heysham. These included a dead porpoise, two adult cuttlebones and some wireweed (Sargassum muticum).

Cuttlebones are the internalised shells of cuttlefish, formed of delicate lemellae and filled with gas, the organ holds the live cuttlefish at a fixed height in the water column, without them having to expend energy swimming. They also limit the maximum depth this animal can attain, as below 50m or so the cuttlebone would implode. A mating pair of cuttlefish were seen by group members at Roa Island some years ago.

The porpoise was a rather sad sight, there are not many reports of these animals in Morecambe Bay, with its shallow waters and treacherous tides. The state of decomposition suggested that the corpse may have drifted in from elsewhere…

Wireweed is not native to British waters, having been introduced accidentally with Pacific Oysters, which are bred around the coastline.

Catching up on a few past events, we were at the Wyre Estuary 24hr Nature Watch (Bio-Blitz) on the 6th June, with Kathy and Jane (pictured above) manning our stand. This was a fascinating event, with lots of things going on, both on land and from the sea. The marine exhibit including tanks of sea life from the estuary for people get up close to, plus plankton samples from the estuary.

Wherever you are in the UK, you are only a few miles away from a true wilderness, were very little of the plant or animal life is tamed or cultivated.

If you would like to know a little more about the wilderness on your doorstep, you are cordially invited to our Marine Life ID course, where members of the local group will provide short introductions to many of the important marine groups – many of which have no terrestrial equivalent…

Marine Life ID course
By Lancashire MCS Local Area Group, with support of the Society of Biology
Saturday 18th July for 10:00 AM at Leighton Moss RSPB Reserve
Price £10
Booking essential Email: Secretary(AT)lancashiremcs.org.uk

For more details, please download our brochure.

Photo-montage: All but one of the photographs in the montage above were taken in the UK, and four were taken in Morecambe Bay. Photos by Gordon Fletcher, Barry and Jo Kaye. CLICK IMAGE FOR A LARGER VIEW!

Presented by Lewis Bambury and Gordon Fletcher of the local area group, these talks on the 12 June 2013 at Capernwray Dive Centre looked at some typical dive sites in the North West of England.

Gordon introduced the topic with reference to the local geology, which was completely re-modelled by the last ice age. Offshore this leaves three dominant ecosystems – extended, shallow, muddy plains dotted with the remains of drumlins which provide a scatter of ill-sorted boulders and pebbles, plus the Lune Deeps – a U-shaped glacial valley that reaches depths in excess of 60m. The fine sediments make for difficult diving conditions, as witnessed by Lewis’ introductory slide, and a diver interested in marine life needs to acclimatise to an environment that is nearly monochrome, covered in a fine silt that lifts into an impenetrable veil with the slightest fin kick.

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Above: approximate location of the Hebe at the entrance of the channel to Preston Docks.

The ecosystems, while shallow, are dominated by animal life due to the fine suspended silt that cuts off the sunlight needed by seaweed. The mud is inhabited by secretive, burrowing worms, molluscs and crustacea – species we don’t see on most popular dive sites. Where a solid substrate is provided either by a wreck, or by a boulder scatter, the species mix is dominated by hornwrack (a common find on the strand-line around the Bay), with sponges, anemones and hydroids also being abundant. Lewis’ photos showed the dramatic difference between the mud plains and the site of the Hebe, a steamship stranded on Horse Bank 11th December 1911, with the plains apparently featureless with the odd worm-cast, starfish or antenna hinting at the presence of life beneath the surface, whilst the old iron plates of the Hebe bloomed with a profusion of plumose anemones, with mussels and hydroids filling any available gap.

Lewis thanked Darwen Sub Aqua Cub (based near Blackburn) for inviting him to join them on visits to the Hebe and the Lune Deeps.

The talk was prefaced by a short introduction to our beach-clean program by Jo Kaye. The next beach cleans at Half Moon Bay are scheduled for Sunday 16th June and Saturday 21st September 2013.

See our diary for full details.

Last month’s meeting on Surveying the Piel Channel, by Ron Crosby, drew another big turn out. The Piel Channel is one of the very few satisfactory shore dives along the coasts of Lancashire and Cumbria. Our coastline has very gently sloping muddy bottoms.These make them very susceptible to disturbance from wind or tide, resulting in very poor visibility. It is not that there is no life here – quite the opposite, but it is often dug in and hard to see…

By contrast the tidal race of the Piel channel cuts the boulder-clay sediment to a depth of about 12m within a few metres of the shore. While visibility is still often very poor, the comparatively steep profile means tat all of the life in the bay is compacted into a small area, and a wide range of habitats is very easily accessible.

For more information on the range of organisms found in the Channel, see our surveys page:

Marine life survey of the Piel Channel, Barrow in Furness

A couple of articles over the last few weeks do make interesting and/or disturbing reading: I think it is pretty much a given that for wild fisheries to have much chance of survival they must be managed. In this light recent gene marker studies on fish sales raise both hopes that we can now clearly identify the provenance of a fish on the fishmonger’s counter, and a warning that some existing certification schemes are not working as well as they need to. Farmed fish may be managed, but that also makes them subject to pretty unpleasant management practices, such as the practice of eye-stalk ablation, which apparently speeds maturity of black tiger shrimp…

We start, however, with one of the big stories in the popular press over the last few weeks, the latest estimate of the total number of species on the planet. To be pedantic we should perhaps say eukaryotic species, though the term ‘species’ is not very easy to apply to prokaryotes…
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The hardest coral on the reef may well be a softie, as much of the rocky structure of these reefs is found to derive from the sclerites from soft corals! This debate over how much support environmental agencies will grow as our economic worries deepen, how high up the scale do you put the environment? Essential for our continued existence on the planet, or jobs/hospitals now (environment later – maybe)? This week DSN reports on the debate in the US in our conservation leader. Our pollution section, however, points out that one of the most damaging aquatic pollutants – nitrogen from fertilisers – can be reduced while saving money and increasing yields…
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