Sponging a living

March 4th, 2016

Micrograph of the bryozoan Flustra

The Bay is home to a vast army of locals, who have survived and adapted to a landscape that appears at first glance to be empty… At our talks on the 10th February we investigated the most overlooked creatures of the Bay. The couch-potatoes. These are animals that, having found a place suitable to put down roots, have stopped there for the rest of their lives. They rely on the tides of the Bay to bring food to their waiting mouths.

The ecosystem of the Bay is driven by phytoplankton blooms, which are at their most extensive in Spring and Autumn. For the rest of the year plant life is comparatively scarce. In this environment our ‘couch potatoes’ play a vital role; every bacterium, every gram of poop, anything that can be recycled is brought back into the food chain. Despite their sedentary nature, these filter feeders are an essential part of life in the Bay.

This intensive re-use of all things organic has, unfortunately, an unexpected side effect. Organic toxins, such as PCBs (banned in the seventies) are held within the marine food web, and are responsible even today for the deaths of top marine predators, such as dolphins and killer whales (See for example: BBC report by Rebecca Morelle).

This sobering fact leads us some way towards our last talk of the Winter series in the Gregson – ‘Human Impact on the Bay’ on Wednesday 9th March. At this meeting we will look at a couple of the ways we impact the life of the Bay, through Fisheries and litter.

More information: Human impact on the bay PDF 77kB

AGM January 2016

January 21st, 2016

MCS logo (small) We were able to look back on quite a successful year at our AGM. Highlights for the group included a well attended Marine Life ID course at Leighton Moss, and ongoing series of meetings at the Gregson – which we hope to repeat, subject to our being able to come up with a suitable theme! The group made a profit of £130 from talks and events over the year, which has been donated to National MCS. A similar sum has been raised through pin-badge sales on our stand, and through Capernwray Dive Centre (to whom again our thanks!).

Events planned for 2016

The plan this year is to focus on beach cleans and out-door events over the summer period, and have a more formal series of lectures over the winter. We are hoping to increase our profile this year with an extended presence at the ‘Catch the Wind Kite Festival 2016‘ in Morecambe, and have a couple of preliminary meetings scheduled to work on this.

Further details of planned events (PDF 101kB)

For updates, please check our diary.

Stuck in the mud

January 14th, 2016

Anemone photographed at Roa Island 2015

The talks on the 13th January looked at life that crawls over the sands of the Bay. Grazers, predators and carrion feeders, these animals have an eye (nose or tentacle) to their best chance, and armour, spines and poison to defend against the rest. Starfish and dogwhelks making shellfish soup, the long-lived lobster (if she isn’t caught and eaten), or the mysterious life of the shrimp – before she is potted…

In our next meeting, we will look at the couch-potatoes of the Bay. Animals that, having found a place suitable to put down roots, have stopped there for the rest of their lives. The tides of the Bay bring food to their waiting mouths, armed with suction pumps or waving tentacles to catch the bounty as it is swept by. There is no terrestrial equivalent to the animal gardens in Morecambe Bay.

Presenters are Louise Smail (Sponges and shellfish), Barry Kaye (Barnacles, bryozoa and worms) and Gordon Fletcher (anemones and sea firs)

Stuck in the mud: Wednesday, 10 February at 19:30 at the Gregson Arts and Community Centre, 33 Moorgate, Lancaster, Lancashire LA1 3PY. All are welcome, £2.00 admission.

Wanderers of the sand

December 12th, 2015

Bernard the hermit crab

At our December meeting we looked at some of the birds and fish that use the Bay – waders feeding on the rich pickings in the mud while the tide is out, replaced by flatfish swimming in with the tide to feed while the mud banks are immersed. The Bay is ranked second most important area for migratory birds in the UK, offering a vital stop-over point on the East Atlantic Flyway, connecting wintering grounds in South Africa with feeding and breeding grounds in Norther Canada, USA and Russia. Rather less is known about the fish population, but both birds and fish are free to move in three dimensions, and have the freedom to exploit the Bay. Our next talk looks at groups of animals that have more limited movement, and must stick to channels, or suffer being flooded and dried out twice a day…

Hunters and hunted – those that crawl the sands of the Bay are an alien band of creatures, armoured, multi-armed, poisonous; whatever it takes to survive… Bernard the hermit crab (above) has sharp eyes, but he is too slow to escape the fish that might snack on him, so he retreats into an old whelk shell, guarding the entrance with his impressive claws.

On Wednesday the 13th January we will have three short talks on starfish, crustaceans, slugs and snails:

‘Wanderers of the Sand’ 19:30hrs Wednesday 13th January at the Gregson Community Centre, Moore Lane, Lancaster LA1 3PY
All welcome – admission £2, proceeds to Lancashire Marine Conservation Society.

The Freedom of the Bay

November 30th, 2015

Photo of a peregrine falcon
At our last meeting we ventured back in time to the last Ice Age, when the Bay was scoured out from the underlying rock by glaciers making their way down from the Scottish Highlands and the peaks of the Lake District. Since then the Bay has been filled with fine silts to a depth of 80m in places, leaving a shallow, productive, estuarine environment. The plants at the bottom of the food-chain in the Bay are microscopic unicellular algae called ‘phytoplankton’, and their lives are governed by the tides and river currents, and they are so small that you may have overlooked them, even though massive numbers of them live in the Bay…

On the 9th December we will turn our attention to two, more visible, groups of wildlife that use the Bay – the fish and the birds. These animals use the winds and the tides, and are able to hunt and explore as they see fit. Among the bird life of the Bay you may spot Percy the peregrine falcon. If you’re lucky you’ll see him doing a ‘fly-past’ over the bay during the autumn and winter and causing a commotion!

‘The Freedom of the Bay’ 19:30hrs Wednesday 9th December at the Gregson Community Centre, Moore Lane, Lancaster LA1 3PY
All welcome – admission £2, proceeds to Lancashire Marine Conservation Society.

The Freedom of the Bay (PDF 55kB).

See our diary for updates or more events.

Peregrine Falcon photo credit: Mike Baird via Wikipedia.

Meet Erika, she is an economic migrant…

October 16th, 2015

Erika Morecembe, photo Gordon Fletcher at Roa.

She looks pretty fearsome, and she will give you a nasty nip if you annoy her, but, like any good parent, all she wants is to give her children a good start in life. To do that she has walked to Roa Island in Morecambe Bay from the deep waters of the Irish Sea. The shallow waters of the Bay are warmer, so her eggs will develop more quickly, and when they hatch there will be an abundance of food – as Morecambe Bay is one of the most productive environments on the planet – honest! (On land you would have to go to a rainforest to do better – yet Morecambe Bay is only a bus stop away!)

Over the winter period Lancashire MCS will be presenting ‘Morecambe Bay at the Gregson’. The first event ‘Introducing Morecambe Bay’ will be on Wednesday November 11th at 19:30. There will be two short talks suitable for a general/family audience, that will introduce the Bay – how it was formed, and what makes it important to the wildlife that calls it home.

‘Introducing Morecambe Bay’ 19:30hrs Wednesday 11th November at the Gregson Community Centre, Moore Lane, Lancaster LA1 3PY
All welcome – admission £2, proceeds to Lancashire Marine Conservation Society.

Introducing Morecambe Bay (PDF 90kB).

See our diary for updates or more events.

Heysham Safari

September 28th, 2015

Photograph of children rock-pooling at Heysham safari 2015

The Bay ‘Super-Estuary’: After the last ice age, the ice sheets that scoured out Morecambe Bay retreated, leading to the formation of the Irish Sea, and flooding the Bay itself. While it still reaches depths of 80m at Lune Deeps, most of the Bay has been filled in with sediment brought down by the rivers Wyre, Lune, Keer, Kent and Leven to form the largest network of intertidal mudflats in the UK.

Satellite imagery shows that the bay as a whole has a very high primary productivity. Fixing around 1.5kg of organic carbon per square meter every year, this ecosystem is one of the most productive in the world. Despite this powerhouse of growth, life in the Bay tends to keep itself hidden, so on Saturday 28th September, Gordon Fletcher led a ‘Heysham Safari’, to expose some of its less commonly spotted inhabitants.

The event, organised with Morecambe Bay Partnership, was a great success, with twenty five participants filling the restaurant at the Royal Hotel, Heysham, for Gordon’s talk! The talk was followed by a shore walk around Throbshaw Point, where we found and identified 26 species in a little over an hour.

Thanks to everyone for attending, and helping to make for such an enjoyable occasion!

Roa Island Beach Walk and Dive

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.

Beach clean (8th July)

August 9th, 2015

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

Wyre Estuary 24hr Nature Watch (Bio-Blitz)

August 9th, 2015

bioblitz_sm

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.