Irish Marine Life
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The Irish Times – Seaweed
Image © Viney, reproduced from Irishtimes.com
Here’s a timely and quality article by Michael Viney on the state of seaweed in Ireland, including the good and the bad, from The Irish Times yesterday.
http://www.irishtimes.com/newspaper/weekend/2010/0821/1224277276531.html
Fairies ag damhsa on the shore
Image © JP Tiernan 2010
Séamus Mac an Iomaire, in his benchmark book on shore life, called them an tonachán, but a man in Connemara advised me yesterday of a different name: an míol críonna. Requiring a slight pause to achieve the correct pronunciation, ‘míol críonna’ sounded nicer we thought, but it is less than accurate, as it really refers to a wood-louse.
His friend offered a different version again, but none of us liked that name; and I’ve already forgotten it, although I suspect it was dreancaid mhara (sea flea). One of the younger members of the party knew them as ‘the sandhopper’, which everyone agreed upon.
I told her to throw the piece of fheamainn (which I had given to her to hold while I explained to the rest how the tonachán lives underneath it) into the fire when she goes home – to listen to them explode. Her mother looked startled; I clarified that I was referring to the air bladders exploding, not the tonacháns.
Noting the air bladders, the man corrected my description of the piece of seaweed she was holding as fheamainn bhoilgíneach. Fheamainn, of course meaning seaweed and bhoilig meaning stomach. Which is what someone a long time ago thought the little air bladders which occur on Fucus vesiculosis, or bladder wrack, looked like; little swollen stomachs.
But back to the tonachán, or míol críonna, or sandhopper. Most people’s first encounter with these cryptic crustaceans is a less scientific and more enchanting experience; an unforeseen after-party maybe, late on a summer’s night. Like this time last year, when we chanced on thousands of them, pulsing and bounding – ag damhsa – to an unheard beat, on a shore which was turning lighter shades of grey as the rising sun threatened to reveal us before we reached home.
The sandhopper resembles a tiny prawn or shrimp, which remains burrowed in the sand or under wrack all day. At night, this leaping activity is simply an excited feeding state, although scientists aren’t sure why exactly it behaves like this. It leaps or hops up to a foot or two off the ground by sudden outward flicks of the lower half of its abdomen, with no control over the direction it lands in.
All this of course we knew, so we didn’t rise the next morning wondering whether we should risk being scorned for our state of sobriety by sharing tales of fairies dancing on the beach the night before … but how many have?
This article appeared in The Mayo News 17/08/2010
And 6,000 miles away from Ireland…
Image © L Duignan 2010
6,000 miles from the shores of West Mayo in the Eastern Pacific Ocean, a large lizard like creature, quite unlike anything else on this planet, crawls lazily over ancient lava rock at sunrise to feed on clumps of seaweed, entirely undisturbed by our presence just a few meters away. It’s a marine iguana, and like so many of the other animals and plants found in this group of volcanic islands, it’s endemic; meaning it occurs here and only here.
Below the surface a half hour later, an underwater data survey is interrupted by another endemic species; an endlessly curious sea-lion that demands our attention as it swims alongside and pulls playfully at our snorkelling fins. Similar in appearance to the harbour seals of Clew Bay, it is entirely unrelated to them and stresses this difference through its engaging and matchless behaviour. If not a sea-lion, then maybe a parrot fish will come and gaze dopily at the human visitors to its rocky reef domain, or a white tip shark will pass by, uninterested and oddly unthreatening. Such are the peculiarities of working in these islands, so often referred to by disbelieving authors as ‘The Enchanted Isles’.
Image © J Tiernan 2010
It’s the same seaweed that the iguana forages for at low tide that brings us, two marine researchers from the West of Ireland, to this remarkable place where we will divert our efforts away from Ireland’s marine life for a month or so. We are tasked with answering questions about the conservation status of the seaweed here and helping the local National Park authorities formulate strategies to ensure its’ and the unique and extraordinary animals that depend on its’ survival.
Despite being a marine reserve and a UNESCO world heritage site, seaweeds have been doing the unthinkable here; going extinct. Vast tracts of the underwater seascape are bare of seaweed and heavy with grazing sea urchins. This has serious implications for the habitats and species they support, including the marine iguana, which doesn’t eat anything else in fact. The oceanographic phenomenon of El Niño which causes unusually warm water here every few years is the main cause, but there may be more insidious reasons to consider: Twenty years ago, the locals tell me, you could stick your hand blindly into the water at night and pull out a lobster, such were their numbers. Too many did this and less lobsters equals more urchins (lobsters eat urchins) which equals less seaweed.
Urchin Barren Zone. Image © J Tiernan 2010
We are a long way from anything like this in Ireland, or are we? Our ecosystem is more resilient but it’s not invincible. Last week was European Fish Week where the major theme was overfishing and what we are going to do about it. In the next few weeks we will complete a week long voyage here documenting where, how many and which types of seaweed are still occurring. In the meantime we will observe this peculiar and mystifying ecosystem and think from afar about what we can learn about our own.
Basking Shark; Achill Island
After a pretty insane day of fishing, snorkelling, doing some kelp forest videoing for the Heritage Council’s ‘Heritage in Schools Scheme’ and exploring caves around pseudo-tropical Achill this Sunday, we had this surprise on the way home in the curragh.
The glassy seas country wide meant sightings shot up over the weekend around the country. check out the IWDG’s sightings page to see where and what was seen.
UPDATE - And from Wednesday´s Irish Times; record numbers of Basking Sharks were tagged over the same weekend off Malin Head, now considered a Basking Shark ‘hotspot’. Read the article here
Snorkel at An Spideal
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An Spideal yesterday evening kicked off the first snorkel of this year and try-out of my new underwater camera housing. A week of north winds (offshore in Spiddal) meant good visibility but water temperatures are still pretty chilly. Nothing too mind blowing was seen, the highlight was a colourful corkwing wrasse which lit up my snorkel with its neon hieroglyphic patterns. This fish reminds me of the Pacific giant hawkfish or hieroglyphic hawkfish, a fish which lit up snorkels in a different ocean once..
The violence of our peaceful seas
Normal North Atlantic order has restored itself after a most remarkable 4 weeks in Ireland’s recent meteorological history. It will be hard now to discern any surface goings-on between shore and horizon with wind and swell likely to run for weeks on end as they often do in January and February, driven to us by lows sweeping across from Newfoundland in our general direction.
These lows stopped for that extraordinarily Siberian month, blocked by a strong high pressure air- mass to our North which made for a very still Atlantic allowing me one evening to sharply define the space between caudal fin and ocean and see through the burst of spray between dorsal fin and sky. It could be September but for the 10 degree water I thought as the three dolphins surged powerfully high out of a flat sea and all of this silhouetted by a low cloudless sunset over Renvyle.
Such acrobatic behaviour, in particular whirling vertical leaps is more noted of the smaller common dolphin which is usually found far offshore over the continental shelf in great numbers. They are only occasionally seen inshore and that’s usually in the southwest of the country. There was not enough light to be sure but these were most likely bottlenoses, which do from time to time leap and spin like this, and bow ride and surf of course too. But then the bottlenoses are continuously surprising us. Reports of porpoises with great shark-like chunks taken from them a hundred miles or so south of here this summer led to the surprising discovery of research, mostly from Britain, on violent bottlenose attacks on porpoises.
Where the two species occur together, the most common cause of washed up porpoises’ death was attacks from bottlenose dolphins according to The British Environment Ministry. They don’t compete for food and scientists are guessing that it is a simple territorial aggression, with serious costs for the muc mhara (the porpoise is the pig of the sea in Irish). Damage recorded to porpoises includes broken ribs, internal organ rupture as well as bite marks. Have some of the many that wash up on Mayo’s shores experienced the same underwater violence? Probably, but data and studies could say for sure.
The bottlenose is not the indifferent play seeker we may have thought and neither does the muc mhara dip from cuain to cuainín in Clew Bay as carefree as it could appear.
The bottlenose dolphin (Tursiops truncatus) is grey to black above and light grey on the underside. They have a tall fin and a long, rounded beak with a curved mouth-line giving the familiar smiling expression. They are usually seen in small groups and frequently inshore where they are engaging and playful. The common dolphin (Delphinus delphis) is smaller than the bottlenose with a distinctive ‘hourglass’ colour pattern on its sides; yellow to the front and light grey to the back. Above this hourglass shape is black and below is white. They have a tall fin and a long black beak. They are more commonly seen in deeper waters in large numbers, but are sometimes seen off coastal headlands in summer. Report your dolphin sightings to The irish Whale and Dolphin Group at www.iwdg.ie
This piece appeared in The Mayo News 02/02/2010 edition
Remarkable weekend for whale watchers in Ireland
Image credit:RTE Website
The Hook Head area was the location last week for some of the most remarkable large marine life activity ever witnessed in Ireland. These pictures from RTE.ie show a humpback whale breaching, with common dolphins, harbour porpoises and fin whales also present in the area. The activity was witnessed by the Irish Whale and Dolphin Group who also succesfully recovered a sample of whale flesh which will allow genetic analysis of the whale’s gender. Such information is of exceptional value given the humpbacks’ threatened status.
Read more about the event on the iwdg.ie website.
The Irish Times – North Donegal Basking Shark Hotspot
The Irish Times today reports on the identification of North Donegal as a basking shark ‘hotspot’. The article reports on increased activity observed by the Irish Whale and Dolphin Group and notes that reports of humpback whale breaching may actually be sharks.
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Wild November, Mild December, New Year
Photo credit: Andrew Butler
In the glassy December stillness after a high energy November, traces of this stormy and violent month made themselves apparent in our marine ecosystem.
The legacy of swell after swell which finally ceased a week into December to a calm orderliness groomed by light easterlies revealed itself if you bore the cold and looked carefully enough over the Christmas holidays. At the north end of the beach waves broke in a place they normally don’t; enough sand had been displaced by the wave action and its accompanying rip currents to form a shallow sandbar just far enough outside the beach to be notable. The sand had been scoured deep around it, focusing the wave energy on the centre, a powerful and perfect wave for those lucky enough to access it.
Such events have a capacity to unearth, to claw at our moveable shores and reveal, more sometimes than is at first apparent. Inside the new sandbar, the beach had lost a few feet of its sand rudely exposing a bed of rocks from their summer covering. Scattered amongst these new additions to the shore’s topography were small rods and fragments of kelp, our perennial indicator of what is happening in the elusive offshore kelp-beds. Contrary to what is often thought (and sometimes taught) the presence of sea rods on the shore is usually determined more by the plants’ life cycle than the action of the ocean. In this instance however, the masses of short, thin fragments littered on the shore implied that the juvenile Laminaria and Alaria species which should be hanging on in their unknown strongholds between Carrownisky and Inishturk for a few more years were interrupted by an extraordinary month.
And not only the deep, but the past was evoked by the legacy of November 2009. A little further down the shore and sand again was divulging its secrets. A section of the cliff bluff, which is nothing more than sediment held in place by resolute marram grass, had given way to incessant westerlies undermining its base. Here, 20 feet above the high tide mark, crumbling out of the cliff face were periwinkles and bairneachs. Many winters ago, somewhere between mesolithic and medieval, these mollusks of the low tide rocky shore made their way to someone’s mealplace by hand. The people who identified a shellfish which would ultimately be harvested and sell well in France (the periwinkle, the bairneach’s taste never found popular favour) laid down their rubbish in a shell-midden for us to consider our past months with as we turn on a New Year. The January sea continues December’s theme steadily bringing us a newer, colder agenda from the north. The winkles and bairneachs make their way back down to the ocean and the sediment as new legacies are deposited and secrets are covered up again by the stealthy sands.
Bairneach is the local name for in English what is called the common limpet (Patella vulgata). It is a marine Gastropod related to periwinkles and land snails all belonging to the Mollusca phylum. It grazes algae when the tide is high and its feeding trails can be seen on the rocks it inhabits in the intertidal. Bairneachs clamp themselves to the rock with remarkable force if disturbed and are presently been studied in Ireland for their bio-adhesive properties. Bairneachs were commonly eaten in coastal areas until recent times.
irishmarinelife
lenny antonelli
