If you were asked to name a nation with coral reefs, it’s likely Ireland wouldn’t be at the top of your list. Well, it might surprise you to know that we’ve got the Atlantic version of the Great Barrier Reef right off the coast of Galway!
Cold-water corals may be lesser known compared to their tropical cousins but are functionally the same habitat-forming fish paradise. In fact, over half the species of coral in the world are cold, deep-water species and many of them can be found in Irish waters. Cold-water corals form patches of colourful reef on the sea floor, developing alongside or on sea mounds which can rise up several hundred metres from the sea floor.
Despite the fact that these reefs live several hundred metres beneath the surface, technological advancements in deep sea monitoring have finally allowed us a glimpse into this mysterious world. A recent project led by the Irish Marine Institute piloted an underwater remote-operated vehicle to collect samples and images in Ireland’s Porcupine Bank, a hotspot for cold-water corals, located on the continental shelf 200km west of Ireland. They discovered novel coral and sponge species, and recorded coral as deep as 1600 metres. Picture 13 Dublin Spires, one on top of the other – that’s how far below the surface these corals live.
A research paper by Roberts et al (2006) explores how this protected pocket isolates some species, much like a forest being separated by a fire. This actively creates novel species which are endemic to Irish sea mounds. A shark nursery was even spotted near Porcupine Bank, illustrating how vital this landscape is for recovering marine life from the brink of extinction.
But they’re not just a pretty sight; reefs increase the health of the ocean ecosystem and hold vital records of ancient seas.
Coral is an ecosystem engineer, providing a rich habitat for marine life, much like an underwater forest. According to the World Wildlife Federation, Irish reefs support a recorded 1300 species of invertebrates and fish, ensuring a balanced and biodiverse environment. This is aided by how sea mounds jut up from the sea floor, disrupting strong ocean currents and essentially creating a barrier sheltering its inhabitants.
But that’s not all, the coral is a living artifact showing us the state of the ocean for the last 10,000 years. Due to very slow growth rates and long lifespans, these coral species store records of the conditions they grow in, akin to the rings on a tree. This means that when analysed by scientists we can reconstruct prior climate conditions, giving us a rare glimpse into the past!
For all the marvels these reefs bring, cold-water corals, much like their tropical counterparts, are under threat. The single largest threat to cold-water coral is industrial fishing practices, most predominantly, bottom trawling. This involves dragging large fishing nets along the sea floor physically tearing up fragile reef systems, trapping any life in its path. Trawling causes a large percentage of bycatch – unwanted species caught up in the net – and irreversible damage to the sea floor. Despite this clear risk, the practice is still permitted in all Irish marine protected areas, including cold-water coral mounds. The devastating effects of this practice are even more pronounced in these areas, as cold-water corals take a long time to recover, due to their fragility and slow growing nature. Monitoring in Darwin Mounds in Scotland, a trawling hotspot for many years, revealed that recovery after ban on trawling took upwards of 15 years.
With the great advances in research on cold-water corals coming from Irish institutions, how are we protecting these vital ecosystems? Currently, we’re not protecting them at all. Along with other EU member states, Ireland has committed to the EU agreement to protect 30% of ocean systems by 2030, but, with under 5 years left until the deadline, only 2% of Irish waters are currently protected. Industrial fishing in Ireland has never taken sustainability into account, with quotas far higher than advised by experts. Atlantic cod suffered a monumental collapse in the ‘90s and at current rates they are still being fished out faster than they can replenish.
Therein lies the solution: Protecting vital sea-floor habitats protects the interests of not only the environment but also the fishing industry. The reef supports a complex web of species, replenishing fish populations at a very high rate. The first step in increasing marine protection and banning trawling is awareness and education. Trawling practices have been further exposed and have captured broad public interest following the release of David Attenborough’s documentary ‘Ocean’. This upsurge in awareness coincides with significant legislative action across Europe. The UK has committed to ban bottom trawling in 41 marine protected areas around its coast – a move which, according to the UK Department for Environment, Food and Rural Affairs will ensure the protection of significant areas of cold coral reefs off the west coast of Scotland. This activism and consequent legislation sets a hopeful precedent for Irish waters.
The success story in Scottish waters demonstrates that it’s not too late to protect these vulnerable ecosystems. By raising awareness of these novel coral reefs and mandating sustainable fishing practices that prioritise the future as much as the present, Ireland can set an example in preserving these most remarkable ecosystems sitting on, or under, our doorstep.
