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’.
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.
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.