This is a blog about the UEA’s field ecology trip to Ireland written by several demonstrators: Kris Sales, Jessie Gardner, Jenny Donelan, Seth Thomas, Ellie Fairfield & Claire Buchan.
UEAs Field Ecology course to the Dingle Peninsula, County Kerry, South West Ireland has run for decades. Originally, students camped in a barn of a farmer near Inch Beach! In more contemporary times, students enjoy over two weeks in self-catered cottages over-looking Inch beach and Sammi’s restaurant-pub-shop-surf shack.
Why would students from near to the most Easterly point of British Isles be taken almost as fast west as possible? Being situated on the Wild Atlantic Way there is an incredible habitat diversity on the peninsula; enough habitats for one every day of the working week! Students, visit each location learning about ecology, evolution, hypothesis formation and experimental design. As students come from several degrees, the groups shuffled daily to encourage new interactions and friendships. In week two they apply their knowledge to carry out original research linked to eco-evo questions, which is presented as posters to the local community at the trips end.
It is no wonder that with amazing habitats, the cultural/social experience and skills learnt make the course unforgettable to many. Often undergrads who stay on as post-graduates relish the opportunity to return to the emerald Isle and share their knowledge. It is surreal that although there is so much dynamism in habitats the feel of Dingle is timeless.
Let’s now take a look at the habitats explored by students and learn about some of the species commonly encountered during the week!
Inch Estuary
This mud on the surface looks barren, but as we dig through it, we can see its teaming with life...
The estuary day begins with a short introduction to the birds and other wildlife students will encounter. The main aim of this habitat day is to learn how to identify birds, and to take note of their behaviours and how these behaviours change as the tide comes in or goes out. These estuarine mudflats close to the mainland are extremely claggy, but as we move further towards fast moving water, we can see how the substrate changes and becomes sandier. So how have birds in this environment adapted to feed in different substrates across the estuary? Two great examples of different species with different feeding adaptations are the Eurasian Curlew and Eurasian Oystercatcher. For example, curlew have very long downward curved beaks, perfect for pulling out lugworms, ragworms and other invertebrates that bury themselves deep down in the estuary mud. In contrast, oystercatchers have shorter more stubby bills, and these are perfect, as their name suggests, for prizing apart the shells of bivalves such as mussels, and cockles. These are only two of many bird species that can be seen across the estuary, and students can expect to see up to 20 or more species of bird, and also Eurasian otters on this habitat day.
We then take the students out on to the mud, which is very fun and often results in some very muddy falls!
This mud on the surface looks barren, but as we dig through it, we can see its teaming with life. This muddy soup is what makes the estuary habitat so productive; in fact, estuaries are some of the most productive ecosystems on our planet! Whilst digging we find a number of invertebrates; mainly lugworms, ragworms and catworms, and each have their own unique adaptations for living deep underground.
One of the most abundant organisms found in, and across the surface of the mud is a small snail named Hydrobia. Barely visible these little 2mm long snails make up a large percentage of the biomass in this estuary. Students will often point out ducks such as wigeon and mallard hoovering up ‘mouthfuls of mud’, and this is how they feed on these abundant Molluscs. We also explore the estuary mouth where freshwater meets the sea. This involves trawling along the waterbed hoping that our sieves will be full of small fish (fry), and Crangon shrimp (which they often are!).
Lastly, after observing how the substrate and invertebrate life changes across the estuarine mudflats we retreat to the bird hides! One of the most important skills in ecology is observing, feeding curiosity and developing ways of answering questions born from this curiosity. During the time in the hides, we ask students to think of questions such as why does that bird do that? Where is that bird feeding and why? How do species distributions across the estuary differ? Do birds change where they feed as the tide is advancing/receding? Students then collect data, such as the number of birds seen at different time intervals. The main goal of this exercise is to hone observational skills; by focusing on patterns and processes then forming testable ideas. After a few hours in the hides, we then walk back to the estuary habitat house, where we look over data and any exciting sightings we may have seen from the hides. One year a group of students were treated to excellent views of otters fishing for two hours!
After a hard day’s rummaging in the mud and birdwatching everyone retreats to their houses, with a newfound appreciation for the beauty of birds!
Woods
Is a long day. It’s a 2-hour round trip to get to Killarney National Park, and a several hour-long walk of rambling. However, it’s well worth it! The route is a loop around the Muckross peninsula cutting through several habitats: an exotic tree arboretum, Victorian gardens, grazing meadows, wet alder Carr, ancient acidic sessile oakwood (the largest stretch to escape medieval clear felling), and dense alkaline yew woodland (the yew wood is only one of three in Europe!). Students are asked to describe the structure and condition of each habitat, what processes are causing patterns they see, and what selection it imposes on organisms that live there. Focus is given to considering a range of ecological, temporal and spatial scales. The relative influence of humans and nature is also discussed. So too are conservation issues in the 10 000 Ha of park including: controlling invasive Rhododendrons, overgrazing by deer and renewing aging climax communities.
While moving the group is on tree safari; there’s no shortage in the woods! Similarly, the mild and wet maritime climate is great for epiphytes (on-plants) like moss, lichen and fungi. The diverse biomass and varied structure provide numerous niches invertebrates can occupy. Oaks alone have over 300 lichen and 400 insect speciesassociated with them! So, there are plenty of interesting interactions and amazing adaptations to discuss. On the walk there are waypoints where we work on activities like keying out flowers, forming hypotheses from observations, theoretically designing experiments, and hands-on sampling of insect and canopy cover data. Other hands-on opportunities include tree hugging and foraging for snacks like zesty wood sorrel, sour sloes and sweet strawberry tree fruit. What is especially cool is that even though the route hasn’t changed over the dozen years its run; not only each year is unique with guides adding their own specialist knowledge, each day is different with new field signs, sightings (with pint related prizes for the spotters) and student idiosyncrasies.
Moors
On this day students make an epic journey up the Slieve Mish slopes. Here they experience a succession from grazing fields, heather, sphagnum bog, acid grass moor then bilberry and moss heath. The mountainous western Ireland can expect over 3000 mm of precipitation a year, spread across three days in four, in the form of frontal and relief rain. Therefore, it’s no surprise that Ireland has the third highest proportion of bog relative to country size in the world! Amongst the waterlogged spongy beds of sphagnum moss the group learn about how organisms adapt to the wet, acidic nutrient poor conditions. For example, the methods used by insidious insectivorous plants like butterworts to capture invertebrates and supplement their nitrate intake. The bogs are also home to the polka dot Kerry slug said to form a rolling wheel to escape. Conservation issues are outlined including pressure of sheep grazing and peat cutting for fuel.
There is plenty of flora for students to identify: heathers, mosses, grasses, edged sedges and rounded rushes. Students also discover a world of microscopic monsters found in the sphagnum moss, like the almost indestructible water bear. This day also has plenty of hands-on survey design and data collection. Quadrat transects down a slope and kick sampling transects down a stream are undertaken for flora and freshwater invertebrate gradients respectively. Studies are studded with bouts of student slapstick. This is usually in the form of students; going deeper than desired when testing the integrity of the bouncy blanket bog, throwing a quadrat 100 m further downslope than expected, or surfing down a slippery slope.
Sand dunes
The dunes habitat day begins with a short walk from the cottages down the beach towards the dune system. The sand dunes in Ireland have developed over the last 5,000 years and derive from glacial sediment unloaded and reworked since then by the tides and wind. Substantial dune accumulations are rare, the Inch system is particularly large, totaling 1,250 hectares.
The learning objectives for this habitat day are to observe the successional gradients of salinity, aridity, and disturbance found across embryo, through yellow to grey dunes. The dune system is a rich area to identify organisms using taxonomic keys; a very useful skill to learn as an ecologist! We identify a number halo- (salt), and xero- (dry), phytic (loving) plants adapted to live in such harsh conditions such as sea spurge, marram grass, sea holly and creeping willow. There is great potential explore variation between plant communities across drastically sandy dune slopes and soggy slacks. There is also surprising variation within population some of which is apparent, some which is still elusive. For example, the coloration and striping of riband snails changes to match the ground colour of dunes they are live on in response to natural selection by bird predation. Less clear is the variation in the degree of yellow, white and purple in the wild pansies of the dunes.
There are plenty of dune beasties. The soft loose soil is particularly good for pitfall trapping, with ample catches of predatory rove and ground beetles. The cattle and rabbits of the dunes attract scarab (dung) beetles. The area is also good for hijinks such as pretending pound coins are found in cow pats, and sand surfing down a huge dune blow-outs!
Shores
It is said that we know more about the surface of the moon than we do about the oceans on our front doorstep
The wind cascades, fluid and effortless over the emerald hills of Inch. These smooth viridian slopes gently guide their invisible tourist, like monolith helping hands whilst it gathers speed; weaving and winding through woodland, rising and falling over moorland, whispering its farewell to estuaries and dunes as it heads perpetually towards the sea. But there is one final obstacle to traverse before the long journey across the sea. The wind must navigate the jagged and unforgiving landscape of the rocky shore, its black rocks more akin to Mordor than the golden sands of Inch Strand that taunt from the comfort of the horizon. The rocky shore is a harsh and changeable environment; it is the only place I’ve known for rain to come from below, its embroiled in an eternal struggle with tide and earth as each tries to claim it for its own. You would be forgiven for thinking that as a result of its turbulent and tumultuous nature, little life would be found on the rocky shore. You would however, be wrong.
So why are these regions so bountiful? What makes them special? Why do we subject our ecology students to a landscape I earlier compared to the home of an evil overlord? Well, Sauron would be so lucky as to call the rocky shore home.
The rocky shore is as diverse as it is changeable. It’s ever-changing state and heterogenous surfaces create a plethora of ecological niches for intertidal organisms to exploit. The golden sands of the horizon lose their sheen when it comes to biodiversity, that soft and comfortable yet uniform substrate offers little shelter or food to support the various fauna and flora of the seashore. On the other hand, the rocky shore effectively encompasses three habitats for the price of one. At the upper extent of the shore, we have a near-terrestrial type ecosystem that we call the littoral zone, in which the land meets the shoreline. Beneath that, we have the intertidal zone, which in lay terms is the area of the shore that is covered and uncovered by the tide each zone. Finally, we have the sub-littoral zone, which is the fully marine part of the shore, that is constantly submerged beneath the tide. So, three zones, that in the UK alone account for a habitat that is 6000 km long. That’s a lot of environment for organisms to make the most of.
Rocky shores also vary distinctly from one another. Putting them all under one banner would be like comparing your local woodland with the Amazon Rainforest or the tropical wilderness of Borneo. The biodiversity of these shores is subject to similar shaping variables as these environments, but also some that are unique to the coasts.
Firstly, let’s talk about gradients. I’d to think we’ve all done it, I know I have on more occasions than I am proud of, we are all familiar with the judgmental gaze of onlookers, the immediate embarrassment, the flush of shame and pang of regret. I’m talking, of course, about falling over (with all of the grace of Bambi on ice on the way home from the pub) down a steep rocky shore. These tumbles are one of the defining factors behind a shore’s biodiversity. Organisms that are well adapted to sticking to rock, such as limpets, barnacles, mussels and seaweeds are going to a much better job at occupying the sheer rock faces than crustacea, small fish and seabirds. By the same logic, they aren’t so abundant on the flat shores where they can easily be scraped off by foraging birds, grazed by snails or pummelled by the waves.
This brings us nicely to our second defining factor, wave exposure. Rocky shores could be characterized on a gradient between sheltered and exposed, which refers to the force of waves that they are exposed to. Certain organisms are better suited to sheltered and exposed conditions respectively. For example, the rocky shore at Inch is home to some sheltered shore indicator species, meaning that by presence of certain organisms we can tell whether a shore is sheltered or exposed. However, a rocky shore is not uniform, so areas of it will be more exposed than others. The top facing surface of a rock for example, is significantly more exposed than the underside. Distribution of organisms reacts to this factor, with many huddling beneath rocks or hugging to the land facing side. Observing which species prefer which conditions is a popular research topic along the rocky shores.
The last (but by no means the least) factor worth discussing is what is left behind when the tide retreats, rock pools. These rock pools are perhaps one of the most extreme microenvironments on the planet. As an organism in one, you’re effectively trapped until the tide returns. This has created a pressure for highly adapted organisms to dwell in these rock pools, this is perhaps best illustrated in The Secret Life of the Rock Pool. Organisms need to be adapted to survive concentrated predation, changes in temperature, nutrients and pH, as well as exposure to the air. The fact that organisms can do this, and do it regularly is a marvel.
These factors combine in a perfect storm to create something unique. These habitats are like microscopic planets. They experience their own weather, a seasonal cycle that happens on a daily scale, their own balance of nutrients and localized species. The organisms within these zones experience forces on an hourly basis that many of us do not experience in a lifetime. It is said that we know more about the surface of the moon than we do about the oceans on our front doorstep. If space is the final frontier, then our oceans are the penultimate. So why do we get our ecology students to study the factors that drive organism’s distribution and diversity on the rocky shores? Because when you peer through the surface waters of rock pool, you are in effect staring through a window to another world. We investigate this environment with deserved fervour, as for an afternoon at least we are not ecologists, but intrepid interstellar explorers, who from their relative shelter and comfort where the biggest threat is the passing of the wind, are able to watch creatures that can only be described as otherworldly; even alien.
All photos were provided by the authors and used with permission.
CEEC science 