Cyfoeth: The Natural Resources Wales Environment Podcast

Episode 2: Skomer Marine Conservation Zone - Part 2

October 08, 2021 Natural Resources Wales Episode 2
Cyfoeth: The Natural Resources Wales Environment Podcast
Episode 2: Skomer Marine Conservation Zone - Part 2
Show Notes Transcript

In this episode, we return to Skomer to learn more about the fascinating shoreline monitoring work done at the Conservation Zone.

Llion:

 Hi there, and welcome back to Cyfoeth: The Natural Resources Wales Podcast and to part two of our visit to the Skomer Marine Conservation Zone. My name is Llion Bevan and I’m a Senior Communications Officer working for NRW.

 

In last month’s episode we spoke to our retiring Senior Marine Environmental Assessment Officer, Phil Newman about the work of the Marine Conservation Zone, and this week we’re going to speak to our colleagues Kate Lock and Mark Burton, who are both Marine Environmental Assessment Officers.

 

You don’t have to have listened to part one to understand this second part, but it will give you a good grounding in our work at Skomer, whereas we’re going into further detail on one element of the work in this part.

 

In part two, Kate and Mark will be telling us all about the shoreline monitoring work they do at Skomer, why it’s important, and what we can learn from it.

 

In this work they monitor the variety and numbers of plant and animal species over time. Key to much of this work is the use of quadrats, which are one-meter square frames that they use to make sure that they monitor exactly the same square metres which allows the results to be comparable over a period of years.

 

In the last episode, I said that we would be meeting up with Phil again for a quick question and answer session, but unfortunately, we were unable to meet up – and Phil has since retired! If you have any questions about our work at Skomer, do let us know and we’ll get them answered by Kate and Mark.

 

So without further ado, lets get started! We’ll start with a conversation I had with Kate, and we’ll then move on to two chats that my fellow Senior Communications Officer, Llinos Merriman had with Mark.

 

 

Llion:

Hi Kate, how’s it going? 

 

 

Kate:

Hia!

 

 

Llion:

You alright?

 

 

Kate:

Yes!

 

Llion:

Thanks very much for joining me Kate. I see you've been busy down by the shoreline today. How are you feeling today?

 

Kate:

Yeah, it's good. It's a lovely calm day today so it's ideal conditions for doing this outside work.

 

Llion:

Excellent and tell me a bit about yourself. How did you come into this line of work?

 

Oh well, I've been working here at the Skomer Marine Conservation for nearly 25 years, believe it or not and before that I was actually working quite close by at Dale Fort Field Centre; one of the Field Studies Council centres where we were teaching rocky shores and marine biology and stuff like that.

 

So that's how I transitioned to come across and start working originally for Countryside Council for Wales and now NRW.

 

Llion:

Great, and what made you want to get into this line of work in the first place?

 

Well, my degree originally was actually Fishery Science and I did a lot of aquaculture initially, but I didn't really enjoy the intensive farming part and I decided that I'd rather get into more sort of marine and conservation and wild stuff.

 

So I went on and did the Masters degree and that then took me to Dale Fort and now here. So I came from an aquaculture background really.

 

Llion:

Ah right, interesting. So I have you always been by the sea? 

 

Well, my mother actually dived during the 70s. You know when it was their old 

homemade wet suits with marigold gloves and stuff and literally wore socks. And so I was brought up with that and I was brought up snorkelling and we lived actually just outside London but we would go down to the Dorset coast regularly. So yeah, I've kind of been in the water along time and snorkelled a long time and then as soon as it was possible to learn to dive, I did so I learned to dive at 18 and really not look back.

 

Llion:

Excellent! You very kindly taking a little break out of your day, but the work carries on in your absence for the time being. What are they doing there at the moment?

 

OK, so what we're doing is we've got quadrats; one-meter squares and we use them to place them on the different areas of the seashore.

 

Now the seashore is sort of divided into what we call shore zones. That’s all dictated by the tidal range as it comes in and out. In this area we get about a 7.8-meter tidal range between the lowest low and the highest high.

 

So we have a large shore area that we can survey. So we divide the shore into what we call the lychen zone, which is really high up. We have the upper shore zone, then the middle shore zone and then the lower shore, which is properly down by the sea, where the boys are doing the work at the moment.

 

So what we have for our monitoring work we have fixed locations, where will repeat the same survey work each year.

 

The first thing we had to do is actually find our corner markers, which is quite tough because they are little screws that are screwed into the rocks and we have to relocate them each year and of course the seaweed and stuff grows over them so the first thing - you know – is scratching our heads and searching around finding those, but that's really important because it means that we position then our quadrat in exactly same place each year and we will photograph within that.

 

We have photo data set that we can look back on, and we also then do a full inventory of all the different species that are in each of those quadrats, and then we can compare that year by year because it's in the same place each time.

 

Llion:

I saw when you were doing a previous slot, you had a pad and paper and you obviously had some sort of table. Is that the different species that you're expecting to see?

 

Kate:

 

Yeah, all the species that we find in this area or that we've ever recorded we have tabulated in a spreadsheet. Or, you know, in a table and then we'll have columns for the recording for each quadrat; each quadrat will have its own column.

 

So that's our target list, but what you find depends on where you are and the shore. We have this at eight different sites around Skomer Marine Conservation Zone, around the island.

 

We have different sites so that is the total list. I had animals on one side of my sheet,

and I had all the plants on the other side, so we have a lot of different species that we can find.

 

Llion:

And do you come across a great variety? Do they tend to be the same kinds of species of plants and animals, or do you get thrown a bit of a wobbly at times?

 

Kate:

I wouldn't say that's a wobbly but the different shores have a different makeup of seaweeds or different makeup of animals, and that's because - being an island - we're going to have north facing, south facing, west facing and east facing shores. 

 

And each of the shores will have different environmental conditions that will impact them. Some are going to be exposed more to sunlight and some are going to be more in the shade. You know, we often have that on land don't we; north facing is more shady.

 

But with this as well on shores and with marine work, we're also looking at the tides 

and also looking at wave action. And because the prevailing wind comes from the southwest across from the Atlantic and hits our shores, that means South West facing shores are going to have all the wave action and the wave action basically means that the species we find there will be very different because they've got to withstand that wave action.

 

Other shores are completely sheltered. The one we are here on at the moment is a really sheltered shore. This is a north facing and it's totally out of the wind as well, 

so we don't have the waves here in the way of impact.

 

So it's an exciting area to have short surveys and intertidal work and other work as well because of the huge range of environmental conditions we are getting one little place, and that's the beauty of an island. Every corner you turn it will be slightly different and so that's why we enjoy doing this work.

 

Llion:

I understand that this work has been going on for quite a bit of time now. Do you know tell me a bit more about that and why that's so important?

 

Kate:

Yes, so this is part of a program of long-term monitoring data. This particular survey we're doing at the moment we started in the early 2000s, but it was also based on work that was initially done as early surveys in the late 80s early 90s.

 

So we did establish the different sites in the early 90s, soon after the reserve got designated and it's all about returning to the same place, having that evidence and being able to look at long term changes.

 

So we set this program up in - I think - about 2002 or 2003. So it's been going on now for nearly twenty years.

 

What we're looking at, then, is what is the norm? What is normal? What is the normal fluctuations that you would see? You know, that’s not being impacted by, things like oil spills and other things.

 

So we need to understand what’s known as natural fluctuations. Because in nature, no single year is the same. The weather conditions are going to be different; the tides are going to be slightly different, the waves and things like that.

 

So, there will be slight changes each year in what we're finding. We almost call that the noise of data, so we need to level that out by looking at the long-term stuff.

 

We can see what the normal trends are for the different shores, and then if something happens, if there's slight changes or we see that trends are suddenly changing slightly – well - is that because we suddenly get more warm water species coming in? Or have we got some non-natives that have come in, or if there's something like an oil spill or a disaster of some sort.

 

We will have a huge baseline of what we know is the normal data so we can see changes if they happen.

 

Llion:

So in terms of this very rich, very long term data set, are there any significant trends that you've been able to see across that time so far?

 

Kate:

I mean, with the large quadrat work that we do, this large stuff, we haven't seen any major changes, but we have picked up some non-native seaweeds that we haven't seen before and within this stuff we also do some subsampling as well. So later on we'll be using callipers and we've been measuring limpets, so we measure about 100 limpets to see what their distribution is doing. And we look at barnacles as well. So yeah, it's more looking at the little things and the little changes. But overall, our job is really just to keep this, maintain this baseline going so we have a, you know, resilience in what we're looking at.

 

Llion:

And is there anything particularly interesting or unusual that you've come across over the years?

 

Kate:

I think spotting some of these non-native seaweeds. It's like, you know when we're 

doing the quadrat like you say, we have our species list that we're looking for and that we normally find. Then it's suddenly ‘oh wait a minute’, not seen that one before or ‘that’s slightly different’ and then we pick those out. I mean it's not exciting but 

but it's kind of like something, it alerts you and it makes it different. And another thing we do here as well, which is slightly unusual and you'll see us do it later is we have a clingfish called the Cornish clingfish and it's basically got a sucker on it and lives under a boulder and we will do time counts on that. So we're looking at the population of that and that's a really unusual fish and it's only found on two of our shores 'cause it's a real boulder specialist and there's not actually that many boulder rich shores like this really in this area, so it's one of the few places we’ll find it.

 

Llion:

And what is the importance of this data overall? So I understand that you're looking for a baseline and in a way you're not necessarily trying to measure change your trying to get as good a picture as possible of what normal is. So when does that come into play?

 

Kate:

Yeah, so because we're doing this at a variety of shores, so we have eight different shores. Some are actually on cliffs, some are actually on boulder shores like this some are in other areas in between, but we also, NRW also has an intertidal monitoring program all around Wales as well and they have slightly different methods, but this method we use in the large quadrants. There are survey sites all the way through the Milfordhaven waterway, so they go up there and they're also down in South Pembrokeshire as well, so it extends and they've got sites up in North Wales too and in mid Wales so this is - we're kind of one little bit of the bigger picture and it's looking at that and looking at changes and looking at how communities vary throughout Wales. 

 

 

Llion:

OK great, thanks a lot for that Kate. I'll let you get back to work now. Thanks for talking to me today.

 

 

 

Llinos:

So Mark is with me here today, so Mark, can you tell me a little bit about yourself?

 

 

Mark:

Well, I've been working here for 20 years. Started with CCW as a seasonal assistant and I’m still here now I guess, I'm a marine biologist. I've worked in marine education, I've worked a lot on boats, but intertidal ecology is probably my strongest thing. But we're also a diving team, so I do the underwater stuff. But yeah, the intertidal bits are my favourite bits. 

 

 

Llinos:

Sounds very varied. What made you get into this line of work?

 

 

Mark:

They have me, it’s as simple as that. I have been in lots of work. I've started off in kitchens. You know, working on boats and then I did a marine biology degree up at Newcastle and I did do a year volunteering in New Zealand at marine conservation zones over there at Lee Marine Reserve and then down at Portobello Marine Reserve. But now I was just doing a mixture of jobs and then got into the Field Studies Council working with marine education in particular, but that was a lot of cleaning toilets and cooking food as well. And then I started here in 2001.

 

Llinos:

Sounds great. Watching you working with Kate across the way there and I think from my novice point of view it all looks really similar, so can you tell me a little bit about what the differences are between the work that you're doing and what we've been watching Kate do?

 

Mark:

Well, Kate's doing part of our survey of the whole MCZ if you like and that is replicated throughout Pembrokeshire, it's not replicated much beyond that. The Marclim work that I'm doing links into the whole of the UK. In fact, the whole of the seaboard going from Norway right down to Portugal. So it's using exactly the same methodology. It's targeted specifically at species which are indicators of climate change. Now they could be northern species that may be retreating, or they could be southern species that are expanding their range if things are warming up. And we replicate - as far as we can we try and do exactly the same methodology. We record the same stuff and then we see how that fits in a big picture across that huge sort of latitudinal range that we've got there. So it's this is putting Skomer in the 

picture of everything going down the sort of Norway to Portugal coastline.

 

 

Llinos:

So sounds like there's a lot of data being collected on this, so how long has it been going on?

 

 

Mark:

Well, we started doing Marclim here in 2003, but the Marclim methodologies were actually designed right back from some of the work that was done in the 50s, 

so the methodologies have been designed to fit with data that has been collected over a very long period of time so just post-war really. The people who started 

that work are now dead, you know, and we're just carrying it on. But that was a deliberate attempt to make sure that the data we collect now can be compared with decades ago, 'cause that's what it needs. And there's a compromise there somewhere. We perhaps would like to record data in a different way now, because we can, but we've got to keep it consistent. And this is one of the big to do's on time series data, long term monitoring, is you've got to be consistent across your 

monitoring time period so that what you collect now is comparable with what happened whenever it started and in this case, it started just at the end of the 40s into the 50s, looking at barnacles and limpets in particular.

 

 

Llinos:

Can you tell me a little bit more about the Marine Climate work? Things like maybe, it would be really interesting to know more around what you can do with the data you 

collecting and what the purpose of it is?

 

 

Mark:

So we're targeting specific species and we know their climate range, if you like in what we would cast as our lifetime, I guess. I mean it will have changed dramatically in 10,000 years, we can only see through our tiny little keyhole that we live in at the moment, but we know where these species have been recorded in their biogeographic range, say from the 1960s, up to the 1980s, and then we look to see if that biogeographic range is changing. So are they spreading North, are they're 

getting more abundant? Or are they retreating South or whichever and we also look at some species in quite a lot of detail so it's not just recording abundances of detail. 

We're actually looking at size classes and population structures, and there were looking to see well are they breeding more often? Are they breeding earlier? 

And having multiple broods in a year rather than just a single brood, which can be another climate change response. So some of the top shells do appear to be able to breed right throughout the year rather than having a single breeding period where perhaps they would have done before. Maybe that’s the effect of milder winters and things like that. There might be a knock-on effect of food sources increasing so they've got more energy to do that.

 

And we're looking for shifts in species where other species will outcompete. Perhaps southern species will come up and outcompete northern species and push them out of their range, and we should be able to see that overlap, so you can produce big maps of the whole of the UK and southern and northern Europe.

 

And you can plot on those maps, species ranges and you can see how that changes. You then overlay onto those maps contours of temperature and predicted changes in temperature and then with enough data you can model the species and say if we see 1.5 degrees rise in global mean temperatures that will equate to perhaps a 0.4 degree rise in sea temperatures in this particular area. What species would we expect to go north and what species would be expected to go South and disappear, and you can test those models then as well. 

 

So it is looked at, not in NRW. We just feed into it. It's now based at Liverpool University. It was with the Marine Biological Association, but it looks every year and we get a report back every year which we feed our data into and then they give us the bigger picture back in the report with things like which species have moved, are there any big changes in reproductive behaviour and it also now looks at invasive species. It wasn't originally designed to do that, but that has become increasingly a focus.

 

So on our set species list we now have a whole series of invasive species we're looking for as well and seeing where they crop up.

 

Llinos:

 

And are you finding them increasing at all?

 

Mark:

 

Certainly, in Milford Haven. Milford Haven must be a hotspot for invasive non-natives because of all the marine activities in there. So they come in on the hulls of ships. There's also been aquaculture there and things like that that tends to bring them in.

 

Out here around the islands, not so much really. We get the occasional seaweed, there's a Barnacle that's been well established since the 1950s. It came in on an Australian or New Zealand ship we think into Southampton and has spread across most of the southern UK now, so that's called Austrominius and we see that a bit on the shores here.

 

But if you go into Milford Haven, Austrominius is now the dominant barnacle in. So in those decades is pretty much ousted the other barnacles and made itself the kingpin.

 

Llinos:

 

And you see similar with other invasive species where they still displacing native species.

 

Mark:

 

Well, there's a big one called Crepidula Fornicata, which is a Slipper Limpet. I mean,

that's certainly dominating Milford Haven. We've found it attached to scallop shells around Skomer, so when we're doing king scallops surveys, we've found little stacks. 

 

They stack up on top of each other, which means they’re reproductive. If they're doing that. So it's a bit worrying, but literally, you can count them on the fingers of your hands at the moment so, but that's certainly something we keep an eye on.

 

I don't think we've got the physical conditions where that one would go rampant, but you know it doesn't want to be spreading up to say, the Menai Straits because it can wipe out muscle lays and things like that. So it has an economic effect as if it goes up into muscle lays.

 

There are areas of Milford Haven you couldn't count: it be in the billions. I mean it is 

just carpeting the seabed up there. I'm not entirely sure there's much you can do about it once he gets that level.

 

Llinos:

 

OK. Is there anything else that we should know about Marine Climate’s work?

 

Mark:

 

Well, I think probably the interesting thing from our work here is that we are not warming. So obviously the world is warming, but climate change is climate change and that doesn't mean everywhere in the world warms, and in fact in the last ten years we've seen, if anything, a very slight cooling point: 0.1 of a degree if we can even have that levels of precision in our data, but that seems to be what the data is showing, and the animals are certainly not showing big responses to warming, which they are in other parts of the UK.

 

So this little area here, this sort of southwest area, it does seem to be quite stable. That's probably really important. Our seabird colonies out on Skomer are also stable, if not increasing, and that bucks the trend of a lot of places where they are seeing big changes in climate, warming of seas or changes of seasonality and the seabirds respond very badly to that, and reproduction is really low.

 

In South Iceland for instance: very low reproductive rates of puffins to the point, they're virtually unable to raise a chick, but our colonies here seem to be doing well, and I wonder if that's because everything has been quite stable for the last two decades, probably. We warmed slightly, going through the 90s there was there was a warming trend, but since the 2000s and onwards, that warming trend stopped, and if anything in the last decade, there's been a very slight cooling.

 

Llinos:

 

So do we have any information around why that's happening?

 

Mark:

 

Not really. I mean, the currents are still as they are. We don't get the Gulf Stream. We get a very small drift off the Gulf Stream: The North Atlantic drift, they call it, which comes up to the Celtic Sea. And we're right on the edge of that effect so we don't get a massive effect from warm waters here. They literally trickle their way up and they literally come to about this latitude for just a month or so and then retreat back down. And we don't get these big frontal systems. And if I was going to say there was any major effects from climate change, I think global storming has been more of an effect in my period in Skomer.

 

We've seen some incredible storms, like almost tropical grade storms just coming this far east, which we've never had before, and it's not fully backed up in the data, but that would be my feeling. We've got bigger waves and more wind rather than warmer waters as such. 

 

Llinos:

So is that impacting on what you can see here, and what’s able to live?

 

Mark:

 

I think it makes it more dynamic and a big storm will totally change a beach like this.

Those guys there which are trying to find quadrats; we made the mistake of putting some of our markers on a boulder and it shifted that quarter of a ton boulder. It's moved sort of five meters up the beach so it's no longer in the high position, but that's what waves can do and we're a relatively sheltered beach here. We're facing north, we're not getting the big southerly swells that you'd get. It’s had a big effect on seals. It has in 2016/17 we had a big storm in that breeding season, which pretty much wiped out 60 seal pups in one afternoon.

 

A big storm came through Storm Ophelia. We had 60 odd pups out on the beach. I found three alive the next morning. You know, which sounds horrendous but so long as that is a one-off event that's not too bad. But if that starts happening every winter and of course seals have timed their breeding because that's the time of breeding when their females are ready then. If those storms come through in October on a regular basis, that will affect the population eventually, but you need a good sort of 5-10 years of storms before that to hit that sort of long-lived population. 

 

And then this year we had storms in May, which are quite unusual with a 16 meter swell: very unusual for May and that just wipes all the lower bird cliffs clean of eggs and nests, and again they've timed their breeding so that they'll avoid those sort of swells. But if those swells, do actually start occurring in May when it should be a lot calmer that will start wiping out seabirds, so we will see a reduced amount of chick productivity for species like Guillemots and Razorbills this year.  Because that, one storm event will have wiped out hundreds of nests, and they won't relay really. They'll try, but most of these seabirds they only have enough energy to give to one chick and a second attempt, they've usually not got the energy to see it all the way through.

 

Llinos:

 

So it's got a real impact.

 

Mark:

 

I think these are things which we're worried about. In general, I'm positive. I think things are very stable. Our seabird populations are much better than other places around the world. Our seal populations are doing well and our shores, dynamic as they are, that's how they should be. So yes, there are lots of changes in, but it's all within the boundaries of what you'd expect to see. And it's all still quite clean and rich, and everything is covered. So that's a good thing. And it's just these little worries that you think, well, you know, in the long term what these changes going to be, and possibly it's more to do with storming around here than it is to do with  warming at the moment.

 

Llinos 

 

It's been really fascinating speaking to you, so thanks very much for your time. I’ll let you go back to your monitoring 

 

Mark: 

 

Right – oh. I’ll go and get my temperature loggers now. 

 

 

Llinos

 

So Mark, we've been looking at the animals and plants along the shore. Can you tell us a bit about what else you want and how you do it? 

 

 

Mark:

 

Well the physical monitoring – the surveillance - is very important, because if you really want to show that the temperature of the sea is warming up, you have to put a thermometer in the sea. And if you want to show that the air temperatures are warming up again, you have to have a thermometer in the air. 

 

So often the headland at the top there we have a full weather station which is recording 24/7 every three seconds, taking readings. But obviously we don't have the luxury of that in the sea. So in the sea I use these little matchbox sized things called temperature loggers. And you set them up to record as often as you want, and these ones are set up to record every 20 minutes which is matched to the tidal cycle in this area. 

 

By recording every 20 minutes rather than every hour, we get a much finer resolution of how the tide is changing, and we tend to catch the point where the tide is in and out and guarantee that.

 

I've got three loggers on the shore here. One is at the very bottom of the shore in what we call the lower shore, and this one spends its whole time underwater, apart from spring tides. So today we can wade out to it and I can download it using this portable downloader and it can give me all the data and then it will be reset and off it goes again, recording every 20 minutes. If I came back here in a neap tide next week, it'll be under water the whole time. I would have to swim to get it and then dive underwater so this one is wet. 

 

Just above it, about 2 meters above it, we've got the middle shore and this one spends its life coming in and out of the water every day. This is giving us a seawater reading and an air temperature reading every single day, 365 days a year. And then another two meters above that, we've got the upper shore logger and this poor little guy spends its whole time in the air, which to us would be brilliant. But if you're a marine organism, this is really hard. This is living in an environment where you're not only desiccated, but you're open to some very extreme temperature regimes because you can have the sun shining on you, or you can have snow on you, whereas if you're in the sea all the time, it tends to be quite a benign temperature.  So that guy up there spends most of the time out of the water and it's only of the spring tide, that they'll actually get covered by water.

 

So these three loggers give us a very detailed picture of how the temperature varies and we've been running these since 2003, so we've got a long time series, longish for us anyway, of temperature data and how that might change if climate change produces different temperature effects in either the air or the sea. These all face North so this is a fairly benign environment. They're on flat rock and they're just   giving us a north facing aspect. I've got another set of loggers which replicate the same titled height differences, and they're on the South side of Skomer Island, so they're more in the direct sun, so they're giving us the picture of organisms that are South facing and in that more sunlight than these ones here and again, they're on flat rock, so the next stage is to look at animals and how they live in microhabitats. 

 

This is where these tiny little loggers come in, which literally the size of a 10p piece. And we stick these in cracks and crevices, so these guys are on an exposed rock face but tucked under a crack. And this one here is a very special one. This is the same logger, but it's actually been built into an old limpet shell. So this not only gives us a disguised temperature logger, but that's not really the reason for it. 

 

A limpet shell is an adaptation to temperature regulation. It's white because it reflects heat, and it's got all these serrations on it and deflective surfaces again. So they reflect light, and it keeps the animal cool. So in theory, the temperature logger that's not inside the limpet shell should be reading higher readings than the temperature logger inside the limpet shell, and this gives us some idea of what should be for the internal temperature of an organism might be inside a limpet. 

 

And then we've got a few tucked right under the rock in some very damp, dark crevices which are quite hard to get to. They are potted onto the rock under there, so they give us an idea of where creatures like to hide, particularly when the tide goes out, they run into these damp and dark crevices, and that's another adaptation to get out of harsh temperatures, is to go and hide in a microhabitat which doesn't actually have direct sunlight on it.

 

So this gives an idea of the crevice temperatures and then we've got one in a rock pool. Rock pools, depends how deep the rock pools are, they can be quite variable actually, but the advantage of being in a rock pool for these animals is actually stop some desiccating, but they can actually experience quite wide temperature regimes as well. It can get up to 40 degrees in a rock pool on a really hot sunny day, so although you’re wet, it might not be the ideal place that you think it is.

 

Llinos: 

 

Sounds a bit warm. That's really fascinating. Thanks for running through that. And is there anything else you think that you'd want to see about that?

 

Mark: 

 

Well, the only thing we're not doing, which does look like it's quite important, is ocean acidification. All of these animals we're talking about here that they're all calcareous, and the shift in ocean pH could have a very serious effect on their abilities to actually create these shells and these little boxes that they live in. And currently we don't have a way of actually monitoring ocean acidification. 

 

It's very difficult in the near shore environment because we've got a lot of other chemical influences from humans, basically pouring stuff down into the sea. So to measure ocean pH accurately enough to say whether there's acidification or not would mean being way out into the Atlantic.

 

Unfortunately, we can't do it here, and we haven't got the equipment to do it. And even if we did, I think we wouldn't be able to tease out from the data what was 

ocean acidification and what was potentially just pollution coming in and affecting the pH of the water. But it's as important as temperature, particularly for these 

calcareous organisms.

 

If they start finding it much harder to get calcium carbonate out of the water because it's become more acidified, then they're going to really struggle to make their little shells. And I guess there be less of them.

 

 

Llinos: 

 

Thanks very much.  That's been really interested in having a look at that, and thanks for talking through it,

 

Mark: 

 

No problem.

 

 

 

Llion:

 

And that’s it for this month! Thanks for joining us once again on our visit to the Skomer Marine Conservation Zone. We will certainly be back to record further episodes in the future.

 

Next month we’ll be in the Cambrian Mountains at our Bwlch Nant yr Arian Visitor Centre near Aberystwyth in Mid Wales. We’ll take you behind the scenes to see what it takes to maintain this award-winning destination.

 

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Thanks for listening.