Welcome to the Marine Biologist podcast.
Join us to discover the latest ocean topics from leading marine
scientists and conservationists. The podcast accompanies The
Marine Biologist, the magazine for members of the Marine
Biological Association, and is presented by the editor, Guy
Baker. We hope you enjoy this episode.
Welcome to the Marine Biologist podcast.
We're honoured today to welcome Professor Stephen Hawkins, an
experimental ecologist who's worked on rocky shores for 60
years. He's Emeritus Professor in the
School of Ocean and Earth Sciences at the University of
Southampton. A Lancaster Research Fellow at
the Marine Biological Association, Steve was also
Director of the MBA from 1999 to 2007.
Welcome Steve. Where are you joining us from?
I'm actually in my wife's flat in in Switzerland.
She until quite recently worked in the Swiss Pharmaceutical
industry, a job that she was not that compatible with my career
as a marine biologist, as they see in Switzerland, first of
all. What three things should we know
about you? Well, I can be pretty grumpy
before 10:00 in the morning, except if I've got up early to
get to work. A good tide.
I'm an outdoors person I've most of my hobbies are things like
going fishing or surfing on my 1960s plywood board that I've
had since I was 12. I quite like walking in the
country, I like walking in Switzerland.
I enjoy skiing, which is going to be compromised by the fact
I'm getting 2 new knees over the next couple of years.
And yeah, I've always, I've always appreciated nature.
And the other thing is I'm, I'm a pretty sporty sort of person.
I've never been very good at sports, but I've always been
competent at things like cricket, rugby, football, field
hockey, not too bad at tennis. So I've always enjoyed playing
sports, but probably not spent as much time playing sports as I
should have done because unfortunately sort of work in
general and Rocky Shaw in particular, sort of has been
probably the major, major thing I've spent my life on over the
last 45 years or so. When did you first work on Rocky
Shaw's? My first encounter with rocky
shore ecology was actually on a field course on the Isle of Man.
I was a student at Liverpool University and in those days
Liverpool University had a marine lab on the Isle of Man
that had been founded in 1992, sadly closed in 2006 and on a
first year field course in 1974 we did the inevitable
examination of of zonation on the seashore and also size and
shape in limpets based on work that JH Orton, who works at the
NBA before going on to Liverpool to become professor there, had
started the 1930s. So this was my first
introduction. And then the first actual bit of
proper research I did on rocky shores was a three day project
on an Elgology field course on the Isle of Man led by George
Russell. And I actually looked at the
seaweeds growing on Olympic shells and the seaweeds growing
in the surrounding area, the grazed area around the Olympics,
because the seaweed shells were a refuge from Olympic grazing
because they're not very agile. And that sort of got me
interested in in seaweeds and it also got me interested in in
Olympic seaweed interactions. So that was the first three day
bits of bits of research I did as a second year student.
And then I decided to do my final year research project, my
honours year research project on rocky shorts, which I did with
Richard Hartnell who then went on to become my PhD supervisor.
So it is actually 50 years this year that I've been interested
in working on rocky shores. Previously I was a bit more
interested in fish and. When did you first visit the
Marine Biological Association? I first visited the Marine
Biological Association in 1978. I went down to visit Alan
Southwood. I was interested in in doing a a
Natural Environment Research Council personal post doc and
for it to be hosted at the Marine Biological Association.
I'd heard Alan give a very, very good talk at the European Marine
Biology Symposium on the Isle of Man about recovery from the Tory
Canyon Hospital. And I decided that this guy was
the guy I wanted to do my postdoc with.
And also my PhD had followed up some of the work that had been
done on the Isle of Man in the 1940s by a guy called Norman
Jones, who was one of Orton's, one of Orton's students, and
also by Alan Southwood, who was supervised by by Autumn.
And I was aware of Alan's work because I was following it, you
know. But having met him, I went down
to discuss a, a student, a fellowship with him that I would
apply for. And I went and visited and, and
I then wrote the proposal which Alan had a look at and said it
was full of jargon. But obviously the jargon worked
because I got the fellowship and I ended up getting a three-year
postdoc at Marine Biological Association, which I started the
following year. So my first visit as a worker to
the MBA was in December 1979 when I started my my Natural
Environmental Research Council NERK funded personal
postdoctoral fellowship. And Alan Salford was a hugely
influential figure in rocky shore ecology, wasn't he?
Not just rocky shore ecology. I mean he did so many different
things. He worked with his wife Eve on
pogonofferer gutless worms, which they'd led to work, they
did on hydrothermal vents. When large pogonofferer were
discovered, he did a lot of work on, on plankton and fisheries in
the English Channel in relation to climate change, also using
rockish or animals as indicators.
He did some fabulous work on recovery from the Tory Canyon
oil spill. I mean, he was a real polymath.
And in those days there was a, a small permanent staff at the NBA
and they were encouraged to work on what they what they wanted to
work on And, and Alan did a lot of things.
I think he was asked to take on the plankton work, which he
hadn't done previously, to basically inherit it from Sir
Frederick Russell when he became director of the NBA, so on.
If you wanted to ever find Alan on a Saturday morning, he would
be in the lab looking at a plankton sample that had been
collected the previous day, which he would examine fresh.
And I I knew when I was doing my postdoc that if I went and
knocked on his door at about 12:30, he would have just
finished his plankton sample and he'd have time for a chat for
half an hour before going back for lunch at the house in in
Plymouth. So yeah, he did a lot of
different things, but his Brocky shore work was basically the
precursor to what I did my PhD on, which was on interactions
between limpets, barnacles and seaweeds and how that determined
distribution patterns on the seashore.
And also community structure, particularly patchiness.
I was very interested in patchiness at the stage of my
career. Yeah, and that begs the
question, why are Olympics so important?
Well, they are, I would say they are the keystone grazer on
particularly north North East Atlantic rocky shores.
And they're, they're grazing activities are akin to a cow or
a sheep in a field. You know, if you took a cow or a
sheep away from a field and waited 500 years, you might get
climax oak woodland. But if you build a little fence
with chicken wire, which I did for my PhD and exclude limpets,
within six months, you get 100% stand of fucoid seaweeds, which
reaches full size within about a couple of years.
So they're grazing activities are basically controlling algal
vegetation on moderately exposed and exposures throughout most of
the NE Atlanta. Well for all of the Northeast
Atlantic other than very, very sheltered shores where the
seaweeds win and the Olympics don't do so well.
And we think the Olympics don't do so well on shelter shores
because they don't like sediment, which we've done a bit
of research on some work I did with Laura Araldi at the NBA
when she was a visitor. They also are subject to more
crab predation, another piece of work which I did jointly with
Richard Thompson, Anna Silver as a student and Deanna Boe
Ventura, where we looked at crab mobile crab predation and rocky
shores. And certainly if we exclude
crabs by little cages on, on, on on more sheltered shores,
Olympics survive. So I think combination of of of
siltation and the siltations aided by ascophilin canopies
which promote algal turfs. The algal turfs trapped silt and
on a very sheltered rocky shore, you'll get limpets and little
clearings which are just managing to keep clear.
So they don't win. The limpets don't win on shelter
shores, but on more exposed shores that they're the dominant
grazer from more or less the top of the shore down to the algal
turf zone. And at that stage on the shore,
the seaweeds can grow faster than the Olympics can grow.
So that's where either side or low waters where the basically
seaweeds win and Olympics just can't, can't grow as fast.
So we've done experiments where we've excluded Olympics
throughout Europe, part of a a European research project called
Euro Rock, which which showed that exclusion Olympics all the
way from the Isle of Man down to Portugal reduced seaweed cover
on the seashore. And we did think that in
southern Europe where it was hotter weather, that the
unfavourable stressful conditions when the tide was out
would be, would actually limit algal growth.
But even in hot conditions, even in experiments we set up over
the summer, in the worst conditions, removal Olympics led
to proliferation seaweeds even in the South of Portugal.
The nice thing about rocky shores though, is you can
actually see the patterns. If you, if you're working on the
sand on a, on a mud flat or a, or a beach, you've got to
actually dig the sand, sieve the sand, look at the species,
identify them, then stick them into some kind of complex
multivariate analysis before you get any idea of the underlying
pattern. But on the seashore you can see
patches of seaweed, patches of barnacles, and the patterns are
very, very apparent. And and that's what makes Rocky
Shores such an important test system for experimental work.
And So what are the bigger questions that you're trying to
answer in your research? Well, at the moment, my research
is in the sort of, shall we say, trending towards retirement
phase. And I suppose I'm trying to tie
up a lot of loose ends and undone things that I've been
working on for the last 50 years.
But throughout my career, the, the, the three main things which
have interested me on on on rocky shores are what's the
relative role of physical factors as ultimate factors and
biological interactions as, as proximate direct factors in
setting distributions and affecting the structure and
composition of rocky shore communities.
And then about 10 or 15 years ago, working with Stuart Jenkins
and other people task Crow, Richard Thompson, we got
interested in what the implications of biodiversity on
rocky shores were for ecosystem functioning, how important
biodiversity was for the way that the ecosystem worked.
And again, using rocky shores as a model system to explore this.
Some very nice work was done by a student at the MBA, John
Gryphon, who's now a full time academic at Swansea University
with Stuart Jenkins and Rich Thompson and myself, where rock
pools were used on rock pools were simulated in the seawater
hall at the MBA to understand how diversity affected ecosystem
processes. And I suppose the other thing
that I've been doing in parallel with this experimental work, and
it was something that I decided to do when I was in Manchester
for a few years and I could, I used to come down to the MBA to
work in the summer because the University of Manchester had
helped establish the MBA in 1888 and the lab and we actually had
a free table there for perpetuity.
So I could come and use the MBA facilities for nothing because
the University of Manchester had given 50 Guineas a year since
1887 to laboratory. So what I decided then was that
I could do broad scale and long term work.
And the interest in this was sparked by a field trip with
Alan Syford in Alan Leaves Southford in March, no April
1980, where we looked at various sites that Alan had been looking
at for many, many years since the 1950s, starting at Lyme
Regis and then going to Portland, couple of sites in
Dorset and then Swanage chasing the tide out as it gets later
along the Channel. And that got me interested and I
think Alan deliberately got me interested in long term and
broad scale observing. One of the things that prompted
this further was when I came to the MBA, my my postdoc, which as
Alan said was full of jargon, was, was looking at using
limpets as a model for, for niche differentiation.
Niche theory was a very trendy subject in the late 1970s, early
80s. And I was interested in using
two coexistent species Olympics, Patella depressor or warm water
species and Patella bulgata or cold water species and looking
at their competitive interactions and trying to use
that as a model to understand and inform niche theory.
Well, I I'd read all the, I'd read all the literature from the
1950s and it said that in the Plymouth area, many sites, there
were about 5050 populations. And this seemed like a, a good
model system to do various removal density manipulation
experiments. So that also prompted my
interest in, in, in long term change because in the 1980s it
was the end of a cold period. And when I turned up, I actually
found that the warm water Olympic was much less common
than it had been in the balmy 1950s.
And when I actually started this long term and broad scale work,
I was actually interested in getting colder.
And in the, in the early 1980s there was lots of stuff in, on
the TV and in newspapers about a new Ice Age coming because from
196263 onwards it'd been a very cold period.
So that's my other interest. And my, my final main research
interest has always been on more applied ecology.
And I've been interested in urban coastlines, particularly
recovery from pollution incidents.
I did a lot of work in Liverpool from Manchester and Liverpool
on, on restoration of this disused dock basins, essentially
inside out rocky shores with artificial rocky shores in the
middle. How to restore those for urban
renewal schemes. And more recently I got involved
in a lot of work on what's now called eco engineering, but it
wasn't called eco engineering when I started it, when I
started getting involved in it, which is actually how you could
modify artificial coastlines to increase biodiversity.
So if you're going to build a sea defence, try to make it
multi multifunctional and try to design it with biodiversity in
mind rather than just engineering functionality in
mind. And that area of research has
really exploded. And a lot of this work was done
with in recent years has been done with Louise Firth, who was
at University of Plymouth, now at University College Cork and
also with Richard Thompson. I mean Richard Thompson LED a
big chunk of an EU project that was involved in in the 2002
thousand and 10's. And this is basically on trying
to apply knowledge from natural rocky shores to make urban rocky
shores or sea defences more attractive from real life, and
also to put in place ecosystem services, one of which of course
are cultural ecosystem services. Because British people love rock
pooling. So I always say eco engineering
is not rocket science. It's more like rock pool
science. So where are your favourite rock
pools in this country? Well, every rock pool is
different and and every rock pool is different because of
different sizes, different shapes, different depths,
different species pools to inhabit them, a different
underlying geology which effects the ultimate factor affecting
how many rock pools and what type are there.
I think some of my favourite rock pools would be on limestone
shores in areas where there's the intertidal sea urchin
paracent well inside on the subtitle sea urchin
paracentroaches lividus, you get some of these in Ireland.
The species doesn't occur in UK, they occur on the French case.
They occur in Portugal. So I think some of my favourite
rock pools are in Portugal. And I've been very fortunate and
I've been involved in work on both natural and artificial rock
pools in Portugal for some time now.
And I was very pleased with my most recent Portuguese student
and probably my last former Portuguese student graduated
this this June after doing some splendid work on rock pools,
both natural and artificial. And I think my some of my
favourite rock pools are definitely Portugal, but Wembley
is pretty good as well.