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Antje Boetius (total time 2:44)
text panel 1: HYPOX activities at the Crimean Shelf (Black Sea)
Hello! My name is Antje Boetius and I am the co-ordinator of the EU project HYPOX. I
work at the Max Planck Institute for Marine Microbiology in Bremen and the Alfred
Wegener Institute for Polar and Marine Research.
So we have chosen the Black Sea as a monitoring site for understanding the effects of
hypoxia on marine communities. The Black Sea is the largest natural anoxic water body in
the world, and when you go to the borders you will find zones where there is a huge
fluctuation of oxygen availabilities. And in those zones we are looking for the effects of
oxygen and small variations in oxygen with time on benthic communities. We have chosen
the Crimea area to look for such dead zones, and we have found a huge area where we find
daily to hourly variations in oxygen that really changes how animals can live in the sea.
When there is not enough oxygen for respiration, fish for example cannot be there, worms
cannot be there, and these organisms have tremendous effects on the functioning of the
ecosystem. They distribute oxygen, they feed on sedimentary organic material, and when
these animals are absent, of course the system changes.
One result of our expedition with the research vessel Merian to the Black Sea was that we got
a much better understanding of how temporal dynamics in oxygen can actually effect
biogeochemical cycling in the sea. So the Black Sea has taught us lessons about how we
should observe oxygen to better understand when the sea changes into an unhealthy mode
causing dramatic changes in services of the eco-system to us humans. We have a better
understanding through the observatories we have implemented that to really monitor and
predict changes you need to understand how physics, geology, and biology are connected. So
it’s not enough to just measure a concentration, you really have to understand how with time
fluctuations occur. The broader implications of our work are – that to better predict the future
of the ecosystem we will have to have to come to a complete understanding of the system. It
is not only about the warming of the sea, it is also about eutrophication. It is also about
disturbances from the slopes, disturbances from human impact, disturbances from single
events like storms that can leave imprints on the health of the community.
text panel 2:
Antje Boetius (Max Planck Institute for Marine Microbiology, Bremen & Alfred Wegener
Institute for Polar and Marine Research, Bremerhaven, Germany).
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
George Papatheodorou (total time: 1:46)
text panel 1: HYPOX activities in Greek land-locked waters
My name is George Papatheodorou. I am a professor of marine geology at the Department of
Geology of the University of Patras, Greece. Together with INGV, Eawag, and other
HYPOX partners, we study three specific environments in Greece. Two of them are
landlocked water bodies and the third one is an open bay environment. Amvrakikos gulf and
Aetoliko (lagoon) are considered to be the fjords in the Mediterranean Sea. And Katakalo bay
is characterised by intense gas seepages from the seafloor.
Repeated oceanographic and remote sensing surveys were carried out within the framework
of HYPOX. We found that Amvrakikos Gulf is seasonally hypoxic and anoxic, with almost
oxygen free areas deeper than 25 meters during the summer. Aetoliko is permanently anoxic
with very high concentration of hydrogen sulphide and methane. This anoxic condition
induced by anthropogenic activities has caused catastrophic events in the local fishing
industry.
We also deploy the GMM benthic module in the Katakalo Bay for long term oxygen
monitoring. Amvrakikos Gulf, Aetoliko and Katakolo Bay are ideal environments to study
oxygen depletion due to oceanographic factors and methane emissions from the sea floor.
Moreover in HYPOX we try to investigate the mechanisms that trigger these catastrophic
events and to study the impact on biotic and abiotic regime of these sites.
text panel 2:
George Papatheodorou (University of Patras, Greece).
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Gilles Lericolais (total time 1:56)
text panel 1: HYPOX activities at the Bosporus / Istanbul Strait outlet (Black Sea)
So I am Gilles Lericolais from Ifremer which is the French Institute for Exploration of Sea.
So we are interested in the Bosporus area, especially the entrance of the Bosporus in the
Black Sea - the Bosporus outlet. As you know the Black Sea is one of the biggest anoxic
body and we have tried to monitor the entrance of the Marmara Sea water which is more salty
and having a higher temperature than the Black Sea area and in fact the idea was to try to
understand how the Marmara Sea water was mixing inside the Black Sea. So for that we have
done some CTD experiment in 2009 onboard the Turkish vessel ARAR from the Turkish
colleagues who are involved in the HYPOX project. And we also have deployed two
PROVOR - two sensors to try to follow the entrance of the salty water into the Black Sea. At
the moment the idea is to try to understand in the future how this mixing of salt to fresh water
is functioning and the idea is to have some information on how the Black Sea started to be
anoxic and how this surface water can be preserved in oxygen.
text panel 2:
Gilles Lericolais (French Research Institute for Exploration of the Sea, Brest, France).
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Guiseppe Etiope (total time 3:23)
text panel 1: HYPOX activities at an Ionian Sea embayment (Greece)
I am Guiseppe Etiope. I am senior researcher at the National Institute for Geophysics and
Volcanology based in Rome, Italy. We work in the framework of HYPOX project in Greece,
and we try to understand the process that is important for several environmental implications.
The process is the link between the gas seepage and oxygen depletion. Gas seepage is a
natural phenomenon due to the natural release of gas, generally methane, released from the
seabed. Once this gas enters the sea water column, oxygen that is in the sea water is oxidized
or there are other kinds of processes for which there is a replacement of gas, so oxygen
disappears and is replaced by methane. So for monitoring these kinds of processes we
selected an area in Greece where there is a big seepage zone due to petroleum reservoir
occurring at depth. So there is a big fault through which gas is escaping to the seafloor. We
deployed a benthic observatory called GMM that means Gas Monitoring Model equipped
with oxygen and methane sensors. So what we try to understand is a time-series to understand
what is the time correlation between methane and oxygen.
And actually we observed that during periods of intense degassing so when there is more
methane escaping from the sea-bed, oxygen in the sea-water tends to be reduced - there are
lower concentrations of oxygen in the sea water. This is an important aspect that has many
implications for the environment. For example, this gas seepage can be natural but can also
be due to accident. [...] So this is important for example in accidents like that occurred in the
Gulf of Mexico, when the Deepwater Horizon platform leaked a lot of gas and petroleum.
And for that event beyond environmental pollution given by hydrocarbon, there were also
processes of oxygen depletion. So we are studying a similar event just looking to what is
happening in a natural site of gas seepage. And the results are very interesting. So effectively
there is this inverse correlation between gas and oxygen. And in future we try to understand
the real mechanism leading to the oxygen depletion due to methane.
text panel 2:
Giuseppe Etiope (National Institute of Geophysics and Volcanology, Rome, Italy).
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Henrik Stahl (total time 4:35)
text panel 1: HYPOX activities at Loch Etive (Scotland, UK)
My name is Henrik Stahl and I come from Scottish Association for Marine Science in
Scotland. And together with the team of scientists from the Scottish Association for Marine
Science I study the effects of hypoxia in Scottish sea loch which is called Loch Etive. This is
a multi-silled fjord with restricted circulation, basically consisting of two basins – one lower
well ventilated basin and upper basin which is considerably deeper and has isolated bottom
waters where the oxygen is decreasing over time into hypoxia.
This is episodic events occurring over time scales of approximately 16 months. [...] This is an
very interesting site because the hypoxia in this sea loch is mainly driven by hydrophysical
circulation rather than eutrophication by import of nutrients since the sea loch is located in
relatively pristine and remote region of Scotland. So this is an ideal site to study the effects of
climate change on hypoxia.
And our achievement so far within the framework of HYPOX is to establish a permanently
cabled observatory system which continuously monitors oxygen concentration and associated
parameters like salinity, temperature and currents. And we monitor these at a very high
resolution to understand the basic hydrography as well as the oxygen concentrations over
longer time scales and to be able to provide input parameters for models to be able to model
the impacts of the hydrophysical conditions in the Sea Loch on the hypoxia.
And in combination with more targeted biogeochemical studies undertaken during number of
field campaigns. And what we have achieved so far is to monitor these relevant parameters
like oxygen and so forth over since November 2009 and we have so far about one and a half
years of data. And so far we showed that the already during the first six months we noticed a
number of overturning event or three consecutive overturning events which proves that the
circulation of the loch can be much more dynamic than previously thought. And these
overturning events where the deepwater became well oxygenated again was related to very
cold weather (extremely cold weather) and so ... And the broader implications of this is that
we can see that this system is very sensitive to climatic factors which is very interesting. And
I think in the future it is very important to continue to have these long term measurements of
oxygen as well as the other relevant parameters in order to fully understand the impacts of
climate on hypoxia in systems with restricted exchange like the Loch Etive and other sea
lochs and embayments.
text panel 2:
Henrik Stahl (Scottish Association for Marine Science, Oban, UK).
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Jana Friedrich (total time 3:33)
text panel 1: HYPOX activities at the north-western Black Sea shelf
My name is Jana Friedrich. I’m a marine geochemist at the Alfred Wegener Institute for Polar
and Marine Research in Bremerhaven in Germany. Our HYPOX monitoring site is located on
the north-western shelf of the Black Sea. We selected that particularly site because this area
had been affected by low oxygen concentrations on the sea floor or almost no oxygen
concentration from the 1970ies to the mid 1990ies of the summer months. And this low
oxygen concentration in the water off course affected the ecosystem on the sea floor. The
reason for this oxygen depletion was fertilization of the shelf-waters from nitrogen and
phosphorus transported onto the shelf mainly by the Danube River. And these nitrogen and
phosphorus fertilized algal growth as it fertilizes agriculture and actually it was from
agriculture from where the phosphate and nitrogen originated from. So we had following the
green revolution in agriculture in the former communist countries, we had an input of these
fertilizers into the sea. And we now wanted to see what the state of the ecosystem is
currently, how the recovery of the ecosystem carries on and also we would like wanted to see
how the hypoxia which is the low oxygen concentration evolves over the summer months and
relaxes during the stormy period in the autumn. So what did we achieve? So we got
continuous three months record of oxygen concentration on the sea floor, we saw how the
oxygen concentration decreases with increasing temperature, and increasing productivity on
the shelf. And we also saw how the oxygen concentration increased again in autumn when
the stormy period begins. So what are the broader implications of our research? So we have
now hand-on the physical and biological controls of the oxygen concentrations on the seafloor on the north-western shelf and we can - or we hope that we can distinguish
anthropogenic influences on the oxygen and also climatic controls on the oxygen. And we
hope we can use this knowledge to estimate how the ecosystem will recover from the past
anthropogenic pressures and we hope we can estimate also the ecosystem resilience to
probably climate related or may be human impact related return to hypoxic conditions over
the summer months on the north-western shelf.
text panel 2:
Jana Friedrich (Alfred Wegener Institute for Polar and Marine Research, Bremerhaven,
Germany. Now at the Institute of Coastal Research, Helmholtz-Centre Geesthacht, Germany)
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Per-Hall (total time 3:19)
text panel 1: HYPOX activities in Swedish fjords
My name is Per-Hall. I am professor at the department of Chemistry, at the University of
Gothenburg in Sweden. Our Hypox monitoring site is the Koljoe Fjord on the Swedish west
coast about 100 km north of Gothenburg. And our main motivation with installing and
running this observatory is to monitor oxygen in the fjord and trying to understand reasons
for oxygen depletion and also occurrence and frequency of water renewal and water
exchange in the fjord which will influence the oxygen status and oxygen inventory in the
Fjord.
We also want to follow of the consequences of oxygen depletion and we want to especially
be able to separate effects of nature - natural variability - caused by water exchange driven by
large-scale physical phenomena and differentiate that from anthropogenic effects that is manmade effects on oxygen depletion such as eutrophication and increase oxygen consumption
due to stimulation of organic production by nutrient enrichment.
We have run an observatory in the neighbouring Fjord called the Havstens Fjord for 18
months studying oxygen, salinity, temperature, and water currents and it has worked very
well. We have followed in different water levels the variability of oxygen with time and we
have been able to also couple the oxygen variability to physical changes that is the changes of
salinity and temperature in the water. And the broad implications of these oxygen
measurements, long-term oxygen measurements which are done with high temporal
resolution is that nature is very variable. Oxygen variability in systems like in ours and in
many other systems, oxygen variability takes very rapidly and quite large differences on short
time scales. These changes you never can pick up by classical ship based measurements
where you go out normally once per month, measure oxygen at a couple of water depths and
then measure oxygen. Then you a miss a lot of the variability and a lot of the dynamics
because you don’t measure frequently enough. You must measure on high temporal
resolution, you must do it on a long time scale then you can really understand what is causing
oxygen variability and how often is oxygen depleted, why is it depleted, and how often is the
fjord renewed again with new water bringing in new oxygen.
text panel 2:
Per Hall (University of Gothenburg, Sweden)
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Ralf Prien (total time 3:36)
text panel 1: HYPOX activities in the Gotland Basin water column (Baltic Sea)
My name is Ralf Prien and I’m a scientist at the Leibniz Institute for Baltic Sea Research in
Warnemünde Germany. And our Hypox site where we do the monitoring is in the Gotland
Basin and this is interesting because we have there anoxic water at the bottom, oxic water on
the top, and an oxycline in between the hypoxic layer that is the Hypox main theme. And we
want to look at the intrusions that are intrusions of oxygen rich water coming all the way
from the North Sea and putting some oxygen into the deeper layers. That’s known for a long
time. But now we want to see how often are the smaller intrusions that also occur do happen
and how fast is the oxygen then consumed and back to the hypoxic conditions. And for that
we need observations that are done on a high resolution in time. When I say high resolution I
mean something like 4 or 8 hours. What have we achieved so far? We have installed a
profiling mooring that means it is an instrument suite that is parked in a depth of about 180 m
and at programmed times it goes up through the water column up to about 30 meters and
takes a profile of the parameters in the water column - so through the hypoxic layers. And
this is done - we have done two deployments so far, one was 33 days. Every 4 hours we took
a profile. And what we saw there is that the dynamics is much more pronounced than we
expected really. Sometimes the conditions between being hypoxic and anoxic, the layer in
between the two is changing by about 20 m within 8 hours. So it is happening very fast.
Now why is that important you might ask. And there are a few consequences of the hypoxic
areas. Of course if you don’t have oxygen higher life is not possible – you have only
microbial life basically. But it’s also important for something like fish stocks. Because some
fish species, the eggs are drifting in mid-water. They have a certain density and if that density
layer is in anoxic waters then the fish won’t hatch and that means the stock won’t be
replenished. And also we want to know how are the conditions now to get an idea of how the
conditions might change with changes in the global warming and things like that.
text panel 2:
Ralf Prien (Leibniz Institute for Baltic Sea Research, Warnemünde, Germany)
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Stefan Sommer (total time 2:29)
text panel 1: HYPOX activities at the Gotland Basin seafloor (Baltic Sea)
My name is Stefan Sommer. I’m working as a senior scientist at the IFM-GEOMAR in Kiel,
Germany. We do our investigations at the Baltic Sea in the Gotland Basin which is one of the
deepest basins in the Baltic Sea. And our motivation is....we are very much interested how
changes in the oxygen content of the bottom border affects biogeochemical cycling and with
that we mostly focus on the cycling of – on nitrogen but off course we look also other major
elements such as iron or phosphorus. During the past 2 years we did several cruises to the
Gotland Basin. During one cruise which was a very stormy one we unfortunately lost our
gears but at the end we were able to retrieve that and we got a very, very interesting and a
very long oxygen record at 90 m water depth in an area which we believed is anoxic but at
the end it was very variable and we saw stormy driven intrusions of oxygen at these basins
which we wouldn’t have come across without the loss of that Lander. And apart from that we
got very interesting sediment flux data, how much nutrients are transported between the
sediment-water interface, in other words how much oxygen is taken up, how much iron is
released from the sediment, how much phosphorus and off course how much ammonium and
other major elements, major nitrogen elements are transported across the sediment water
interface. With regard to broader implications I think it is very important to know the nutrient
load or the internal cycling of nutrients in the Baltic Sea because it’s a huge issue since all the
nutrients which come not only from internal cycling but also from external inputs, lets say
from atmospheric deposition or from anthropogenic inputs due to farming for example which
causes eutrophication and at the end the spread of hypoxia. And this is a huge issue and that
is why we need to have these data.
text panel 2:
Stefan Sommer (Helmholtz Centre for Ocean Research, Kiel, Germany)
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Thomas Soltwedel (total time 2:54)
text panel 1: HYPOX activities at the Fram Strait (Atlantic-Arctic Ocean transition)
My name is Thomas Soltwedel. I’m from the Alfred Wegener Institute for Polar and Marine
Research in Germany. I am representing the only open ocean site within the HYPOX project
and this is the deep sea long term observatory Hausgarten. Hausgarten is situated in Fram
strait in the transition zone between the North Atlantic and Arctic ocean. And that is in a
region rather sensitive to the global change. Hausgarten was established in 1999. We go there
every year taking samples but we have also moorings out there. Moorings equipped with all
sorts of instruments including instruments which could register over longer time scales and
since 2004 we are also monitoring oxygen concentrations in the water column. Now
fortunately Hausgarten is far away hypoxia but nevertheless climate models suggest that
oxygen will decrease in the ocean warming scenario and in fact we actually could register a
slow rather slight decrease in oxygen concentrations from the years 2004 till 2009. So from
2004 on we actually registered a slow decrease in the oxygen concentrations in the water
column actually also at 2500 m water depth but since 2009 we registered reverse trend that is
increasing oxygen concentrations which are coinciding with the decrease in temperatures in
Fram Strait. Right now we cannot say whether we face some sort of decadal oscillation in
oxygen concentrations or whether this slight increase in oxygen during the last year is some
sort of intermezzo within the generally decreasing trend of oxygen concentrations in the open
oceans. But this off course shows that we urgently need long term observations in the ocean
to get an idea about the environmental conditions in the future ocean.
text panel 2:
Thomas Soltwedel (Alfred Wegener Institute for Polar and Marine Research, Bremerhaven,
Germany)
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Andrew Dale (total time: 2:45)
text panel 1: HYPOX activities in Eckernförde Bay (western Baltic)
Hallo, my name is Andrew Dale. I work at IFM-GEOMAR which is in Kiel in Germany. And
as part of the HYPOX projects one of our main working areas is the Eckernförde Bay in the
western Baltic Sea. Within this bay is a small deep channel called Boknis Eck and its around
28 m water depth and during summer this channel becomes stratified due to changes in
circulation of water and in the deeper parts of the channel it becomes hypoxic or even anoxic
in late summer. Now as part of the HYPOX what we are interested in doing is observing this
site to see how these changing or decrease in oxygen from winter to summer affects the
change of nutrient fluxes from the sediment to the water column during this period. And the
reason why these changes occur is because oxygen is a major lets say consumer of energy
within the sediments and the return fluxes of nutrients to the water column have an important
impact for the productivity of the surface waters. So we have been here for a year now and
what we have discovered over the period is that the amount of animals which are living in the
sediment really rapidly decrease over the summer and the oxygen flux into the sediment
becomes almost zero.
So at the moment we have been looking at the flux of the ammonium, nitrate and phosphate
out in the sediments so these are the nutrients for probably productivity and we have
discovered that during this anoxic period the flux of these nutrients increases rapidly out of
the sediments. Now this is interesting from not only from an annual point of view but also if
you look over longer time periods because at this site the oxygen concentration is decreasing
year on year - so the period of anoxia is becoming more severe as time goes on. So what we
should expect to find in a few decades or so is that this anoxic period becomes more normal
and it extends for longer periods throughout the year. Now what are the global implications
of this, well this site we are looking at is a very small localised area but the effects within the
sediments are probably going to be more or less the same in other areas of the world where
oxygen minimum zones or this decrease or increase in hypoxia is occurring and becoming
more frequent. So based on this one particular study site we could expect that the flux of
nutrients out of the sediment into the water column, this recycling efficiency becomes more
efficient year on year or as these oxygen minimum zones expand.
text panel 2:
Andy Dale (Helmholtz Centre for Ocean Research, Kiel, Germany)
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011
Carsten Schubert (total time: 2:07)
text panel 1: HYPOX activities in Swiss lakes
Hello! My name is Carsten Schubert and I am a scientist at the EAWAG in Switzerland. We
are working in our research group basically on five different systems, we work in the Black
Sea, we work in Greek Lagoons but we mainly focus on Swiss lakes and we have chosen
three different lakes because they are different in the oxygen concentrations so there is one
lake which mixes every year and so this lake takes a deep breath basically; there’s one lake
which never mixes which is Lake Lugano and there’s another lake called Lake Zurich and
this one mixes eventually but not completely every year. So what did we achieve in our
research group is that we measured oxygen, we constructed new sensors. we are able to
measure oxygen now down to about 50- 100 times lower than we were able to before. So this
gives us really high resolution data about what is happening in the water column, where do
we have oxygen and where we don’t have oxygen. We use biomarkers which are organic
molecules from which we try to reconstruct what has happened in the past, we are taking
sediment cores from the bottom and there we can see which kind of organisms have lived in
the water column and how this organic material is degraded under different oxygen
conditions so we have cores in the oxygen part, we have cores in the hypoxic part and we
have cores from the anoxic part and we compare this. This data is also supported by noble gas
measurements which enable us to say something about the oxygen concentration in the water
in the past.
What are the broader implications? Well first we want to see how these organic markers are
changing under these different oxygen concentrations and this data can be used not only in
the systems we investigate but can be used in all other lake systems around the world
basically.
text panel 2:
Carsten Schubert (Swiss Federal Institute of Aquatic Research, Kastanienbaum, Switzerland)
FP7 project HYPOX (EC Grant 226213)
text panel 3:
Video Manfred Schloesser
Editing Nils Strackbein
Max Planck Institute for Marine Microbiology, 2011