First HYPOX observatory deployed in the Koljö Fjord area, Sweden

Per Hall, Anders Tengberg, and coworkers from the HYPOX team at Gothenburg University (UGOT) deployed the first HYPOX observatory in the Havstens Fjord. Havstens Fjord is located in the Koljö Fjord area and supplies the Koljö Fjord with water. After successful testing in October 2009 a string type observatory was deployed on 3.11.2009. The deployment is planned to continue until at least March 2010.
The string observatory hosts three oxygen optodes and four sensors for conductivity (salinity) distributed at water depths between 6 and 18m. At the lower end of the string (at ca 25 m water depth) there is a recording current meter (“Seaguard”, AADI, Norway), measuring currents and pressure (depth and sea level change), and logging all sensor data. Temperature is measured at all depths. For future deployments, a total of fourteen sensors can be connected to the string at seven different depths at a vertical distance of 3m. To prevent damage from ice cover in winter the string is deployed without surface buoy.


The string-type observatory on deck of the UGOT R/V Skagerak just before deployment (photo: Per Hall, UGOT).

Autumn-expedition to the Tarkhankut gas seep region by HYPOX partner IBSS

In November 2009, the Institute of Biology of the Southern Seas (IBSS) performs a land-based expedition to the Tarkhankut gas seeps region – a shallow area near the Crimea Peninsula. In continuation of the last field trip in September the intention is to follow up on the former investigations and to monitor seasonal changes that may occur. The observations conducted include physico-chemical as well as biological parameters:

Water column above the gas seeps: Dissolved oxygen, oxygen demand, temperature, pH

Seep-associated microbial mats: Sulfide and oxygen, redox-potential, pH, organic matter content (unstable and stable); micro- and macrozoobenthos under hypoxic conditions.

Preliminary conclusions:

Hypoxic conditions in the seep associated microbial mats as well as in the nearby water column prevail also in late autumn. However, compared to the situation in September, oxygen was found to penetrate deeper into the mat while sulfide concentrations decreased. Higher organisms adapted to microbial mats were observed to tolerate high sulphide concentrations and oxygen depletion for at least two months.

Fig. 1: Natasha Orekhova and Yury Vnukov in front of a profiling device that advances microsensors for oxygen and sulfide at 1mm steps into microbial mats (photo - M.Gulin).

Video: Vitaly Timofeev (diving) and Maksim Gulin (operating the rubberboat) take samples of mats, zoobenthos, and the water column (video - N.Orekhova).

Oxygen optode calibration workshop at the Max Planck Institut in Bremen (9.-11.12.09)

The Max Planck Institute for Marine Microbiology in Bremen (MPI, www.mpi-bremen.de) hosts a three-day workshop on the calibration of macro oxygen optodes. These sensors, that are manufactured by the Aanderaa Data Instruments in Norway (AADI; www.aadi.no), determine dissolved oxygen concentrations based on the changes in optical properties of an oxygen sensitive fluorophor. Due to their outstanding long-term stability and their insensitivity to pressure, macro oxygen optodes have become a standard tool for long term monitoring of dissolved oxygen in the water column and will be the main sensor type used for oxygen monitoring in HYPOX. The main goal of the workshop is to test a simplified procedure for the calibration of these sensors. This is done by exposing optodes of unknown or outdated calibration (“test optodes”) and known calibration (“reference optodes”) to a large variety of temperatures and oxygen partial pressures in a big airtight calibration vessel. Different partial pressures are established when water temperature (and, hence, oxygen solubility) is changed in the vessel. By running a temperature gradient at several oxygen concentrations the entire range of environmentally relevant temperatures and oxygen partial pressures can be covered with a reasonable effort. The workshop was attended by eight people from the Gothenburg University, the MPI, and AADI.


The workshop participants (Photograph: M. Schloesser, MPI)


Close up of the optodes in the calibration vessel (Photograph: M. Schloesser, MPI)


M. Holtappels and F. Janssen filling the calibration vessel (Photograph: M. Schloesser, MPI)

hypox expedition to a methane seep area at the Crimean Shelf

From 4. to 6.9.2009 the Ukranian hypox partner "Institute of Biology of the Southern Seas" (IBSS) conducted a land-based expedition to a shallow methane seep area at Tarkhankut Cape (NW Crimea peninsula, Black Sea).


Fig. 1: The site (photograph: Sergei Konovalov)


Video: methane seeping from the seafloor (Maksim Gulin)

The work was centered at effects of methane seeping on water column oxygen concentration, sediment biogeochemistry and benthic communities. Sampling and measurements were conducted by divers. Voltammetric microprofiles of diverse constituents (O2, Fe2+, Mn+, H2S, various other sulfur compounds...) were measured immediately on the beach. Analyses of meiofauna distributions and other sediment parameter are currently performed at IBSS.


Fig. 2: Sediment coring (photograph: Sergei Konovalov)


Fig. 3: Voltammetric profiling on the beach (photograph: Vitaly Timofeev)

First results indicate that hypoxic conditions may be present in the bottom waters where gas seeping occurs. Microbial mats found at the surface of the seafloor. For the first time it was observed that fishes fed on the mats or the associated fauna leading to dispersal of parts of the mats into the water column.


Fig. 4: The IBSS team: Sofia Konovalova, Sergey Konovalov, Vitaly Timofeev, Maksim Gulin, Natasha Orekhova (left to right)

Surveys of hypox-partner GeoEcoMar at the Romanian Black Sea Shelf

The Romanian Shelf is one of the hypox target sites for hypoxia studies in the Black Sea. For decades, the north-western shelf received particularly high nutrient loads, mainly through the discharge of the Danube. Eutrophication resulted in an increase in deposition of organic matter and seabed oxygen consumption that led to recurrent and widespread seasonal bottom water hypoxia and a deterioation of the of the benthic system: Sea grass, benthic macroalgae communities, and mussel beds disappeared. Thus, in combination with overfishing, eutrophication led to complete collapse of the pelagic and benthic ecosystems. Reduced riverine nutrient discharges following the breakdown of industry and agriculture in eastern European countries led to the decrease in occurrence of large-scale bottom water hypoxia since the 1990’s and allowed for a slow recovery of the pelagic and benthic ecosystems. The Romanian shelf is thus of particular interest to investigate processes that benthic systems undergo upon recovery from previous hypoxia and understand the complex interaction of nutrient input, climate forcing, and oxygen availability.

Already in May (i.e., project month 2) Marian-Trajan Gomoiu and colleagues from the hypox partner GeoEcoMar (National Institute of Marine Geology and Geo-ecology of Romania) conducted a cruise to the Romanian Shelf. Investigations included sampling of the benthic communities as well as mapping of oxygen distributions in shelf waters and at the seafloor. At this time of the year hypoxic conditions with dissolved oxygen concentrations below 63µmol/L or 2mg/L were largely restricted to water depths >100m, i.e., around and below the shelf break. The same sites will be revisited several times within the time course of the project to follow the temporal and spatial dynamic of oxygen distributions and the response of the bethic communities.


Fig. 1: Overview of the stations visited during the GeoEcoMar cruise in May


Fig. 2: An example of the distribution of dissolved oxygen along a transect on the Romanian Shelf

Kick-Off Meeting of GEO Task ST-09-02

Hypox Scientist Christoph Waldmann from the Center for Marine Environmental Sciences at Bremen University (MARUM) participated in the Kick Off Meeting of the Group on Earth Observation's (GEO) task ST-09-02. The task was initiated as part of the 2009-2011 workplan of GEO to promote the development of a Global Earth Observation System of Systems (GEOSS). The main goal of this task is to promote awareness and benefits of GEOSS in the scientific and technological communities in order to engage the research community in GEO and GEOSS. Activities include the forming of links with major scientific research enterprises and to actively encourage relevant scientists and technical experts to contribute to GEOSS.


Fig. 1: The nine societal benefit areas of GEO (taken from the slide library The Group on Earth Observation: An Introduction; www.geo-tasks.org/slide_library/)

The Kick-Off Meeting took place on 27.-28.7.2009 at the ESA/ESRIN centre in Frascati, Italy and was attended by 19 participants from Europe and the US. As representative of the European Comission (EC), Vojko Bratina reported on the efforts of the EC to foster some of the Task activities as well as other GEO-related projects. Within the Framework Program 7 (FP7), the EC funds GEO-relevant projects. A central requirement of the EC is compliance with the GEOSS standards, including registration of data sets and services in GEOSS registries. HYPOX is one of four projects that got funded in 2008. In 2009 and 2010, another twelve GEO-related projects are expected to be funded by the EC.


Fig. 2: The European Space Agency- European Space Research Institute ESA/ESRIN ground facilities in Frascati (Rome), Italy (www.esa.int/SPECIALS/ESRIN_SITE/SEMQPWY5D8E_0.html)

At the meeting, lively discussions took place. Part of them centered on establishing a "GEO label" to denote that data sets and products with the label had been validated/quality controlled according to a set of well-defined rules. This activity was strongly challenged as a GEO quality control (QC) may interfere with already established quality assurance procedures of space agencies and other organizations. One result of task ST-09-02 is the organization of a Union Session at the AGU Fall Meeting 2009. During this session, "compelling examples" will be shown to demonstrate how GEOSS works for science.

Further information about the Kick-Off meeting and meeting minutes are found here: www.geo-tasks.org/st0902/meetings/

Black Sea cruise in the Istanbul Strait area

From 9-21 November 2009 a HYPOX research cruise is conducted using Istanbul Universities' Research Vessel "Arar". The work is carried out close to the mouth of the Istanbul Strait area within the Turkish economic zone of the Black Sea. The cruise is joined by HYPOX project partners from Istanbul University's Eastern Mediterranean Centre for Oceanography and Limnology (N. Çagatay, U. B. Ulgen, E. Damci, Z. Erdem), the Ukranian Institute of Biology of the Southern Seas (S. Mazlumyan, I.P. Bondarev) and the German Max Planck Institute for Marine Microbiology (M. Holtappels, A. Lichtschlag, G. Klockgether).

Fig. 1: the working area in the istanbul strait area (41.35°– 42.00°N and 29.00° E – 29.80° E)

The first objective of the cruise is to study the present and past oxygen conditions of the Black Sea area using geophysical subbottom profiling and sediment coring along transects from 70 m to 300 m water depth. The cores are analyzed for inorganic and organic proxies and benthic communities. The second objective is to study the effect of lateral intrusions of warm, saline, oxic Mediterranean waters on the biogeochemical cycling and microbiologic communities in the anoxic Black Sea water column. This will be done by a combination of chemical measurements and various 15N/13C incubation experiments.

Fig. 2: RV "Arar" of Istanbul University