After a very pleasant evening with barbecue, beer and talk, most of the conference participants have managed to get out of bed and into the Bailey Allen Hall at the University for the day’s first session on “Mapping habitats and determine the ecological status”. As the title indicates, most of the presentations have a more bureaucratic character.
Opening speaker is Dr. David Connor, a marine biologist with over 30 years of experience in marine monitoring and surveying (including MESH, which maps the Baltic Sea), who is now on a loan to the EU for four years to work with the EU’s Water Framework Directive (WFD).
David shows many of the maps that they are now working on in order to get an overview of Europe’s seabeds. The maps have a resolution of 250x250m per pixel. Imagine that for a terrestrial map…However, it is much more difficult, and expensive, to make detailed maps underwater.
In addition to identifying the type of bottom substrate (sediment, rock, sand) they aim to include biological factors, energy exchanges and much more. The goal is that the European seabeds will be mapped down to 5000 meters depth, with relevant factors and good resolution.
Matt Frost followed with a talk about the benthic habitats and their classification in the EU’s Water Framework Directive, and whether there is such a thing as a sustainable habitat loss and if you can measure it to calculate when it is no longer sustainable. The basis for this work is the EU’s Habitats Directive. The data he shows includes more than one hundred researchers’ work over some years, published in the chapter “Habitat thresholds” in the report State of Seas from 2010.
Matt highlights the problems with getting hold of reliable data from all countries, and the difficulties in collecting good quality data at different depths and in different environments.
He concludes by saying that more research is needed before we can set quantitative targets for habitats, that we need to work out better methods for mapping, and that it is not possible to either set or verify quantitative habitat targets at present.
Dr. Xabier Guinda presents how they have managed to implement the EU’s Water Framework Directive for intertidal and shallow areas in Spain, France and Portugal, and the methods they have used to identify them. Primarily, they have used transects, which is the same as we do in Sweden.
Artem Isachenko presents how they have been able to identify mudflats with the presence of Arctica islandica (Ocean quahog) in the White Sea (where we from the BalticSeaWeed blog are eager to go for collecting some seaweed). To find relevant bottoms with the right type of sediment, they use side-scan sonar in Rugozerskaya strait, and received some very fine maps of bottom topography.
They even managed to interpret the sonar signal to determine the density of the large, very thick shelled Ocean quahog in the sediment, where it lives burrowed. Very convenient and comfortable!
They also checked the calculated numbers by taking pictures of the mudbottoms and count the number of Ocean quahog siphons sticking out of the mud (they are easy to recognize). The study shows that Ocean quahog can live in densities up to 400 individuals per square meter!
Henna Rinne, our Finnish colleague and friend, finish off the habitat mapping theme by presenting data from FINMARINET, which she has worked on for almost ten years. The Project is part of Natura 2000, where they have worked with habitats sandbanks (1110), reefs (1170) and small islands and islets (1620). The numbers are the code of the habitat within Natura 2000.
One of the biggest problems they have encountered when trying to map the coast of Finland is to get data. It exists, but is classified. If they get hold of the data, they are not allowed to publish it. Being from Sweden, we recognize the problem and sympathize. Today when every row boat has an echo sonar and a GPS with better resolution than many charts, one might feel it is no longer necessary to protect the depth data from Charlie (which certainly may find whatever data necessary for an invasion via Google Maps).
After a cup of tea and a stretch of the old legs, it’s time for one of the conference’s two female keynote speakers (a total of 9). Professor Maria Byrne did her bachelor here in Galway, but has since moved to Australia and work with echinoderms.
The presentation is about how the echinoderms entire life cycle, from egg to larva to juvenile and adult, is affected by changes in the aquatic environment. For a species to be able to survive in a changed environment, all stages of the life cycle must be able to be completed. Echinoderms builds up their body with calcium carbonate, so the major threats are ocean acidification (see yesterday’s talk) and increased water temperature.
Two species of sea urchins has clearly been affected. A cold-water species creeps slowly down towards Antarctica and have decreased along the Australian East Coast (Great Barrier Reef), while a temperate species have increased in number and extent as the water has become warmer.
Maria and her research group has investigated whether the response to the stress of increasing temperature and acidification are different, depending on whether the species is a polar water species or from temperate waters. It seems that the polar species are most sensitive to a decrease in pH, whereas species from temperate and tropical waters seem to have a greater ability to cope with acidification. Lowered pH seems to be the most important factor for the survival and growth of sea urchin larvae.
If one then adds a temperature rise of 3 degrees Celsius to different acidification stages and try it on the tropical sea urchin Tripneustes gratilla, commonly farmed as food in Asia, one sees that there is a clear synergistic effect on the growth of the larvae, and in later stages of life also in the gonads, which is what you eat. Thus, if it just gets a bit warmer, but not much more acidic, the urchins from tropical waters thrive down in South Australia in the future. The question is how it will affect the rest of the ecosystem. Sea urchins are known to graze heavily on seaweed!
In Starfish, they have instead seen that a rise in temperature inhibit growth. It seems that the sensitivity lies in the planktonic stage, so that species that have larvae with short planktonic stage, who does not need to build skeletons before they settle on the bottom, are less affected.
It’s always great fun to listen to someone who has worked for long in one area and it is a shame that time passes so quickly.
Baltic Sea Weed Blog 
