Today we began with oxygen-free bottoms off the Mississippi River delta. Mississippi has a catchment area covering more than 40% of the U.S. and even reaches in to Canada. Totally awesome! What the researchers have seen is that when large masses of fresh water floods into the sea, after Heavy rain and storms, zones are formed that are completely anoxic, lasting for various length depending on amount of water. Clifton Nunally is working in the area, known as The Mississippi Dead Zone. Dramatic!

Karin Troost from Holland asked whether the pacific oyster (Crassostera gigas) is taking over mussel beds in the Wadden Sea off the Dutch coast. It seems to vary depending on where along the coast they are investigating. Eastern Wadden Sea is now heavily dominated by oysters, but they also create a substrate for mussels, so the result is mixed beats with both mussels and oysters.
In the western Wadden Sea, oysters have colonized areas outside the mussel banks instead.
It seems like there is no need to worry, the oysters will not outcompete the mussels. They will move in and create mixed banks, with more complexity than before. What we do not know yet is how oysters moving in will affect the birds that eat the mussels. Will it be more difficult for them to access mussels? Also, oysters have incredibly sharp edges which birds might rather avoid. The question is also whether there will be food for both oysters and mussels to grow properly, something that Karin is working to calculate.

Sarah Ann Woodin from the U.S., now retired (which does not mean that she no longer does research), show how they have mapped the distribution of larvae from the polychaete Diopatra along the European coast (yeah, she has been sponsored by NASA). This worm builds lovely pipe-formed houses out of shell pieces. The worm larvae spread both naturally through the ocean currents, but also by human impact, hitchiking on mussels that are moved between different cultures along the French coast. It is an incredibly large study, but the advantage is that they get to eat as much mussels as they like while they are working. Wonder if they need an assistant?

In the afternoon, our Estonian colleague Jonne Kotta talked about the importance of temporal and spatial scale when talking ecology, and on what scale you are seeing changes caused by the climatic conditions. Changes on land, like the floods that hit Europe during the last year, for example, are obvious and get a lot of media attention of course. But the changes that occur in the water is not as high profile, and not as well mapped. Jonne has been part of mapping much of the Estonian coast. Once again, the problem with the absence of high-resolution maps of the sea, that we only see tiny parts of the seabed and that the amount of modeling required also need to be checked with actual observations, is discussed.

The second (and last) female plenary speaker of this conference is Cindy Lee Van Dover, who is working with hydrothermal vents (like chimneys of hot water from volcanoes on the sea floor). Her presentation is about the impact humans have on these communities as they mine these habitats for minerals. These environments enriches several minerals from sea water and can grow very large. One such, Godzilla, was 15 storeys high (!!!) before it collapsed during a small local earthquake in 1996.

It’s incredibly exciting with deep-sea research, in which ecosystems are not based on plants that capture solar energy, but is entirely chemosynthetic, wich means that they are instead based on sulfur. Cindy shows stunning images of volcanoes erupting under the water and what it looks like one, two, and three years later, when the animals will return and new structures are forming.

There are one or two embarrassed laughs as she shows different categories of trash you find in the deep sea around these environments. Most are scientific instruments left behind. Luckily, they are mostly classified as less disruptive to the environment. Since this type of environment was discovered 34 years ago, scientists have made more than 700 visits down to there. It leaves a lot of research equivalent of coffee cups and cigarette packets.

So, the problem arises if you venture to mine for minerals, mainly sulfur in these areas. When structures that are built up of mineral deposits disappears, the animals that depend on those structures for living environment and nutrition also disappears. Mining the sea floor also means that it whirls up a lot of sediment, something that many animals do not appreciate. The actual process of mining today, includes pumping shallow water down to the depths, causing a chemical imbalance.

Cindy does not condemn the mineral mining, which has not actually started yet in the areas she works with, but is concerned that they should set limits on how much of these unique environments you are prepared to lose and ensure that these limits are followed before embarking. Here’s a chance to do it right, or at least make minimal mistakes.

Hege Vestheim, originally from Norway, does research on deep sea brines (super salty water layers) in the Red Sea at Saudi Arabia’s University in Jeddah. Hege has investigated 25 deepwater basins along the Saudi Arabian coast that has extremely high salinity. Here, the environment is so extreme that they found no life at all in some of these basins (a dead octopus does not count). In some of them they found arrow worms (Chaetognatha), a clam of the family Solemya and some small anemones that sat on a protruding structure. But as they explore these salt pools they find more and more species, and we were shown an ROV video from some of the pools at more than 1000m depth, with several fun new species. Cool, Hege!

After an opening welcome by Herman Hummel and Bob Kennedy, the first day started with four talks about climate change.

Opening speaker is Professor Jason Hall Spencer from Plymouth University, England. Jason and his team are focusing their research this year on deep coral reefs in the Arctic, satellite tracking of fishing vessels in order to identify possible marine protected areas, as well as studies of underwater volcanoes and how to use these to predict the effects of acidification by elevated levels of carbon dioxide in the atmosphere.

An increased amount of carbon dioxide in the atmosphere affects the balance of carbonate and bicarbonate in the sea, and thus all the animals that build shells and skeletons of lime (clams, snails, corals, echinoderms, etc.). The effect is an ocean acidification (OA). Acidification is measured as pH, where a value above 7 is alkaline and below 7 is acidic. The pH of the ocean has fallen from 8.20 in year 1800 to 8.05 in year 2000. It may seem little, but one should keep in mind that pH is measured on a logarithmic scale. One can already see the effects of mussel larvae, which is 20% fewer larvae in water with lower pH.

Another effect of the increased amount of carbon dioxide in the atmosphere is increasing temperature. This affects several marine species, who are unable to survive in high temperatures. Temperature in combination with acidification can have devastating consequences for marine life on a global scale.

To try to understand how acidification and temperature rise will affect the different ecosystems of the oceans, researchers are trying to conduct experiments that extend over a longer period of time, preferably over a few generations of different organisms, in order to distinguish the cause from the effect. The difficulty is to include all parameters when doing an experiment in the lab, and time is always in short supply for ecologists.

Naturally acidic areas in the ocean can be found outside Sicily, where cracks from Mount Vesuvius are bubbling up carbon dioxide into the water column. Here, the researchers have placed various organisms and examined how they were affected by the lowered pH. Several of our larger species, such as the sea grass Posidonia, seems unaffected, but many of the species found in seaweed beds are adversely affected, sometimes missing altogether. It is mainly red algae with a high calcareous content disappears.

Another potential problem is that other invasive species will gladly take over where seaweed has disappeared. It may seem good that someone fills in the gaps, but these algae do not have the same ecological function as seagrass, and also prevents the seaweed from reestablishing. There is a difference between macrophyte and macrophyte, indeed.

What happens if you move animals with calcareous skeletons between low and high (normal) pH? Depending on the organism you move, they are affected more or less. Some clearly show that they are capable of moving between normal and acidic pH as long as it’s cold, but if it occurs during the summer when it’s really hot in the water, they die.

Jason concludes that we must classify carbon dioxide as a marine pollutant, and the faster we can get policy makers and politicians to understand this, the better.

Dr. Andrea Gori continued in the same vein by showing how beautiful cold-water corals, mainly Dendrophyllia cornigera, are affected by rising temperatures and acidification. Dendrophyllia can be found at 200 m depth off the Canary Islands, where it is the dominant benthic (bottom-dwelling) species.

The results show that these corals can handle a fairly wide range of temperatures between 8-16 degrees Celsius. The study also shows that the species seem to thrive and grow better in temperate environments (12-16 degrees Celsius) than in cold water, where Lophelia pertusa is the dominant coral species.

Our Finnish colleague Tiina Salo, presented data from studies on Zostera marina (eelgrass), which she performed at Roskilde University in Denmark together with dr. Morten Foldager-Pedersen.

Tiina preaches seagrass

Tiina and Morten have examined the interactive effects of salinity and temperature, which has not previously been done for seaweed. The scenario is particularly relevant for the Baltic Sea, where a reduction in salinity is expected to be the largest impact of the ongoing climate change.

The study shows that salinity and temperature have a combined effect on the seaweed, especially on number of leaves formed in both young seedlings and adult individuals. Generally, young plants are more sensitive than adults, and they died completely in the treatment exposed to the highest temperature and lowest salinity.

Thus, future climate changes affect eelgrass in the Baltic Sea, and its vegetative propagation will be more important for the species’ distribution and survival.

Last out before the coffee break (or tea, this being Ireland), is Dan Smale with a summary of Extreme Climatic Events in the marine environment, or Marine Heat Waves, and how they can affect entire ecosystems.

The example is the heat wave along the west coast of Australia in 2011 caused by extreme El Niño conditions, that lasted for two weeks. Before the heat wave there were dense kelp Forests. These could not survive the heat, as they were already living on the edge of their heat tolerance. When the kelp disappeared, the cleared surface was covered again with dense turf algae that effectively prevent kelp from coming back.

The kelp forest has decreased significantly, and this has in turn affected the amount and species number of fish found in these areas. In the region where the kelp previously existed, were also previously found 6 species of mobile invertebrate fauna (sea urchins, snails, etc.). These species have not succeeded in re-establishing themselves in the affected area, as their base habitat, kelp, is no longer there.

Since only two weeks of heat can have such a major impact on an ecosystem, one dares hardly think of how a long heat wave would affect marine life.

Mark Costello – ona divine mission

After refreshment of coffee, tea and cake, the last session of the day is opened by Professor Mark J. Costello, a heavy name in marine biology, who among other things, helped to found WoRMS. He starts off by pointing out that in the Bible’s book of Genesis, God gave man the task of naming species (and maybe a few more irrelevant tasks as well), and that he, as a taxonomist, is working on it. The title of his presentation is “Can we discover Earth’s species before they go extinct?”

The estimated number of marine species that we have identified today is between 320,000 to 760,000 if you use the WoRMS database, and 704,000-972,000 using different assumptions and methods, often described as expert estimations. Mark highlights how inadequate sampling methods may produce very large differences, and why it is obvious that there are more species in the oceans than on land, when seas are so much greater.

Hardly surprising, physically large groups, such as birds, whales and turtles, were early discovered and mapped (if not hunted to extinction), while smaller organisms like bryozoans and tube worms have been “discovered” in greater numbers during recent years. Looking at the timeline of species Discovery, it shows a marked peak in year 1900, when some big expeditions went out and collected large amounts of marine animals. The trend, of course, fell during the World Wars, but has climbed steadily since the 1950s. Some species, however, have been described several times. Spermwhale has no less than 19 (!!) different scientific names. Sometimes itis because the species look different as young and adult, or because the male and female have completely different colours.

Mark estimates that only 61-64% of the planets alge are described (micro and macro algae). If you divide up the animals in the micro fauna (less than 1 mm) and macrofauna (larger than 1 mm), one sees that there are ten times as much microfauna than macrofauna. One can discover a lot by seeing the world through a magnifying glass or a microscope.

The humor reaches the nerdiest of levels, when he shows diagrams of how taxonomists (someone who works with describing new species, like Linnaeus) have increased over the years, although rumor has it that they are becoming extinct, how it differs for marine and terrestrial, between single versus co-published species descriptions and across the continents. He concludes by summarizing that taxonomists are not an endangered genus, but that it presumably requires more work to find new species today when so many are already described. He criticizes the articles that claim it is because the species are dying out at an accelerating rate.