Highlights of the Ecotoxicology Sessions at the 2010 SETAC Europe Annual Meeting
Ryszard Laskowski, Institute of Environmental Sciences, Jagiellonian University, Poland
The domain of ecotoxicology was certainly represented by the largest number of presentations during the conference. This should not come as a surprise; even if neither SETAC itself nor SETAC Europe’s annual 2010 meeting in Seville bear the word “ecotoxicology,” most participants probably consider themselves ecotoxicologists. When it comes to official statistics, we had 16 sessions under the general headline of ecotoxicology, with 125 platform and 441 poster presentations. Although it is hard to tell the total number of presentations addressing ecotoxicological problems directly, I estimate it to be over 800.
Rather than trying to summarize such a large number of presentations and sessions, I will extract a few more general issues that either dominated the meeting or were for some reason especially important—e.g., novel approaches and challenges or just the opposite: long-lasting, persistent problems that have not been solved despite years of hard work. Accordingly, this is going to be a very personal point of view, but that is not necessarily its weakness; actually, if it raises some discussion about priorities, importance of problems to be solved and questions to be answered, I will consider this short story a success—as the whole Seville 2010 SETAC Europe meeting certainly was. That said, I think that it may be useful to group these leading themes into three categories: those that are getting strong after years of efforts, those relatively new “emerging topics,” and crosscutting problems that clearly extend across different areas of ecotoxicology and could be traced in different sessions.
Combined stressors: you may call it too personal, as Martin Holmstrup and I chaired a session on this topic, but indeed I believe that effects of combined stressors is one of the main (possibly the main?) avenues to understanding effects of toxic chemicals in the real world. Although the topic is certainly not that new (some important papers were published some 25-30 years ago, and even older works can be found), it is finally making its way to the broader scientific community. The problem was discussed during the SETAC Europe meetings in Warsaw (2008) and Gothenburg (2009), but I have the impression that it really got the kick this year, even if “other stressors” sometimes seem a major source of headache for both theoretical ecotoxicologists and practitioners, as summarized nicely by one of the presenters: “Toxic impact on organisms and whole communities in field studies are hard to interpret due to possible combined effects of stressors” (Stefanie Rotter et al.,).
Linking biomarkers and higher-level effects: this is another topic worth mentioning, mostly due to immense progress this area of ecotoxicology experienced in recent years. While just a few years ago we could barely make clear links between effects on enzyme activity and responses at the level of individuals, nowadays serious efforts are undertaken to build bridges between gene expression and population-level effects. There is certainly a long way to go, but our understanding of the role of particular genes in biochemical responses to toxicants and, then, their effects on populations is indeed impressive.
”Omics” no longer a fashion but a real tool in ecotox studies: this is a part of success story in linking biomarkers and higher-level effects. This year I had for the first time the impression that most of the “omics” studies (with genomics, in particular) were used with purpose, and not just because we have the means. Surprisingly (although it should not come as a surprise when you really think about it), the number of studies in which (gen)omic methods were used was lower than in a few previous meetings. I consider this a sign of maturation of this specific art in ecotoxicology: we started to use (gen)omics where we really need it and have a chance to understand the underlying mechanisms. There were, by far, fewer of those beautiful pictures of myriads of colorful buttons (microarrays, I mean) with rather vague meaning but when they appeared, the authors were usually able to tell some story about cause-effect-consequences relationships.
Community and ecosystem vulnerability: this topic was not that strongly represented during the conference, but I found it worth mentioning because of, to some extent, the novelty of this approach in risk assessment. Although we are certainly a ways from bringing this type of reasoning into practice, there were a number of very good presentations showing this approach as a possibly fruitful tool for environmental management and decision making.
Natural toxins: although present on earth virtually since the origin of life, these substances have been largely neglected until recently. Granted, there were dozens of studies on algal blooms and toxins but not much more than that. Natural toxins are, however, virtually all around us, and this meeting showed a growing interest in their direct effects on organisms as well as in interactions with toxic chemicals of anthropogenic origin. The topic converges also nicely with the “combined stressors” approach.
Studies of indirect effects: to some extent, these are yet another way of understanding effects of pollutants in the real world. Tremendously difficult to study, with all the links between a toxicant and its effects sometimes next to impossible to trace, studies of indirect effects are a major challenge for ecotoxicology. Here are such phenomena as changes in predation efficiency or food availability caused by pollutants, indirectly affecting organisms that do not even need to be exposed to any direct toxic effects to be seriously in danger of population decline or even extinction. The lesson learned years ago with biomagnification of pesticides was, however, convincing and showed how important some indirect effects can be. This area will certainly experience growing interest in coming years.
Behavioral studies in ecotoxicology: this year showed a small bloom of such studies, although they are still a rarity. This apparently happened thanks to availability of newly developed modern techniques that made such studies not only easier and more straightforward, but more importantly, possible for some organisms and environments that have been excluded until recently from such observations. I mean, in particular, those methods that allow us to quantify the activity of animals in nontransparent media such as soil and sediments, which opens the whole new area to ecotoxicologists.
Need for multigenerational studies: although there was probably just one presentation openly calling for multigenerational studies, I found it worth stressing as it explicitly formulates an important message coming from a number of studies. The necessity for multigenerational studies was obvious for years to those interested in adaptations and evolution in contaminated environments. This time, however, a couple of presentations showed clearly that even relatively simple ecotoxicological tests can give different results depending on whether they are performed on a single generation or several. This is a strong and important message in the world where time is money.
Population models: these tools have been with us since the birth of ecology, and ecotoxicologists gladly implemented them in their research. It is now commonly agreed that population models can bring us much closer than more traditional measures of toxicity (such as LC50, not mentioning no observed effect concentrations and related concepts) to ecological risk assessment (ERA). A number of interesting presentations showed how close we are to this goal, and if there is any general message here, I would say yes, we are ready and we should implement population thinking and modeling in ERA.
Adaptations to pollutants: this is yet another topic that has been present at SETAC meetings for years. One could suppose that we have plenty of information on this interesting subject such that everything is clear and we really do understand how evolution works in contaminated environments. Surprisingly, this is not the case and it was stressed in some presentations that, as a matter of fact, we have very few hard data on adaptations (possibly with the exception of those related to pesticides).
This summary is certainly neither exhaustive nor exclusive, and lots of other interesting topics were addressed during the meeting (remember, some 800 presentation on ecotoxicology alone!), but in my personal view these were the most important issues discussed in Seville. There is, however, yet another topic that I would like to mention: a session on “environmental animal alternatives.” With an ever-increasing number of chemicals to be tested, with ever-tougher risk assessment requirements, the need for alternatives to animal testing becomes obvious. Thus, it came as a surprise to notice that despite the session devoted specifically to that problem, real alternatives to animal testing were difficult to find. What was mostly presented were tests on fish embryos; but are they indeed the alternative to animal testing?
I am eager to see how these topics will develop in the foreseeable future. Will we soon be able to predict the fate of populations and metapopulations based on genetic-level effects that take into account interactions with natural stressors? When will ecosystem vulnerability be implemented in ecological risk assessment? Developments in a few areas seem impressive and possibly some answers to these questions will be given during the next SETAC Europe meeting in Milan in 2011 or in the 2012 Berlin World Congress. Certainly, these will be exciting places to be in the coming years for any ecotoxicologist.
Author contact information: email@example.com
Return to the Globe