Eutrophication and fish depletion add up

The Baltic Sea is the world’s biggest brackish water body. The main threats for this unique ecosystem are eutrophication and overfishing. In coastal ecosystems eutrophication is considered to be the main factor causing the observed regime shift from long living canopy forming macroalgae towards systems dominated by ephemeral filamentous algae. Canopy forming macroalgae build nursery habitat, store nutrients, decline turbidity, and enrich water with oxygen whereas ephemeral algae can build large scale floating mats causing hypoxia and increase turbidity. Loss of top predators is known to cause trophic cascades. In the simplest scenario top predator loss means an increase in mesopredators, a decrease in grazers and thus an increase in algae growth. There is growing evidence that nutrient related algae blooms are not independent of top-down regulation. However, both threats, eutrophication and overfishing, are so far managed independently of each other by focusing either on reducing nutrient loads or defining fishing quotas for threatened species.

In a combined study using field data and evidence of two experimental studies Eriksson et al. show that decline of top-predators and nutrient load have similar and additive effects on the abundance of ephemeral algae. Both factors together increased abundance of ephemeral algae many times! The field data revealed a strong negative correlation between the abundance of fish and ephemeral algae. When fish was depleted high abundances of their prey and at the same time high cover of ephemeral algae was observed. The experiments very nicely proofed these observations. By excluding predatory fish Eriksson et al. show that (i) the abundance of small mesopredators increased, (ii) the smaller gastropod grazers became smaller, and (iii) the net production of ephemeral algae increased. Moreover, the predator effect depended on grazers and habitat complexity. In the absence of grazers predator removal had no effect on algae growth. In the absence of canopy cover, i.e. a proxy for habitat complexity ephemeral algae growth doubled.

This paper makes a strong point that to successfully combat eutrophication the so far unidirectional view on either bottom-up or top-down forces should change towards an integrated approach taking into account both factors.


Britas Klemens Eriksson, Lars Ljunggren, Alfred Sandström, Gustav Johansson, Johanna Mattila, Anja Rubach, Sonja Råberg, Martin Snickars (2009) Declines in predatory fish promote bloom-forming macroalgae. Ecological Applications: Vol. 19, No. 8, pp. 1975-1988. doi: 10.1890/08-0964.1

Podcasts from the Center

Looking for interviews with scientists and managers working on important ecology and conservation issues? Luckily, a new project, called the Voyage of the Beagle has recently started archiving interview podcasts. Jai Ranganathan, a postdoctoral associate at the National Center for Ecological Analysis and Synthesis started this site to promote current research and researchers and to make lively conversations about research accessible to everyone. Check it often, three new interviews will be posted every week!

The latest podcasts are fed into our blog roll on the right sidebar.

Emergent linkages in seemingly unconnected food chains

Food webs are notoriously complex, and a difficult aspect of ecology is to offer a priori model-derived predictions of food web processes. There are some ecologists, such Neo Martinez and Jordi Bascompte, who have advanced our understanding of the general mechanisms of food web properties and dynamics through tools such as network theory. Such advanced approaches rely on direct interactions among species, or at least indirect interactions that are mediated through changes in abundance of different network players. However, what is missing from our general understanding of food web interactions is the role that behavioral responses can affect patterns of consumption and network connectivity.

Washington State University ecologists, Renée Prasad and William Snyder convincingly show how behavioral responses to predation can fundamentally alter food web interactions and link previously independent predator-prey interactions. They used two spatially independent insect predator-prey links in a novel, factorially-designed experiment. The two food chains consisted of a ground-based one, where ground beetles consume fly eggs and a plant-based one, where green peach aphids feed on the plants and are consumed by lady beetles. Under the ground-based chain only, the ground-based chain plus aphids, or ground-based chain plus lady beetles, the ground beetles consume a high proportion of the fly eggs. However, when both aphids and lady beetles are present, aphids respond to lady beetles by dropping off the plants and the ground beetles switch from consuming fly eggs to aphids. Under this last treatment, very few fly eggs are consumed, fundamentally altering the strength of the linkages in the two food chains and connecting them together.

This research highlights the inherent complexity in trying to understand multispecies systems, where the actors potentially have behavioral responses to other species, changing the nature of interactions. These types of responses may also generally increase the connectedness of such networks, which may result in more stable food webs, but this would need to be empirically tested. Regardless, this type of experiment offers food-for-thought to scientists trying to work general processes into a broad understanding of food web dynamics.

Prasad, R., & Snyder, W. (2009). A non-trophic interaction chain links predators in different spatial niches Oecologia DOI: 10.1007/s00442-009-1486-7

Eco-label Promotes Biodiversity on Farms

At first glance, potato farms might seem like an unlikely candidate for conservation efforts.

But Wisconsin researchers are demonstrating that biodiversity can be restored even in the midst of large-scale farming.

Paul Zedler, professor of Environmental Studies at the University of Wisconsin (UW)-Madison, and his colleagues are working with potato farmers to restore pre-settlement habitats on growers’ lands.

In central Wisconsin, 42,600 acres are devoted to potatoes. Since the landscape is dominated by agriculture, some proportion of farmland must be set aside for conservation to preserve biodiversity in this part of the state.

Restoration is a requirement of the Wisconsin Healthy Grown potato program, a partnership between UW–Madison, the Wisconsin Potato and Vegetable Growers’ Association, and NGOs such as the International Crane Foundation, Defenders of Wildlife, and the World Wildlife Fund.

The groundwork for the Healthy Grown program was laid out in the 1980s, when a group of potato growers voluntarily discontinued use of the high-risk pesticide aldicarb. The farmers turned to UW-Madison researchers for pest-management advice. This grassroots movement eventually drew attention from conservation agencies.

To be certified under the Healthy Grown eco-label, potatoes must be grown under a set of standards that restrict pesticide and fertilizer use. The program was able to draw from an extensive body of UW-Madison research to guide the formulation of these in-field standards. But farmers and environmentalists were interested in doing more.

Since the program's conception, growers had expressed interest in managing their farms as whole ecosystems rather than just focusing on crop production on a field by field basis. At the same time, the NGOs saw the program as an opportunity to bring farmland into regional-scale conservation plans.

Satisfying this interest in developing a conservation standard for the eco-label was challenging for researchers because fewer precedents existed. Even the largest and most well-known eco-label, USDA Organic, does not include a conservation requirement in its certification standards.

Zedler and his colleagues looked to the Nature Conservancy, which had established a system for making strategic conservation decisions and measuring conservation success at sites where the objective is to improve biodiversity on whatever land can be spared from intensive human use.

Potato farms in central Wisconsin are unusual in their tendency to contain significant patches of marginal land without crops because these patches cannot be irrigated – a necessary factor in growing potatoes. The result is a complex mosaic of land in which remnant patches of disturbed natural habitat are isolated within an agricultural matrix. Zedler and his colleagues focused their research efforts on these patches of non-crop land.

Their research suggests that prescribed burns and control of invasive plant species can help restore disturbed non-crop land to the habitats that characterized central Wisconsin before European settlement: prairie, oak-pine savannah, and sedge meadow.

Thus far, the Healthy Grown program has restored more than 400 acres of privately owned farmland. According to Zedler and his colleagues, farmers’ strong ties to their land motivate their commitment to the conservation standard of the Healthy Grown eco-label.

Zedler, P. H., T. Anchor, D. Knuteson, C. Gratton, and J. Barzen. 2009. Using an ecolabel to promote on-farm conservation: the Wisconsin Healthy Grown experience. International Journal of Agricultural Sustainability 7(1): 61-74. DOI:10.3763/ijas.2009.0394

(Image courtesy of FotoosVanRobin at flickr under a Creative Commons license)

Time management for grad students and researchers

As researchers, we all have incredible demands on our time. These demands can quickly snowball, leaving us feeling like things are out of control. This lack of control over your priorities and responsibilities can lead to anxiety and depression and perhaps to dropping out of graduate school. Getting control and developing good time management skills can go a long way towards preserving your sanity and making grad school and a career in academic research enjoyable. All it really takes is planning, and knowing the things to plan for. The critical priorities that every student and/or researcher must plan, includes:

• Writing/outlining research questions
• Taking courses
  
• Teaching
• Appointments with supervisor and committee
• Design/set-up experiments/studies
• Data collection
  
• Analyzing data
  
• Writing papers/chapters/articles
  
• Rewriting papers/chapters/articles
  
• Meetings/presentations
  
• Finding a publisher/lay out/submitting manuscripts
  
• Administrative duties
• Holidays
  
• The unexpected!

All these things tugging at you all at once can make it difficult to start any single thing -because you feel the anxiety about not starting other things. Here are seven strategies for controlling your time and priorities, and helping you to cope with time stress.

1 - Live by the calendar, die by the calendar. Basically, schedule everything. With freely available calendars like Google's or Sunbird there is no reason to not adopt a calendar. Web-based calendars, mean you can be anywhere, on any computer and still have access. Be sure to share the calendar with lab mates and professors, so they know when you are booked. Schedule everything from meetings, to large slots of time dedicated to time-intensive things like reviewing a manuscript or data analyses.

2- Gimme a break! Working for four straight hours without a break will cause you to be less productive, than four hours with a 5 minute break every 40-60 minutes. Don't be afraid to get up from your desk in between tasks to reset your brain. You could also call or chat with someone, make a coffee, watch a Daily Show clip, update your Facebook status, etc. Don't feel guilty about the 5 minute solitaire game (only about the 2 hour ones).

3- Leave. Have a secret work spot. It could the back corner of a library, a coffee shop, home, or some special place. The point is to have a productive site where you are not tempted to do nonproductive things when you need to be focusing on a task. Leave your e-mail behind if possible and do not let colleagues know where you are. Make it your time.

4- Delegate. You do not need to do everything yourself. If you are collaborating, don't be afraid to ask collaborators to do something. If you are at a big university, search for undergrad volunteers to help out. If you are really swamped, ask a friend to help out with an experiment.

5- Write it down or lose it. I write down everything, and I do it for two reasons. First, I will forget it if it is not written down in front of me (which saves me anxiety about forgetting things). Secondly, these notes become defacto to-do lists which saves me time from having to think about what to do next. If I have ten minutes before a meeting and my list has me e-mailing someone, then I get the reward of ticking something off the list.

6- Enough is enough. Remember, it will never be perfect. Likely, the 13th draft of paper is not appreciably better than the 12th. Plus, reviewers will ALWAYS recommend revisions and you will never win a literary award for it. So if you pour your soul into a manuscript and take 2 years to write it, likely you'll be devastated when you are asked for major revisions. The important thing is getting it submitted and learning when enough is enough can go a long way toward freeing up valuable time.

7- Have fun. Likely, you got into research because you love science. If your work is tedious and boring, find some fun research to offset it. If you have to choose between two projects, and one seems like it will be personally more enjoyable, go for that one. Don't be afraid to shelve a unrewarding project for one that is fun and exciting. Most importantly, reward your self! When you submit a paper, take the rest of the afternoon off. When you finish an intense summer of field work, go to the beach for four days. Tell your close colleagues when you get a paper accepted or an award -you are not bragging, and they will always say 'congrats' or 'awesome', which feels nice. Whatever works as a reward, use it.

Remember, at the end of the day what matters is getting papers out and being a good collaborator/student/mentor/human being. Control of priorities and successful time management will make it a lot easier to get those papers out and be a relaxed, good person to be around.

Conscientious conservation?

A colleague once said at a bar that she didn't believe in "conservation genetics". I'm not quite sure which aspect she was disputing, but one certain conflict is between gearing research toward conservation, while watching chemicals and consumables go into the waste stream. Most of the reactions in my lab are done using pipet tips and tubes made of virgin polypropylene. Nobody wants to recycle this stuff - even though 99% of the chemicals we use are fairly meek reagents like ethanol, water, nucleotides, and barnacle DNA, there's just no way to guarantee the waste stream coming from a building that does molecular research (e.g. you'd probably balk if that plastic got melted down and used for toys). Researchers have enough problems with reactions going wrong to also worry about whether their supplies are contaminated with the products of reactions past. Still, we have to constantly consider how we can minimize waste in the lab.

Lab Waste from Eva Amsen on Vimeo.

As a marine biologist, I'm also very conscious where all this plastic eventually ends up. I'm entertaining ideas for tip and tube recycling, though it is barely worth the effort for a single lab to do so: my lab probably consumes about 10kg of virgin polypropylene a year, into the trash. Super bummer. But that recycling effort could be balanced out if I just got my entire lab (including me) to stop drinking so much soda! Better would be to find institutional solutions, and we're a long way off on that.

Of course a lab is more than plastic. There are chemicals - which we've chosen to avoid some of the nastier ones, like ethidium bromide (using Ames-tested GelRed instead), isotopes (fluorescent-labeled primers), but still must use a little bit of polyacrylamide and a few other things in very small quantities that you wouldn't want to put in a smoothie. There are heating and cooling costs, which we can't do a lot about in our grumpy 1980's-era building at the University of Georgia (we'll assume that under budget constraints physical plant is doing what they can in that regard, though we did install some motion sensors on lights in the auxiliary rooms).

And then, there are all the gizmos. For the holidays I got a fun gift: a Kill-A-Watt. As procrastination during grant writing, I decided not only to check the energy consumption of things at home, but things in the lab. I don't know whether I believe paying to balance carbon emissions works (though at $3/month, I do it anyway), but it is interesting to know what the footprint of a lab like mine is. To make a long story short, it's mostly about the computers. Each computer in my lab used around 5kWh/day - up to $150 in annual energy bills, and actually the only things that compete with computers are my big chromatography fridge and my ultracold freezers (the -80° will use around 6000kWh/year!). Anyway, by unplugging some things that weren't being effectively used - one of the refrigerators, some water baths, an incubator, 2 of the computers - and ensuring that the rest were using the most appropriate power-saving settings - I cut the kWh consumption of my lab (only counting plug-in stuff) by over 10%.

The question is, how does this energy usage affect the science? One could argue that my research program hasn't expanded to fill the resources I had available, or that I can only cut back to the detriment of productivity. Only time will tell! We may have to devise a metric for productivity per kWh - but right now if I calculate my Hirsch index per kWh, it is not the thrilling kind of number I want to run to the administration with. I better get back to work.

Fall colors redux

For those of us in temperate deciduous regions, now is the time of landscapes splashed in red, orange and gold. Here is a link to a post I wrote back in March about the evolutionary meaning of autumn colors. It seemed appropriate to dig it up.

Adaptation and dispersal = (mal)adapted

Ever since Darwin, we often think of organisms as being in a constant battle against other organisms and local environments. Thus natural selection and the resulting arms race results in organisms highly adapted to local conditions and against local antagonists. At the same time, and especially driven by theoretical advances in the 1990's, researchers began to ask how dispersal -that is, the flow of genetic material from elsewhere, can disrupt local adaptation. On the one hand it may provide genetic variation allowing for novel solutions to new difficulties. On the other hand, dispersal may reduce the prevalence of fitness-increasing genes within local populations.

In a simple but elegant experiment, Jill Anderson and Monica Geber performed a reciprocal transplant experiment, moving Elliott's Blueberry plants between two habitats. One population was from highland, dryer habitats and the other from moist lowlands. They further evaluated performance in greenhouse conditions. Their results, published in Evolution, show that these two populations have not specialized to local conditions. Rather, due to asymmetric gene transfer, lowland individuals actually performed better when planted in highlands than compared to their home habitat. Further, in the greenhouse trials, lowland species did not perform better under higher moisture conditions. While genetic or physiological constraints may also limit adaptation, Anderson and Geber present a fairly convincing case that gene flow is the culprit.

These results reveal that populations may actually be relatively mal-adapted to local conditions, which has numerous consequences. For example, we need to be cognizant of adaptations to particular conditions when selecting populations for use in habitat restoration and when trying to predict response to altered climatic or land-use conditions. Importantly what does this mean for multi-species coexistence? Dispersal seems to limit the ability to adapt, and thus, better use local resources or maximize fitness, making for a better competitor. At the same time, dispersal can offset high death rates, allowing for the persistence of a population that would otherwise go extinct. Understanding how these two consequences of dispersal shape populations and communities is an interesting question, and work like Anderson and Geber's provides a foundation for future studies.

Anderson, J., & Geber, M. (2009). DEMOGRAPHIC SOURCE-SINK DYNAMICS RESTRICT LOCAL ADAPTATION IN ELLIOTT'S BLUEBERRY (

)
Evolution DOI: 10.1111/j.1558-5646.2009.00825.x

Mycorrhizal Networks: Socialists, capitalists or superorganisms?

Mycorrhizal networks – fungal mycelium that colonize and connect roots of one or more plant species – are a very intriguing type of fungal-plant association. There is evidence of substantial facilitation between plant individuals via these fungal networks. This can have drastic implications for our understanding of nature, given that the common perception is that other mechanisms, like competition, herbivory or dispersal, are the main drivers of plant community associations. This may be far from reality if the existence of “socialist” networks is widespread (e.g. the ability to connect and profit from a network may be more important than competitive abilities). In the last issue of the Journal of Ecology ( that has a very interesting special feature on facilitation in plant communities), Marcel Van der Heijden and Tom Horton conducted a review of the topic. They found a general positive effect of mycorrhizal networks on seedlings and large plants (i.e. plants tend to grow better if they are associated with a network). However, the reviewers also found some networks can have a neutral or even a negative effect on plants. The plant responses were highly variable depending on other variables including fungal species, nutrients availability, and plant identity. The positive effect of some fungal networks on seedlings growing nearby adult trees of its same species is somehow opposite to the predictions of the Janzen-Connell hypothesis. We need further studies to understand the overall importance of mycorrhizal networks in relation to other better understood mechanisms.

van der Heijden, M., & Horton, T. (2009). Socialism in soil? The importance of mycorrhizal fungal networks for facilitation in natural ecosystems Journal of Ecology, 97 (6), 1139-1150 DOI: 10.1111/j.1365-2745.2009.01570.x

The making of an open era

With the availability of open access (OA) journals, academics now have a choice to make when deciding where to send their manuscripts. The idealistic version of OA journals represents a 'win-win' for researchers. The researchers publishing their work ensure the widest possible audience and research has shown a citation advantage for OA papers. The other side of the 'win-win' scenario is that researchers, no matter where they are, or how rich their institution, get immediate access to high-caliber research papers.

However, not all researchers have completely embraced OA journals. There are two commonly articulated concerns. The first is that many OA journals are not indexed, in most notably Thomson Reuters Web of Knowledge, meaning that a paper will not show up in topic searches, nor will citations be tracked. I for one do not like the idea of a company determining which journals deserve inclusion, thus affecting our choice of journals to submit to.

The second concern is that some OA journals are expensive to publish in. This is especially true for the more prestigious OA journals. Even though such OA journals often provide cash-strapped authors the ability to request a cost deferment, the perception is that you generally need to allocate significant funds for publishing in OA journals. While this cost may be justifiable to an author for inclusion in a journal like PLoS Biology, because of the level of readership and visibility. However, there are other, new, profit-driven journals, which see the OA model as a good business model, with little overhead and the opportunity to charge $1000-2000 per article.

I think that, with the rise of Google Scholar, and tools to assess impact factors (e.g., Publish or Perish), assessing difference sources for articles is available. The second concern is a little more serious, and a broad-scale solution is not readily apparent.

Number of Open Access journals

Regardless, OA journals have proliferated in the past decade. Using the directory of biology OA journals, I show above that the majority of OA journals have appeared after 2000. Some of these have not been successful having faltered after a few volumes, such as the World Wide Web Journal of Biology which published nine volumes with the last in 2004. I am fairly confident that not all these journals could possibly be successful, but I hope that enough are. By having real OA options, especially higher-profile journals, research and academia benefit as a whole.

Which journals become higher profile and viewed as an attractive place to submit a paper is a complex process depending on a strong and dedicated editorial staff and emergent property of the articles submitted. I hope that researchers out there really consider OA journals as a venue for some of their papers and become part of the 'win-win' equation.