Beware of the fake conference

I don't know about other researchers, but I get inundated with e-mails about upcoming conferences from organizations I've never heard of, on topics that, at best, only tangentially relate to my work. I think that most of these are put on by for-profit groups that try to cash in on hot topics. But now there are truly fake conferences that are fronts designed to get your financial information. In a new post by Bob Grant on The Scientist news blog, he relays a detailed example of such a scam conference. He went so far as to contact the venues and speakers listed by the scammers, and of course none of those listed had ever heard of the conference. The ultimate enticement was the offer to pay for travel expenses, and the presumption is that they would offer to reimburse you, but need your bank account information. The evolvability of internet scammers is truly impressive.

Something fishy

Of the many victories wrought by DNA barcoding - the ability to place an unknown sample in a phylogenetic, and often taxonomic, context using short fragments of DNA sequence data - some of the most useful applications for management have come from the sea. One of the best citation-to-data ratios in this regard belongs to a 2004 study by Peter Marko. This project extended naturally from Marko's molecular ecology course: students purchased samples of "red snapper" from various fish markets, and sequence data from the mitochondrial cytochrome b gene region showed that most of these specimens were not, in fact, Lutjanus campechinus - they were often understudied and probably rare relatives, or in some cases not snapper at all. The conservation implications from this study were huge, and a number of papers have followed suit, looking at a variety of similar systems. If you aren't interested in adding to your list of papers to read, check out the short film based on work done in Steve Palumbi's lab that documents their work to identify shark fins.

In a paper by Lowenstein et al., published last week in PLoS ONE, the focus was on sushi, specifically tuna. The common labeling errors were caught again: there were mismatches between what restaurants called the fish, and what was actually being offered. In some cases, very phylo-distant species are being sold as "tuna", and these species can actually make consumers ill. The story is an interesting one of how fraud develops in samples of organisms that can no longer be visually tied to the species they came from, and the difficulties in protecting consumers from fraud under current regulations. Obviously, the perils of overfishing are becoming quite clear and interested readers should carry their Monterey Bay Aquarium seafood guides or similar (there's even an iPhone app for that!) with them before ordering at restaurants.

A particularly interesting advance in this study was taking the barcoding approach beyond the visual appeal of tree-building and similarity with databased sequence data. One concern about barcoding has been that even when a new clade appears in a phylogeny, taxonomy cannot be updated without some sort of diagnostic characters. It is uncommon for new species (especially of animals) to be described based on DNA sequence data alone, but it is nevertheless the norm to define the character states that uniquely define a species from its relatives. In Lowenstein et al.'s paper, they identified 14 diagnostic DNA substitutions that could be used to uniquely identify all species of Thunnus and suggested that focusing on particular characters within the "barcode gene" (mitochondrial cytochrome oxidase I) will also be necessary for new technologies to accelerate in-the-field identification.

This latter step is of interest for anybody interested in cryptic species, or identifications when other reference material is not available. I hassled one of my former Ph.D. students endlessly as she revised her dissertation because we had been comfortably using a phylogenetic tree to assign unknown individuals to one of three cryptic taxa (in the isopod genus Idotea), but prior to publication we knew that diagnostic characters would be necessary for subsequent work to be readily comparable. And, since the undergraduate evolution lab at the University of Georgia repeats Marko's work on red snapper every few years (the local Kroger now knows not to advertise their special on "red snapper from Indonesia"), perhaps the lab can be extended by having the students generate these characters for the genus Lutjanus as well. I don't seem to have any problem convincing students to do their homework when it involves going out for sushi.

Ross Crozier, evolutionary biologist and conservation biologist

Sadly, one of Australia's leading evolutionary biologists, Ross Crozier passed away suddenly last week (Nov. 12th, 2009). As a Professor at James Cook University, he worked on a plethora of evolutionary issues, from understanding the evolution of sociality in insects to population genetics and molecular phylogenetics. To my mind, his most influential papers were on how we can use patterns of evolutionary history in guiding conservation decisions -the agony of choice. While he promoted the conservation of phylogenetic diversity, per se, his great insight was that even comparing species that are relatively divergent does not mean that they are equally valuable, and we should consider information content as well. That is, a species with 80,000 genes is more valuable than a species with 20,000 genes, since the 80K-gene species has greater information content.

"Differences in the information content of genomes led to the realization that, other things being equal, some organisms have intrinsically higher conservation worth than others." -Ross Crozier

Ross also recently was the handling editor, at Ecology Letters, on a paper of mine and his insights and support were greatly appreciated and helped to improve our manuscript in numerous ways.

Here are my two favorite papers of his.

Crozier, R. H. 1992. GENETIC DIVERSITY AND THE AGONY OF CHOICE. Biological Conservation 61:11-15.

Crozier, R. H. 1997. Preserving the information content of species: Genetic diversity, phylogeny, and conservation worth. Annual Review of Ecology and Systematics 28:243-268.

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