Mercury in Birds and Bats

I want to highlight this research report for a couple of reasons.   First, it’s a summary of a lot of research on birds and bats–and it is alarming.  Major findings include:

• Current environmental mercury loads have the ability to significantly reduce reproductive success in several songbird species of conservation concern in the northeastern U.S. including the saltmarsh sparrow and rusty blackbird.
• Bats also build up significant body burdens of mercury;  individuals from multiple species from all 10 areas sampled exceeded the subclinical threshold for changes to neurochemistry.
• Mercury loading in songbirds is not only restricted during the breeding season; some species, such as the northern waterthrush, build up high levels of mercury during migration and in tropical wintering areas

Basically, this expands what we know about the dangers of biomagnification out into song birds and bats.  I’ve written about some of the research this report is based on before.

From an interview with an author:

“It is a game-changing paradigm shift,’’ Evers said. “For years, we’ve understood the notion that birds like an eagle can obtain toxins by eating a bass, which has eaten a perch, and the perch has eaten a fly. Now we understand the same kind of analogy can be applied to a water thrush, which eats a spider, which has eaten a smaller spider, which has eaten a fly.’’

The other reason I want to point you at this is because it’s a great example of how to produce a report on complex research and make it really accessible.  They don’t just have data; they have information on how to interpret the graphs.

The PDF report itself is beautiful to look at, and focuses on specific actions/conclusions that can be drawn from the data.  It’s a report that I could hand to any of my non-scientist coworkers and be confident they could read it and understand it.  The PDF is presented within the context of a page with lots of supplemental info, including jpgs of some of the figures.  This makes it easy for journalists to build a story.

A thermometer is used to indicate risk to certain species–which cleverly uses something commonly associated with Mercury, but also something a lay-person knows how to interpret without a lot of special background knowledge.

Lastly, they cited their research through the report in ways that let you look up the original research, but that doesn’t detract from your reading.  It makes a powerful case that we need to really start paying attention to the mercury in our environment–because it’s not just the birds that are exposed.

Additional Reading:

• Aquatic mercury in food webs
• USGS: Mercury in the Environment
• Game Changers: a report on how global warming and toxins might change hunting and fishing.
• EPA advisories on which states have fish too contaminated to eat

Shiny! (not in a good way, alas)

A lot of discussion occurs about “light pollution” at night, but some recent research suggests there’s another issue–polarized light pollution during the day.

Smooth, dark buildings, vehicles and even roads can be mistaken by insects and other creatures for water, according to a Michigan State University researcher, creating “ecological traps” that jeopardize animal populations and fragile ecosystems.
It’s the polarized light reflected from asphalt roads, windows – even plastic sheets and oil spills – that to some species mimics the surface of the water they use to breed and feed. The resulting confusion could drastically disrupt mating and feeding routines and lead insects and animals into contact with vehicles and other dangers, Bruce Robertson said.

This isn’t a new issue–there is a long history of papers documenting the attraction of cars to aquatic insects laying eggs.  A 2006 paper specifically looked at different colors of cars–apparently red vehicles attract other things besides police cars.

You just can’t help but be depressed reading some of the papers–this one covers how glass buildings act as a “polarized light trap” and lure hapless caddisflies to their doom.

Are we so far down the road of shiny plastic and glass objects that we can never come back? Unfortunately, I have to conclude that we are.  What this will mean for insect populations, we can only speculate.

But I’m betting it won’t be good.

Link to the actual papers:

Horváth, G., Kriska, G., Malik, P., & Robertson, B. (2009). Polarized light pollution: a new kind of ecological photopollution Frontiers in Ecology and the Environment DOI: 10.1890/080129

Kriska, G., Csabai, Z., Boda, P., Malik, P., & Horváth, G. (2006). Why do red and dark-coloured cars lure aquatic insects? The attraction of water insects to car paintwork explained by reflection–polarization signals Proceedings of the Royal Society B: Biological Sciences, 273 (1594), 1667-1671 DOI: 10.1098/rspb.2006.3500

Kriska, G., Malik, P., Szivák, I., & Horváth, G. (2008). Glass buildings on river banks as “polarized light traps” for mass-swarming polarotactic caddis flies Naturwissenschaften, 95 (5), 461-467 DOI: 10.1007/s00114-008-0345-4

G Kriska, G Horvath, & S Andrikovics (1998). Why do mayflies lay their eggs en masse on dry asphalt roads? Water-imitating polarized light reflected from asphalt attracts Ephemeroptera. Journal of Experimental Biology

What’s lurking in your neighborhood?

One of the fun things I did this semester was arrange a meeting between our fall semester undergrads and an environmental consulting company manager.

The idea was to give the students an idea of how the ecological principles they are learning can be applied in practice.  And, of course, learn about possible careers.

What we ended up talking about–at length–was the manager’s work identifying and remediating brownfields.  Brownfields is a term the EPA uses for  abandoned industrial and commercial facilities.  These are typically not preferred for development, since there are usually lurking (or obvious) environmental contaminants.  No one wants to buy a property that they might be on the hook for decontaminating–for a huge price–later on.

Ideally, communities work with developers to try to clean up a brownfield site and make it suitable for use again with grants from the state and the EPA.  (And that’s where our environmental consulting firm comes in.)

There is a nifty little tool that you can use to look up what is being remediated, or at least has been identified, in your neighborhood.  It includes superfund sites and federal sites that are dirty too.

One of our students discovered he lived rather close to this site, which was a bit of a surprise.

Through that, I also discovered Surf your Watershed, an index of both watershed quality assessments and Citizen-Based Groups active in the areas. You probably don’t want to look at the Toxic Release Index for your state.

[Thanks to Brutal for the photo.]