Why I Love Lichens But Oppose Nuclear Power

Parmelia sulcata, one of the lichen species from which litmus powder can be extracted

Nature has unexpected sensors. Students are always astonished to learn that litmus, the simplest of acid-base indicators, is extracted from lichens. Lichens, which have no roots but a thallus, also bioconcentrate SO2 pollution and radioactive fallout from the air. The thallus is the non reproductive part of the lichen that, depending on the genus, can have a variety of appearances as shown below.

Four different groups are growing together on this iron-rich rock. The island-like boundaries are those of the prothallus. From http://www.lichens.lastdragon.org/faq/lichenthallustypes.html
There are at least three examples of how lichens have ended up concentrating radioaoctive isotopes:
(1) In studies of fallout following atomic bomb tests in the 1950s, it was found that both Alaskan Eskimos and Scandinavian Laplanders had unusually high levels of radioactive strontium and cesium. This happened even though polar regions received less fallout than tropical areas. The cause? In polar areas, bioconcentration by lichens and subsequent bioaccumulation occurred as the isotopes moved through the food chain from caribou ( who eat reindeer moss which is a lichen) , which are then hunted by Eskimos and Laplanders.
(2) Through the same mechanism, reindeer (what Laplanders call caribou) also became unfit for human consumption after the Chernobyl accident of 1986.

(3) More recently, the concentration of cesium isotopes (134Cs and 137Cs ) in lichen within a 30 km radius of Fukushima were more than 3 times the acceptable limit.

The Fukushima disaster is a dim reminder of the dire consequences that nuclear energy can have, even when it’s used “peacefully”. A 20-kilometre zone around the reactors had to be evacuated. Food was contaminated and six years later, 97 000 people have still not returned to the area. This includes people who still have to be barred from the region, not just those who opted to live elsewhere. Although it seemed initially that the tidal wave was the primary cause of the nuclear accident, there was in fact serious damage to piping in at least one of the reactors before the tsunami hit them. In the 2015  film Fukushima-a-nuclear-story former Prime Minister Naoto Kan reveals that Tokyo and all of Japan was saved from a much greater catastrophe by chance when a faulty gate caused water to accidentally flow and cool the top of a reactor.

Largely in response to the Fukushima disaster, Switzerland almost voted in favour of a strict timetable for a nuclear power phaseout. And a long-term plan to shift to renewables does exist in a country which presently derives 45% of its electricity from nuclear energy.

Even though nuclear energy is hailed as being carbon-free, I have long held my reservations about the technology. Here’s why.

Where nuclear reactors are found worldwide. From euronuclear.org
 (1) There are presently no long-term solutions for the storage of nuclear wastes.
(2) Using nuclear technology to generate electricity is far more expensive than other forms.
(3)  A thorium-based technology is currently not being used, even though it would create less waste. Part of the reason it wasn’t chosen as a fuel is simply because countries have always wanted the plutonium from current uranium-based technology for weapons-purposes. But thorium’s short term radiation from its fission products is harder to contain, which would further raise the costs.
(4) Because of the magnitude of a large-scale explosion, the low probability of its occurrence will be no consolation if it actually occurs. And the likelihood will increase if nuclear power becomes more ubiquitous.
(5) The record of the industry has been far from impeccable and its attitude far from sincere. Things will not get any better with ageing reactors.

Here’s a list of countries that do not use fission reactions to boil water to turn turbines —who,  as I once heard an activist say, “don’t burn the house down to make toast.”

  • Australia
  • Austria
  • Belize
  • Cambodia
  • Colombia
  • Costa Rica
  • Greece
  • Ireland
  • Italy
  • Latvia
  • Liechtenstein
  • Lithuania
  • Nepal
  • New Zealand
  • Peru

Protected Areas In Florida Tourist Zones

The sand pine (Pinus Clausa) is endemic to Florida and southern states. It is the dominant tree in sand scrub ecosystems that harbor threatened or endangered species. From Hobe Sound National Wildlife Refuge.

Most of us in the Northeast just see Florida as an escape from our cold winters. Yet, ecologically it’s a special place: 11% of all the vegetation consists of species that are endemic to the state. Scrub jays, whose 1-year old offspring help their mother raise new chicks, are found nowhere else. The same applies to 13 species of fish, amphibians, reptiles and mammals. But technology, wealth and the escape-perception have severely impacted these organisms and their ecosystems. And it has also made human residents there more vulnerable.

To make more land available for home building and agriculture, 19th and 20th century developers in Florida drained swamps and cut down forests. In addition, wetlands bordering bays, lakes, and rivers were filled in. To manage shorelines where much of the growing population concentrated, seawalls were built. From overuse, the state’s shallow aquifers have also become increasingly stressed, and the Everglades National Park, though protected from further development since 1947, receives insufficient water.

Luckily, there are active conservationists in the state. The Jupiter Inlet Lighthouse Outstanding Natural Area is part of the Bureau of Land Management’s 27-million acre National Landscape Conservation System. As we walked through the area, I noticed a few scattered animal trails as they scurried across the path before the trail’s concrete had a chance to set. It was comforting to see evidence of animals advertised at the park’s entrance. The rate at which concrete sets—a series of reactions in which calcium silicates get hydrated –—increases with temperature. So if these tracks are authentic, it reveals that the animals all crossed in less than 12 hours.

From top left and clockwise: (eastern cottontail?) rabbit, heron, wolverine and raccoon. Given the wolverine’s rarity and my lack of expertise in ID-ing tracks, I could be wrong.
Powdery puffy lichen from Jupiter Ridge Natural Area

A few miles away, at the Jupiter Ridge Natural Area, I spotted a southern species of lichen, the powder-puff. (Cladina evansii)  Lichens consist of a pair of mutualistic organisms, a sac fungus and an algae. The fungus secretes acids and dissolves minerals from its rocky or woody substrate. In return, the green algae  provide carbohydrates. If nitrogen-fixing cyanobacteria partners up with the fungus, ammonium ion is also bartered. Florida’s powdery puffy lichen is not poisonous, like over 99.9% of the 20 000 lichen species. That does not imply that it is palatable. Unless you’re a reindeer whose four-chambered rumen harbors microorganisms and protists who can break down the lichen’s fiber and acids, you can’t eat it raw. You have to first treat it with bicarbonate or ashes, which are alkaline.

I was  reminded that lichens are sensitive to pollution because of their structure—they essentially consist of a pair of fungus-networks that sandwich algal cells. There’s no tissue or wax acting as a barrier or buffer against environmental contaminants. Most students and teachers don’t realize that when they use litmus to test pH, they are in fact using lichen extracts.The United States Forest Service lists ways of using lichen to monitor sulfur dioxide, nitrogen oxides, acid deposition, ozone and a number of other pollutants.

To thrive, lichen need clean air, undisturbed surfaces and time. It’s also the prescription needed by Florida’s ecosystems.


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