Wednesday, May 30, 2007

our ginkgo tree

The Ginkgo tree is one of the oldest trees on earth. Fossils of Ginkgo relatives have been found in rocks dating back 270 million years. For centuries, people thought the Ginkgo was extinct, until is was found growing in remote parts of China in the mid-1700s.

The word Ginkgo comes from a misspelling of the Japanese word "ginkyo" or "silver apricot." Other people attribute the word to the older Chinese word meaning "silver fruit."

Not that you'd want to hang around the fruit of the female ginkgo tree. While most plants are hermaphrodites, ginkgos have separate male and female trees. The female trees produce fruit that become a mushy, foul-smelling mess on city sidewalks in the fall. The fruit contains butanoic acid, which makes it smell like rancid butter. For this reason, landscape suppliers will only sell male cultivars, or trees that are male clones of existing trees, to ensure maleness. Don't know if your Ginkgo is male or female? Don't let a few years of non-smelliness convince you - female trees will not fruit for 20 years more. (Ours is a male cultivar.)

Ginkgos are very successful in urban settings and are well-known for being disease and pest-free. (Although, I am not sure they are immune to the ovipositors of the female cicadas. That's why we decided to cover our new Ginkgo for the duration of the 2007 periodical cicada emergence!)

Ginkgos are deciduous dioecious gymnosperms (deciduous = they lose leaves yearly, dioecious = male and female are separate, gymnosperm = "naked seed," meaning their seeds are not encased in ripened fruit, although the females do not produce actual cones.)

Kingdom Plantae -- Plants
Subkingdom Tracheobionta -- Vascular plants
Superdivision Spermatophyta -- Seed plants
Division/phylum Ginkgophyta -- Ginkgo
Class Ginkgoopsida
Order Ginkgoales
Family Ginkgoaceae -- Ginkgo family
Genus Ginkgo L.

The only living member of the Order Ginkgoales is the Ginkgo biloba! The word biloba means "two-lobed" and refers to its distinctive leaf shape.

Many people take Ginkgo biloba extracts (widely available at drugstores) for a variety of health issues, however, most often as a memory enhancer (to improve memory). "Some smaller studies for memory enhancement have had promising results, but a trial sponsored by the National Institute on Aging of more than 200 healthy adults over age 60 found that ginkgo taken for 6 weeks did not improve memory," as reported in a 2002 JAMA article.

SOURCES: Ohio State Horticulture Page, National Institute of Heath (NIH) Ginkgo Fact Sheet, The Ginkgo Pages.

Saturday, May 12, 2007

bad day at the fish farm

If I ever think I'm having a bad day at work, I will think of this story. Four workers in Turners Falls, Massachusetts fell into a 18-foot filtration tank filled with a mixture of sandy fish feces. The workers were standing on a pad, attached to the tank by a bracket, when the bracket broke, plunging them into the vat of fish waste. The men were rescued, treated and expected to be fine.

Turners Falls Fire Capt. David Dion comments, "It was very slimy and it was heavy," he said. "Never seen anything like it in my life."

The Australis Aquaculture fish farm in Turners Falls farms barramundi, a replacement for grouper. While we're on the topic, did you ever think of where your fish comes from? There are two types, wild and farm-raised. While fishing fish in the wild can quickly destroy ecosystems (think Happy Feet), farm-raised fish can cause similar havoc.

According to a 2002 article in Time Magazine, aquaculture (as opposed to agriculture) is already the world's fastest-growing food industry, with production increasing more than 10% a year. This is good because "about half the world's wild fisheries have been exhausted by overfishing. In the North Atlantic, one of the most depleted oceans, populations of popular fish are just one-sixth of what they were a century ago." Theoretically, when you eat farm-raised fish, you are saving a wild fish from being removed from the wild.

In fact, ecologists and economists warn that, at the current rate without any changes, the world will run out of seafood by 2048. According to the Washington Post, "the journal Science, concludes that overfishing, pollution and other environmental factors are wiping out important species around the globe, hampering the ocean's ability to produce seafood, filter nutrients and resist the spread of disease."

However, there are many critics of fish farming. According to that same Time article, Otto Langer, a biologist who worked 30 years for Canada's Department of Fisheries, says "a large salmon farm may pour as much liquid waste into the sea as a small city." Not only can fish farms contribute to polluting the waters, but they deplete the supply of wild fish in order to feed their farm-raised counterparts. This leads to some pretty unnatural stuff.

Because salmon are voracious eaters of smaller species, it takes several pounds of wild fish, ground up into meal, to yield 1 lb. of farmed salmon — an exchange that depletes the world supply of protein. The diet of farmed salmon lacks the small, pink-colored krill that their wild cousins eat, so the flesh of farmed fish is gray; a synthetic version of astaxanthin, a naturally occurring pigment, is added to the feed.
Also consider the effects of disease, parasites, severe overcrowding of fish, and the antibiotics (farmers give to protect their fish) leaking into the waters.. Also there are potential problems when farm-raised fish escape into the wild, interfering with the natural ecological balance of the area.

Shrimp are particularly damaging to the environment. Shrimp farms can actually raise the salinity of surrounding waters, and the waste run off can kill trees in area. Interestingly enough, Time has some praise for particular invertebrate farms.

On an eco-friendly scale, bivalves generally rate highest among the more than 220 species of fish and shellfish that are cultivated commercially. Mussels and oysters are filter-feeders that make the surrounding water cleaner, so small-scale farming of them is not usually harmful to the ecosystem.