Keeping Your Pond Alive

The water in your garden pond is very sensitive to change. Depending on a number of factors, a pond can soon go from crystal clear to pea soup without any apparent explanation. You will quickly learn that pond pollutants can hide in the clearest water.

frog in a pond


An easy first step to ensuring a healthy pond environment is the use of a good filter and you should contact a specialist retailer, like Swell UK, who can advise you on the best solution. Biological filters will break down harmful toxins, like ammonia from fish waste, so they can be either removed or absorbed by the plant life in your pond. A UV filter will also help keep green water and algae at bay and keep down the levels of bacteria that could be harmful to the life in your pond.

A good water balance

High nitrate or pH levels in your pond can bring about the most common pond problem: algae. Algae can cause havoc in ponds, keeping light and oxygen from the plants and animals that need them. Regular testing should be carried out to keep on top of the environment in the water before an algae problem breaks out. You can pick up kits for any potential problem from online stores like Swell UK. These give you the all important heads-up you need to take action.

A key part of maintaining the right water balance is ensuring you use a good liner that will not only resist damage but ensure any outside nitrate sources, like fertilizer, are prevented from seeping through.


Oxygen plays a vital role in ensuring the good health of your pond. Without oxygen, certain bacteria found towards the bottom of ponds will begin to produce acids and toxins that will harm the fish, insects and helpful bacteria that may live in your pond. By planting particular oxygenating plants, you can create a natural balance of oxygen levels, but only during the day. By making use of an air pump or any water feature that will disturb the water surface, you can maintain a good oxygen level throughout the day, protecting the well being of your pond.


Pobblebonk Frogs in Australia

Rosemary Horton from Australia likes to keep Frogs Are Green readers up to date with her efforts to save frogs.

The photos below were taken with an ordinary digital camera through the lens of a school microscope, and shows the eggs and development of Pobblebonk Frogs (Limnodynastes dumerilii) to where she is ready to return them to suitable unpolluted areas.

Pobblebonk frog eggs Australia
Pobblebonk frog eggs Australia
Pobblebonk frog eggs Australia
Pobblebonk frog eggs Australia
Pobblebonk frog eggs Australia
Pobblebonk frogs Australia

About Pobblebonk Frogs from Wikipedia.org:

Limnodynastes dumerilii is a frog species from the family Myobatrachidae. The informal names for this species, and its subspecies, include Eastern or Southern Banjo Frog, and Bull frog. The frog is also called the pobblebonk after its distinctive “bonk” call, which is likened to a banjo string being plucked. It is native to eastern Australia and has been introduced to New Zealand. There are five subspecies of L. dumerilii, each with different skin coloration.


Rachel Carson's Legacy

Just this past week, I re-read Rachel Carson’s groundbreaking book Silent Spring. First published in 1962, Silent Spring was a wake-up call, warning people about the devastating effects of chemical pesticides on humans and on wildlife. The book spurred changes in laws affecting our air, land, and water.


My husband reminded me that when he was a boy in the pre-Silent Spring era, he and his friends chased the “Skeeter Truck” on summer days in his suburban Philadelphia neighborhood, breathing in clouds of DDT fumes. DDT has since been banned in this country, and obviously we’ve learned a lot since then. And yet we still don’t fully understand the effects of the various chemicals that are in the products we consume, eat, drink, and use on a regular basis.

A few days ago, New York Times columnist Nicholas Kristof wrote an op-ed piece, “It’s Time to Learn from the Frogs.” After watching Hedrick Smith’s Frontline show, “Poisoned Waters,” he became concerned about chemicals called endrocrine distruptors (you can watch the show online). These chemicals—widely used in agriculture, industry, and consumer products—have been connected to increases in frog deformities and might also be connected to the rise of abnormalities in newborn boys, particularly genital deformities.

If you go to Kristof’s blog, On the Ground, you can read over 200 comments about his op-ed piece (published June 27th). One of the commenters mentioned that the Rachel Carson Homestead is sponsoring a conference on September 25, 2009, to address this issue. If you click here, you can download from their website an informative 6-page PDF about endrocrine disruptors. I admit I was surprised to learn that a type called phthalates are found in plastics used for food and drink containers, plastic wraps, soft plastic children’s toys, shampoos, shower curtains, and nail polish—to name just to name a few. One would have to live in a plastic bubble to avoid them (or rather an organic non-plastic bubble). In a another post, I will explore the ways in which we can avoid at least some of these chemicals.

Carson’s legacy continues….

UPDATE:  A couple of days after I wrote this, I found out that Stephen Colbert interviewed Nicholas Kristof about this subject on June 27th. Here’s a link to the Colbert Nation where you can watch the episode.  I’m a big fan of Stephen Colbert. Here’s a fun fact you might not know: he once wanted to be a marine biologist.


Frogs: A Chorus of Colors

On Sunday Susan and I ventured into New York City to see Frogs: A Chorus of Colors at the American Museum of Natural History, a traveling exhibit from Clyde Peeling’s Reptiland. The exhibit features over 200 live frogs in recreated natural habitats, complete with rock ledges, live plants, and waterfalls.

If you live near NYC or need an excuse to visit the Big Apple, I highly recommend this exhibit. Most of the exhibits are eye level for even the youngest kids, who had fun trying to spot the well-camouflaged frogs. They can also push buttons to hear frog calls and view videos of frogs in action.

Here are a few things we learned:

  • The Cuban tree frog is probably the smallest frog at only 1/2 inch in length
  • The cane toad lays 35,000 eggs in a single string
  • The Australian water-holding frog digs in desert soils and can remain underground for years
  • The world’s biggest frog is the West African goliath at 15 inches and weighing 7 lbs, as much as a newborn infant.

We saw a leaf mimic frog, whose head resembles a curving brown leaf to help it hide in the leaves. We saw other frogs that blended in perfectly with the moss, rocks, and bark. We watched one miniature frog, about the size of a fingernail, leaping from leaf to leaf, finally leaping and sticking on the glass right in front of Susan’s nose.

The stars of the exhibit were the poison dart frogs. Their blue, yellow, and green jewel-like colors warn predators not to eat them. One type of poison dart frog can kill 20,000 mice or 10 people with its poison, which is excreted through the skin. As the label on this exhibit says, “Don’t kiss these frogs!”

Bumblebee poison dart frog copyright Taran Grant/AMNH

Bumblebee poison dart frog copyright Taran Grant/AMNH


What the Frogs Are Telling Us

In 1995, a teacher and her students in southern Minnesota discovered a pond full of frogs with deformities: some frogs with extra legs or eyes missing, others with extra eyes or missing limbs.

A Plague of Frogs by William Souder tells the story of what happened next as these deformed frogs were later found all over Minnesota, and in other parts of the US. The book is both an ecological detective story and a tale of scientific investigation. Were the deformities a natural occurrence or were they caused by toxins in the environment?

Ultimately Souder concludes that ecosystems are so complex and the organisms in them so interconnected that it is difficult for scientists to tease out the exact causes of these malformations. It’s likely, however, that the frogs were physically manifesting the unhealthiness of our environment.

As Souder writes:

So frogs are telling us a lot—so much, perhaps, that we cannot fully understand the message. Frogs are succumbing to parasites, to pesticides, to increases in ultraviolet radiation, to global warming. The earth is changing and the frogs are responding.


This book was written in 2000, before the chrytid fungus that is causing massive die-offs of amphibians became so widespread. I do think it’s worth a read, however, if only to remind us that we have to be careful what chemical and toxins we release into the environment because ultimately we don’t really know what the effects will be on wildlife—and on us. We need to listen to what the frogs are telling us.


The Coqui, Pride of Puerto Rico

June is traditionally the month of the Puerto Rican Day parade in New York City, and in other cities around the country, so it’s a good time to celebrate the unofficial symbol of Puerto Rico—the common coqui, a frog species endemic to Puerto Rico. If you click on the video below, you will hear the sound of this frog that makes a ko-kee noise. Imagine a chorus of these frogs.

A friend from Puerto Rico says he remembers being lulled to sleep by the calls of the coqui. After the birds quiet at dusk, the frogs start their night music and sing all night long. A recent exhibit at the Bronx Zoo about the coqui brought a record number of visitors, who no doubt also had memories of being serenaded to sleep by this tiny (one-inch long) tree frog. Only male coquis sing—both to fend off other males and establish their territory and to find a mate. Here’s more info about this beloved island amphibian, whose numbers are declining due to deforestation, among other reasons.