From The Archives: The Flea Circus

Jan 22, 2026 - 4 months ago

Chemist Marco Solinas and technician Ted Tunstall are the ringmasters for an aquatic circus of 1,000 trained fleas now performing at MacMillan Bloedel Research for scientific rather than entertainment purposes.

From the Archives: The Flea Circus — Technician Ted Tunstall, left, and chemist Marco Solinas check on “Daphne the Waterbug,” a millimeter-long water flea — one of 1,000 of the marine organisms being used in the experiments at MacMillan Bloedel’s research subsidiary.

The water fleas are a key ingredient in efforts by MacMillan Bloedel’s research subsidiary to develop faster, cheaper and more efficient methods of testing pulp mill effluent for toxic elements.

The researchers hope that if their experiments — known informally as “Project Daphne The Waterbug” — are successful, the water fleas could replace fish fry in standard toxicity tests at MB mills.

“We got involved in this work as part of our continuing research efforts which support pollution abatement programs at MB mills,” said Solinas.

“Although our results so far are at a very preliminary stage, there are good indications that we’ll be able to work out a program of effluent tests using the water fleas instead of fish fry.”

Other MB Research teams, he said, are already investigating several methods of eliminating toxic elements from various types of mill effluent. But the first step is to determine whether toxicity is present, and if so, in what quantity.

That’s where Daphne comes in. Her formal Latin title is daphnia pulex, but she’s more commonly known as the simple water flea, an aquatic organism about a millimeter in length that lives in most North American freshwater systems.

Solinas and Tunstall are using Daphne as a stand-in for the rainbow trout and coho salmon now used in government-approved biological water toxicity tests. Water fleas and freshwater fish are susceptible to similar toxic elements.

“Every time we try a new method of treating mill effluent we have to ensure that it is working,” said Solinas.

“To date the only practical way to do this has been by using fish fry. These tests are called fish bio-assay tests and they measure the effect on fish fry over a given period. The results are then compared with government toxicity standards.”

Emphasizing that the “Daphne” experiments have produced only preliminary results, Solinas said that bio-assays using water fleas are a lot quicker and easier to perform.

The researcher said he’s been using young water fleas, 12 to 24 hours old — to ensure they don’t die of old age or natural causes — as substitutes for the fish.

A female water flea has a two-month lifespan and produces young at the phenomenal rate of 20 to 30 every couple of days, which means there’s never any supply shortage at MB Research.

“The test itself is very simple. We just take a standard number of fleas, normally seven to ten, and put them in a test tube that contains the effluent we are studying, and after 24 hours we record how many fleas survive.”

At the same time, Solinas and Tunstall have been continuing the fish tests. By correlating the data they get from both sets of tests, they hope to work out an exact chart relating the effects of the effluent on fish and fleas.

“We’re still at an early stage, but there seems to be quite a definite trend — the more toxic the effluent to fish, the more toxic to daphnia. If we can perfect this test, we will use it in routine bio-assays for research purposes and possibly at our mills,” said the chemist.

The French government, he said, already uses water fleas as a method of checking water toxicity for several types of industrial effluent, although as far as he knows, MB is the first Canadian company to experiment with the organisms in relation to pulp mill effluent.

Solinas and Tunstall launched the project last year by reading all the available literature on water fleas, then ordered 1,000 fleas from a biological supply company. Care and feeding was the next order of business.

The fleas at MB Research now dine on what to them is a gourmet mixture of brewer’s yeast and horse manure. Solinas had to resort to some novel methods to keep his fleas fat and happy.

“Ted brings in the yeast from home,” said Solinas. “We get the manure from one of our maintenance people who has an acreage and a couple of horses.”

Solinas added that Daphne the Waterbug is “quite an unusual organism” from a biological standpoint. She reproduces without benefit of male participation if conditions are good and the food supply is plentiful.

However, if things get crowded in the aquarium, she starts producing male offspring and reproduction takes place in a more conventional fashion.

This article first appeared 50 years ago in the February 1976 issue of The Supply Post.

Supply Post February 1976