Submitted by commenter blackbart
These snails are prolific. Theoretically one pair can become 8 to 10 billion individuals in their 5 to 7 year life span. Let these 8 billion continue for another half a generation and you could have a population of 16 quadrillion. Scary. Not only can they bury themselves when the climate isn’t right for them, they can do so for up to 6 months, and they can repair their shells from the inside. The GAS is likely the finest example on this planet of a species that can survive and multiply. Can we eradicate them? I doubt it however it has been shown that during the initial period of infestation the population increases dramatically and then begins to fall reaching a level of coexistence. How much time this takes I don’t know. I believe in Sri Lanka it was 50 years before it stabilized in most of the country.
Yes we have to use bait but as judiciously as possible. This poison, metaldehyde, does kill snails and slugs rather efficiently. The problem is that it is the leading cause of deaths among pets and it, the agonizing convulsions, is not a nice way to die. Furthermore other animals and birds in our habitat will ingest this poison and die. Last but not least metaldehyde will attract and kill all snails and slugs, not just the pest. These creatures are extremely useful to our planet as they break down rotting vegetation into soil. It has been postulated that mankind would not live long in a world devoid of snails.
As an aside, I dropped by the Min of Ag station the other day only to drive back out quickly when I read the sign, ‘No Pellets, Liquid Only’. I really didn’t mind. My first trip there was scary. They gave me 2 paper bags of pellets which they had repackaged on the premises. The air in the warehouse stank of the poison and an employee was busy sweeping up the contents of a spilled pallet. It was very obvious that these employees had not been trained to handle this poison. Metaldehyde is considered by the WHO as a moderately hazardous pesticide when ingested, slightly toxic by dermal absorption and highly toxic by inhalation. The US EPA classifies metaldehyde as a Restricted Use Pesticide because of its potential short-term and long term effects on wildlife. Metaldehyde is toxic to all organisms that ingest it, either directly or as a result of secondary poisoning from consuming poisoned prey. Long term repeated skin exposure can result in dermatitis in humans while prolonged eye exposure can cause conjunctivitis. The autopsy of a 2 ½ yearr old boy who lived for 33 hours after ingesting metaldehyde revealed areas of collapse and congestion in the lungs as well as cellular changes in the liver and kidneys.
A year and a half ago I ejected two Min of Ag employees from my land. Our old gardener had let them talk him into allowing them to spray the pellets on our property. They sprayed everywhere, walkways, on top of hedges, in piles. The directions state that distribution should be such that each pellet is within a 10 to 12 cm diameter.
We are not the first country to be infested. The GAS have been on a world tour since leaving east Africa two centuries ago. It was only a matter of time before they reached our shores. It has been found that hand collecting is the best way to do away with them however you then have to kill them. Immersion in salt water doesn’t work too well and the odor produced is not pleasant. One test found that there was an 85% survival rate after 48 hours of soaking. Burning works but stinks. Same for boiling. The surest method is to make sure that the shell is well broken. I propose that the Min of Ag distribute appropriately coloured and stenciled plastic bags that homeowners can put out with the garbage. At the dump they can easily be sorted out, run through a crusher and buried in a deep trench.
When to collect them. Don’t waste your time if it hasn’t rained for 2 or 3 days but if it rains off and on and is overcast much of the day the snails will be out foraging. During the rainy season you can usually go out at 5 p.m. and collect several hundred before 6:30 p.m. If you go out at 5 a.m. you will likely be able to collect 6 to 700 per hour through to 8 a.m. when you will no longer find enough to warrant the effort. I roam over 2 acres of land every morning and some evenings. My best day I collected 3,000. For the month of November my total was 42,000. Since then the dry season has yielded an average of 15,000 per month. This is exercise. I no longer feel a need to go to the gym and my back muscles have strengthened considerably.
As you collect these snails night after night you will begin to notice a pattern of where they are concentrated on your property and where their travel routes are. I keep a record of the numbers I collect by area. Then when I apply the bait I do so where it will be most effective. I also carry a spray bottle of liquid metaldehyde to use when I encounter a recently hatched nest of tiny ones. I also spray a little in the collector bags every so often as they fill up but I’d rather know that they were going to killed properly in a manner such as I have outlined above without the use of this toxin.
And while you’re collecting the live ones also collect the ones that have been killed by poison or natural causes. Their shells can hold a fair bit of water and provide a breeding ground for mosquitoes. Also they stink as they rot and attract flies.
Are they edible? Yes, and an excellent food source at that being, 15% protein and only 2% fat.
Can they carry parasites? As with most creatures yes they can, specifically something called rat lung disease which they get from eating rat feces. The US CDC website states that there have been no known deaths reported from rat lung disease and that the symptoms are akin to a mild flu. It further states that human beings can be infected with rat lung disease if they eat raw or undercooked snails. It cannot be had by handling the snails or after cooking them well. A survey was conducted in Barbados in 2004 and no rat lung disease was found. Lastly may I say that in countries where these snails did not become part of the food chain the infestation was far worse than where they were included in the diet.
Questions:
- Can Roberts figure out a way to use this excellent source of protein in their production of animal feed?
- Can Supercentre tell us how many cans of canned snails they sell, 8 oz for $9.79, in a year and if they would be prepared to offer locally canned snails instead?
- Could the Sanitation Dept. tell us if they could sort out bright orange plastic snail collection bags at the dump and crush and bury them properly?
- Could the Min of Ag please assure us that they are handing out complete and concise directions on the proper use of metaldehyde and the consequences of misusing it?
Sorry for being so long winded but we have a major and complex problem on our hands that isn’t going to go away too soon. There is a lot more information to be had in a book originally published in 1961 and now available for free on line. It is The Giant African Snail: A Problem in Economic Malacology and is the result of over a decade of toil and dedication by Mr. Albert R. Mead.
The blogmaster invites you to join the discussion.