The Resilience Hub & Portland Maine Permaculture Message Board › Fresh water snails okay in a backyard pond?

Fresh water snails okay in a backyard pond?

user 3022592
Portland, ME
Post #: 73
Dear All,

I'm eager to upload the photos from our Open House but am delayed a bit right now...

When I do you'll see that a sweet little girl, Kai, brought 2 frogs to our Open House. But when I saw that her plastic container held also two large fresh water snails I announced this fact out loud, joyfully.

One person, however, took me aside and suggested I look into this before adding the snails.

In talking it over with Pam our pond with waterfall designer, Pam thought at first they would be just fine, but then remembered that slugs are in the snail family too. And frogs eats slugs.

Yet Kai's mother said that the snails came as the frogs did, from Evergreen Cemetery's pond.

Pam also thought that when the snail multiply too much we could just remove them and they'd provide shells for our compost!! (But how would they die? Just from being removed from the water? Not sure I like this. )

Any ideas?

David S.
Washington, ME
Post #: 62

Be aware that introducing snails into your pond means you will likely introduce parasites like protozoans and flukes that could be unhealthy for fish and possibly frogs as well. They can be an intermediate host in a disease/parasite process of fish.

Lisa F.
Group Organizer
Portland, ME
Post #: 171
Elaine, my first instinct would be that it's OK to add the snails, especially if the whole specimen of water/frogs/snails came from a healthy pond (i.e. the snails didn't cause a problem there...most likely they won't cause a problem for you once your pond ecosystem finds its equilibrium). I'm also thinking that when introducing any new factor into a system (a pond into a hitherto dry yard, snails into a pond, etc.) there can be a few seasons until the system does find its own equilibrium. So, might you have a snail "bloom" for one season until the natural predators figure it out? Perhaps...

If the snails are not from a healthy pond and came from somewhere else, I would hesitate.

I also found this quote on a USDA web site: "You'll also need scavengers, such as aquatic snails and tadpoles, to help control algae".
user 3022592
Portland, ME
Post #: 74
Thank you both for your input, David and Lisa!

The tipping point for me, now that you underline it, Lisa, is that the snails came from the same pond the frogs did.

Pam herself had made the point I forgot to add which is repeated in the excellent nrcs article on backyard ponds, -- that snails eat algae. Pam thought too, as you noted, Lisa, they're likely to multiply or "bloom." But it'd be interesting to see what natural predators restore balance (rather than our having to scoop or scrap them out ourselves to add crushed shells to our compost pile which had me squeaming.

Since we learned today that the replacement solar pump (The first was defective) will not be shipped out until the week of Sept 16, I think I'll add those two snails tomorrow so they can eat up the algae.

So here goes, -- experiment!

Thanks both of you,
A former member
Post #: 18
Hi Elaine,
When I put in my tiny pond several years ago, a friend brought me fresh water clams and snails but neither made it thru the winter to the next season. (They may have gotten frozen as my pond is very small) To help control algae, I keep the plant cover ( lilies) around 75% of the surface area ( to decrease the light and nutrients available to algae), skim decaying plant debris periodically, try not to let nutrient-rich garden water seep into the pond and for the last two years, have used a sub-surface barley-straw device that supposedly releases substances that kills the algae (but not wildlife) as the barley decays. I haven't seen that it really makes a difference tho and my pond always has algae. In the spring, there's always a seasonal algae bloom that turns the water a pea-green but then it clears somewhat but never entirely. My fish do well tho and my pets prefer the pond to their water bowl. It will take a season for your pond to develop its ecology and settle. A solar pump is on my wish list so I'll be interested in how yours does.

Hope this helps,
A former member
Post #: 59
A word about frogs. This spring when I cleaned my pond out there were perhaps 20 dead frogs, some small and some I'd guess 2 years old. The large gold fish did survive, so there must have been water that did not freeze. I can only guess that they tried to burrow into the muck at the bottom but it was not deep enough to be cold enough? Two frogs did survive, one large and one small. The larger one stayed in the pond all summer and I was glad to have him as no new ones came this year.

My water lilies had eight blooms this year! Winnie brought me some water hyacinth and it bloomed twice--the blooms were just beautiful. I am going to try to overwinter it inside in a bright window.
Powered by mvnForum

Our Sponsors

People in this
Meetup are also in:

Sign up

Meetup members, Log in

By clicking "Sign up" or "Sign up using Facebook", you confirm that you accept our Terms of Service & Privacy Policy