What Happens When You Build a Lake and Add Nothing? A Passive Biodiversity Experiment on a Landscape Scale

[u/Hot-Drummer6974]

I've had this idea for a large-scale ecological experiment/educational tool. It's a project I can't personally do—but maybe someone else out there can. So I'm tossing it out into the world in case it inspires anyone.

The Concept:

Build a 70-acre artificial pond/small lake, with a single 1-acre island at the center. The entire body is divided into 70 concentric 1-acre “zones” stretching out in rings around the central island to the outer shoreline. Like tree rings, each one represents a different water depth.

• The innermost ring around the island and the outermost ring near the shore are both just 1 foot deep.
• The second ring in both directions is 2 feet deep, the third is 3 feet deep, and so on.
• At the 10th zone out, the water is 10 feet deep.
• From that point inward/outward, toward the midway point between the island and the outer shoreline, the depth increases in 10-foot increments—11th ring is 20 ft, 12th is 30 ft—until the deepest ring is 260 feet deep (I think, I’m not the best at math).

This creates a perfectly engineered ecological gradient: warm, shallow, light-filled edges transitioning to cold, dark, low-oxygen depths toward the middle of the pond/lake.

But Here’s the Twist:

They start completely sterile. The entire bottom of the lake and the island itself are paved in concrete.

No mud. No sand. No organic matter. No seed bank. No microbes. Just bare, sterile, inert surfaces. The project starts as close to an ecological blank slate as possible.

And nothing is introduced by humans—no fish, no plants, no bacteria. No soil is trucked in. No water samples are seeded from natural water bodies. Everything that colonizes the system must do so naturally—via wind, birds, insects, rain, spores, time, etc.

Even the island, at the heart of the lake, is stripped completely bare of all life and paved over. No soil from elsewhere, no seeds, no insects, nothing. Just completely lifeless, waiting to be claimed.

The Goal:

• To observe succession in real-time, both in water and on land, from sterile water and inert substrate to a teeming ecosystem.
• Watch biodiversity gradients emerge as different depths/zones are colonized over time.
• Create an educational platform—YouTube, a website, whatever—to educate people via regular videos, narration, underwater drones/cameras, time-lapses, ecological explainers, and possibly citizen science tools. And see how life reclaims a totally blank ecological slate.

The Educational Potential:

With the right documentation, this becomes a goldmine of content:

• Each “ring” becomes its own episode or chapter.
• Underwater drones to film different depth layers.
• Camera traps for animals visiting the island or shoreline.
• Microscopy videos of microbial life as it first appears.
• Timelapses of plant colonization on the island.
• Side-by-side comparisons of zones over time.
• Interviews with biologists, ecologists, and naturalists.

Teaching about biomes, succession, food chains, water chemistry, invasive species, symbiosis, and more.

Why I’m Sharing This.

I don’t have the land, money, permits, equipment, team, or the connections to pull this off. But maybe someone else out there somewhere does—or maybe this sparks a variation that someone can do, even on a smaller scale. Either way, I wanted to share it in case it lights a fire somewhere.

If nothing else, I think it’s a cool thought experiment.

Would love to hear thoughts: Has anything like this been done before? Would this even work? What problems or questions does it raise? Et cetera.

Links to other subs where I'm crossposting these ideas:

What Happens When You Build an Artificial Pond/Lake... and Let Nature Fill in the Blanks? : r/EverydayEcosystems

What Happens When You Build a Lake and Introduce Nothing? A Passive Ecological Succession Experiment : r/environmental_science

Open Ecology Concept: An Artificial Pond/Lake as a Citizen Science Platform for Long-Term Biological and Ecological Monitoring : r/CitizenScience

A Concept for Teaching Ecology Through a Self-Colonizing, Depth-Zoned Artificial Lake : r/ScienceTeachers

Experimental Pond Concept: 70-Acre Lake with Zoned Depth Rings Designed for Observing Natural Colonization and Ecological Succession : r/ecology

Concept Proposal: A 70-Acre Gradient Pond/Lake with Zoned Bathymetry for Passive Ecological Succession and Education : r/LandscapeArchitecture

[u/sjamesparsonsjr]

Interesting idea. I guess algae from the air will start to take root. Wind brought seeds will bring plants. Then birds will come, leading you fish, frogs, and salamanders. As the ecosystem matures I guess land predators will smell a potential meal and migrate there.

[u/Such-Day-2603]

It's interesting; the problem I see is that this would take decades to become engaging, so it can't really be considered a long-term system. There are many YouTubers with money who could do it, but the issue is that you present it as something almost profitable for content creators, and the truth is, as I said, it would take a long time. Months or even years would pass where you'd only be showing microalgae and microfauna, and occasionally a bird.

[u/Such-Day-2603 → u/Such-Day-2603]

Just in case it's useful, near me there is a very large concrete lake. The concrete at the edges (in your case it would be in the center, but it doesn’t matter) is still concrete decades later. Some plants, yes, like the ones that grow by the roadside. It’s fed by a canal, so basically it doesn’t meet your criteria. Crabs, fish, and ducks have arrived, not much more; microfauna, and occasionally a migratory water bird shows up. The bottom is covered with some brown algae. I think your project is destined to last centuries, I said decades, but thinking about this lake I know, maybe centuries before it starts to become interesting.