Stone walls and historical harbors are unexpected havens of biodiversity | Hacker News Reader

Stone walls and historical harbors are unexpected havens of biodiversity

hakaimagazine.com

61 pointsbenbreen23 comments

The common blenny is an inshore fish that can spend brief periods out of the water, where it waits to surprise unsuspecting scientists.

This article is delightful.

I clicked through to the video in the last paragraph about ancient clam gardens. The events of The Irish Potato Famine[1] have been on my mind in recent weeks and I don't really know where to go with this thought rattling around in my head. But I've been thinking that if the Irish had somehow supported clam digging for families in crisis due to the Potato Famine such that they didn't eat them raw and end up sick, that could have gone differently.

So it's interesting to see that clam gardens are being restored in my neck of the woods and that provides potential local food security to hedge against supply chain issues and other stresses in the world today.[2]

[1] https://news.ycombinator.com/item?id=36690467

[2] https://www.eopugetsound.org/magazine/climate-resilience-and...

Generally speaking the issue is scale.

Oysters are also currently being restored in New York. They had largely disappeared and one of the reasons was over-consumption; at one point there were a billion oysters being harvested per year. The current goal is to just get back to one billion at all. https://untappedcities.com/2022/08/04/history-new-york-oyste...

Oysters love organic pollution.

Pipe some sewage into a bit of shallow sea with a rocky seafloor and in a matter of months you'll have a billion oysters.

The best oyster farms grow kinda close to sewage outlets...

The problem was that until recent decades, New York harbor was so full of pollution it was overwhelming the oysters. (19 million people's worth of sewage and runoff is a lot.)

A couple of large investments into waste treatment plants and now it is slowly getting back on its feet.

The Irish genocide happened because the British took their food and only left them with potatoes, which were suffering from a fungal disease. What makes you think the Empire would have let them keep their clams?

Because clams don't travel well in a world before refrigeration.

They can if they’re canned.

Ireland was very much an agrarian place at the time, with very little manufacturing or heavy industry. I'm not at all sure there would have been support for industrial-scale canning.

There were plenty of factories in nearby Manchester and Liverpool.

Both of which are in the middle of England which would have involved shipping shellfish to England before the invention of refrigeration. Oceanic travel on the fastest steam powered passenger vessels of the time maxed out at 13 knots or approximately 15 mph. Cargo ships are going to be slower many will be using sail so closer to 6 knots. Dublin to to Liverpool is about 191 miles by sea. So 31 hours away just counting transit how long are these warm clams good for?

> warm clams

Was it warm in the North Atlantic in the 1840s winters? Shellfish will keep for a few days to a week at refrigeration temperatures, 31 hours seems feasible at least several months a year in this hypothetical scenario.

Not to mention that, pre-refrigeration, they did literally ship ice around the world: https://crystalicela.com/how-ice-delivered-before-refrigerat....

American independence well predated canning.

I thought we were talking about the potato famine?

Oh, I thought it was a reference to the oysters from New York being claimed by the British.

Reminds me of the permaculture principle "use edges and value the marginal". https://permacultureprinciples.com/permaculture-principles/_...

We are far from the sea here, in the mountains of inland Portugal, but here too walls are unbelievable havens for biodiversity - old stone walls here will one one side harbour a plethora of mosses, liverworts, sedums and similar, and on the other, ferns and epiphytes. With them come inspect life, and animal and bird life. Every nook and cranny, a world of its own. Plenty of species I see growing from walls that I rarely if ever see elsewhere here.

While there’s plenty of bedrock exposed around here, even the most fractured shale can’t compare in nookiness to a nice stone wall.

How much life could the ocean support if we built it up with structures? I'm imagining huge underwater structures so creatures can build onto them. What's the bottleneck?

Some countries do sink old (stripped) ships to create artificial reefs, which house fish. The Florida Keys National Marine Sanctuary contains several. eg:

https://floridakeys.noaa.gov/shipwrecktrail/duane.html

A lot of artificial reefs had been tried before ranging from old train wagons to piles of concrete blocks or tied tires. Is been done on purpose since 70's at least.

They are super effective, but don't last. Either end buried in the sand, are displaced by the currents (creating a danger for ships) or disintegrate after a few years. To have a Titanic you need absence of changes and coastal areas are very dynamic, with all those tidal forces, storms and coastal currents

On the other hand, sand ecosystems are fragile and valuable also in its own way. Wouldn't have any sense to replace al soft bottoms by hard bottoms just because.

So it works, for a while, but is expensive, can block shrimp fisheries, and the trend is not so hot as it was.

Reminds of the scorpions living in a dock wall in Kent

https://www.bbc.co.uk/kent/content/articles/2009/07/09/scorp...

Can we just have a moment of appreciation for how clean that site was 14 years ago? No interstitials, no modal "SIGN UP FOR CONTENT! (YES PLEASE/MAYBE LATER)" popup, just simple text.

Any underwater stone will do it. If you go snorkeling, go where the stones are if you want to have sea life to see.

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