What is the impact of glass on our oceans?

Seaside Scavenge organized another beach clean up last weekend, this time in Coogee. As usual, there was plenty of plastic laying around, with the main culprits being lollipop sticks, straws and candy wrappers.

However, there was one item that really stood out; one I had never noticed before. 

Glass Collected at the Beach
Glass collected at Coogee Beach

I took this picture with my phone and made it pretty with Instagram but that really doesn’t change the fact that this glass did not belong in the ocean. There’s probably a kilo or two worth of glass in there and that’s only half of what we caught.

Here’s the thing though: I can’t tell exactly how nefarious it is for the oceans. I’ve researched it online and I couldn’t find any scientific studies on the impact of glass in marine live. So here’s what I’m thinking…:

  1. Before they had that beautiful round shape, those fragments were more than likely sharp. If they were sharp, then there’s no telling what kind of damage they might have caused to marine life (or humans for that matter).
  2. Most of those pieces were clearly from bottles which begs the question: what happened to the remaining components of those bottles, i.e., plastic/metal bottle caps? So, even if glass per se is not particularly nefarious, the object it came from probably is. So the fact that that much glass was found is concerning since it hints at how much littering must have occurred for it to end up in there.
  3. This article suggests that 2 tonnes of CO2 are necessary to produce 1 tonne of glass. So the fact that all this glass ended up in the ocean means that tonnes and tonnes of CO2 were essentially wasted. It also suggests that an opportunity to recycle was missed.
  4. Littering (of any form or shape) is bad for the environment in ways that we cannot even calculate. Here’s an article that makes that very clear.

Based on the above, I think it’s safe to assume that glass ending up in the ocean is bad news. However, I can’t determine how bad glass in itself might be. It appears that it’s not as bad as plastic, nylon or aluminum though, which is kind of a silver lining (particularly considering how much of it we found at Coogee Beach).

Footnote: While researching for this post, I realized that there’s an entire community dedicated to collecting sea glass. You can even get an award for “Shard of the Year“! This tells me that clearly enough people have inquired about where all this glass comes from so there’s certainly some level of awareness there. As we know, awareness is the first step towards doing something about an issue.

Read some more of my stuff on climate change.