How much are we damaging the oceans?
John - I sometimes wonder how great is the damage humans are causing to the oceans by discharging so many chemicals and excreted drugs into them?
Chris Smith asked Danni Green, a marine biologist, about John's question...
Danielle - Another Aussie. The Aussies are coming up with all the good questions here. This is something that is a big concern. So basically everything we put down the sink, so disinfectants, things that are in shampoos and soap, also pesticides and different chemicals from runoff can end up in the ocean. And it’s particularly an issue where they build up locally, so in coastal ecosystems and these chemicals can cause issues for organisms.
Some of them can act as endocrine disrupters so they can mess with the endocrine system and affect the way that hormones signal and the production of hormones and this can affect the organism’s growth rates, their ability to reproduce. It can also cause intersex which is when an animal has both male and female characteristics and this can occur in all sort of different animals - invertebrates like gastropods and crustaceans. Also vertebrates - fish and there’s evidence of it in mammals too.
So it is quite a huge problem and we are cracking down on a lot of these chemicals. So the pesticides, there’s strong regulation that has been brought in in 2016 for some of those. As far as detergents and things go, there’s still quite a bit of work to be done there I believe. But yeah, it is a concern.
Chris - Going back to the conversation we were having earlier about how long things like plastic do dwell in the environment though, many of these molecules are very long-lived. So even though we might put the kibosh on using them now, we may actually have a very long time before we see that they’re completely gone?
Danielle - Yeah. And the problem with some of the research as well is that you might not have strong enough evidence because in your laboratory experiment, you’re using high concentration which aren’t currently found in the natural ecosystem. But this should be treated as a risk assessment of what can happen in the future if we allow levels to keep building up. So yeah, the accumulation is a really important thing to remember.