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  • Writer's pictureMMRP

A trash day on the water...

Updated: Apr 22, 2022

Standing on the beautiful beaches of O`ahu, you could easily be forgiven for thinking the ocean is pristine. The crystal clear waters go literally as far as the eye can see, and the blue is a particular color that I’ve never seen anywhere else – even after many years working at sea.

Before long though, you start to notice the tell-tale signs of human habitation floating on top of the water. Drinks bottles… beach shoes… balloons…. pool noodles... all the usual suspects, lost to the waves. When we’re out on fieldwork, of course, we pick these up when we are able to, but it’s not possible to get everything. What we see at the surface also, I’m sure, represents a very small proportion of the trash that’s actually present.

We had a stark reminder of the consequences of this pollution on one of our dolphin surveys recently. Our field team saw a mother-calf pair of spinner dolphins making their way northwards along the coast. It’s unusual to only see two animals of this species on their own anyway, and as we got closer to take identification photographs, we noticed that the adult animal had something stuck on her rostrum. It's hard to see exactly what this might be, but it looks like a plastic or metal ring of some kind. Unfortunately, it is lodged in such a way that it would be almost impossible for her to open her mouth. If she’s unable to dislodge it – there’s a high chance both her and her calf will starve.

Photos were taken under NOAA Research Permit 21476 by dolphin volunteer, Ava Sergio (top) and MMRP's Brijonnay Madrigal (below).

When bowriding, the trash stuck on the rostrum of this dolphin is clearly visible. Whilst it looks loose from above, the side view shows it is wedged tight.

It's always hard when you encounter an animal in distress, and doubly so when it’s an animal coming from a population that you have spent months getting to know. Our photo-identification initiative is all about recognizing individuals when we see them repeatedly over time; getting to know them - where they go, who they hang out with, whether they have calves. Over time we learn more and more about them as individuals and in long studied populations, individual life histories can be known in great detail.

We were unable to assist her on this occasion, having neither the permits, expertise or equipment on our research boat to enact a rescue. We notified the stranding response teams, and people have been keeping an eye out for them. I’m hoping we resight her again soon, and she’s managed to get free of the trash. We’ve done a couple of surveys in the area since, with no sign so far – but it’s possible she’s just moved somewhere else. Let’s hope so!

This dolphin was seen near the Ko Olina resort – so if you see this one, or indeed any other marine mammal in distress – check out this link for more information on how to report your findings

And remember folks… discard your fishing lines appropriately, and it goes without saying, but please don’t litter!



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