Would you like to support local journalism?

(with some quirky flair)

Regular News FEEDINGS via social + online. by locals for locals

HomeNewsManly algal boom turns sea red- tonight it could be bio blue

Manly algal boom turns sea red- tonight it could be bio blue

Are you looking for this more recent story? Manly bioluminescence returns, sprawls magic across the region

An algal bloom has turned the water red down at Shelly this morning, which could signal bioluminescence for this evening.

The the algae caused a vibrant blue bioluminescence already before sunrise this morning, similar that pictured by Jarvis Liu in Palm Beach earlier in the week, so it could return when night falls.

Shelly Beach today. Photo: @petaquirk

This is not entirely uncommon and is not a pollution event.

It is likely Noctilluca Scintilla or sea sparkle or sea twinkle, a red algae.

Algal blooms occur in response to changes in temperature or rain or nutrients in the water. They are little organisms, so while not toxic to humans it can cause a bit of skin irritation.

Bioluminescence at Palm Beach in August 2023. Photo: Jarvis Liu @jarvisliu559

We last reported on a similar event in 2021, which explains the phenomenon in detail.


Support quality local news

Manly Observer is an experiment in providing non-sensationalist hyperlocal news on Sydney’s Northern Beaches. We cover the big news across the LGA, but with a hyper focus on the Manly electorate encompassing Balgowlah, Seaforth, Freshwater, Brookvale and Curl Curl up to Dee Why. It is run by those living in the community for the benefit of an informed community. We care about an informed and connected community. That’s it. Simple. Thank you for your support in keeping quality local news alive!

Kim Smee, Editor

Become a supporter