WARMER OCEANS - WHAT DOES THIS MEAN?
Despite being an ocean swimmer who likes the water a little warmer, I am beginning to ask myself, should we all be getting concerned that unseasonably warm water can be catastrophically detrimental to the ocean environment we love?
Everyday, until just recently I would wake up to the post from the temperature guy (recently retired) at Manly giving the water temp for the day. He has measured the water for the last 4 years and written on a sea wall at Manly. August has always seen the coldest water temps until now. In August last year we saw a change - 19.7C on a Monday in August!!
And now its mid March and the water is still at 24.3C which is so warm and highly unusual. Something is not right!
It may feel a whole lot nicer for swimming but what consequences does water this warm have for the ocean and its inhabitants? This brings me to the crux of this blog…..the Algal Bloom that is currently wreaking havoc on the coastline of South Australia.
I was recently on the Fleurieu Peninsula, in South Australia, a unique destination about 40 minutes south of Adelaide. It’s a place I visit often and a place I like to swim. I will go in the water regardless of air and sea temperature and I always come out feeling invigorated and ready for the day ahead.
It normally looks like this....
My last visit, last year I couldn’t go in!
The beaches all along the coast are being impacted by an algal bloom. The bloom has been caused by three factors: nutrient-rich floodwaters from the 2022–23 River Murray floods, a cold-water upwelling that brought nutrients to the surface, and a prolonged marine heatwave since September 2024 which provided warm conditions for the algae to flourish. These events combined to create the ideal environment for the microalgae Karenia mikimotoi to form a large and harmful bloom.
This bloom is toxic to fish and other marine life and causes health issues like respiratory and eye irritations for humans. It covers the water and sand with a foamy white residue and breathing in the sea air can be enough to cause irritations. Although not fatal for humans, that we have seen so far, it is however decimating the marine life. The shorelines are covered in dead fish and sea creatures both large and small and marine experts have no way of fixing this issue or of knowing how long this bloom will be about.
Click below to see an ABC video report on the situation:
For me it’s personal, as swimming at the beaches of Port Willunga, Moana, and Aldinga, which I do for multiple weeks of the year, when I am visiting family, provides me with a peacefulness I don’t always get in Sydney, my home city. I swim everyday at Balmoral or Manly and there are hundreds of us all out there experiencing the awe of ocean and its inhabitants. In South Australia the beaches are quieter and I get that special time, feeling like I have the ocean all to myself. The sea is made just for me and the calm and energy it provides is all encompassing. I don’t need solitude like this always, as I am the first to say I love my swimming groups in Sydney but I do cherish my quiet South Australian visits to the beach.
Whilst checking out the beaches one morning to see if I could get in the ocean, I introduced myself to 2 local marine biologist surfers and questioned them on whether the state of the water was ok for swimming. I was hopeful they could tell me it was all ok. I found out that they were actually working with the Government team trying to find a solution to the problem. Unfortunately they had no good news for me as they said it was best to steer clear of the water and beaches. They also said that there doesn’t appear to be anything that can be done to get rid of the bloom and that it is just a waiting game to see if the ocean can manage to clean herself.
Even this guy below didn't want to hang out in the water...... he was hiding in the caves on Port Willunga beach.
All it seems I can do, is keep my fingers crossed that when I return to my beloved SA beaches, that the ocean has been cleansed and that hopefully the marine life has re-bounded. It’s high hopes I know and although this has been treated as a naturally occurring event it does however provide us with a lesson. The lesson is, that we need to ensure that whatever we are doing in our environment that we are not contributing to the ocean becoming warmer. Let’s be mindful of our interactions with the ocean and the environment we live in and take none of its beauty and bounty for granted.
Keep up to date on the Algal bloom through the official website.
or check out the latest report and controversy by watching a special report on Four Corners aired last night 17/3/26.
And for those of us swimmers in Sydney and the east coast of Australia, just remember with the abnormally warm sea temperatures that we have experienced over summer with Balmoral and Manly hovering at 24C, Byron hitting 26C and Noosa being as high as 28C, this "algal bloom" phenomena could rear its ugly head on our beaches too!! Also let's not forget the other issue we have experienced due to the warm waters on the east coast this summer - The over abundance of sharks has really impacted all of us who spend lots of time in the sea and we have watched many tragic events unfold recently.
So fingers crossed this overly warm water is an anomaly. Let's make sure we are not doing anything that is contributing to its presence.
Let's look after our oceans 🌊 and earth!🌍
Cathy 💙🐬🐟