Tag Archives: Bioluminesence

Whale Feeding Frenzy & Bioluminescent Sea Magic

And just like that, the first two months of the season have passed. We’ve had some incredible days filled with wildlife encounters, from whales to seals and sea birds along the rugged backdrop of the Tasman National Park. As one of our passengers says: ‘A little bit wild and a whole lot jaw-dropping’ (Narinda S. on Tripadvisor).

Whale mass feeding event on 4th October

Well over hundred Humpback Whales came together to feed within a 1km radius just out of Eaglehawk Neck on the Tasman Peninsula in October 2023.

Looking back at the last two months, two days really stood out. One was the mass feeding of well over hundred Humpback Whales not far off the coast of Eaglehawk Neck. The groups of whales were tight and they literally gorged themselves on krill that accumulated in the area. This was truely a once in a life-time experience for all passengers onboard.

We spoke to whale researcher Dr. Olaf Meynecke who is the Manager of the Whales and Climate Program about the mass feeding event:

“Mass feeding events of humpback whales have been reported from a number of places in recent years. Humpback whales in general either feed on fish or krill solitary or in small groups of a few individuals. Having hundreds of humpback whales feeding closely together is not only very unusual but also a sign of change. Very likely an adaptation to deal with food shortages in traditional feeding grounds and taking the opportunity to share high density of food with a larger group of whales.

We are yet to understand the reasons behind this change in feeding patterns but we already know that it will need to be included in future conservation efforts. The recent event in Tasmania is likely one of the largest feeding aggregations of humpback whales we have been able to witness.”

Bioluminescence or sea sparkle in Pirates Bay

Bioluminescent sea sparkle in Pirates Bay, captured by Dolly Sun and Chaboo Wang @followustotassie. Note the pink hue in the ocean behind the waves.

Bioluminescent sea sparkle is a captivating natural phenomenon found in the open ocean, where certain types of marine organisms produce light through a chemical reaction within their bodies. This phenomenon primarily involves tiny, single-celled organisms called dinoflagellates and other bioluminescent creatures like some jellyfish, plankton, and certain species of fish. At night, these dinoflagellates emit a mesmerising blue-green light when they are disturbed or agitated.

Dinoflagellate bloom or ‘red tide’ during the day on our boat tour.

‘How to find the sea sparkle’ you may ask?

During the day, you may spot an unusual pink hue in the ocean. That is a good indicator of certain species of algae accumulating in high concentrations in the water. These algal blooms can discolour the water, often giving it a reddish or brownish tint. The recent algae bloom in November was pretty major as you can see in these images.

Dinoflagellate algae accumulating in the caves along the Tasman National Park in November 2023.

Environmental impact

While some red tides are harmless, others can produce toxins harmful to marine life and humans. Certain species of algae involved in red tides can release toxins into the water, which can have detrimental effects on fish, shellfish, marine mammals and birds. These toxins, when accumulated in shellfish, can cause illness or even death if consumed by humans.

Red tides can occur naturally due to various factors, including favourable environmental conditions such as warm water temperatures, sunlight, and nutrient-rich waters. However, human activities, such as nutrient pollution from agricultural runoff or other sources, can exacerbate and contribute to the frequency and intensity of these algal blooms.

Would you like to learn more about these natural phenomenons and see some Tasmanian marine life in their natural environment? Head over to our online booking platform and reserve your seat!