Will the Coral Spawn later next week January 2024?

It is always exciting watching and waiting to see when the Norfolk Island coral around our coastline and in the lagoon at Kingston will spawn. I have seen the spawning a few times in recent years and have attached images from Ball Bay, when the coral spawned late in December 2021. During the morning for 2021 spawning, many Norfolk Island locals smelt the smell in the air, the odour of the coral spawn was drifting around the coastal areas. The coral spawn odour is described like an oily fishy smell or fertiliser.

The coral spawn floats on the water and is a pinkish oily in appearance. I looked back at previous photos of the sightings and counted the days from the full moon, and I predicted that the Norfolk Island coral would spawn approximately 8 to 10 days after the December full moon. The last full moon was 27 December 2023, and I predict the next spawning dates will be around the 4, 5 or 6 January 2024, this is my guess for the Norfolk Island summer spawning.

I enjoy photographing the coral, and I have been monitoring the changes during December, watching closely to see if the coral is ready to spawn. These images from 2021 showed that the coral was preparing to spawn, and I have learnt that the pink tips showed the egg at the ends of the coral branches.

Research plates attached to blocks have been positioned in the lagoon and coastal areas in multi places, I have seen a few in Slaughter Bay. Please to not touch or move these as they are collecting important information about the Norfolk Island coral spawning and environmental conditions in the lagoons.

In the past few years, I have enjoyed following the coral spawning news of the Great Barrier Reef. The reports on television documentaries, have reported the events with stunning underwater images and also many marine experts talking about the wonderful annual event. The Norfolk Island coral reef appears to spawn about a month after the Great Barrier Reef.

I have learnt that the coral polyps simultaneously release their eggs and their sperm bundles, and they float to the surface as a mass event annually. I have been told that they look like underwater popcorn as the water fills with the coral spawn. As the coral spawn float on top of the water, eggs are fertilised as they drift the ocean and then settle onto the reefs or the sea floor and hopefully a new coral life begins for a new generation.

I also found this interesting read about the reproduction of coral reefs.

https://oceanservice.noaa.gov/facts/coral-spawning.html

Once a year, on cues from the lunar cycle and the water temperature, entire colonies of coral reefs simultaneously release their tiny eggs and sperm, called gametes, into the ocean. The phenomenon brings to mind an underwater blizzard with billions of colourful flakes cascading in white, yellow, red, and orange.

In ways that scientists still do not fully understand, mature corals release their gametes all at the same time. This synchrony is crucial, because the gametes of most coral species are viable for only a few hours. The “blizzard” makes it more likely that fertilization will occur.

The gametes, full of fatty substances called lipids, rise slowly to the ocean surface, where the process of fertilization begins.

When a coral egg and sperm join together as an embryo, they develop into a coral larva, called a planula. Planulae float in the ocean, some for days and some for weeks, before dropping to the ocean floor. Then, depending on seafloor conditions, the planulae may attach to the substrate and grow into a new coral colony at the slow rate of about .4 inches a year.

Nature is so amazing, we are so privileged to have the sheltered lagoon at Kingston filled with coral, fish and marine life. The Norfolk Island underwater world is wonderful to explore and for those who are not able to snorkel it is worth a trip out on the glass bottom boat, so you too can enjoy the beautiful underwater corals and beautiful fish.

Here are a few photos I have taken of the coral spawn at Ball Bay and the beautiful coral in the lagoon at Kingston. Please remember to look after the coral and marine environment. Do not touch or stand on the coral, look and enjoy, we are so privileged to have this amazing underwater world on our doorstep

Betty Matthews

29 December 2023