Cauliflower coral not spawning

Cauliflower coral and arc-eye hawkfish

Cauliflower coral

Cauliflower coral was once a mainstay of reefs along the west coast of the Big Island, but has been in decline for a while. Then, in late 2015, high water temperatures caused a huge coral bleaching event, which resulted in a die-off of more than 90% of the area’s cauliflower coral. In some places, nothing was left. Because of this, the reproduction of surviving corals has become of increased importance.

Different corals have different methods of reproduction. Cauliflower coral reproduces in a synchronized spawning event. During this event, the corals release gametes (eggs and sperm) into the water, creating a milky cloud. For many corals, the spawning event takes place at night, but research indicates that cauliflower corals spawn shortly after sunrise, two or three days after the May full moon. At least, that’s what I was told.

Consequently, twice last week, I got up at an early hour in order to be in the water before 7 a.m. in the hope of witnessing a cauliflower coral spawning. Yes, that’s the kind of life-on-the-edge that I lead.

The first priority was to find some live cauliflower coral, easier said than done. There were a few patches in deeper water, but since visibility was not great, it would be almost impossible to tell if and when they spawned. After some finning around, I found a shallow spot with three small clumps and decided to pin my hopes on them. The live coral was part of a larger mass, part of which had died, as can be seen in the photos. Also to be seen in the photos are an arc-eye hawkfish (above), and two four-spot butterflyfish (second photo) among others. Corals are very important to fish stocks because many small fish, and the young of bigger fish, use the coral for protection, a place to hide when threatened.

What’s not to be seen in the photos is any evidence of spawning, because I didn’t see any. It was unlikely that I would. Conditions might not have been right for the coral or my timing could have been off. The May full moon is actually on the 29th so it might be that the spawning will be at the end of the month, not the beginning. I’ll try again then.

Posted in response to this week’s WordPress Photo Challenge ‘Unlikely.’

8 thoughts on “Cauliflower coral not spawning

  1. Pingback: Unlikely – Captain of the Ship | What's (in) the Picture?

    1. Graham Post author

      It really is. One positive lately is that the legislature has passed a law banning the use of sunscreens that have chemicals which kill coral. Hope there’s some left by the time it goes into effect.

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