Oct 23, 20232 min read

Spawning Prediction Calendar 2023: Insights from Roatan and Guanaja

Updated: Dec 5, 2023

Broad Valleys Brain Coral (Colpophyllia natans – CNAT) spawning.

In August and September, particularly during the full moon of each month, we monitored Roatan Island to confirm the presence of additional species for our 2023 spawning prediction calendar. Over these two months, 14 days were dedicated to monitoring on Roatan Island, concurrently with monitoring on Guanaja Island. However, the tracking period on the latter island experienced some adjustments due to adverse weather conditions.

RMP teamed with the West Bay Divers Diving Center to monitor the Broad Valleys Brain Coral (Colpophyllia natans – CNAT) and Symmetrical Brain Coral (Pseudiploria strigosa – PSTR). The monitoring occurred from August 6 to 10, between 6:00 and 8:00 p.m., with approximately ten volunteers rotating daily. The CNAT and PSTR monitoring was conducted during days 5 to 9 following the full moon, with a possibility of spawning between days 6 and 8.

For the Elkhorn Coral (Acropora palmata – APAL), monitoring was carried out from August 1 to 7, running from 8:00 to 10:00 p.m., with the support of RMP volunteers. The APAL and ACER monitoring was executed in Guanaja from August 2 to 7 during the same hours. These species were monitored during days 0 to 6 following the full moon, with an expected spawning period of 3 to 6 days.

RMP Teams simultaneously monitored APAL species in both Roatan and Guanaja. During both August full moons, no APAL spawning events were observed. The elevated ocean temperatures could have disrupted the coral's usual spawning behavior. However, with the ACER species, successful spawning was observed in Guanaja during the first full moon of August, specifically on day six after the full moon (August 7). Subsequently, during the second full moon, spawning was witnessed in the RMP nursery on Roatán Island on the same day, seven days after the full moon (September 6), occurring between 8:35 pm to 8:48 pm. This achievement allowed us to include this species in our spawning prediction calendar.