Coral Spawning Guide 2026

The Bahamas Coral Innovation Hub (BCIH) is a center for development, implementation, and dissemination of scalable coral restoration techniques to help counteract coral reef decline. The research facility, based at the Cape Eleuthera Institute, hosts a network of integrative people, such as coral scientists, conservation managers, local stakeholders, students, and educators from around the world. Located in South Eleuthera, The Bahamas, the Hub is a collaboration between the Perry Institute for Marine Science (PIMS), the Cape Eleuthera Institute (CEI), and The Nature Conservancy (TNC).

The Hub has been compiling coral spawning predictions for The Bahamas since 2020 based on past and current observations. The predictions have consistently proven accurate, pinpointing peak spawning dates for coral mass spawning events in the region.

This booklet showcases examples of key Caribbean coral species and has become a valuable resource for local scientists, grassroots nonprofits, dive organizations, and volunteers.

Our larval propagation work is made possible thanks to the contributions of SECORE International and Wageningen University & Research (Marine Animal Ecology)

WHY SUPPORTING CORAL RESTORATION MATTERS GROOVED BRAIN CORALS IN 5 YEARS

This coral thrived for decades and produced countless offspring but was lost within months

Massive spawning 2021

Heatwave: adults bleached

Massive mortality

2022

2023

2024

2025

2026

Sexually reared juvenile

Juveniles remain healthy during bleaching event

Stony Coral Tissue Loss Disease outbreak

Juveniles found on reefs, micro-fragmentation project started

Sexually reared corals thriving

Adults standing dead

This coral was sexually reared in 2021, survived a massive bleaching event and is thriving

In 2023 an extreme marine heatwave caused a massive bleaching event followed by disease outbreaks. Brain coral populations decreased dramatically; lots of parents didn’t make it, but their offspring did. At The Bahamas Coral Innovation Hub, we are assisting the new generation of corals using different propagation techniques like micro fragmentation to increase abundance and larval propagation for genetic diversity

MONITORING CORAL SPAWNING • Predictions are based on previous observations in The Bahamas • It is expected to observe spawning during the suggested times but there is no guarantee • It is recommended to dive on the highlighted dates, but spawning may occur the day before and/or after • Most of the species listed are hermaphroditic broadcast spawners, meaning their polyps release both egg and sperm contained in gamete bundles • Gonochoric species release either eggs or sperm

PLANNING MONITORING DIVES • Adjust personal watch and camera to the local time • Find a shallow area (Max. depth: 40 feet/12 meters) with high coral cover • Follow bottom times respecting nodecompression times and diving rules • Dive lights could attract worms and some jellyfish are more active at night, therefore it is highly recommended to be fully covered • It is possible to observe other reef creatures releasing gametes, such as soft corals, brittle stars, sea urchins and Christmas tree worms

GREAT STAR CORAL

(Montastraea cavernosa) 0-35 minutes after sunset

-Gonochoric spawner -Spawns right after sunset -First males release sperm and then females release eggs

BOULDER BRAIN CORAL

GROOVED BRAIN CORAL

(Diploria labyrinthiformis) 0-70 minutes before sunset -Hermaphroditic broadcast spawner -Spawning could be seen with daylight since happens before sunset -Butterflyfish and sergeant major aggregations can be used as a cue for spawning -Setting lasts a couple of seconds

(Colpophyllia natans) 30-60 minutes after sunset

-Hermaphroditic broadcast spawner -Large gamete bundles -Setting lasts a couple of seconds Highlighted dates when spawning is possible, likely or very likely Zone 1: Bimini, Grand Bahama, The Abacos, The Berry Islands, Andros, Nassau, Paradise Island Zone 2: Eleuthera, Harbour Island, The Exumas, Ragged Island, Long Island, Musha Cay, Cat Island, Conception Island, Rum Cay Zone 3: San Salvador, Acklins & Crooked Island, Mayaguana, Great Inagua Island, Little Inagua Island

ELKHORN CORAL

(Acropora palmata) 80-160 minutes after sunset

-Hermaphroditic broadcast spawner -Highly unpredictable species -Spawning peak has not been identified in The Bahamas -Setting time can last several minutes

STAGHORN CORAL

(Acropora cervicornis) 140-190 minutes after sunset -Hermaphroditic broadcast spawner -Highly unpredictable species -Spawning peak has not been identified in The Bahamas -Setting time can last several minutes Note: Both species are highly unpredictable, observations needed Highlighted dates when spawning is possible, likely or very likely Zone 1: Bimini, Grand Bahama, The Abacos, The Berry Islands, Andros, Nassau, Paradise Island Zone 2: Eleuthera, Harbour Island, The Exumas, Ragged Island, Long Island, Musha Cay, Cat Island, Conception Island, Rum Cay Zone 3: San Salvador, Acklins & Crooked Island, Mayaguana, Great Inagua Island, Little Inagua Island

SMOOTH FLOWER & GREAT STAR CORAL

(Eusmilia fastigiata & Montastraea cavernosa) 180-230 & 190-240 minutes after sunset -Gonochoric spawners -Hold eggs in tentacles for several minutes -Expose their tentacles at night

Highlighted dates when spawning is possible, likely or very likely Zone 1: Bimini, Grand Bahama, The Abacos, The Berry Islands, Andros, Nassau, Paradise Island Zone 2: Eleuthera, Harbour Island, The Exumas, Ragged Island, Long Island, Musha Cay, Cat Island, Conception Island, Rum Cay Zone 3: San Salvador, Acklins & Crooked Island, Mayaguana, Great Inagua Island, Little Inagua Island

SYMMETRICAL BRAIN, BLUSHING & SMOOTH STAR CORAL

(Pseudodiploria strigosa, Stephanocoenia intersepta & Solenastrea bournoni) 210-240 & 215-260 minutes after sunset Symmetrical Brain Coral: Hermaphroditic broadcast spawner, could spawn earlier at night Blushing & Smooth Star Coral: Gonochoric spawners

Highlighted dates when spawning is possible, likely or very likely Zone 1: Bimini, Grand Bahama, The Abacos, The Berry Islands, Andros, Nassau, Paradise Island Zone 2: Eleuthera, Harbour Island, The Exumas, Ragged Island, Long Island, Musha Cay, Cat Island, Conception Island, Rum Cay Zone 3: San Salvador, Acklins & Crooked Island, Mayaguana, Great Inagua Island, Little Inagua Island

LOBED & MOUNTAINOUS STAR CORAL

(Orbicella annularis & Orbicella faveolata) 220-310 minutes after sunset Lobed & Mountainour Star Coral: -Hermaphroditic broadcast spawners -Setting time lasts a couple of minutes

Highlighted dates when spawning is possible, likely or very likely Zone 1: Bimini, Grand Bahama, The Abacos, The Berry Islands, Andros, Nassau, Paradise Island Zone 2: Eleuthera, Harbour Island, The Exumas, Ragged Island, Long Island, Musha Cay, Cat Island, Conception Island, Rum Cay Zone 3: San Salvador, Acklins & Crooked Island, Mayaguana, Great Inagua Island, Little Inagua Island

OUR TEAM & COLLABORATORS Natalia Hurtado, M.Sc.

Research Faculty - Coral Program Lead (CEI) Bahamas Coral Innovation Hub Manager (PIMS) Ph.D. Candidate (Wageningen University) Natalia is a Colombian marine biologist who has been actively monitoring coral spawning since 2009. She has been involved with many coral projects in Colombia, The Netherlands, Bonaire, Curaçao, and Qatar. Now, she is applying her expertise to The Bahamas Coral Innovation Hub, based at the Cape Eleuthera Institute. She hopes to help rehabilitate threatened coral populations through sexual and asexual propagation to grow and research different coral species.

Silia Woodside, B.Sc.

Coral Programs Training Coordinator (CEI) Research Technician (PIMS) Silia was born and raised in The Bahamas and has always had a passion for the ocean. Based at The Bahamas Coral Innovation Hub at the Cape Eleuthera Institute, she contributes to coral restoration, research, outreach, and education efforts in South Eleuthera. Silia joined the team as an intern supported by The Nature Conservancy in 2019. She has since been promoted to Research Technician, then Research Assistant, and is now a full-time research scientist.

We invite readers to share their observations and pose any questions by reaching out to our lead scientist on site, Natalia Hurtado, via email: nataliahurtado@islandschool.org or nhurtado@perryinstiute.org.