A Teacher’s Perspective

We understand in concrete ways that the ocean is the lifeblood of Earth – and life itself. In Cayman, the threats to our oceans are compounded.  We see the real impact of these threats, but also the potential impacts we can make, ourselves, via the choices we make every day. We understand the need to educate ourselves and others about the potential of these impacts.

I’m a grade two teacher at Cayman International School. My students do a project based learning unit on the ocean exploring the question, “How are we connected to the sea?” Engaging students in the Grouper Moon Project each year is one of the many ways that I develop my students’ conceptual understandings about how we affect and are affected by our ocean. 

Joining the Grouper Moon Project as a team member this year was an absolute dream come true! It not only allowed me to experience the project by literally diving in with the thousands of Nassau grouper, but I was also able to engage my students and their families with the project. While I was on my expedition to Little Cayman with the Grouper Moon Project team, my students engaged in REEF’s Grouper Education Program. They learned about the food web and engaged in a game of food web jenga, viewed the PBS Changing Seas Grouper Moon documentary, went on a virtual ‘dive’ and completed their own diver interviews, made estimations of the Nassau grouper population and graphed their estimates on a class bar graph, discussed ocean issues such as overfishing and plastic pollution and played the board game ‘Grouper Race for Survival’, and also played an exciting game of ‘Tag the Grouper.’ You can find links to all of these resources below. Additionally, students were able to send questions that they had to me, and I was able to send videos to them with the answers to their questions. 

The Grouper Moon Project is a Cayman success in every way. Because the island was quick to realize the impacts of overfishing and protected both Nassau grouper and their spawning aggregation site, the Nassau grouper are recovering from the impacts of decades of overfishing. This is a direct result of people coming together, educating others, and making a difference. 

Throughout students’ engagement with the ocean project based learning unit, students complete individual research projects and work in teams to combine information, connect understandings and grow ideas. Students then use what they learn about ocean issues to advocate for them, inspire others, and make change.

Students’ curiosity always brings me joy, and to see them curious about the world around them and what is happening here in Cayman makes teaching and learning more engaging for the students and me!

Grouper Moon The Next Phase: A Guy Harvey Expedition

PBS Changing Seas Grouper Moon 

Grouper Race Gameboard Grouper Race For Survival Game

Grouper Race Gameboard


Diver Interviews

Tag the Grouper





Nassau Grouper Color Phases

Nassau groupers are typically seen in what is considered their ‘barred’ color phase. This phase is their non-spawning phase and consists of brown and white bands with blotches along the sides of the grouper. Each Nassau grouper has a pattern that is unique to only him or her, sort of like our fingerprints. This unique pattern is being used by researchers to photo identify the fish using AI software.

The day of spawning, the team noticed several things on the morning dive that were clues that  the spawning might start later that evening. They noticed that the female groupers bellies were swollen with eggs, and many more of the fish were in the bi-color or dark phase. There were very few fish in the normal or barred color phase.

Nassau Grouper Population and Diver Interviews

An important part of the dives and research is estimating the population of Nassau grouper at the spawning aggregation site. Both fish faces and video pan research methods are used for this, in addition to each team member’s estimates of the number of fish after each dive. After each dive, each diver completes a diver interview. The questions consist of where the fish were, what percent of each of the color phases the fish were in, what task the diver was assigned to, where the fish were located, what color phase the fish were in, what other species were noted, in addition to anything else the diver wishes to share about their dive. These interviews help the researchers to categorize footage, estimate the fish population, and record important anecdotal data about the dive. Attached is my video after Sunday evening’s exciting and very EPIC dive since it was the first night of the Nassau grouper spawning! 

If you’re a teacher reading, you can have your students watch a video of the spawning aggregation site on a ‘virtual dive’ and they can work in pairs to do their own ‘diver interviews’ to practice their speaking and listening skills.

Example diver interview for students.


In the Cayman Islands, long term surveying of shark populations to monitor Caribbean reef sharks is underway. Education about the critical role that sharks play in maintaining a healthy marine environment and the need for a healthy respect for sharks is key in changing public perception to a positive attitude. 

With the help of acoustic tags, baited remote underwater video (BRUV) surveys, diving surveys and satellite tags, the Department of Environment together with Marine Conservation International, supported by the Cayman Islands Brewery’s White Tip Shark Conservation Fund, have been studying, monitoring and working to protect local shark populations in the Cayman Islands since 2009. 

All sharks are protected species in the Cayman Islands. Their population is fragile and small, making their protection and research key elements for conservation. 

On the evenings of the Nassau grouper spawning, the Grouper Moon team was treated to several Caribbean reef shark sightings when they swam through the Nassau grouper aggregation spawning site, which was an exciting way to watch the food web in action with the incredible apex predators amongst the groupers.

Conservation Success

The Cayman Islands is home to the last known intact spawning aggregations of Nassau grouper in the world. The reason why is a conservation success story! 

Historically, thousands of Nassau grouper gathered in aggregations around the Caribbean to spawn during the January and February full moons. According to REEF, nearly 50 of these aggregation sites have been documented around the region, but due to overfishing, the majority of them are no longer viable. The last remaining site is on the west end of Little Cayman. So far, results have shown that banning fishing at these sites has a direct and positive effect on the Nassau grouper population. That’s why many scientists advise its continued protection. 

Because of the Cayman Islands’ conservation management, this particular spawning aggregation has been protected since 2003. Additionally since 2003, Reef Environmental Education Foundation (REEF) has partnered with the Cayman Islands Department of Environment to better understand and protect the spawning aggregation of Nassau grouper through the Grouper Moon Project. Through studying the Nassau grouper population size, fish lengths, juvenile habitats, genetics, and ocean currents, researchers continue to learn more about the Nassau grouper.

Protecting the Nassau grouper by imposing a fishing ban on the spawning aggregation ensures a healthy fish stock to keep fishermen in business for years to come, and supports a healthy ecosystem on the reef.

For more information on the project, visit https://www.reef.org/programs/grouper-moon-project

Keystone Species

A keystone species is a species that a large number of other species in an ecosystem depends on. If a keystone species is removed from a system, the species that it supported will also be impacted, as well as any other dependent species. Nassau grouper are a keystone species and influence both the structure of reef communities and promotes coral health. Unfortunately, it is estimated that 60 to 80% of Nassau grouper aggregations have been wiped out due to overfishing at the spawning aggregation site. Because Grouper don’t reach maturity until four to eight years of age, and juveniles are frequently predated upon, Nassau groupers’ population is slow to rebuild. This is why the protection of the remaining aggregation sites, like the largest known site in Little Cayman so important to the protection and recovery of the species. 

The Cayman Islands government has taken a series of management actions aimed at recovering collapsed stocks of Nassau grouper as a result of overfishing. The government partnered with academic and nonprofit organizations to establish a research and monitoring program (Grouper Moon) aimed at documenting the impacts of conservation action. Over the last 15 years, the Nassau grouper population on Little Cayman has more than tripled in response to conservation efforts. The findings demonstrate that spatial and seasonal fishing closures aimed at rebuilding aggregation-based fisheries can foster conservation success. From 1 December to 30 April there is a closed season for Nassau grouper in the Cayman Islands. In May, the limit is 5 per person or 5 per boat per day, whichever is less. Additionally, once the fishing season begins in May, only Nassau grouper between 16″ and 24″ can be taken, and only with a hook and line.



Sunday evening marked the first evening that we observed the Nassau grouper spawning at the aggregation site! It was an incredible site to witness. The groupers would shoot upward into the water column as they were spawning, like fireworks.  As the female went up into the water column swimming to release her eggs, several male groupers would follow, swimming in spirals around her. We also had several Caribbean reef sharks swim through the Nassau grouper aggregation site, which was an exciting way to watch the food web in action with the incredible apex predators amongst the groupers.

The day of spawning, we noticed several things on the morning dive that were clues the spawning might  start later that evening. We noticed that the female groupers bellies were swollen with eggs, and many more of the fish were in the bi-color or dark phase. There were very few fish in the normal or barred color phase. We also noticed changes in the current and the presence of other fish that we don’t typically see on the reef either. For example, two of the divers saw a school of blackfin tuna near the surface! This species is typically found far offshore in the blue ocean, not on the reef. Researchers think that the Nassau grouper possibly chose this particular spot off Little Cayman because the currents tend to push inward and down, to possibly keep the Nassau grouper eggs close to their home reef in Little Cayman, instead of using the currents to get some place else, like sea turtle hatchlings do. The researchers have special scientific instruments near the aggregation site to measure the currents and how the currents change. There are many questions about the Nassau grouper that the Grouper Moon Project team have and are researching. This is yet another reason why it’s important to stay curious and always ask questions about the world around you. Do you have any questions for the Grouper Moon Project team? If so, post them as a comment on the blog, and the team will try to answer them for you.



Plastic Pollution

Today at the Nassau grouper spawning aggregation site, we sadly found a large plastic bag floating in the ocean. Paul Chin from the Grouper Moon Team was able to remove the bag from the ocean.

Plastic pollution is an ever growing problem around the world. Seeing large plastic bags like this in the ocean is devastating as sea turtles, fish, or other marine life could easily become entangled or ingest the plastic.

It is estimated that eight million tons of plastic enters our ocean every year, which is in addition to the estimated 5.25 trillion pieces of plastic already in the ocean.

You can help to reduce plastic pollution in our oceans by refusing items that come in single-use plastic packaging, recycling, participating in beach cleanups, and educating others about plastic pollution. Together, we can make a difference.