Hello Everyone!

Did you know that Nassau Grouper can talk to each other? Its true!

In 2017, Dr. Katherine Cameron, who was a student at SCRIPPS at the time, was working with hydrophones, which are underwater microphones, to collect the sounds, or vocalizations, the Nassau make. It turns out, grouper make a number of booms and grunting sounds!

Here is a picture of the hydrophone used to record the sounds the grouper make. It is called a Loggerhead DSG:

And here is a picture taken at the spawning aggregation site. On the left side of the photo, below the diver on the left, you can see a gray metal cylinder sitting on the ocean floor. That’s one of the two hydrophones we have at the SPAG. Can you find it?

Here are three sound files of different Nassau vocalizations recorded at the SPAG. Check it out and let me know what you think!

Go Grouper Moon!

Todd

As the population of Nassau Grouper has increased on Little Cayman, so has the number of sharks visiting the spawning aggregation site in hopes of an easy meal. Here is a picture taken a couple years ago of a Hammerhead Shark on the SPAG. Click on the link below to see a video of the Hammerhead!

Hammerhead Shark Blog – Large 540p

Here is picture of a Blacktip Reef Shark circling the spawning aggregation:

Speaking of sharks, during our last livestream, we talked about a Nassau Grouper we have seen multiple times on the aggregation who appears to have survived a shark attack. We call him Lucky. It is truly amazing that this fish not only survived a shark attack, but also continues to spawn on the aggregation!

Lucky is one tough Nassau!

Can you guess what other species of sharks we have seen on the spawning aggregation? Post your ideas in the comments below!

Go Grouper Moon!

It was so wonderful to see everyone on yesterday’s livestream!

One of the topics we discussed was how the Grouper Moon researchers count all those fish, which is no small task. One way that we are estimating the number of fish is by tagging a set number of grouper with brightly colored tags. Once the tags have been placed on the fish, divers start counting fish. Each time, a diver will count 50 fish and then make a notation of how many of those fish have tags on them. We have several divers out there counting those fish, three times a day, collecting as much data as possible. We can then estimate the total number of fish based on the number of tagged fish we count.  Dr. Lynn Waterhouse created this is graphic just for you to explain the math behind tagging Nassau Grouper:

Hello Everyone!

Nassau Grouper are truly a unique and beautiful fish. Something that really makes them stand out is their ability to change color. Much like an octopus, the Nassau Grouper can change their color in the blink of an eye. Grouper change their color for a number of reasons, such as camouflage. The Nassau can make itself lighter or darker to better blend in with its habitat.  Another purpose of its color changing behavior is for communication. The Nassau will often change its coloration when it encounters other Nassau, to let them know they see them. How cool is that?!

Here is a graphic showing the different color phases of the grouper:

Color Phases!

Hello Everyone,

It was so great to see you all at yesterday’s underwater live-stream. You had such wonderful and thoughtful questions! While we had planned to stream from the grouper’s spawning aggregation site (SPAG), at the last minute, we changed course and moved to Little Cayman’s world famous Bloody Bay Wall, because the Nassau do not appear to be at the SPAG. Typically, at this point during the Grouper Moon, we expect to see this:

Instead, this is what Grouper Moon researchers have been seeing over the last few days:

As you can see, the fish are not there. While I have heard a number of theories proposed by different researchers here on Little Cayman, it remains a mystery. What do you think is going on with those grouper?

During yesterday’s live-stream, Dr. Brice Semmens suggested the recent earthquake may have played a role in interrupting this year’s spawning. What do you think? If you have any ideas or theories, post them in the comments below and I will share them with the researchers and give you their feedback!

Hello everyone,

After 20 hours of travel and four different planes, I finally arrived on Little Cayman! Take a look at this video I took as we were landing!

As I arrived, a group of divers were already out diving at the SPAG (spawning aggregation site) collecting all sorts of data on the Nassau Grouper, which we will be sharing with you all on tomorrow’s live-stream! The weather conditions on Little are quite windy with 4-6 foot swells, which is keeping everyone in their toes. Luckily there has been very little current, which helps the scientists and researchers to collect their data. If all things go as planned, this will be us tomorrow!

Here are Christy and Brice Semmens talking to a classroom from the Nassau Grouper’s spawning site on Little Cayman.

Alright, I’m off to begin preparations for tomorrow’s live-stream! Remember, you can leave comments or questions on any of my blog posts and I will respond, so if you have questions, feel free to post them here!

Go Grouper Moon!

Todd

REEF Educator

Hello Grouper Moon Educators!

todd@reef.org

Cleaning stations are an incredible, natural phenomenon that occur on coral reefs. During its day to day life, a fish will build up parasites, dead skin, and mucus on it’s body. To clean themselves fish, like a Nassau grouper, will pull up to a cleaning station where smaller fish like gobies, wrasses, shrimp and other small marine life literally eat these parasites and dead skin off the body of a larger fish. It is a lot like a car wash! This is an amazing example of a mutualistic relationship where all species involved benefit. The larger fish gets cleaned while the smaller organisms get a meal. Cleaning stations can be found just about anywhere on a coral reef, but on the spawning aggregation, they are often found in and around large barrel sponges. Click on this link to see some video of a cleaning station that was taken just yesterday on Little Cayman: Cleaning Station

Hello Everyone!

Today, we had our first Grouper Education livestream! I want to thank all the classrooms that were able to join us. Your support and engagement are critical to the success the project. Especially, I would like to thank all the teachers for going the extra mile to make this happen. We all appreciate you so much! If you were unable to attend today’s livestream, you can view it anytime on REEF’s YouTube page. Today’s livestream highlighted a number of scientists working on the project and some incredible footage of the spawning aggregation here on Little. You can watch them here: Spawning Burst 1 Spawning Burst 2

Also, on today’s livestream, we talked a bit about sharks on the aggregation. We definitely see them out there and sometimes they’re able to get ahold of a Nassau, but these are some tough fish. Take a look at this grouper, affectionately known as Lucky, who clearly had a bite taken out of him in the past, but he healed and continues to show up on the aggregation each year! Amazing!

Lucky, the Nassau Grouper 

Remember to tune in for our second livestream tomorrow at 10:30am. Go Grouper Moon!

Hello Everyone!

Nassau Grouper are truly a unique and beautiful fish. Something that really makes them stand out is their ability to change color. Much like an octopus, the Nassau Grouper can change their color in the blink of an eye. Grouper change their color for a number of reasons, such as camouflage. The Nassau can make itself lighter or darker to better blend in with its habitat.  Another purpose of its color changing behavior is for communication. The Nassau will often change its coloration when it encounters other Nassau, to let them know they see them. How cool is that?!

Here is a graphic showing the different color phases of the grouper:

Color Phases!