Climate Change and Nassau Grouper Larvae

 

One of the members on the Grouper Moon Team is Janelle Layton. She is a masters student in Fisheries Science at Oregon State University and works with Dr. Scott Heppell. Her research focus is concentrated on the impacts of climate change on Nassau grouper by understanding differences in both morphological traits and gene expression. This research will help to predict what might happen to the Nassau grouper due to increasing ocean temperatures as a result of climate change.

Janelle has set up 6 large bins/tanks with sea water in her lab on Little Cayman. She is keeping the different tanks at various temperatures to represent the rising ocean temperatures that scientists are predicting over the next 100 years. The first set of tanks is at 27 ° C, the second is 29° C, and the third is 31° C. She also has control tanks that are set at 25 ° C. The first set of tanks at 27° C represents the current water temperature that we have been recording at the aggregation site. This is already an increase of 2°C from what the researchers first recorded when they began the Grouper Moon Project 20 years ago.

 

After the first evening of spawning on Friday evening, the Grouper Moon Team collected Nassau grouper eggs from four spawning females for Janelle’s research. Friday night the team divided the eggs across four different temperatures. Then we filtered out the unfertilized eggs first using a large funnel and then using pipettes. Every morning and evening we removed dead larvae from the tanks and preserved the dead larvae in RNA Later. The RNA Later is a solution that helps to preserve the genes and protein that a genetic lab will analyze further. The lab will gather data on the heat shock proteins in the larvae. 

Every evening, we also collected living larvae samples from the temperature bins to preserve in RNA Later and formalin. The formalin helps to preserve the structure of the larvae in their various stages of development. They analyzed the larvae for six days after the spawning.

Her hypothesis after examining the initial data is an increase in larvae mortality with increasing temperatures. At higher temperatures, the fish are using more energy to develop in high stress situations that they are possibly completely absorbing their yolk sac too quickly before they can form functional jaws. This causes the fish to be unable to feed themselves when they run out of their yolk sac. However, there is a lot of genetic variability so certain individuals could possibly  be more resilient to the increasing ocean temperatures than others. This is what Janelle expects to see, but we will have to wait for the lab results and her data analysis to find out for certain. 

What do you think will happen? Post your hypothesis in the comments section. 

 

Spawning!

Friday night marked the start of spawning for the Nassau grouper! 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. There were several Caribbean reef sharks swimming 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, the team noticed several things on the morning dive that were clues the spawning might  start later that evening. 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.

The Grouper Moon Team collected some eggs for  a research study being conducted by Janelle Layton and Dr. Scott Heppell from Oregon State University. The research focus is concentrated on the impacts of climate change on Nassau grouper by understanding differences in both morphological traits and gene expression. To collect the eggs, the team used bags to collect samples from various spawning females.

The spawning continued both Saturday and Sunday evenings making for an exciting weekend for both the groupers and the team!

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.

Is love in the water for the Nassau Grouper this Valentine’s Day?

This year is unique in that it is what Grouper Moon researchers consider a ‘Split Moon.’ This means the full moon falls in the middle of the month. The Grouper Moon team didn’t see any spawning activity during the January full moon, so we are anticipating spawning activity in the days after the February full moon.

The Grouper Moon Team made their way back to Little Cayman today so stay tuned for more updates from in the field and to see what the February full moon brings.

To learn more about the Grouper Moon Project, including links to documentaries, published papers, and the education program, visit www.REEF.org/groupermoonproject.

What do you think? Will the Grouper Moon team see the Nassau grouper spawning this week? Post your predications in the comments.

 

Climate Change and the Nassau Grouper

One of the members on the Grouper Moon Team this year is Janelle Layton. She is a masters student in Fisheries Science at Oregon State University and works with Dr. Scott Heppell. Her research focus is concentrated on the impacts of climate change on Nassau grouper by understanding differences in both morphological traits and gene expression.

This research will help to predict what might happen to the Nassau grouper due to increasing ocean temperatures as a result of climate change.

Earlier today, I got a tour of Janelle and Scott’s lab that has been set up in one of the bedrooms at our rental house on Little Cayman.

Janelle has set up 6 large bins/tanks with sea water. She is keeping the different tanks at various temperatures to represent the rising ocean temperatures that scientists are predicting over the next 100 years. The first set of tanks is at 27 ° C, the second is 29° C, and the third is 31° C. She also has control tanks that are set at 25 ° C. The first set of tanks at 27° C represents the current water temperature that we have been recording at the aggregation site. This is already an increase of 2°C from what the researchers first recorded when they began the Grouper Moon Project 20 years ago.

This evening we hope to collect some eggs from the spawning Nassau groupers! Janelle and Scott will then put the eggs in the various tanks and look at the impacts of the higher ocean temperatures on the larvae. They will examine the gene expression of heat shock proteins.

Stay tuned to see if we have spawning on this evening’s dive! Make your predictions on whether or not the team will see the Nassau grouper spawn in the comments.

Sharks!

Hammerhead Shark Video – Click Here

Yesterday at the Spawning Aggregation Site (SPAG) the team saw a hammerhead shark! This is the first documented sighting of a hammerhead at the SPAG in the 20 years that the Grouper Moon Project Team has been researching the site.

In the Cayman Islands, long term surveying of shark populations to monitor shark populations in 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 afternoon and evening dives each day, the Grouper Moon team has been treated to several Caribbean reef shark sightings in addition to the hammerhead sighting when they swam 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.

As an added treat, this morning while walking down the dock to the boat, we saw 4 blacktip sharks, 2 lemon sharks, and a juvenile Caribbean reef shark swimming around the dock as a divemaster was cleaning lionfish.

It’s always a highlight of the dive to see a shark and we have been very lucky so far this trip with 20 shark sightings total!

“Sharks are beautiful animals, and if you’re lucky enough to see lots of them, that means that you’re in a healthy ocean. You should be afraid if you are in the ocean and don’t see sharks.” – Dr. Sylvia Earle

 

 

REEF Volunteer Fish Survey Project

This morning on the Grouper Moon Project Livestream, Dr. Christy Pattengill-Semmens mentioned how you can get involved with Reef Environmental Education Foundation’s volunteer fish surveys. Here is some more information so that you can get involved in this exciting citizen science project.What is the REEF Volunteer Fish Survey Project?

Reef Environmental Education Foundation (REEF) protects marine life through education, service, and research. REEF facilitates programs that actively engage divers, snorkelers, and other marine enthusiasts in marine conservation. This is primarily accomplished through the Volunteer Fish Survey Project. Since its launch in 1993, this citizen science program has generated one of the largest marine life databases in the world. In 2020, the database surpassed 250,000 surveys conducted at almost 15,000 sites throughout the world’s oceans by over 16,000 volunteer divers and snorkelers worldwide.

With knowledge, training, and the opportunity to get involved, these marine citizen scientists make significant and ongoing contributions. REEF provides varied training opportunities to encourage wide participation, and has a comprehensive experience-rating system and QA/QC checks for data submission to ensure high quality data. The survey methodology was developed with support from The Nature Conservancy (TNC) and guidance by the Southeast Fisheries Science Center of the National Marine Fisheries Service (NMFS).

The project allows volunteer SCUBA divers and snorkelers to collect and report information on marine fish populations as well as selected invertebrate and algae species in temperate areas. To find out more about the REEF Invertebrate & Algae Monitoring Program, click here. The data are collected using a fun and easy standardized method, and are housed in a publicly-accessible database on REEF’s Website. These data are used by a variety of resource agencies and researchers.

How do I participate?

Anyone, anywhere can participate in the Volunteer Fish Survey Project. REEF volunteers use the Roving Diver Technique (RDT), a visual survey method specifically designed for volunteer data (see below). The only materials needed are an underwater slate and pencil, a good reference book, and access to the internet to submit the data online. REEF has developed several survey materials that make things easy, including pre-formated underwater paper and waterproof ID guides. These supplies, as well as slates, pencils, and training courses are available through REEF’s Online Store.

Check out the VFSP Survey Toolbox for a complete list of resources available to REEF surveyors in each of our ten regions.

Can I collect data while snorkeling or freediving?

Snorkelers and freedivers are valuable assets and can also conduct surveys. You do not have to be a scuba diver to conduct REEF surveys and collect important data.

If snorkeling is your thing, you can view much more information on doing surveys while snorkeling here.

If you’re into freediving, we’ve got some vital info and handy surveying tips for you here.Submitting your data

Following the dive, each surveyor transfers the information about their survey dive, including survey time, depth, temperature, and other environmental information, along with the species sightings data, to the REEF database. A separate survey submission is done for each dive.

Information is submitted one of two ways:

The location of the survey is recorded using the common dive site name and the REEF Geographic Zone Code. The Zone Codes are a hierarchical list of codes.

For instructions and more info, visit the Online Data Entry Tips and Info page.

Grouper Moon Team

The Grouper Moon team heading out for an evening dive on the spawning aggregation aboard the Sea Keeper. The Grouper Moon Project is a collaboration between REEF ( Reef Environmental Education Foundation) and the Cayman Islands Department of Environment with scientists and researchers from Scripps Institution of Oceanography, Oregon State University, and NOAA Sanctuaries.

Nassau grouper fish counts!

Yesterday the researchers tagged 150 Nassau grouper using a special tag called a Floy Tag. Each tag has a unique number on it and a colorful visible green tag that our team of divers can easily see underwater.Today I did a fish count survey which is used by the scientists to estimate the population of Nassau grouper. For a fish count survey, I had a clipboard with a piece of underwater paper to record the data.

To complete the survey, I swam alongside the group of Nassau grouper that were up in the water column. I counted each Nassau grouper that I saw, counting up to 50.  I would record any tagged fish that I saw  within the group of 50. I counted a total of 7 groups of 50 fish and counted only 2 tagged fish. This means that there are much more fish at the SPAG than we estimated since we didn’t see many of the 150 fish that we had tagged just yesterday! It left us wondering, where are our tagged fish friends that we saw just yesterday. What do you think? Post where you think the fish might be in the comments.

Nassau Grouper Talk!!

Hello Everyone!

It was so great to see you all today on the live stream! I hope you enjoyed it.

Today we talked about some of the different tools scientists are using observe and collect data about the Nassau Grouper.  A few years ago, a graduate student from SCRIPPS, Katherine Cameron, studied the sounds Grouper make when they are spawning. (Yes, they actually “talk” to each other!) Using hydrophones that were placed on the ocean floor, she collected the sounds, or vocalizations, the Nassau make. Below is a picture of hydrophone as well as three sound files of different Nassau vocalizations she has recorded. What do you think they’re saying?  Post your comments below!

 

Hydrophones were placed in several locations near the SPAG.

 

From some to many!

Hi, everyone!

Amanda here, joining the Grouper Moon Team in Little Cayman. 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.

Today was our first official day of diving and collecting research from the Spawning Aggregation (SPAG) Site in Little Cayman, it also marks the full moon! The full moon is what marks the beginning of the Nassau grouper migration from their homes on the coral reefs around Little Cayman to the SPAG for the spawning. Starting from today we will begin to see more and more Nassau grouper aggregate at the site. The incredible thing about this aggregation is that the Nassau grouper are usually a solitary fish. You don’t typically see them together…until the Grouper Moon!

Today the team did three dives – a morning, an afternoon, and an evening dive. What was most surprising about today’s dives was the increase in the number of Nassau grouper at the SPAG over the course of the day!

Here is a video from this morning’s dive. How many fish do you think there are? You can post your estimates in the comments. I’ll share the team’s estimates on the blog tomorrow!

This is a video from our evening dive! I was amazed to see how many more fish came to the SPAG over the course of the day! How many fish do you think were there by the end of the day?

Another exciting moment for our team was the we had our first shark sightings! On the boat ride out to the site this evening we saw three shark fins. We’re not sure of the species since we didn’t get a close enough look. Later, when we jumped in for our last dive of the day, we were greeted by a Caribbean reef shark! The shark cruised around us for the beginning of the dive. Seeing sharks on the dives is a sign of a healthy fish population and a healthy ocean, and always a special moment for our team of researchers!

Don’t forget to join our team for the Livestream from Little Cayman tomorrow morning at 10:30 am. You can join the Livestream from the REEF YouTube Channel. See you tomorrow! Special shout out to my Grade 2 students at Cayman International School, can’t wait to have you ‘join’ our team in Little Cayman!