Author: Christy Pattengill-Semmens, Ph.D., Co-Executive Director: Science & Engagement
So far in 2026, 10,657 surveys have been submitted to the REEF Volunteer Fish Survey Project (VFSP) by 780 volunteers at thousands of sites around the world. Every single survey makes a difference! The ongoing nature of the VFSP and its broad geographic coverage have helped make it one of the most impactful ocean citizen science programs in the world.
Since the beginning, these data have been made available to everyone. Anyone can query the database and generate summary reports on the REEF website. Our staff also facilitate access to raw data files for scientists, government agencies, and other groups to use in a wide array of studies and policies to better understand and protect the oceans. REEF data have contributed to more than 100 scientific publications! Visit this page to explore the full list.
Here are just a few highlights from recent scientific papers that demonstrate the incredible value of the data you collect:
Proving the Power of Citizen Science (2024)
How do REEF volunteer surveys compare to data collected by professional scientists? Researchers from Scripps Institution of Oceanography and REEF compared 25 years of REEF surveys with data from federally coordinated fish surveys at 60 sites off Key Largo, Florida. They found that the two datasets showed similar population trends for most of the 87 fish species studied. This research provides important scientific validation that REEF volunteers collect reliable data that can be used to track changes in marine ecosystems over time. Read the study.
Tracking Endangered Hammerhead Sharks (2024)
REEF data helped researchers investigate encouraging signs for two critically endangered shark species in the Cayman Islands. By combining REEF survey observations with other scientific data, researchers documented evidence that Scalloped Hammerheads (Sphyrna lewini) may be returning to waters where large schools had not been reported for decades. Great Hammerheads (Sphyrna mokarran) also appear to be becoming more common in the area. This study demonstrates how long-term sightings data can help scientists track changes in populations of threatened species. Read the study.
Informing Goliath Grouper Conservation (2023)
REEF surveys provide a valuable long-term perspective on Goliath Grouper (Epinephelus itajara) populations in Florida. A study published in Marine Policy examined the species’ recovery following decades of fishing restrictions and the conservation concerns surrounding Florida’s decision to reopen a limited fishery. The researchers identified the REEF database as the best available source of long-term information on adult Goliath Grouper in Florida. This is a powerful example of how your observations can contribute to discussions about fisheries management and protecting vulnerable species. Read the study.
Exploring New Ways to Monitor Marine Life (2026)
Could divers someday collect DNA samples while conducting their regular REEF surveys? A new study explored this possibility by attaching passive eDNA filters to REEF volunteer divers while they conducted fish surveys. Scientists compared the environmental DNA (eDNA) collected from seawater with the species recorded by divers. The results showed that eDNA can be a valuable complementary tool, particularly for detecting difficult-to-observe species, while visual surveys remain important for capturing detailed information about fish communities. This research demonstrates how the VFSP can help advance new marine monitoring technologies. Read the study.
Every Survey Matters!
These studies are just a small sample of the many ways REEF data are being used to advance marine science and conservation. Whether you’re surveying a familiar local dive site for the hundredth time or exploring somewhere new, the observations you record contribute to a growing body of knowledge about our oceans. And remember, documenting the common species is just as important as recording the rare ones! It’s the consistent observations, collected across many locations and over many years, that make the VFSP database such an extraordinary resource.
Thank you for being part of this incredible community of ocean citizen scientists. Keep diving, keep surveying, and keep making every fish count!
Author: Hilary Penner, Citizen Science Coordinator
The Error Checking team processes your surveys and, as you may know, emails you asking for a photo or description of a possibly questionable sighting. This two-step process ensures the accuracy of our database. Here are some common corrections the team comes across:
Remora, Sharksucker, and Whitefin Sharksucker
What people report: Remora (Remora remora). Divers and snorkelers often use “remora” as a general term for all fish that attach onto larger fish, but it is actually the family name for this group of fish. Actual Remoras tend to have a long yet robust body and an overall greyish-brown color, sometimes with some speckling. They are often associated with Giant Mantas (Mobula birostris) or Whale Sharks (Rhincodon typus) in pelagic waters.
What people most likely saw: Sharksucker (Echeneis naucrates). This is the most common of the three species. Sharksuckers are the fish most commonly seen on sea turtles, sharks, larger fish, and sometimes us! They have a long, slender gray body. Juveniles have two thin white borders on their dark tails.
What people most likely saw: Whitefin Sharksucker (Echeneis neucratoides). They have the same coloration and body shape as a Sharksucker, but with wide white borders on the dark tail. These borders tend to be a brilliant white.
These two can be tricky to distinguish if their tails are folded. A photo or close observation will help you tell them apart.
Fairy Basslet and Spanish Hogfish
What people report: Fairy Basslet (Gramma loreto) in Florida or the Florida Keys. This region is outside the geographic range of the Fairy Basslet.
What people most likely saw: Spanish Hogfish (Bodianus rufus), juvenile. While young, these fish act as cleaners on the reef and have very distinct half purple, half golden-yellow bodies, just like the Fairy Basslet.
Neon Goby, Caribbean Neon Goby, and Sharknose Goby
What people report: Neon Goby (Elacatinus oceanops) outside of Florida. The Neon Goby is found from Georgia to Florida and in the Gulf of Mexico. This fish has a dark, elongated body with an iridescent blue stripe along its side that runs to just past its eye.
What people most likely saw: Caribbean Neon Goby (Elacatinus lobeli). Found in Belize and Honduras, this species has a dark, elongated body with an iridescent blue stripe topped by a thin gray stripe. These run along its side to just past its eye. Both of these gobies share similar habitats on coral heads and the outside of large sponges.
What people most likely saw: Sharknose Goby (Elacatinus evelynae). Outside of Belize, Honduras, and Florida, this species is often reported as a Neon Goby, or vice versa. The Sharknose Goby has a white to yellow “V” on its nose that continues in bright blue down the side of its elongated body.
Cleaner and sponge gobies have very specific geographic ranges. See the REEF Goby Guide for locations.
Author: Hilary Penner, Citizen Science Coordinator
Since 2001, REEF has been counting sea turtles on surveys through a partnership with Seaturtle.org. It’s always fun to see these reptilian friends underwater. Sometimes close up and sometimes in the distance, they can be easy to identify or pose a real challenge. Hopefully, these tips will help if you see one close up munching on sponges, or as a shadowy shape in the distance on your safety stop. The most commonly reported sea turtles are:
Loggerhead (Caretta caretta): Look for the BIG head that allegedly drunken sailors thought was a floating log. Its shell is a uniform reddish brown. Range: All REEF regions.
Green (Chelonia mydas): Look for a small to proportionately sized head relative to its body. Its shell has radiating streaks of brown. Greens have two prefrontal scales between their eyes. Range: All REEF regions.
Hawksbill (Eretmochelys imbricata): Look for the hooked, hawk-like beak. If you can’t see its head, look for a shell with flecks of amber, black, and gold (true tortoiseshell). Juveniles have serrated edges on their shells. Hawksbills have four prefrontal scales between their eyes. Range: All REEF regions.
Kemp’s Ridley (Lepidochelys kempii): A wide, rounded shell with wide scutes. Body and shell are grey overall. Range: TWA, SAS.
Olive Ridley (Lepidochelys olivacea): A heart-shaped shell with wide scutes. Body and shell are olive in color. Range: IORS, SIP, CIP, TWA.
Visit this page for a handy identification guide and more information. When in doubt, snap a photo! You can also report them as Unidentified Sea Turtle on your survey.
Author: Stacey Henderson, Field Survey Trips Program Manager
Are you looking for your next adventure? Our 2027 REEF Field Survey Trips schedule still has spaces available, along with a few trips in 2028 and 2029. REEF Trips are led by marine life experts and include diving, fish ID classes, and fun with friends. Divers, snorkelers, and families are welcome on REEF Trips. To find out more or book your space, email trips@REEF.org. We'll send you an invoice to submit a deposit to secure your space.
For individual trip details and more info, visit the links below or check out www.REEF.org/trips. REEF Trips fill up fast, so don’t wait to grab a spot on your favorite destination.
-2027-
January 17-27 – Palau – Aggressor – Led by Mead Krowka - Click here for trip details - Waitlist
February 20-27 – St Vincent – Dive St. Vincent - Hilary Penner - Click here for trip details - Waitlist
April 3-10 - Colombia - Oceano Scuba – Sierra Barkdoll - Click here for trip details - Waitlist
April 7-17 – Solomon Islands – Bilikiki – Stacey Henderson - Click here for trip details - Spaces Available
May 1-8 – Saba – Sea Saba – Noa Parks - Click here for trip details- Spaces Available
May 11-23 - Socorro/Clarion – Mexico Liveaboards – Stacey Henderson - Click here for trip details- Spaces Available
June 26 – July 3 – Roatan – Coco View - Martha Klitzkie and Rose Kelly - Click here for trip details- Spaces Available
July 17-24 – Costa Rica – Bill Beards – Stacey Henderson - Click here for trip details- Spaces Available
August 21-31 – Madagascar – Deep Blue Adventures - Led by Christy Semmens Ph.D and Brice Semmens, Ph. D - Click here for trip details - Waitlist
September 11-18 – Cyprus - Undersea World – Mead Krowka - Click here for trip details- Spaces Available
September 25 – October 4 – Philippines - Buceo Anilao Beach and Dive Resort – Hilary Penner - Click here for trip details- Spaces Available
October 23-30 - Grand Cayman – Sunset House – Shelby Thomas - Click here for trip details- Spaces Available
November 4-18 - Australia – Spirit of Freedom - Christy Semmens Ph.D. and Brice Semmens, Ph. D. - Click here for trip details - Waitlist
December 4-11 - Cozumel – Chili Charters – Tracey - Click here for trip details- Spaces Available
-2028-
March 18-29 – Indonesia - Dewi Nusantara – Stacey Henderson - Click here for trip details - Waitlist
July 11-21 – Best of Borneo – Arenui - Christy Semmens Ph.D. and Brice Semmens, Ph. D - Click here for trip details - Waitlist
September 10-22 – Explore Baja – Rocio del Mar - Christy Semmens Ph.D. and Brice Semmens, Ph. D - Click here for trip details- Spaces Available
-2029-
April 14-25 - Indonesia - Damai I - REEF Staff - Click here for trip details - Waitlist
Author: Janna Nichols, REEF Citizen Science Program Manager
In temperate (colder) water regions, REEF asks surveyors to also monitor a select regional list of invertebrates and algae. This is in addition to monitoring all fish seen during a survey.
- PNW: Pacific Northwest & Alaska
- CAL: California
- NE: Northeast US & Eastern Canada
- SAS: South Atlantic States
- EAM: Eastern Atlantic & Mediterranean
In these regions, surveyors have the option to conduct a Fish Only (FO) survey, an Invertebrates Only (IO) survey, or a Fish and Invertebrates (FI) survey.
When monitoring invertebrates (and algae), record every species observed from the regional list shown on the underwater paper and color ID card. Leaving an invertebrate or algae species unrecorded indicates it was not seen. You can find a list of what is monitored in each temperate region here.
Surveyors at Experience Levels 4 and 5 should consistently conduct Fish and Invertebrates (FI) surveys, though Fish Only or Invertebrates Only surveys are fine once in a while.
For more about the invertebrate and algae monitoring program, visit www.REEF.org/vfsp/invertebrates.
