Citizen science is growing increasingly important for managers and conservation science. The REEF Volunteer Fish Survey Project provides an accessible and flexible way for divers to contribute observations to a large database. This flexibility comes with challenges for analysis, but these challenges can be addressed with analytical models that account for variation in survey effort in time and space. For this study, the authors used simulations as well as data collected in The Bahamas and Turks and Caicos from 1994–2020 to identify model approaches that were able to predict trends in both observation frequency and abundance at the survey level as a function of dive duration, location, and other covariates. The models identified a significant decline in Queen Triggerfish, which was used as a model organism for this study. This research opens the door for more in depth study of other understudied reef dwelling species, allows for higher resolution modeling of predictors of presence and abundance, and expands the set of tools available for researchers using REEF data.
This study, conducted as part of the Grouper Moon Project, reports on the movement patterns and spawning behavior of Tiger Grouper during their reproductive season. Tiger Grouper is one of over 20 species of reef fish that are known to use the western tip of Little Cayman in the Cayman Islands as a spawning ground. This multi-species aggregation is best known for being home to the largest and one of the last known spawning aggregations of Nassau Grouper. Unlike the mass spawning behavior seen with Nassau Grouper, male Tiger Grouper defend territories to attract mates in a lek-like reproductive strategy. Tiger Grouper spawn during winter full moons, typically a few days after the Nassau Grouper. The Grouper Moon research team acoustically tagged ten spawning male Tiger Grouper at the Little Cayman spawning aggregation. Using a hydrophone array surrounding the island, the researchers tracked the movements of the tagged fish for 13 months. The authors observed 3 migratory strategies: resident fish that live at the aggregation site, neighboring fish that live within 4 km of the site, and commuter fish that travel over 4 km for spawning. Fish began aggregating 2 days before the full moon and left the aggregation site 10–12 days after the full moon, from January to May. This research helps shed light on an important, but poorly studied, member of Caribbean coral reef ecosystems. Tiger Grouper reach sexual maturity around two years of age, and live at least nine years. They are protogynous hermaphrodites, meaning they start life as female and then change to male as they get larger. They are largely piscivorous, and play an essential ecological role in structuring coral reef food webs.
This publication from the Grouper Moon Project addresses the question of where fertilized eggs go after being released by Nassau Grouper at their spawning site off the west end of Little Cayman. On nights of spawning in 2017, researchers physically tracked clouds of tiny, transparent Nassau Grouper eggs through the night with an underwater microscope developed by scientists at Scripps Oceanography. Results show that fertilized eggs from Little Cayman floated back onto reefs on the island. Drawing on these direct observations and ocean current data collected on spawning nights at Little Cayman, the authors also used a computer model to investigate where the fertilized eggs likely went in 2011 and 2016. The model predicted that many of the baby Nassau Grouper ended up back at Little Cayman in 2011, a suggestion that dovetails with prior research (see here) showing that the 2011 reproductive season led to a significant population increase around Little Cayman. For 2016, the model predicted that currents carried some fertilized eggs to the nearby island of Grand Cayman.
This study highlights how reproductive success and the final destination of the grouper eggs can vary from year to year, while also showing that local conservation measures to protect Nassau Grouper are boosting local populations and sometimes providing spillover benefits to neighboring islands. It is also an example of the power of collaboration - scientists from several departments at Scripps Institution of Oceanography led the work, who were assisted by REEF's Grouper Moon field team and supported in the field by the Cayman Islands Department of Environment vessels and crew. To learn more about the Grouper Moon Project, visit www.REEF.org/groupermoonproject. To read more about this study, visit this Scripps article about the work.
Long-term data are key to understanding how species, communities, and habitats change over time. Citizen science programs can support data collection at greater spatial and temporal scales than other types of scientifically collected data which tend to be project-specific and are often tied to short funding periods. This is particularly true for environments that are difficult to sample such as subtidal ecosystems. Reef Environmental Education Foundation (REEF) citizen science SCUBA surveyors have been collecting fish, invertebrate, and algae data in British Columbia since 1998. This study demonstrates how citizen science data from REEF can be used to answer scientific questions via case studies, the first on Lingcod (Ophiodon elongatus) population responses to management decisions and the second on detecting rockfish species (Sebastes spp.) young-of-year abundance pulses. The results of these case studies suggest that data from REEF, despite limitations, can be used to improve our understanding of nearshore marine ecosystems.
The Salish Sea in Washington and British Columbia is home to hundreds of fish species, and REEF citizen scientists play an important role in documenting and monitoring the health of fish populations in this biologically diverse region. This paper shows that the REEF Volunteer Fish Survey Project helped monitor more than half of the total fish species known to occur in the Salish Sea. Furthermore, REEF surveyors expanded the known range of multiple species within the ecosystem and documented the presence of a fish species not previously known to occur in the Salish Sea — the Striped Kelpfish (Gibbonsia metzi).
The research was led by SeaDoc Society. SeaDoc has partnered with REEF for almost two decades to help train volunteer divers in the Pacific Northwest. REEF citizen scientists have been surveying the Salish Sea since 1998. The study was also informed by a list of species published by fisheries biologists Theodore Pietsch and James Orr, which reported on 261 known fish species from the Salish Sea. The authors compared data from 13,000 REEF surveys collected from about 800 sites in the Salish Sea over 21 years (1998-2019). Volunteers observed 138 of the 261 species and expanded the range of 18 species, meaning they were spotted in an area of the Salish Sea where they previously had not been documented to exist.
Not all fish species have an equal chance of being spotted by a scuba diver. Some might live hundreds of feet deep, expertly hide themselves, or only rarely venture into the Salish Sea. The authors took this into account and categorized each fish based on its potential for encounter by a diver. REEF divers sighted 85% of fish species that lend themselves to visual observation. For these fishes, experienced citizen scientists can expand what scientists know about range, life history, population status, size, age, behavior, and more.
Early life history stages of fish have been shown to be sensitive to environmental changes. Given predicted changes in the coming century to the world’s tropical oceans, it is important to characterize how these changes will affect growth and survival of species with commercial and ecological importance. The Grouper Moon Project team has been conducting preliminary research on early life history of Yellowfin Grouper (Mycteroperca venenosa) with eggs and larvae collected from a Yellowfin Grouper spawning aggregation on Little Cayman, Cayman Islands, adjacent to the larger Nassau Grouper aggregation that is the primary focus of the Grouper Moon Project. Findings on Yellowfin Grouper growth and condition of eggs and larvae reared in varying temperature regimes was presented at the 2022 American Fisheries Society conference. From these baseline characterizations, we can inform future studies to better understand how a warming ocean will affect the species.
As part of the Grouper Moon Project in Little Cayman, Cayman Island, this study used the sound produced by Nassau Grouper, Red Hind, Black Grouper, and Yellowfin Grouper to monitor the positions of these fish during the Nassau grouper spawning event that occurred in 2017. By using fish sound recorded by multiple instruments, we were able to monitor the presence and location of these fish before, during, and after the spawning. These continuous and overnight records added valuable observations to the limited period of times when divers are able to survey the area. Knowing the locations of the fish, it was possible to measure how loud these fish sounds are and determine how far they may be detected. The authors found that Nassau Grouper sounds were the loudest and may be detectable up to 300 m at this location. Additionally, the timing and locations of sound production suggest that there is no Nassau spawning events that occur during the night, but there may be overlap in space and time between Red Hind and Nassau Grouper spawning aggregations.
REEF was one of five citizen science (CS) project teams that participated in a multi-year study funded by the National Science Foundation to understand CS volunteers’ accuracy and skills. This paper is the culmination of that study, which included several facilitated exercises and meetings between external researchers and the project participants. The CS teams identified a wide range of skill variables that were “hiding in plain sight” in their data records that could be explored as part of a secondary analysis. Each team identified a small number of evaluation questions to explore with their existing data. REEF's "hiding in plain sight" was using surveys collected in different scenarios (solo surveyor, surveying with a buddy, surveying in a group during a REEF Trip) to evaluate skill gains as measured by the number of species reported on each survey. The results from these analyses were then used to inform the design of both existing and new CS projects, and to inform the field more broadly through a range of dissemination strategies.
First sighted in Lebanon in 2012, invasive lionfish have since become well-established in the Mediterranean Sea. In an effort to provide policy recommendations for the lionfish invasion within the Mediterranean Sea, REEF joined in a global collaborative effort with researchers from Europe, Asia, Africa, North America, and the Caribbean to share successes and failures from two decades of lionfish management in the Western Atlantic. As a result of this work, a paper titled "Lessons from the Western Atlantic lionfish invasion to inform management in the Mediterranean” was recently published in the journal Frontiers in Marine Science.
Invasive lionfish control will require rapid and strategic management approaches, multinational coordination and broad cooperation among and between governments and stakeholders. The infographic (above) accompanying this article details some of the recommended and failed approached for lionfish management. Lessons for invasive lionfish management identified in the paper include:
• Conducting routine removals by spearfishing with scuba can effectively suppress local abundances of lionfish
• Encouraging the development of recreational and commercial lionfish fisheries can facilitate sustainable lionfish population control
• Engaging local communities can help achieve lionfish removals, market-development, research, and public education.
The authors also advised against failed approaches such as feeding lionfish to native fish to promote predation and implementing bounty programs to incentivize lionfish harvest. A detailed table of lionfish management strategies in both the Western Atlantic and Mediterranean was compiled by REEF staff to support the article and can be found here.
East Pacific Green Sea Turtles (Chelonia mydas) have undergone substantial population recovery over the last two decades because of comprehensive protection at nesting beaches and foraging areas. Starting in 2014 in southern California (United States), at the northern end of their range, Green Sea Turtles have been seen in more areas and in greater numbers. A resident population of Green Sea Turtles has established near La Jolla Shores (off San Diego Country), a protected site with daily marine tourism (e.g., kayakers, snorkelers, divers). The REEF Volunteer Fish Survey Project, a global citizen science marine life monitoring program, has included sea turtle sightings since 2001. The REEF dataset from San Diego, CA, was used as one of several sources of information to study this local population of sea turtles. This paper summarizes the authors' findings. The study is the first to look at the apparent behaviors and condition of Green Sea Turtles observed in the La Jolla Shores area and the first to provide information about Green Sea Turtle distribution throughout southern California based on opportunistic sightings by the general public.