2024

Greenberg, DA, CV Pattengill-Semmens, BX Semmens

The state of biodiversity for most of the world is largely unknowable due to a lack of long-term population monitoring data. Citizen science programs could substantially contribute to resolving this data crisis, but there are noted concerns on whether methods can overcome the biases and imprecision inherent to these programs. The authors of this study evaluated these concerns by comparing data collected as part of the REEF Volunteer Fish Survey Project, a long-term citizen science fish monitoring program for recreational divers and snorkelers, with data collected as part of fishery-independent survey coordinated by scientists from National Oceanic and Atmospheric Administration (NOAA). Both datasets were conducted over the same time period at the 60 sites off Key Largo, Florida (US), from 1993 to 2018, and both sampled populations of similar coral-reef fishes (n = 87 species). The majority of species exhibited similar trends over the 25-year time span in both population time-series datasets, but there was variation between the two datasets among certain taxonomic and trait-based groups. Overall, these results suggest that citizen scientists can be effective sentinels of ecological change, and that there may be substantial value in leveraging their observations to monitor otherwise data-limited marine species.

Appendix and Supplementary Materials available online here.

Conservation Letters
doi.org/10.1111/conl.13009
2024
Program: 
Volunteer Fish Survey Project
Repetto MF, ME Torchin, GM Ruiz, C Schlöder, and AL Freestone

Tropical regions are, in general, more diverse than ecosystems at higher temperate latitudes. A commonly held hypothesis is that the diverse predators in tropical regions cause predation to have a relatively stronger role in shaping communities. Data from the REEF Volunteer Fish Survey Project (VFSP) were used by Michele Repetto and colleagues from the Smithsonian Tropical Research Institute to test for underlying differences in regional fish diversity that could contribute to variation in predation intensity and impact. Their study spanned across the Isthmus of Panama, including two tropical ocean basins. The research team combined field experiments and VFSP data collected by REEF volunteers from both the Tropical Western Atlantic (TWA) and Tropical Eastern Pacific (TEP). Their findings demonstrated that while the influence of predation is highly variable, even within tropical systems, increases in predator diversity due to localized abiotic factors (e.g. seasonal upwelling) led to an increased influence of predators on their prey base.

The study's authors observed striking spatial and seasonal variability in predation impact and intensity on coastal marine invertebrate communities. This variability likely has important consequences for food web dynamics and patterns of species diversity and ecosystem functioning. The Isthmus of Panama offered a unique opportunity to explicitly test factors that influence temporal and spatial variability of predator effects in tropical marine communities. The analysis included data on115 fish species from 16 families in the TWA and 89 species from 18 families in the TEP. Because the REEF VFSP program occurs world-wide, this citizen science dataset provides a valuable source of information to scientists and researchers from government and academic institutions that is otherwise not available.

Proceedings of the Royal Society B
Volume 291Issue 2026 https://doi.org/10.1098/rspb.2024.0868
2024
Program: 
Volunteer Fish Survey Project
Gore, M, J Kohler, R Ormond, A Gallagher, T Fernandes, T Austin, and C Pattengill-Semmens

The Scalloped Hammerhead shark (Sphyrna lewini), a critically endangered species with a decreasing global population, is characterised by its occurrence in large schools. Such schools are still observed today in the Pacific Ocean, but this is generally not the case in the Atlantic Ocean, and in the Cayman Islands not since the 1970s. The authors of this paper report a recent record of a school of S. lewini in deep water off Grand Cayman, and describe a recent, concomitant increase in numbers of the species, and its critically endangered congener, the Great Hammerhead (Sphyrna mokarran), around the Cayman Islands. Relative population trends and seasonal patterns were assessed using data from shallow and deep-water BRUVS, scientific longlining, citizen science projects including the Sharklogger Network and REEF Volunteer Fish Survey Project, and social media reports. It appears that the Scalloped Hammerhead may be slowly re-occupying the area, selecting and using deeper waters to school, while the Great Hammerhead has also become less scarce than Scalloped Hammerhead.

Frontiers in Marine Science
11:1347285. doi: 10.3389/fmars.2024.1347285
2024
Program: 
Volunteer Fish Survey Project

2023

Coleman, FC, JACC Nunes, AA Bertoncini, LS Bueno, MO Freitas, M Borgonha, JR Leite, MJCA Lima-Júnior, B Ferreira, B Bentes, CC Koenig, CR Malinowski, EG Sanches, M Hostim-Silva, and CLS Sampaio

Laws protecting the Atlantic Goliath Grouper Epinephelus itajara from fishing in federal and state waters of the United States occurred in 1990 after the species was identified as being severely overfished. Population increases that occurred during the first 20 years of the closure were followed by a decline in the 10 years thereafter. Despite the National Oceanic and Atmospheric Administration’s call to retain full protection for this species in federal waters, the Florida Fish and Wildlife Conservation Commission (FWC) opened a limited fishery in state waters for juveniles in 2022. This paper reviews available scientific literature and datasets on Goliath Grouper trends (including the REEF Volunteer Fish Survey Project database, which represents the best available long-term data on adult Goliath Grouper in Florida), and presents information on the limits of Goliath Grouper recovery, the varied threats the species is facing, and the ensuing factors that precipitated the species subsequent decline. The authors discuss the risks associated with management decisions that ignore the best available scientific information, and they compare management differences and difficulties among nations within the Atlantic Goliath Grouper’s global range. 

Marine Policy
155; doi.org/10.1016/j.marpol.2023.105752
2023
Program: 
Volunteer Fish Survey Project
Urquhart, JP, DB Olson, and EA Babcock

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.

Fisheries Management and Ecology
https://doi.org/10.1111/fme.12617
2023
Program: 
Volunteer Fish Survey Project
Sleugh, T, CM McCoy, CV Pattengill-Semmens, BC Johnson, SA Heppell, L Waterhouse, BC Stock, and BX Semmens

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.

Environmental Biology of Fishes
https://doi.org/10.1007/s10641-023-01399-w
2023
Program: 
Grouper Moon Project
Stock, BC, AD Mullen, JS Jaffe, A Candelmo, SA Heppell, CV Pattengill-Semmens, CM McCoy, BC Johnson, and BX Semmens

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.

Proceedings of the Royal Society B
https://doi.org/10.1098/rspb.2023.0551
2023
Program: 
Grouper Moon Project

2022

Campbell, J, J Yakimishyn, D Haggarty, F Juanes, S Dudas

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.

Fisheries
doi.org/10.1002/fsh.10831
2022
Program: 
Volunteer Fish Survey Project
Ashley, EA, CV Pattengill-Semmens, JW Orr, JD Nichols, and JK Gaydos

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.

Environmental Monitoring and Assessment
194. https://doi.org/10.1007/s10661-022-09857-1
2022
Program: 
Volunteer Fish Survey Project
Layton, J, A Candelmo, BX Semmens, C Pattengill-Semmens, BC Stock, L Waterhouse, CM McCoy, B Johnson, D Heppell, S Barkdoll, S Huber, and S Heppell

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.

American Fisheries Society (AFS) 152nd Annual Meeting Conference Proceedings
08/22/2022
2022
Program: 
Grouper Moon Project

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