The authors of this study (including REEF staff Lad Akins) examined the recent case of Indo-Pacific lionfish invading Northern Gulf of Mexico coastal waters. The authors compared traditional reef fish monitoring efforts to less traditional data including the observations of divers through REEF's Volunteer Fish Survey Project and spearfishers. They found that citizen observations documented lionfish 1-2 years earlier and more frequently than the more traditional monitoring efforts. The authors also explored the willingness of spearfishers to help minimize impacts of the invasion by harvesting lionfish. They found that spearfishers who had encountered more lionfish while diving perceived them as more harmful to the habitat than less experienced divers and were also more likely to participate in harvesting initiatives. The authors also report that encouragement from scientists and managers was a far better motivator than the desire to harvest lionfish for personal consumption. This study demonstrates the value of engaging citizens for assessing and responding to large-scale and time-sensitive conservation problems.
There is an increasing need to examine regional patterns of diversity in coral-reef systems because their biodiversity is declining globally. The authors used REEF data from 80 sites from 6 eco-regions throughout the Caribbean to evaluate patterns of biodiversity. Specifically, they used "additive partitioning", which quantifies the contribution of different types of diversity (alpha and beta; comparing diversity between sites within a region and between regions) to total diversity across different spatial scales. The primary objective was to identify patterns of reef-fish diversity across multiple spatial scales under different scenarios, examining factors such as fisheries and demographic connectivity. Total diversity at the Caribbean scale was attributed to β-diversity (nearly 62% of the species), with the highest β-diversity at the site scale. α⎯⎯-diversity was higher than expected by chance in all scenarios and at all studied scales.
This suggests that fish assemblages are more homogenous than expected, particularly at the ecoregion scale. Within each ecoregion, diversity was mainly attributed to alpha, except for the Southern ecoregion where there was a greater difference in species among sites. β-components were lower than expected in all ecoregions, indicating that fishes within each ecoregion are a subsample of the same species pool. The scenario involving the effects of fisheries showed a shift in dominance for β-diversity from regions to subregions, with no major changes to the diversity patterns. In contrast, demographic connectivity partially explained the diversity pattern. β-components were low within connectivity regions and higher than expected by chance when comparing between them. The author's results highlight the importance of ecoregions as a spatial scale to conserve local and regional coral reef-fish diversity.
The authors describe the behavioral interactions of piscivorous mid-water and demersal fishes at subtropical live-bottom reefs off the coast of Georgia and off the west coast of Florida in the northeast Gulf of Mexico. The observations are used to construct a topological behavior web of the interactions of mid-water and demersal piscivores, their prey, and those associated species that modify predator-prey interactions. Results show that inter-specific behavioral interactions are common attributes of piscivores in these reef fish communities. The authors propose a framework for assessing the demographic consequences of such interactions. Data for this study were collected using a modified Roving Diver Technique, the method employed by REEF surveyors. One of the co-authors, Dave Grenda, is a member of REEF's Advanced Assessment Team.
Research conducted by Dr. Ben Holt from University of East Angila in the UK shows that methods to record marine diversity used by REEF surveyors returned results consistent with techniques favoured by peer-reviewed science. The findings give weight to the growing phenomenon of citizen science programs such as REEF's Volunteer Survey Project. The field study compared methods used by REEF volunteer SCUBA divers with those used by professional scientists to measure the variety of fish species in three Caribbean sites in the Turks and Caicos. The divers surveyed the sites using two methods – the 'belt transect', used in peer reviewed fish diversity studies, and the 'roving diver technique', used by REEF volunteers. Two teams of 12 divers made 144 separate underwater surveys across the sites over four weeks. While the traditional scientific survey revealed sightings of 106 different types of fish, the volunteer technique detected greater marine diversity with a total of 137 in the same waters. Dr Holt led the research in partnership with the Centre for Marine Resource Studies in the Caribbean and the University of Copenhagen, Denmark. He said: "The results of this study are important for the future of citizen science and the use of data collected by these programs. Allowing volunteers to use flexible and less standardised methods has important consequences for the long term success of citizen science programs. Amateur enthusiasts typically do not have the resources or training to use professional methodology. Our study demonstrates the quality of data collected using a volunteer method can match, and in some respects exceed, protocols used by professional scientists."
This paper presents reconstructions of coral reef food webs in three Greater Antillean regions of the Caribbean: the Cayman Islands, Cuba, and Jamaica. The REEF Volunteer Fish Survey Project dataset is one of several used to construct the food webs. The datasets presented in this publication will facilitate comparisons of historical and regional variation, the assessment of impacts of species loss and invasion, and the application of food webs to ecosystem analyses (e.g. Coral Reefs in Crisis: The Reliability of Deep-Time Food Web Reconstructions as Analogs for the Present, 2018, PD Roopnarine and AA Dineen)
Invasive lionfish in the western Atlantic are known to be voracious predators. Their unusual hunting behavior suggests that they could prey on most fish species within their gape size limits. Significant research by REEF researchers and others has been conducted looking at stomach contents of lionfish to identify prey. However, relatively few prey species have been identified because of the challenge of identifying partly digested prey. It is also difficult to know how well the identifiable diet reflects the unidentified portion. The authors of this study addressed this issue by DNA-barcoding unidentifiable fish items from the stomachs of 130 lionfish. They identified 37 prey species, half of which had previously not been recorded. The visually identifiable species only accounted for 25% of the total prey items, making it clear that extrapolating total prey from the identifiable portion is not accurate. The barcoding technique used can increase the ability to predict the impacts of invasive predators on recipient communities.
A database of fish surveys conducted by volunteer recreational divers trained by REEF was used to examine fish populations in Monterey Peninsula, California, between 1997 and 2011. Over 3,000 surveys were conducted as part of this ongoing citizen science effort. The analysis was conducted using a numerical conversion method to calculate population estimates from REEF log-scale data (this method was described in a companion paper published in the same CalCOFI Reports issue). Variations in relative density over time are reported for 18 fish species, including several fisheries-targeted species. Two recruitment pulses of young-of-the-year rockfish (Sebastes spp.) were observed over the study period, with subsequent increases in older rockfish. Several predator species increased and subsequently declined, peaking two years after prey populations. Strong concordance was found between REEF data and those collected by Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), a consortium of academic institutions. Results show that data collected by REEF has great potential to augment and strengthen professional research data and serve as a valuable baseline to evaluate marine reserves.
Despite being the world’s largest rays and providing significant revenue through dive tourism, little is known about the population status, exploitation, and trade volume of the Mobulidae (mobulids; Manta and Mobula spp.). There is anecdotal evidence, however, that mobulid populations are declining, largely due to the recent emergence of a widespread trade for their gill rakers. Researchers from Dalhousie University and eShark.org used expert divers’ observations from two citizen science programs, REEF's Volunteer Fish Survey Project and eShark.org, to describe global manta and devil ray abundance trends and human use patterns. The study highlights the relative rarity of aggregation sites on a global scale and reveals that many populations appear to be declining. The authors warn that newly emerging fisheries for the rays gill-‐rakers likely exceed their ability to recover. The study also demonstrates the deficiency of official catch reports, as only four countries have ever reported landing manta or devil rays– Indonesia, Liberia, Spain and Ecuador. However, numerous diver reports compiled in the paper illustrate that many other countries are regularly landing and selling these rays without reporting.