The authors of this study examined drivers of public involvement and success at invasive removal in tournaments (derbies) to catch Indo-Pacific lionfish (Pterois volitans/miles) in the Western Atlantic. Information on 69 lionfish derbies held in the wider Caribbean region from 2010 to 2015 was compiled, including REEF Lionfish Derbies. The authors found that the number of lionfish caught increased with effort and with time since lionfish were established in an area. They also found that derby participation was best predicted by national wealth (GDP per capita) and number of local dive shops. These findings support that, from the point of view of public engagement, derbies should be held in areas where lionfish are well established, and where the pool of potential participants is large. However, alternative strategies may be more effective in areas where few lionfish are present.
A diminutive, non-native damselfish (Neopomacentrus cyanomos) was recently discovered inhabiting coral reefs near Veracruz, Mexico—far removed from where it is native in the Red Sea and the Indo-Pacific. This publication, co-authored by REEF's Director of Special Projects, Lad Akins, evaluates the threat of establishment and spread in the invaded range.
The quantities found in the Gulf of Mexico (GOM) suggest that the fish has already established a self-sustaining population in this new ecosystem. There is understandable concern, therefore, that this new arrival may become invasive and spread, yet the invasion risk imposed by this fish has not been assessed. In this study, a computer model was employed to deliver a forecast of the potential range of incursion of the damselfish in the GOM spanning 5 years. The model incorporated oceanic water flow in the region, tolerances of this damselfish to the ocean environment, and their reproductive strategy in order to supply a temporal and spatial forecast of their spread. From this study, targeted early detection and removal of the fish can be directed if the fish is deemed a threat to native fauna. On the basis of this work, it is foreseeable that the reefs presently harboring Regal Damselfish will likely see increased abundance of this damsel. Immediate attempts to eliminate the fish, therefore, should be focused in nearshore shallow waters spanning Veracruz to Frontera, Mexico. Further, water flows in the southern GOM are not widely conducive to long-distance transport of marine organisms with pelagic larvae, reducing the risk of this damsel permeating the greater GOM over 5 years. Aside from Regal Damselfish, this study implicitly adds to mounting evidence supporting a biogeographic disconnect between the Veracruz reef complex and the greater GOM and the Caribbean.
REEF surveyors are on the lookout for Regal Damselfish in the Gulf of Mexico and western Caribbean.
Despite uncertainties surrounding the population status of the protected Atlantic Goliath Grouper’s, fishery managers are under pressure to end the harvest moratorium in place since 1990. This study sought to measure the proportion of anglers interested in reopening the goliath grouper fishery and to identify key reasons for this interest. The authors also estimated the amount that anglers would be willing to pay for a Goliath Grouper harvest tag (the right sold to an angler to harvest one goliath grouper). REEF data on Goliath Grouper were used to compare with the fishermen-perceived grouper population trends. REEF data have been cited as the best available index of abundance for Goliath Grouper in Florida (see Koenig et al., 2011, http://www.REEF.org/db/publications/9754). The study found that about half of Florida’s recreational anglers believe that the ban on fishing for goliath grouper should be lifted, with many anglers reporting that they feel "there are too many goliath grouper and that their populations need to be controlled." These anglers are willing to pay between $34 and $79 for the right to harvest one goliath grouper in Florida.
As fishery managers work to determine the future of goliath grouper in Florida and the rest of the southeast United States, this study's findings can help them better understand stakeholder intentions and better communicate to the public. Additionally, fishery managers can compare the amount of money recreational anglers are willing to pay to open the fishery to the amount of money other stakeholders, such as recreational divers who visit goliath grouper, are willing to pay to keep the fishery closed.
Several studies conducted at the scale of islands, or small sections of continental coastlines, have suggested that mangrove habitats serve to enhance fish abundances on coral reefs, mainly by providing nursery grounds for several species known to have different habitats as juveniles and adults. However, evidence of such enhancement at a regional scale has not been reported, and recently, some researchers have questioned the mangrove-reef subsidy effect. Authors of this paper used the REEF database to evaluate mangrove-reef connectivity at the Caribbean regional scale. They specifically asked: (1) Are reef fish abundances limited by mangrove forest area?; and (2) Are mean reef fish abundances proportional to mangrove forest area after taking human population density and latitude into account? They tested for Caribbean-wide mangrove forest area effects on the abundances of 12 reef fishes that have been previously characterized as “mangrove-dependent”. Results showed that average reef fish densities of at least six of the 12 focal fishes were directly proportional to mangrove forest area. This is the first scientific study to show that at a large regional scale (i.e., the Wider Caribbean), greater mangrove forest size generally functions to increase the densities on neighboring reefs of those fishes that use these shallow, vegetated habitats as nurseries.
This study is a great example of the power and impact that long-term, wide-spread citizen science programs such as the REEF Volunteer Fish Survey Project can have on addressing important ecological and management questions that would otherwise be near impossible to evaluate.
Managing natural populations and communities requires detailed information regarding demographic processes (or status of a population) at large spatial and temporal scales. This combination is challenging for both traditional scientific surveys, which often operate at localized scales, and citizen science designs, which often provide data with few auxiliary information (i.e. no information about individual age or condition). The authors of this study combine citizen science data collected at large scales (REEF Volunteer Fish Survey Project data) with recently developed statistical demographic modeling techniques. The model analysis included two managed reef fishes in the Gulf of Mexico to estimate demographic trends, habitat associations, and interannual variability in recruitment of Goliath Grouper and Mutton Snapper. The results identify strong preferences for artificial structure for the recovering Goliath Grouper, while revealing little evidence of either habitat associations or trends in abundance for Mutton Snapper. Results are also contrasted with a typical modeling approach to demonstrate the importance of accounting for the statistical complexities implied by spatially structured citizen science data. Results also highlight the utility and management benefits of combining demographic models and citizen science data.
REEF data were used to validate population estimates of Black Rockfish throughout western Canada, Washington State, and Oregon. These results were then used to evaluate the efficacy of marine reserve networks in these areas. The authors of the study estimated the scale of dispersal from genetic data in the black rockfish, and compared this estimate with the distance between Rockfish Conservation Areas that aim to protect this species (essentially evaluating whether the reserves are "connected" enough). Their findings showed that within each country, the distance between conservation areas was generally well connected. The distance between the networks in the two countries, however, was greater than the average dispersal per rockfish generation.
This paper presents results from a study conducted as part of REEF's Grouper Moon Project, evaluating the potential ecosystem-level effect of Nassau Grouper aggregations. In particular, the study looked at the impact the spawning aggregation has in creating biogeochemical "hot moments", which occur when a temporary increase in availability of one or more limiting nutrients results in elevated rates of biogeochemical reactions. In this case, the limited nutrients are nitrogen and phosphorus, and the temporary increase is resulting from all of the grouper excrement that results when approximately 5,000 Nassau Grouper gather in a small area for 10 days during the spawning season.
Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150 mm), where the tag was up to 7.6% of the lionfish's mass. Our study offers a novel in situ tagging technique that can be used to provide critical information on fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible.
The study, conducted by Dr. Stephanie Green (OSU/REEF), Lad Akins (REEF), and others, confirms for the first time that controlling lionfish populations in the western Atlantic Ocean can pave the way for a recovery of native fish. Even if it's one speared fish at a time, data are showing that removals can be effective. And not every lionfish need be removed…the research findings document that reducing lionfish numbers by specified amounts will allow a rapid recovery of native fish biomass. Over 18 months, the biomass of native prey fishes increased an average 50-70% on reefs where lionfish numbers were suppressed below target levels predicted to cause prey depletion. On reefs where lionfish numbers remained higher than target levels, the biomass of prey fishes decreased by a further 50%. While complete eradication of lionfish from the Caribbean is not likely, groups are actively removing them from coastal areas (mostly via spear and net). This study is a first step in showing that strategic local efforts that suppress the invasion to low levels can help protect and recover native fish communities affected by lionfish. This ground-breaking invasive lionfish research was conducted as a collaboration between REEF, Oregon State University, Simon Fraser University, and the Cape Eleuthera Institute.
This study, co-authored by scientists from REEF's Grouper Moon Project, evaluated genetic connectedness between Nassau Grouper populations throughout the Caribbean. The authors obtained genetic tissue samples from 620 Nassau Grouper from 19 sites across 9 countries, including the Cayman Islands. They found evidence for strong genetic differentiation among Nassau Grouper subpopulations throughout the Caribbean. These results suggest that, despite a lack of physical barriers, Nassau grouper form multiple distinct subpopulations in the Caribbean Sea. Oceanography (regional currents, eddies) likely plays an important role in retaining larvae close to spawning sites at both local and regional spatial scales. These findings highlight the importance of conservation initiatives such at REEF's Grouper Moon program in the Cayman Islands.