Biology, ecology, control and management of the invasive Indo-Pacific lionfish: An updated integrated assessment

Venomous Indo-Pacific lionfish (Pterois miles and P. volitans) are now established along the Southeast U.S.A. and parts of the Caribbean and pose a serious threat to reef fish communities of these regions. Lionfish are likely to invade the Gulf of Mexico and potentially South America in the near future. Introductions of lionfish were noted since the 1980s along south Florida and by 2000 lionfish were established off the coast of North Carolina. Lionfish are now one of the more numerous predatory reef fishes at some locations off the Southeast U.S.A. and Caribbean. Lionfish are largely piscivores that feed occasionally on economically important reef fishes. The trophic impacts of lionfish could alter the structure of native reef fish communities and potentially hamper stock rebuilding efforts of the Snapper –Grouper Complex. Additional effects of the lionfish invasion are far-reaching and could increase coral reef ecosystem stress, threaten human health, and ultimately impact the marine aquarium industry. Control strategies for lionfish are needed to mitigate impacts, especially in protected areas. This integrated assessment provides a general overview of the biology and ecology of lionfish including genetics, taxonomy, reproductive biology, early life history and dispersal, venom defense and predation, and feeding ecology. In addition, alternative management actions for mitigating the negative impacts of lionfish, approaches for reducing the risk of future invasions, and directions for future research are provided

The Role of Citizens in Detecting and Responding to a Rapid Marine Invasion

Documenting and responding to species invasions requires innovative strategies that account for ecological and societal complexities. We used the recent expansion of Indo-Pacific lionfish (Pterois volitans/miles) throughout northern Gulf of Mexico coastal waters to evaluate the role of stakeholders in documenting and responding to a rapid marine invasion. We coupled an online survey of spearfishers and citizen science monitoring programs with traditional fishery-independent data sources and found that citizen observations documented lionfish 1–2 years earlier and more frequently than traditional reef fish monitoring programs. Citizen observations first documented lionfish in 2010 followed by rapid expansion and proliferation in 2011 (+367%). From the survey of spearfishers, we determined that diving experience and personal observations of lionfish strongly influenced perceived impacts, and these perceptions were powerful predictors of support for initiatives. Our study demonstrates the value of engaging citizens for assessing and responding to large-scale and time-sensitive conservation problems

Evaluating the Potential Efficacy of Invasive Lionfish (Pterois volitans) Removals

The lionfish, Pterois volitans (Linnaeus) and Pterois miles (Bennett), invasion of the Western Atlantic Ocean, Caribbean Sea and Gulf of Mexico has the potential to alter aquatic communities and represents a legitimate ecological concern. Several local removal programs have been initiated to control this invasion, but it is not known whether removal efforts can substantially reduce lionfish numbers to ameliorate these concerns. We used an age-structured population model to evaluate the potential efficacy of lionfish removal programs and identified critical data gaps for future studies. We used high and low estimates for uncertain parameters including: length at 50% vulnerability to harvest (Lvul), instantaneous natural mortality (M), and the Goodyear compensation ratio (CR). The model predicted an annual exploitation rate between 35 and 65% would be required to cause recruitment overfishing on lionfish populations for our baseline parameter estimates for M and CR (0.5 and 15). Lionfish quickly recovered from high removal rates, reaching 90% of unfished biomass six years after a 50-year simulated removal program. Quantifying lionfish natural mortality and the size-selective vulnerability to harvest are the most important knowledge gaps for future research. We suggest complete eradication of lionfish through fishing is unlikely, and substantial reduction of adult abundance will require a long-term commitment and may be feasible only in small, localized areas where annual exploitation can be intense over multiple consecutive years

A Symmetric Intraguild Predation Model for the Invasive Lionfish and Native Grouper

Abstract Lionfish are top-level venomous predators native to the Indo-Pacific Ocean. Over the past decade, the species Pterois volitans and P. miles have become established throughout most of the western Atlantic Ocean, where they drastically impact coral reef communities. Overfishing of native species, such as grouper, who share their niche with lionfish may be the reason for the lionfish's success; research has suggested that at high density, groupers can act as a lionfish biocontrol. To determine if competition or predation is the mechanism behind lionfish suppression, we construct a symmetric intraguild predation model of lionfish, grouper, and prey. Thus, we assume lionfish and grouper compete for prey in addition to consuming juveniles of the other species. Holling type I functional responses are used to represent fecundity and predation. We conduct an equilibrium stability analysis and bifurcation analysis of the general model, and find that the system is able to coexist in an equilibrium or sustainable oscillations. After estimating parameter ranges, simulations and a sensitivity analysis indicate the parameters most influential to lionfish growth rate. The implied control strategies are then tested by varying harvesting and predation rates

A Review of Present and Alternative Lionfish Controls in the Western Atlantic

Lionfish (Pterois volitans and Pterois miles) are the first recorded invasive piscivore in the Caribbean and have become a threat to native species. As generalist consumers, lionfish have a broad diet and reduce prey and competitor abundance and juvenile recruitment. To confront this problem, this paper serves to review all of the current and alternative future controls available to manage lionfish populations in the Western Atlantic and determine where focus is lacking. Derby and cull efforts are the only management efforts in place and are not effective in their current state as these local events have short-term benefits, but lionfish populations recover quickly. Alternative strategies to culls include the use of biological controls and genetic engineering. Both strategies have their associated risks and ethical concerns, but may provide significant levels of control. Biological control agents include the introduction of parasites or disease from their native range that specifically target lionfish or the recovery and conditioning of natural Western Atlantic predators to consume lionfish. Genetic modification is gaining public acceptance for use against pest species and therefore, if made as safe as possible, could provide some of the best results for controlling lionfish. Quantitative analysis of derby and cull data revealed that focus is lacking in key locations throughout the Western Atlantic such as Cuba and the Meso-American Barrier Reef. The vast majority of derbies were located along the U.S. Eastern and Gulf coast. However, lionfish controls must implement in regions of the greatest larval connectivity to reduce the amount of larval recruitment and subsequent recovery of adult populations after local removals. Monthly, basin-wide removals of 20% lionfish biomass were determined to be the most effective strategy, reducing lionfish biomass to near-zero levels in only 36 months. Therefore, to effectively reduce lionfish biomass in the Western Atlantic, an international strategy is needed to produce management efforts in all regions simultaneously

Lessons From the Western Atlantic Lionfish Invasion to Inform Management in the Mediterranean

Major invasions of Indo-Pacific lionfish (Pterois volitans and P. miles) are underway in the Western Atlantic Ocean and the Mediterranean Sea. While the establishment of lionfish in the Western Atlantic is perhaps the most well-studied marine fish invasion to date, the rapidly expanding invasion in the Mediterranean is more recent and has received less attention. Here we review and synthesize successes and failures from two decades of lionfish management in the Western Atlantic to give policy recommendations for their management in the Mediterranean. Two failed approaches that were attempted multiple times in the Western Atlantic and that we advise against are (1) feeding lionfish to native fish to promote predation and (2) implementing bounty programs to incentivize lionfish harvest. Broadly, the most important management lessons that we recommend include (1) conducting routine removals by spearfishing with scuba, which can effectively suppress local abundances of lionfish; (2) encouraging the development of recreational and commercial lionfish fisheries, which can promote long-term, sustainable lionfish population control; and, (3) engaging local communities and resource users (e.g., with lionfish removal tournaments), which can concurrently achieve multiple objectives of promoting lionfish removals, market-development, research, and public education. Managers in the Western Atlantic often needed to adapt current conservation policies to enable lionfish removals in areas where spearfishing with scuba was otherwise prohibited for conservation purposes. The risk of abusing these policies was mitigated through the use of gear restrictions, diver trainings, and through participatory approaches that integrated scuba divers and stakeholder organizations in lionfish research and management. Our review of policies and practices in the Mediterranean Sea found that many of our recommended lionfish management approaches are not being done and indicate potential opportunities to implement these. We expect and fully recommend that work continues towards multinational cooperation to facilitate regional coordination of research, control, and management efforts with respect to the Mediterranean lionfish invasion. As with other major biological invasions, lionfish are unconstrained by political borders and their control will require rapid and strategic management approaches with broad cooperation among and between governments and stakeholders

Guide to Lionfish Management in the Mediterranean

File replaced (incorrect version) on 20/04/2022 by KT (LDS).Lionfish (Pterois miles) are spreading in the fastest fish invasion ever reported in the Mediterranean Sea where they are disrupting ecosystems and have the potential to impact livelihoods. First found in Lebanon in 2012, lionfish quickly became established throughout the eastern Mediterranean and are now spreading west. This management guide is based on lessons learnt during the European Union part-funded RELIONMED project which started in 2017. Local citizen scientists, stakeholders, divers, fishers, researchers and managers worked together to tackle the lionfish threat to conserve biodiversity in priority habitats. This Guide is designed to inform lionfish management in the Mediterranean region, key topics include (1) lionfish removals, (2) development of markets, (3) outreach, (4) research and monitoring, and (5) regional cooperation

Understanding pro-environmental behavior and improving social network research methods to inform conservation management

Includes bibliographical references.2022 Fall.Conservation issues exist in the context of social-ecological systems, with human activities driving threats to species, habitats, and important ecosystem functions. The successes and failures of conservation efforts depend on how humans behave. Likewise, human behavior is crucial to rectifying these problems. Understanding why humans behave in ways that help or hinder conservation efforts is vital to effectively manage and prevent threats to natural resources, such as invasive species. Research specific to each social-ecological context on how social networks, knowledge, and other cultural and social psychological factors influence behavior is needed to inform management decisions. In addition, effective and efficient social science methods are needed for practitioners to assess relevant behaviors more easily. This dissertation contributes evidence that advances our understanding of pro-environmental behaviors that help control invasive lionfish (Pterois volitans) in Belize and Florida and provides insights into data collection methods on social networks. Each manuscript assesses factors that influence a specific target behavior. The first manuscript (Chapter 2) explores what factors affect consumption of the venomous, but edible, invasive lionfish in Belize. To determine the viability of a lionfish market in Belize, a national study of Belizeans (n = 400) and foreign tourists (n = 400) was implemented using structured surveys that assessed consumers' willingness to try lionfish, knowledge about lionfish, attitudes toward purchasing lionfish, and fear of trying new foods, or food neophobia. Findings show that most Belizeans and foreign tourists are willing to eat lionfish given the opportunity, but that a misperception that lionfish is not safe to eat and availability are barriers to eating lionfish. Belizeans, though concerned about lionfish, are less willing to consume lionfish than tourists and more likely to believe lionfish are unsafe to eat. In addition, when asked why they would not eat lionfish, the most common reasons Belizeans described were related to perceived danger or preference. These and other findings about consumer behavior toward seafood in Belize, such as that Belizeans primarily choose to eat seafood for health reasons and prefer snapper to other types of seafood, provide important insights into opportunities to grow demand for lionfish and decrease barriers related to risk perceptions. The second manuscript (Chapter 3) shares findings from a mixed methods study to understand how motivation and social capital affect removal of lionfish in Florida by spearfishers who hunt lionfish, or lionfish hunters. Findings are shared from semi-structured interviews (N = 75) as well as an online structured survey of 186 lionfish hunters. Results show that lionfish hunters who are motivated by money kill more lionfish than those motivated by other reasons. However, this group is very small in number and is sensitive to decreased lionfish numbers because it is prohibitive to commercial spearfishers' ability to profit from them. In addition, lionfish hunters who have a social contact who helps them sell lionfish kill more lionfish. However, this is still a small group. Most lionfish hunters in Florida are motivated to kill lionfish to protect Florida's reefs, to eat lionfish, and because it's fun. In addition, most feel an obligation or duty to kill lionfish in order to protect the reefs. Effective management strategies, therefore, should engage lionfish hunters across motivations to maintain consistent and long-term control of the population. In addition, practitioners should continue to cultivate a community around lionfish removal to better support money-motivated lionfish hunters' efforts to sell lionfish. The third manuscript (Chapter 4) investigates the efficacy of including an example social network map in an online structured survey to increase responses to questions about social network contacts. Social network research can be inhibited by willingness of respondents to provide names and contact information of themselves and their acquaintances. For social network research to be more feasible among practitioners in the conservation field and beyond, effective methods for collecting this type of information are essential. This experimental study compared responses (N = 186) to social network questions between those who completed a survey with an example social network map versus a survey without a map. Results show that the example map did not increase provision of network contacts and did not influence the types of ties reported. Therefore, while a map may not help in collecting more data, if it is necessary to include for explanatory purposes in a social network survey, it likely will not bias responses. Resistance among respondents to providing this information in this study demonstrate the need for further exploration into effective social network data collection methods for large groups, especially when snowball sampling is necessary

Total mercury concentrations in invasive lionfish (Pterois volitans/miles) from the Atlantic coast of Florida

Invasive lionfish (Pterois volitans/miles) pose a serious threat to marine ecosystems throughout the western Atlantic Ocean and Caribbean Sea. The development of a fishery for lionfish has been proposed as a strategy for controlling populations; however, there is concern about consumption of this species by humans due to its high trophic position and potential for bioaccumulation of mercury. We analyzed total mercury (THg) in tissues of lionfish from two locations on the east coast of Florida. THg in lionfish increased with size and differed by location and sex. THg was highest in muscle tissue and was strongly positively correlated among tissues. THg in lionfish was lower than other commonly consumed marine fishes, and falls into Florida\u27s least restrictive advisory level. Consumption of lionfish poses a low risk and concerns over mercury bioaccumulation should not present a significant barrier to lionfish harvest

An Ecosystem-Based Approach to Evaluating Impacts and Management of Invasive Lionfish

<p>Species invasions in marine ecosystems pose a threat to native fish communities and can disrupt the food webs that support valuable commercial and recreational fisheries. In the Gulf of Mexico, densities of invasive Indo-Pacific Lionfish, <i>Pterois volitans</i> and <i>P. miles</i>, are among the highest in their invaded range. In a workshop setting held over a 2-week period, we adapted an existing trophic dynamic model of the West Florida Shelf, located in the eastern Gulf of Mexico, to simulate the lionfish (both species) invasion and community effects over a range of harvest scenarios for both lionfish and native predators. Our results suggest small increases in lionfish harvest can reduce peak biomass by up to 25% and also that reduced harvest of native reef fish predators can lead to lower lionfish densities. This model can help managers identify target harvest and benefits of a lionfish fishery and inform the assessment and management of valuable reef fish fisheries.</p