Lionfish Removal Research Articles

Serving conservation from reef to plate: Barriers and opportunities for invasive lionfish consumption in restaurants

Abstract Invasive lionfish (Pterois volitans, Pterois miles), introduced to Florida in the 1980s, colonized coral reef ecosystems in the western Atlantic and have been documented beyond recreational diving depths. In addition to threatening coral reef ecosystems, invasive lionfish have been linked to economic damage in the form of reduced native fish yields for local fishers and high management costs incurred in the physical removal of lionfish. While few examples exist of successful management of marine invasive species, studies show that lionfish removal can mitigate their harmful impacts. One promising market‐based approach that offers benefits to both human livelihoods and marine ecosystems is increasing the demand for the consumption of lionfish. This study focuses on Florida's consumptive lionfish market and fills a gap in understanding of the lionfish supply chain for Florida's restaurant industry. Twenty culinary professionals in Florida were interviewed to determine their perceptions of barriers and opportunities for increasing their use of lionfish. The most commonly identified barriers were price and consistency of supply, while the most prominent opportunities were improved awareness and culinary potential. Conservation managers, culinary professionals and policymakers should leverage these findings to facilitate opportunities, address barriers and promote public education about invasive lionfish and their impacts.

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.

Regular monitoring and targeted removals can control lionfish in Mediterranean Marine Protected Areas

Abstract A lack of biosecurity in the Suez Canal has combined with global warming and other human pressures to cause abrupt changes in the Mediterranean Sea. Throughout this region an influx of species is influencing the outcome of efforts to protect and restore nature. Despite calls for targeted removals of invasive species from protected areas, there is limited information about the effectiveness of this course of action from both an ecological and a socio‐economic perspective. In this study, coordinated removals of lionfish (Pterois miles) by volunteers/scuba divers at three marine protected sites in Cyprus were conducted. The removal efficiency was monitored using visual‐census surveys and citizen science data. Removals significantly decreased lionfish numbers but long‐term suppression of lionfish would require monitoring and repetition of removals when necessary, since population recovery was sometimes rapid. Citizen science yielded the data needed to understand lionfish population changes and guide the timing of removal events, but was characterized by large variation and potential outliers, highlighting the need for large sample sizes. Questionnaire surveys were used to assess the social impact of participation in lionfish removals; these showed that involvement had a strong positive impact on knowledge about lionfish and motivation to support marine conservation activities – the divers were even willing to pay extra to remove lionfish. Management reforms would be needed to capitalize on this societal motivation, and enable effective lionfish removals by scuba divers, coordinated by competent authorities. The EU aims to protect at least 30% of the marine waters by 2030. Removal events could help shield selected conservation sites from the adverse effects of lionfish and at the same time help establish links with local communities, strengthening the sustainable use of marine systems both at corporate and at societal levels.

Broad-scale acoustic telemetry reveals long-distance movements and large home ranges for invasive lionfish on Atlantic coral reefs

Tracking studies for invasive lionfish (Pterois volitansandP. miles) in the Western Atlantic can provide key information on habitat use to inform population control, but to date have likely underestimated home range size and movement due to constrained spatial and temporal scales. We tracked 35 acoustically tagged lionfish for >1 yr (March 2018-May 2019) within a 35 km2acoustic array in Buck Island Reef National Monument, St. Croix, US Virgin Islands (an area 10× larger than previous studies). Tracking lionfish at this scale revealed that home range size is 3-20 times larger than previously estimated and varies more than 8-fold across individuals (~48000-379000 m2; average: 101000 m2), with estimates insensitive to assumptions about potential mortality for low-movement individuals. Lionfish move far greater distances than previously reported, with 37% of fish traveling >1 km from the initial tagging site toward deeper habitats, and 1 individual moving ~10 km during a 10 d period. Movement rates, home range size, and maximum distance traveled were not related to lionfish size (18-35 cm total length) or lunar phase. Lionfish movement was lowest at night and greatest during crepuscular periods, with fish acceleration (m s-2) increasing with water temperature during these times. Our results help reconcile observed patterns of rapid recolonization following lionfish removal, and suggest complex drivers likely result in highly variable patterns of movement for similarly sized fish occupying the same habitat. Culling areas ≥ the average lionfish home range size identified here (i.e. ~10 ha) or habitat patches isolated by ≥ ~180 m (radius of average home range) may minimize subsequent recolonization. If the shallow-deep long-distance movements observed here are unidirectional, mesophotic habitats may require culling at relatively greater frequencies to counteract ongoing migration.

Use of social-media networking to facilitate a grass-roots lionfish removal program in the British Virgin Islands

Use of social-media networking to facilitate a grass-roots lionfish removal program in the British Virgin Islands

The Invasive Species Diet: The Ethics of Eating Lionfish as a Wildlife Management Strategy

ABSTRACT This paper explores the ethical dimensions of lionfish removal and provides an argument supporting hunting lionfish for consumption. Lionfish are an invasive species found around the world. Their presence has fueled management strategies that predominantly rely on promoting human predation and consumption. We apply rights-based ethics, utilitarian ethics, and ecocentric environmental ethics to the question of whether hunting and eating lionfish is ethical. After applying these perspectives, we argue that, from a utilitarian perspective, lionfish should be culled. Rights-based ethics, on the other hand, are not applicable in this case, while ecocentric environmental ethics would support lionfish removal.

Perceptions of diver-fishermen and recreational divers on lionfish as a threat in the Parque Nacional Arrecife Alacranes, southern Gulf of Mexico

Worldwide, biological invasions remain an unrelenting environmental disaster. In the last years, the Indo-Pacific lionfish, Pterois volitans, has become one of the most highly surveyed biological invasions in Western Atlantic Ocean. This predator fish has the potential to affect the invaded ecosystem due to its voracity, fast population growth, and strong competition with native fauna for resources, which in turn implies a threat to coral reefs. A common strategy addressing this invasion relies on culling, which requires systematic volunteer's efforts on given areas of lionfish abundance to be effective. Understanding volunteer's perceptions towards this invasion is vital to engaging volunteers in culling campaigns. Here, we analyze perceptions, based on open questions, Likert-scale type, and Damage Schedule format, of volunteers (diver-fishermen and recreational divers), towards lionfish in the Parque Nacional Arrecife Alacranes (PNAA), off northern coast of the Yucatan Peninsula, Mexico. The results showed heterogeneous perceptions of volunteers shaped by distinct interests these groups have in the area, with diver-fishermen's concerns most related to their lobster catch and recreational divers referring mainly on uncontrolled tourism a major environmental problem in the PNAA. This scenario implies both groups remain unaware of the effects from this invasion on the coral reef ecosystem, but they showed willingness to participate in lionfish removals. A lack of robust awareness of these groups within a natural protected area in the southern Gulf of Mexico is of concern. We recommend further evaluations of users perspectives on lionfish as a threat and on lionfish as a viable market of consumption as strategy to control its population.

Precipitous Declines in Northern Gulf of Mexico Invasive Lionfish Populations Following the Emergence of an Ulcerative Skin Disease

Invasive Indo-Pacific lionfish Pterois volitans/miles have become well-established in many western Atlantic marine habitats and regions. However, high densities and low genetic diversity could make their populations susceptible to disease. We examined changes in northern Gulf of Mexico (nGOM) lionfish populations following the emergence of an ulcerative skin disease in August 2017, when estimated disease prevalence was as high as 40%. Ulcerated female lionfish had 9% lower relative condition compared to non-ulcerated females. Changes in lionfish size composition indicated a potential recruitment failure in early summer 2018, when the proportion of new recruits declined by >80%. Remotely operated vehicle surveys during 2016–2018 indicated lionfish population density declined in 2018 by 75% on natural reefs. The strongest declines (77–79%) in lionfish density were on high-density (>25 lionfish per 100 m2) artificial reefs, which declined to similar levels as low-density (<15 lionfish per 100 m2) artificial reefs that had prior lionfish removals. Fisheries-dependent sampling indicated lionfish commercial spearfishing landings, commercial catch per unit effort (CPUE), and lionfish tournament CPUE also declined approximately 50% in 2018. Collectively, these results provide correlative evidence for density-dependent epizootic population control, have implications for managing lionfish and impacted native species, and improve our understanding of biological invasions.

Integrating remote sensing and diver observations to predict the distribution of invasive lionfish on Bahamian coral reefs

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 623:1-11 (2019) - DOI: https://doi.org/10.3354/meps13067 FEATURE ARTICLE Integrating remote sensing and diver observations to predict the distribution of invasive lionfish on Bahamian coral reefs Alexandra C. D. Davis* Oregon State University, Department of Integrative Biology, 3029 Cordley Hall, 2701 SW Campus Way, Corvallis, OR 97331, USA Present address: Department of Biological Sciences, University of Alberta, CW 405, Biological Sciences Building, Edmonton, AB T6E 4R4, Canada *Corresponding author: acdavis@ualberta.ca ABSTRACT: The ongoing invasion of coral reefs in the greater Caribbean region by Indo-Pacific lionfish (Pterois spp.) poses challenges for managers. Although the dynamics and ecological effects of lionfish invasions have been examined in detail at the scale of individual reefs, relatively little information is available on the patterns of the invasion over larger areas. This study combined species counts and microhabitat observations from SCUBA surveys with satellite-derived bathymetry and habitat data to create predictive species distribution maps of lionfish in a 58 km2 region along the southern edge of the island of Eleuthera in the Bahamas. Models predicted lionfish presence, absence, and density, and were created iteratively using various resolutions and types of data to mimic the datasets that may be available to management in the region. The best-fit model for presence and absence, which combined physical variables derived from remotely sensed satellite data and diver-collected microhabitat data, predicted 89% of lionfish presence and absence. The best-fit model for lionfish density used 2 resolutions of physical habitat data as well as biological data on densities of large native groupers and accurately predicted 67% lionfish density. These results suggest that physical habitat may be more important for initial lionfish presence and that biotic interactions influence lionfish density on the reefs. Understanding the limitations and value of each type of data when creating models may be advantageous for planning targeted lionfish removals and prioritizing sites for conservation efforts. KEY WORDS: Lionfish · Pterois · Species distribution models · Remote sensing · Invasive species · Habitat mapping Full text in pdf format Information about this Feature Article NextCite this article as: Davis ACD (2019) Integrating remote sensing and diver observations to predict the distribution of invasive lionfish on Bahamian coral reefs. Mar Ecol Prog Ser 623:1-11. https://doi.org/10.3354/meps13067 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 623. Online publication date: July 30, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.

Detection and removal efficiency of invasive lionfish in the northern Gulf of Mexico

Mitigating the negative impacts of invasive lionfish (Pterois volitans/miles complex) is a top priority for marine reef fisheries management, with human removals considered the most viable approach to population control. Control efforts via diver spearfishing removals have annually removed tens of thousands of lionfish throughout their invasive range, but the effectiveness of removal efforts to remove 100% or achieve target lionfish densities in a given reef system has not been fully evaluated. Accounting for detection and removal efficacy is necessary for developing and evaluating lionfish management targets, as population- and community-level effects of lionfish removals may be diminished by undetected lionfish remaining in the system. This study quantified lionfish detection, catchability, and removal efficiency to evaluate the effectiveness of lionfish surveys and removal efforts on northern Gulf of Mexico (nGOM) artificial and natural reefs. Detection was assessed during crepuscular and midday time periods via diver and remotely operated vehicle (ROV) video surveys, with covariates for time of day and survey methodology assessed using generalized linear mixed models. Catchability and removal efficiency were estimated via depletion models based on serial removals via spearfishing on 6 artificial reefs and 9 natural reefs. A priori, we had expected lionfish detection to be higher during crepuscular periods given lionfish in the Caribbean and in their native range have been shown to forage more actively away from reefs then. However, we found lionfish detection was not significantly different between midday and crepuscular periods. Survey methodology affected detection, with 24% fewer lionfish being detected via ROV surveys versus diver surveys at artificial reefs and 72% fewer lionfish detected via ROV surveys at natural reefs. Therefore, density estimates on nGOM natural reefs, which constitute of >99% of the region’s habitat, may be higher than previously reported and problematic for lionfish management. Mean catchability for spearfishing lionfish was 0.88 on artificial reefs and 0.69 on natural reefs standardized for area. Mean removal efficiency for the first removal event was 87% on artificial reefs and 67% on natural reefs, higher than removal efficiency computed for Caribbean reefs (47%). Incomplete detection and <100% removal efficiency, in concert with density-dependent processes, may explain recent findings that sustained lionfish removal efforts had no discernible positive impacts on native reef fish communities.

The effectiveness of small-scale lionfish removals as a management strategy: effort, impacts and the response of native prey and piscivores

The effectiveness of small-scale lionfish removals as a management strategy: effort, impacts and the response of native prey and piscivores

Ongoing removals of invasive lionfish in Honduras and their effect on native Caribbean prey fishes.

The invasion of Indo-Pacific lionfish is one of the most pressing concerns in the context of coral reef conservation throughout the Caribbean. Invasive lionfish threaten Caribbean fish communities by feeding on a wide range of native prey species, some of which have high ecological and economic value. In Roatan (Honduras) a local non-governmental organisation (i.e. Roatan Marine Park) trains residents and tourists in the use of spears to remove invasive lionfish. Here, we assess the effectiveness of local removal efforts in reducing lionfish populations. We ask whether reefs subject to relatively frequent removals support more diverse and abundant native fish assemblages compared to sites were no removals take place. Lionfish biomass, as well as density and diversity of native prey species were quantified on reefs subject to regular and no removal efforts. Reefs subject to regular lionfish removals (two to three removals month−1) with a mean catch per unit effort of 2.76 ± 1.72 lionfish fisher−1 h−1 had 95% lower lionfish biomass compared to non-removal sites. Sites subject to lionfish removals supported 30% higher densities of native prey-sized fishes compared to sites subject to no removal efforts. We found no evidence that species richness and diversity of native fish communities differ between removal and non-removal sites. We conclude that opportunistic voluntary removals are an effective management intervention to reduce lionfish populations locally and might alleviate negative impacts of lionfish predation. We recommend that local management and the diving industry cooperate to cost-effectively extend the spatial scale at which removal regimes are currently sustained.

A brief review of gears associated with lionfish removals

A brief review of gears associated with lionfish removals

The role of conservation volunteers in the detection, monitoring and management of invasive alien lionfish

Across the Caribbean, targeted fishing is gaining momentum as a cost-effective method to control invasive alien lionfish (Pterois volitans and Pterois miles) by suppressing population numbers below site-specific threshold levels i.e. a population density that is predicted to cause declines in native fish biomass. Yet in marine reserve no take zones (NTZs) or reefs at depths of >18 m) where commercial fishing is either not permitted or impractical, alternative methods of lionfish control are required. This study evaluates the potential for conservation volunteers to act as citizen scientists monitoring invasive lionfish populations and to support removal efforts in Bacalar Chico Marine Reserve (BCMR), Belize. Two underwater visual census techniques were trialled with conservation volunteers, each with associated benefits and drawbacks. A log of opportunistic lionfish sightings on SCUBA dives has been used to record sightings per unit effort (SPUE) data 2011–2015. In 2014, more rigorous lionfish focused searches (lionfish-adapted belt transects) were introduced. Opportunistic lionfish sightings contributed to a five yearSPUE dataset that suggests that lionfish population growth rate has slowed in BCMR, where a lionfish removal program was also carried out by conservation volunteers over the same timeframe. However, lionfish focused searches showed that the mean density in 2014 was high (mean = 27.05 ± 8.77 fish ha-1, 1–30 m) relative to lionfish populations in their native ranges, particularly at sites at depths > 18m (mean = 43.39 ± 13.76 fish ha-1, 18–30 m). Drawing on lessons from Belize, we discuss the potential for conservation volunteers to support invasive alien species (IAS) monitoring and control efforts in marine environments.

Experimental assessment of lionfish removals to mitigate reef fish community shifts on northern Gulf of Mexico artificial reefs

Substantial declines in reef fishes were observed at northern Gulf of Mexico artificial reef sites between 2009�2010 and 2011�2012, a period that bracketed the appearance of invasive lionfish in this ecosystem. Small demersal reef fishes, the predominant prey of lionfish in other sys- tems, displayed the greatest declines. However, a confounding factor during this time was the Deepwater Horizon Oil Spill (DWH) in summer 2010. In some areas, targeted lionfish removals have been demonstrated to mitigate negative effects on native fishes. Therefore, we conducted a 2 yr experiment to examine the effectiveness and ecological benefits of targeted lionfish removals at artificial reefs (n = 27) off northwest Florida, USA, where lionfish densities reached the highest recorded in the western Atlantic by 2013. All lionfish were removed via spearfishing from 17 reefs in December 2013, 9 of which were periodically re-cleared of lionfish through May 2015. Remain- ing sites served as uncleared controls. Both juvenile and adult lionfish quickly recruited to cleared reefs, with lionfish reaching pre-clearance densities in <1 yr on reefs cleared only once. Removal treatment significantly affected reef fish community structure at experimental reefs, but removal effort was insufficient to achieve substantial gains for most taxa, and declines in several taxa were observed throughout, regardless of treatment. It is unclear whether chronic effects of the DWH or regionally high lionfish densities were more important factors in explaining trends observed in reef fish communities, but small-scale targeted lionfish removal efforts had few positive impacts overall on native reef fish communities in this study.

Invasive lionfish increase activity and foraging movements at greater local densities

Density-dependent changes in predator foraging behavior due to intraspecific com- petition for food can have important implications for population dynamics of both the predator and its prey. The Indo-Pacific red lionfish Pterois volitans is an invasive predatory reef fish that has reached high population densities and can cause large reductions in small native fishes. To deter- mine whether lionfish behavior or movement varies with local lionfish and/or prey densities, I con- ducted observations of lionfish on 16 coral patch reefs in The Bahamas. Lionfish foraging activity and movement varied significantly with lionfish density. At higher densities, lionfish exhibited greater activity levels, time away from shelter, and more short-term foraging movements between coral patch reefs and surrounding seagrass habitats. However, these changes were not uniform throughout the day, with differences in activity occurring only at dusk and differences in move- ment occurring at both dawn and dusk, but not midday. Although some lionfish foraging behav- iors varied with prey density, overall lionfish density was more strongly related to differences in lionfish activity patterns. These temporal and spatial changes in lionfish foraging behaviors are consistent with the predicted effects of intraspecific competition and may have important conse- quences for lionfish removal efforts and native prey populations. Specifically, in areas with higher lionfish densities, prey fishes that are more active at dusk and/or inhabit seagrass beds near coral patch reefs may be more vulnerable to lionfish predation. By culling lionfish, managers may reduce the local foraging movements of lionfish and thus help maintain native fish communities in multiple habitats.

A lionfish (Pterois miles) invasion has begun in the Mediterranean Sea

Until now, few sightings of the alien lionfish Pterois miles have been reported in the Mediterranean and it was questionable whether the species could invade this region like it has in the western Atlantic. Here, we present evidence from divers and fishermen that lionfish have recently increased in abundance and within a year colonised almost the entire south eastern coast of Cyprus, likely due to sea surface warming. At least 23 different fish are reported of which 6 were removed. Groups of lionfish exhibiting mating behaviour have been noted for the first time in the Mediterranean. Managers need this information and should alert stakeholders to the potential ecological and socio-economic impacts that may arise from a lionfish invasion. Actions could involve incentives to engage divers and fishermen in lionfish removal programmes, as these have worked well at shallow depths in the Caribbean. Given that the Suez Canal has recently been widened and deepened, measures will need to be put in place to help prevent further invasion.

Measuring Bahamian lionfish impacts to marine ecological services using habitat equivalency analysis

Marine ecological services provide goods, amenities, food resources, and economic benefits to millions of people globally. The loss of these services, attributed to the infiltration of marine invasive species such as the Indo-Pacific lionfish (Pterois volitans/miles), is measurable. The highly successful lionfish now flourishes in great densities in the US Gulf of Mexico and Atlantic waters and the entire Caribbean, yet the loss of ecological services attributed to the invader has not yet been assessed. In this study, we employ a derivative of a well-utilized method of ecosystem valuation known as habitat equivalency analysis to measure the time-value-adjusted loss of biomass- and recruitment-related ecosystem services brought by lionfish to Bahamian reefs. Drawing upon the literature examples of tangible lionfish damages in the Bahamas, we (1) quantitatively evaluate the loss of ecosystem services instigated by lionfish by measuring the total service-year losses partitioned over yearly time steps, (2) provide a metric by which ocean managers may value the remunerations of Bahamian lionfish controls when weighed against removal costs, and (3) deliver a tool to quantify changes in ecosystem services as a consequence of invasive species impacts and control. We found that the invader imposed losses of 26.67 and 21.67 years to recruitment and biomass services per km2 of Bahamian reef if left uncontrolled. In the same accord, the most conservative Bahamian lionfish removal regime modeled, i.e., which produced a 50 % recovery of pre-lionfish ecosystem function over 10 years, provided service gains of 9.57 and 4.78 years per km2. These data deliver a platform upon which to quantify present and future fiscal costs of the lionfish invasion and also to value lionfish control efforts.

Ecology and management of the invasive lionfish Pterois volitans/miles complex (Perciformes: Scorpaenidae) in Southern Costa Rica.

Invasive species alter ecosystem integrity and functioning and are considered one of the major threats to biodiversity on a global scale. The indopacific lionfish (Plerois volitans [Linnaeus, 1758] / miles [Bennet, 1882] complex) is the first non-native marine fish that has established itself in the Western Atlantic. It was first reported in Florida in the 1980s and then spread across the entire Caribbean in subsequent years. In Costa Rica, lionfish were first sighted by the end of 2008 and are now present in all South Caribbean reefs. Lionfish are a major problem for local fisherman by displacing native fish species. The aim of this study was to determine population density, size and diet of lionfish populations at four study sites along the Southern Caribbean coast of Costa Rica. Two of the sites were located inside the National Park Cahuita where regular lionfish removal occurs, whereas the other two study sides do not experiment this kind of management. Total length and wet weight of >450 lionfish individuals were determined between March and June 2011. Three relative metrics of prey quantity (percent number, percent frequency, and percent weight) were compared from approximately 300 lionfish caught with the polespear in shallow waters (<7 m depth). Population density was assessed weekly through visual transect surveys. Our results showed that lionfish preyed mostly upon teleosts and crustaceans. Teleosts dominated lionfish diet in percent frequency (71%) and percent weight (85%), whereas crustaceans had the highest percent number (58%). The top five teleost families of dietary importance were Pomacentridae, Acanthuridae, Blennidae, Labridae and Serranidae. The average total length (+/- SD) of lionfish was 18.7 (+/- 5.7)cm and varied significantly between sites (p<0.001). Mean density of lionfish was 92fish/ha with no significant differences between sites. Smallest fish and lowest densities were found at the two sites inside the National Park Cahuita. Despite management efforts on a regional scale, nationwide efforts are ineffective and lionfish control activities are poorly implemented. We conclude that there is an urgent need to develop an improved institutional framework for local lionfish control that promotes effective coordination among the relevant stakeholders in order to deal with invasive lionfish in Costa Rica.

Spatial and temporal distribution of the invasive lionfish Pterois volitans in coral reefs of Tayrona National Natural Park, Colombian Caribbean.

The lionfish Pterois volitans is an invasive species throughout the Western Atlantic that disturbs functioning of local ecosystems such as coral reefs via fast and intense consumption of small fish and invertebrates. In 2009, lionfish populated the bays of Tayrona National Natural Park (TNNP), a biodiversity hotspot in the Colombian Caribbean that is strongly influenced by changing environmental conditions due to a rainy and dry season. So far, the spatial and temporal distribution of P. volitans in the bays of TNNP is unknown. Therefore, this study assessed the abundance and body lengths of P. volitans during monthly surveys throughout the year 2012 in four bays (thereof two bays where lionfish removals were undertaken) of TNNP at 10 m water depth in coral reefs using transect tools. Findings revealed lionfish abundances of 2.9 ± 0.9 individuals ha−1 with lengths of 20–25 cm for TNNP, hinting to an established, mostly adult local population. Actual TNNP lionfish abundances are thereby very similar to those at Indo–Pacific reef locations where the invasive lionfish formerly originated from. Significant spatial differences for lionfish abundances and body lengths between different bays in TNNP suggest habitat preferences of P. volitans depending on age. Lionfish abundances were highly variable over time, but without significant differences between seasons. Removals could not reduce lionfish abundances significantly during the period of study. This study therefore recommends improved management actions in order to control the already established invasive lionfish population in TNNP.