Species

We recorded the first sighting and collection of the non-native, invasive red lionfish (Pterois volitans [Linnaeus, 1758]: Scorpaenidae) in the southern Gulf of Mexico, off the northern Yucatan Peninsula. In December 2009, two individuals were sighted (one of them speared) at 38 m depth over a reef formation, about 58 km northwest of the Alacranes Reef National Park, which is located 130 km off the northern coast of the Yucatan Peninsula, Mexico. More than 20 years after the introduction of P. volitans into the western Atlantic, specifically off the Florida and North Carolina coasts, the invasion circuit now appears to be closing in, since this new record was made about 800 km from the Dry Tortugas and Marquesas, Florida. This recording appears to be the first introgression of the P. volitans population into the Gulf of Mexico via larval transport. 

Management Recommendations:

• To keep collecting data for long term monitoring programs. It is fundamental for the proper management of our natural resources.
• Given the lack of staff and the achievement of the objectives, lower the frequency of the surveys and use the new methodology that requires only one surveyor.
• Increase the number of staff in the Natural and Historic Resources Unit.
• Discuss possible management actions to mitigate or eliminate the threats discovered at the roost. 

The use of satellite tracking for the fundamental and applied study of marine turtles began in the 1980s but has undergone rapid growth in recent years. To provide a background against which to judge the past success and future directions of these research efforts we carried out a comprehensive review of over 130 scientific papers on the use of this technique in this taxon. We show how satellite tracking has changed over time as well as outlining biases in spatial, species and lifestage coverage. Descriptions of migration routes and other habitats have offered novel insights into the basic life history patterns of some species, highlighted focal areas for conservation and reinforced the multi-national nature of the stakeholders of many populations. In foraging areas, knowledge is growing as to how animals move within dynamic seascapes, thus facilitating our understanding of 3-dimensional habitat use and seasonal patterns of behaviour. More experimental approaches have elucidated navigational capabilities and post-release survival following fisheries interaction and long-term captivity. In addition, through the Internet and other media, satellite tracking appears to have been effective in engaging public attention in many countries. Finally, we discuss why the use of the technique has increased so markedly over time and point out key areas of concern that we feel should be addressed by the community of researchers and donors who focus on sea turtles

The invasion by Indo-Pacific lionfish (Pterois volitans and P. miles) of the western Atlantic, Caribbean and Gulf of Mexico is emerging as a major threat to coral reef communities across the region. Comparing native and introduced populations of invasive species can reveal shifts in ecology and behaviour that can accompany successful invasions. Using standardized field surveys replicated at multiple sites in Kenya and the Bahamas, we present the first direct comparisons of lionfish density, body size, biomass and behaviour between native and invaded coral reefs. We found that lionfish occur at higher densities with larger body sizes and total biomass on invaded Bahamian coral reefs than the ecologically equivalent species (P. miles) does on native Kenyan reefs. However, the combined average density of the five lionfish species (Pterois miles, P. antennata, P. radiata, Dendrochirus brachypterus and D. zebra) on Kenyan reefs was similar to the density of invasive lionfish in the Bahamas. Understanding the ecological processes that drive these differences can help inform the management and control of invasive lionfish.

The rapid invasion of lionfish into the Western North Atlantic and Caribbean will undoubtedly affect native reef fishes via processes such as trophic disruption and niche takeover, yet little is known about the dynamics of this invasion. We constructed a stage-based, matrix population model in which matrix elements were comprised of lower-level parameters. Lionfish vital rates were estimated from existing literature and from new field and laboratory studies. Sensitivity analysis of lower-level parameters revealed that population growth rate is most influenced by larval mortality; elasticity analysis of the matrix indicated strong influence of the adult and juvenile survival elements. Based on this model, approximately 27% of an invading adult lionfish population would have to be removed monthly for abundance to decrease. Hierarchical modeling indicated that this point estimate falls within a broad uncertainty interval which could result from imprecise estimates of life-history parameters. The model demonstrated that sustained removal efforts could be substantially more effective by targeting juveniles as well as adults.

Findings:

The main conclusion of this study is that the shallow, warm and saline back-water habitat which is continuing to increase in importance within Lac Bay is unable to support meaningful mangroves, seagrass or algal meadows, nor the key nursery species. As the natural process of land reclamation by mangroves carries on, the bay’s important nursery habitats will come under additional salinity stress and likely continue to decrease in coverage and quality at an accelerated rate.

Distribution of sea grass and algal beds in Lac Bay

• The valuable seagrass and mangrove habitats of Lac are currently trapped in an enclosed bay.
• High light-intensity and well-circulated shallow habitats that fringed the mangroves of the central bay have the richest assemblages with the highest biotic coverage.
• Isolated mangrove pools have the lowest total cover, species richness and biodiversity of all habitats.
• Biotic diversity and cover decrease towards the deeper parts of the bay.
• There is an alarmingly rapid invasion of the bay by the invasive seagrass H. stipulacea.

Fish species utilization of contrasting habitats in Lac Bay

• Fish community variables differ consistently among habitats and are influenced by the percent cover of seagrass vegetation or presence of mangrove-root structure.
• Mangrove fringe habitats are a premier habitat since multiple life stages of a variety of species showed highest densities there. Mangrove fringing open waters had highest overall fish densities and species diversity.
• The various vegetated sub-habitats all play a unique role for different size-classes of different fish species. 

Management Recommendations:

• Management action is needed to stem further erosion of nursery habitat quality and ensure that a tipping-point is not reached beyond which recovery may be difficult or impossible.
• Measures should be taken to help restore water depth and circulation to relieve the bay’s ecosystem of thermal and salinity stress caused by the shallow backwaters. This includes excavating accumulated erosional and biogenic sediments as well as dredging to restore former feeder channels by removal of mangrove overgrowth (as already started by Stinapa).
• Further studies to assess the impacts of the invasive seagrass H. stipulacea on the bay’s flora and fauna.

We here provide an overview of 72 invasive animals of the terrestrial and freshwater environments of the Dutch Caribbean, eleven of which are no longer present. All invasive animals that are principally agricultural pests and or animal and plant diseases (46 species) are excluded as these are discussed separately elsewhere. The 61 species documented and discussed here as presently living in the wild or semi-wild state on one or more of the Dutch Caribbean islands, amount to 12 exotic mammals, 16 birds, 13 reptiles, 5 amphibians, 2 freshwater fishes, 3 insects, 2 mollusks and 8 exotic earthworms. For most species, the ecology, distribution, status and current impact remains poorly known as few invasive species have been object of directed studies. Some of the most deleterious animal introductions have been mammals, particularly the grazers and the predators, most of which have been introduced in the historical past. Among these, the four key species are grazing goats, the mongoose the cat and the black rat. In most cases, such species cannot be eradicated because they are widespread and firmly established or even kept as livestock. Nevertheless, these species must urgently be controlled in sensitive areas where possible. Our review also shows that many introduced mammals and reptiles are still present in relatively small populations, making eradication still very feasible. Seven species have the status of being native in parts of the Dutch Caribbean but introduced to other parts where they are not native. The most threatening of this last category is the green iguana, as introduced to St. Maarten where it outcompetes and hybridizes with the weaker Lesser Antillean iguana.

The key priorities for successful action against invasive exotic animals are:

• the control of goats;
• control of introduced predators (rats and cats) near seabird breeding colonies;
• eradication of several small populations of exotic mammal predators and reptiles as long as this is possible before the get a strong foothold and spread; 
• eradication of introduced species from small satellite islands which serve (or served) as seabird breeding habitat.

In addition to such on-island action against species already present, it is critical to prevent further introductions. The most important pathways to focus control on are the container transport of goods, the international trade in pets and the trade in ornamental plants. Two key action points are urgently needed: a) develop the existing legislation and b) invasive species management teams (ISMTs) empowered for action. It is essential that these initiatives be firmly imbedded in a policy framework. The first step ahead in these respects should be to outline an Invasive Species Strategy and Action Plan (ISSAP). However, in the interim, the lack of an ISSAP should not hinder directed critical action at the local level (eg. against goats in the national parks and cats at seabird breeding sites).

This research is part of the Wageningen University BO research program (BO-11-011.05-004) and has been financed by the Ministry of Economic Affairs, Agriculture and Innovation (EL&I) under project number 4308202004. 

This document serves as a reference for the controlling and management of the invasive Indo-Pacific lionfish (Pterois miles and P. volitans complex). Lionfish are expected in St. Maarten waters in the near future and can have serious detrimental affects to the island’s marine environment, particularly to the populations of both ecologically and economically important fish species. Coral reef ecosystems can also experience degradation due to predatory stress caused by lionfish on coral reef grazers such as parrotfish (Scaridae).

The invasive lionfish also poses a threat to public health; the species has fourteen venomous spines over the length of its body which can inflict a painful sting. Particularly vulnerable to lionfish envenomations are those stakeholders of the Marine Park who have the potential of coming in close contact with the species such as fishers and divers. Recreational beach goers also face the potential of being envenomated. Envenomations can be particularly dangerous to infants, the elderly, individuals with a compromised immune system and those sensitive to the venom.

Due to the nature of the invasion of aquatic species in general and lionfish more specifically, it must be realized that a complete eradication of the species is impossible, therefore this plan will seek to actively manage lionfish in St. Maarten territorial waters. The goals and objectives of this management plan are to adequately control the impact the species will have on the ecosystem level and with regards to the risk it poses to the community and to the local economy. Management goals and objectives are coordinated and communicated with different agencies to ensure local and regional cooperation, education of and outreach to stakeholders, research and management option development on the nature of the infestation, and a species control mechanism which will seek to limit the effects of species arrival.

Management actions should be clear in both the management of the species on a local level and contributing species information on a regional and international level. Management actions in this plan are divided into two stages; pre species arrival and post species arrival actions. Actions within the two stages can belong to phase one management actions, which are the first actions to be implemented, or phase two actions, which follow phase 1 actions and are continuous. Some management actions belong to both phase one and phase two management actions. The proposed management actions for the controlling of lionfish in St. Maarten waters include education and outreach on the nature and threats of the invasion, coordination with other agencies and organizations on management options, infestation research and development such as stomach content analysis and genetic sampling, planning and assessment in the form of lionfish action protocols and lionfish sweeps, and specimen control mechanisms such as species collection and eventual culling.

Appreciation is expressed to all those who assisted with technical support regarding this Response Plan, particularly the insight gained from the St. Eustatius Lionfish Action Plan (Bervoets 2009), on which this document is based, during the Lionfish Workshop hosted by the Bonaire National Marine Park in cooperation with the Reef Environmental Education Foundation and funded by the Dutch Caribbean Nature Alliance, and various workshops given by Chris Flook of the Bermuda Museum and Zoo.