Control Strategy Scenarios for the Alien Lionfish Pterois volitans in Chinchorro Bank (Mexican Caribbean): Based on Semi- Quantitative Loop Analysis (original) (raw)

Predicted impact of the invasive lionfish Pterois volitans on the food web of a Caribbean coral reef

Environmental Research, 2011

The invasion of lionfish in the Caribbean is causing grave concern because of its deleterious impacts on coral reef food-webs. We have used an Ecopath-with-Ecosim model to predict the impacts of lionfish invasion on a coral reef community based on pre-invasion fish community data. Forty-six groups were defined, and an initial Ecopath model was balanced with a near-zero biomass of lionfish. In Ecosim, the near-zero biomass was eradicated by applying a very high fishing pressure in the first year of simulation. We subsequently (re-)introduced lionfish with a very low biomass, and allowed them to increase to very high abundance. With a near-zero lionfish biomass, the great majority of mesocarnivorous/omnivorous coral reef fish were predicted to be dominant while sharks were predicted to be the apex predators. Different management scenarios were established in the ecosystem to explore the eradication and resilience of lionfish. The management scenarios showed that if all adult lionfish were exploitable it will in theory be possible to fish the lionfish to a very low level, but the fishing pressure will have to be maintained, or the lionfish will recover. If the largest individuals are unexploitable it will be much more difficult to control the lionfish population.

The impacts of the invasive lionfish on Caribbean food webs

Increased rates of species extirpation or extinction have often been attributed to the foraging behavior of invasive predators, with drastic effects on native food webs. In the Caribbean, the invasive red lionfish (Pterois volitans) is of primary concern, as it reduces the overall recruitment and biomass of reef fishes by as much as 80% and 65%, respectively. Understanding the functional role that this predator plays in the context of entire communities is critical to assessing how it impacts those that have already experienced regime shifts due to disturbance. Here, a trait-based ecospace was employed to characterize the functional role of red lionfish trophic behavior, focusing on a regional pool of reef fishes from Jamaica, Cuba, and the Cayman Islands. A high-resolution model of a Greater Antilles coral reef food web, including micro- and macrobiota, producers and consumers, and invertebrates and vertebrates, was used to assess the impacts of P. volitans on community structural ...

Flow of Economic Benefits From Coral Reefs in a Multi-Use Caribbean Marine Protected Area Using Network Theory

Frontiers in Marine Science, 2021

Adaptation to changes in the delivery of ecosystem services while maintaining resilience of natural systems is one of the main challenges faced by multi-use marine protected areas (MPAs). To overcome this, it is crucial to improve our understanding of interdependencies among resource users and ecosystems. In this study we used networks to model the socio-ecological system of a multi-use MPA in the southern Caribbean. Using a mixed-method approach, we built a socio ecological network (SEN) from the flow of economic benefits that stakeholders obtain from coral reefs in Los Roques National Park. We specifically looked at how these benefits are distributed among stakeholder groups and how the structure and other network properties can inform management. For this, four networks (simple, weighted, directed and directed-weighted) were built from 125 nodes representing three services and six stakeholder groups, linked through 475 edges. The SEN structure indicated an open resource use patte...

A multi-agent ecosystem model for studying changes in a tropical estuarine fish assemblage within a marine protected area

Aquatic Living Resources, 2013

As marine protected areas (MPAs) are increasingly being utilised as a tool for fishery management, their impact on the food web needs to be fully understood. However, little is known about the effect of MPAs on fish assemblages, especially in the presence of different life history and ecological traits. Modelling the observed changes in fish population structures may provide a mechanistic understanding of fish assemblage dynamics. In addition, modelling allows a quantitative estimate of MPA spill-over. To achieve this purpose, we adapted an existing ecosystem model, OSMOSE (Object-oriented simulator of marine biodiversity exploitation), to the specific case of the presence of fish with multiple life histories. The adapted model can manage 4 main categories of life history identified in an estuary MPA: fish that (1) spend their entire life cycle locally, (2) are present only as juveniles, (3) enter the area as juveniles and stay permanently except during reproduction periods, which occur outside the estuary, and (4) are present occasionally and for a short time for foraging purposes. To take into account these specific life-history traits, the OSMOSE code was modified. This modelling approach was developed in the context of the Bamboung Bolong MPA, located in a mangrove area in the Sine-Saloum Delta, Senegal. This was the ideal case to develop our approach as there has been scientific monitoring of the fish population structure inside the MPA before fishery closure, providing a reference state, and continuous monitoring since the closure. Ecologically similar species were pooled by trophic traits into 15 groups that represented 97% of the total biomass. Lower trophic levels (LTL) were represented by 6 compartments. The biomass of the model species was calibrated to reproduce the reference situation before fishery closure. Model predictions of fish assemblage changes after fishery closure corresponding to the Bamboung MPA creation scenario were compared to field observations; in most cases the model reproduces observed changes in biomass (at least in direction). We suggest the existence of a “sanctuary effect”, that was not taken into account in the model, this could explain the observed increase in biomass of top predators not reproduced by the model. Finally, the annual MPA fish spill-over was estimated at 11 tons (~33% of the fish biomass) from the model output, mainly due to diffusive effects.