Home range, space use, and vertical distribution of Nassau grouper (Epinephelus striatus) during non-spawning times in Western Puerto Rico

Understanding animal space use patterns is critical for ecological research and conservation efforts. An organism’s home range territory serves as the fundamental unit of space use and is the area repeatedly used for routine activities. Nassau grouper, Epinephelus striatus, once of high commercial fishery importance, are now on the IUCN’s Red List designated as Critically Endangered due to overexploitation. Known for the formation of large spawning aggregations, information on their movements and space use dynamics outside of the reproductive period are lacking. In this study, we used acoustic telemetry to quantify the non-spawning horizontal and vertical space use patterns of Nassau grouper at the Bajo de Sico seamount, a seasonally closed marine protected area (MPA) in Puerto Rico. Twenty-nine groupers were tagged with acoustic transmitters, of which, fourteen were tracked continuously over a three-year period. Tagged individuals displayed high site fidelity to home reef locations and individuals occupied home ranges of relatively small size that remained constant between years. There was a high degree of overlap of home range territories and in locations where multiple individuals occupied the same home reef, individuals maintained discrete vertical distributions. Nassau groupers were recorded making multiple forays to the spawning site outside of the reported spawning season, and two individuals underwent home reef site relocation. Results indicate relatively low contribution to ecological connectivity during the non-reproductive period, therefore high relative abundances of this species are needed to fulfill their ecological role at the community level. The results also highlight the importance of Bajo de Sico, an isolated seamount of relatively deeper depth, as critical habitat for primary home reef sites of Nassau grouper. These results provide a basis for adapting the current management strategy at this MPA to provide adequate protection to the non-spawning population of Nassau grouper

The Purr of the Lionfish: Sound and Behavioral Context of Wild Lionfish in the Greater Caribbean

Passive acoustic technology has become a useful and cost-effective method to collect data with very high temporal resolution that can be used to detect the presence, distribution, and remotely monitor soniferous marine biodiversity. In order to maximize the potential of bioacoustic and soundscape research in the oceans, understanding the association between the different realms of sound sources, species-specific calls and behavioral context of sound production are fundamental. A previously unknown vocalization was associated with a behavioral display of lionfish (Pterois spp.) by recordings with synchronous audio and video at deep coral reefs in both Puerto Rico and the Florida Keys. Calls of variable length in bouts of intermittent calls were heard along displays between pairs of lionfish. Calls had a mean frequency of 251 Hz and very low mean SPL (72-67 dB re 1μPa). This sound may be classified as courtship related as it was observed between two lionfish that appeared of dissimilar size (presumably male and female), engaged in following and circling displays. The sound occurred in the afternoons near sunset at both sites. This is the first reported sound produced by lionfish in association with a behavioral display in the wild. Low sound pressure levels suggest this is a quiet signal for communication between individuals in close proximity. With this description the presence of lionfish in areas deeper than normal diving limits or during inaccessible times, e.g., during the evening, could be pursued

Français

The current state of the biodiversity and ecosystems of the Caribbean is a complex predicament developed from the historical interactions of human populations. Resource and ecosystem conservation requires an understanding of the human and natural dimensions of the problems and a research and conservation strategy that unifies both experiences. We believe that the current emphasis on ecosystem-based fisheries management (EBFM) approaches—among the fisheries management community—present the greatest opportunity to achieve this. EBFM aims to protect the structure and quality of habitats, maintaining ecosystem integrity and function, with a precautionary approach, and recognizes “limits to production” and seeks to “control rates of extraction.” On a theoretical level, the EBFM must operate under the social-ecological system framework (“a coupled human-environment system”). Much is said about the need to incorporate the social sciences into EBFM strategies, and lip service is paid to the importance of the human dimension, but in reality, that is seldom achieved, if ever. Furthermore, there are no specific plans or models to approach this human dimension in principled, formal ways. This paper discusses the current use of EBFM in the Caribbean and presents a handful of recommendations to make it work.El estado actual de los ecosistemas caribeños se encuentra en una difícil situación como resultado de las presiones de uso a través de la historia. La conservación de los recursos naturales requiere de la comprensión de las dimensiones naturales y humanas del problema, así como el desarrollo de una estrategia de investigación y conservación que unifique ambas experiencias. El manejo de pesquerías basado en el ecosistema (EBFM, por sus siglas en inglés) presenta una gran oportunidad para lograr esto. El EBFM busca proteger la estructura y la calidad de los hábitats, manteniendo la integridad y función del ecosistema, empleando un enfoque precautorio y reconociendo los límites naturales y económicos del recurso pesquero. Teóricamente, el EBFM debe operar bajo el marco del sistema ecológico-social (“un sistema humano-ambiental acoplado”). Se ha hablado mucho sobre la necesidad de incorporar a las ciencias sociales en las estrategias del EBFM, pero han quedado como promesas incumplidas, ya que es difícil encontrar planes concretos que logren incorporar efectivamente la dimensión humana al manejo de las pesquerías. Este artículo discute el uso actual del EBFM en Puerto Rico y el Caribe, y presenta un puñado de recomendaciones puntuales para lograr su funcionamiento.L’état actuel de l’écosystème caribéen se trouve dans une situation difficile à cause des pressions exercées par la population à travers leur histoire sur son utilisation. La conservation des ressources naturelles nécessite une compréhension des dimensions naturelles et humaines du problème, ainsi qu’une stratégie de recherche et de conservation réconciliant les deux expériences. La gestion de la pêche basée sur l’écosystème (connue par son sigle anglais EBFM) offre une grande opportunité de grandes perspectives pour y arriver parvenir. L’EBFM cherche a vise à protéger la structure et la qualité de l’habitat, en préservant l’intégrité et le fonctionnement de l’écosystème, en mettant l’emphase sur la prévention et utilise une approche préventive, et en reconnaissant les limites naturelles et économiques de la pêche en termes d’exploitations piscicoles. Théoriquement, l’EBFM doit opérer dans le cadre du système socio-écologique (une liaison entre le système humain et l’environnement). En dépit de nombreuses discussions, presque rien n’a été fait dans une perspective d’équilibrer les stratégies de l’EFBM et les sciences sociales, car il est difficile de trouver des plans concrets permettant l’intégration des dimensions humaines dans la gestion de la pêche. Cet article traite de l’utilisation actuelle de l’EBFM à Porto Rico ainsi que dans la Caraïbe, et présente une poignée de recommandations visant à favoriser son efficacité

Recovery when you are on your own: Slow population responses in an isolated marine reserve.

Geographic isolation is an important yet underappreciated factor affecting marine reserve performance. Isolation, in combination with other factors, may preclude recruit subsidies, thus slowing recovery when base populations are small and causing a mismatch between performance and stakeholder expectations. Mona Island is a small, oceanic island located within a partial biogeographic barrier-44 km from the Puerto Rico shelf. We investigated if Mona Island's no-take zone (MNTZ), the largest in the U.S. Caribbean, was successful in increasing mean size and density of a suite of snapper and grouper species 14 years after designation. The La Parguera Natural Reserve (LPNR) was chosen for evaluation of temporal trends at a fished location. Despite indications of fishing within the no-take area, a reserve effect at Mona Island was evidenced from increasing mean sizes and densities of some taxa and mean total density 36% greater relative to 2005. However, the largest predatory species remained rare at Mona, preventing meaningful analysis of population trends. In the LPNR, most commercial species (e.g., Lutjanus synagris, Lutjanus apodus, Lutjanus mahogoni) did not change significantly in biomass or abundance, but some (Ocyurus chrysurus, Lachnolaimus maximus), increased in abundance owing to strong recent recruitment. This study documents slow recovery in the MNTZ that is limited to smaller sized species, highlighting both the need for better compliance and the substantial recovery time required by commercially valuable, coral reef fishes in isolated marine reserves

Author Correction: Global status and conservation potential of reef sharks

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.</p

Widespread diversity deficits of coral reef sharks and rays

A global survey of coral reefs reveals that overfishing is driving resident shark species toward extinction, causing diversity deficits in reef elasmobranch (shark and ray) assemblages. Our species-level analysis revealed global declines of 60 to 73% for five common resident reef shark species and that individual shark species were not detected at 34 to 47% of surveyed reefs. As reefs become more shark-depleted, rays begin to dominate assemblages. Shark-dominated assemblages persist in wealthy nations with strong governance and in highly protected areas, whereas poverty, weak governance, and a lack of shark management are associated with depauperate assemblages mainly composed of rays. Without action to address these diversity deficits, loss of ecological function and ecosystem services will increasingly affect human communities

Global status and conservation potential of reef sharks

Decades of overexploitation have devastated shark populations, leaving considerable doubt as to their ecological status1,2. Yet much of what is known about sharks has been inferred from catch records in industrial fisheries, whereas far less information is available about sharks that live in coastal habitats3. Here we address this knowledge gap using data from more than 15,000 standardized baited remote underwater video stations that were deployed on 371 reefs in 58 nations to estimate the conservation status of reef sharks globally. Our results reveal the profound impact that fishing has had on reef shark populations: we observed no sharks on almost 20% of the surveyed reefs. Reef sharks were almost completely absent from reefs in several nations, and shark depletion was strongly related to socio-economic conditions such as the size and proximity of the nearest market, poor governance and the density of the human population. However, opportunities for the conservation of reef sharks remain: shark sanctuaries, closed areas, catch limits and an absence of gillnets and longlines were associated with a substantially higher relative abundance of reef sharks. These results reveal several policy pathways for the restoration and management of reef shark populations, from direct top-down management of fishing to indirect improvement of governance conditions. Reef shark populations will only have a high chance of recovery by engaging key socio-economic aspects of tropical fisheries