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Coral reefs and associated fish populations have experienced rapid decline in the Caribbean region and marine protected areas (MPAs) have been widely implemented to address this decline. The performance of no-take MPAs (i.e., marine reserves) for protecting and rebuilding fish populations is influenced by the movement of animals within and across their boundaries. Very little is known about Caribbean reef fish movements creating a critical knowledge gap that can impede effective MPA design, performance and evaluation. Using miniature implanted acoustic transmitters and a fixed acoustic receiver array, we address three key questions: How far can reef fish move? Does connectivity exist between adjacent MPAs? Does existing MPA size match the spatial scale of reef fish movements? We show that many reef fishes are capable of traveling far greater distances and in shorter duration than was previously known. Across the Puerto Rican Shelf, more than half of our 163 tagged fish (18 species of 10 families) moved distances greater than 1 km with three fish moving more than 10 km in a single day and a quarter spending time outside of MPAs. We provide direct evidence of ecological connectivity across a network of MPAs, including estimated movements of more than 40 km connecting a nearshore MPA with a shelf-edge spawning aggregation. Most tagged fish showed high fidelity to MPAs, but also spent time outside MPAs, potentially contributing to spillover. Three-quarters of our fish were capable of traveling distances that would take them beyond the protection offered by at least 40-64% of the existing eastern Caribbean MPAs. We recommend that key species movement patterns be used to inform and evaluate MPA functionality and design, particularly size and shape. A re-scaling of our perception of Caribbean reef fish mobility and habitat use is imperative, with important implications for ecology and management effectiveness.

Every summer, divers across Florida don their masks and fins and embark on a mission to provide data about one of the world’s largest groupers. The Atlantic goliath grouper (Epinephelus itajara, hereafter referred to as goliath grouper) is a large, long-lived reef species that can reach lengths exceeding 2 m and ages of at least 37 years (Bullock et al., 1992). Occurring in subtropical/​tropical waters of the South Atlantic and Gulf of Mexico, the species suffered significant overfishing and population declines through the 1980s. In 1990, the harvest of goliath grouper was prohibited in the United States, and the species remains protected from harvest in all federal waters of the United States at this time (although the state of Florida recently approved a limited, highly regulated harvest opportunity for goliath grouper in state waters; FWC, 2022). The state of Florida has historically been a center of abundance for this species, and although numbers have been rebuilding in some areas since the moratorium, stock assessment remains complicated and the status of the population is unclear (Koenig et al., 2011; SEDAR, 2016; Locascio et al., 2023).

Lionfish (Pterois volitans/miles) have invaded the majority of the Caribbean region within five years. As voracious predators of native fishes with a broad habitat distribution, lionfish are poised to cause an unprecedented disruption to coral reef diversity and function. Controls of lionfish densities within its native range are poorly understood, but they have been recorded in the stomachs of large-bodied Caribbean groupers. Whether grouper predation of lionfish is sufficient to act as a biocontrol of the invasive species is unknown, but pest biocontrol by predatory fishes has been reported in other ecosystems. Groupers were surveyed along a chain of Bahamian reefs, including one of the region's most successful marine reserves which supports the top one percentile of Caribbean grouper biomass. Lionfish biomass exhibited a 7-fold and non-linear reduction in relation to the biomass of grouper. While Caribbean grouper appear to be a biocontrol of invasive lionfish, the overexploitation of their populations by fishers, means that their median biomass on Caribbean reefs is an order of magnitude less than in our study. Thus, chronic overfishing will probably prevent natural biocontrol of lionfishes in the Caribbean.

We tracked locations of three fish species in two bays with differing hydrology in SW Florida in 2018–2020 to test the hypotheses about fish residency, movements, and environmental variables. Due to extensive watershed modification, one bay receives less freshwater and the other receives more relative to natural conditions. Home range duration differed for gray snapper (54 ± 6 days), red drum (132 ± 39), and goliath grouper (226 ± 63). Distances between relocation movements were similar for gray snapper and red drum (~ 1.2 km), but farther for goliath grouper (2.3 ± 0.3 km). Relocations were primarily seaward for gray snapper (83%) but varied for the other species. Home range duration related to age for goliath grouper (< 100 days for 1–1.5-year-olds, 300–425 days for 4–4.5-year-olds). Generalized additive models marginally related probability of gray snapper relocating to salinity and temperature whereas relocations of the other species occurred during all environmental conditions. Movement simulations lacking environmental cues produced similar emigration patterns as observed in tagged fish. Overall, results suggest that movements here are not strongly linked to environmental conditions, will be resilient to watershed restoration that should moderate salinity, and have implications for understanding the impacts of localized depletion due to recreational fishing.

The goliath grouper Epinephelus itajara (Perciformes: Epinephelidae) is a large, critically endangered fish distributed across coastal habitats in the western Atlantic Ocean, from Florida to southern Brazil, and with additional populations in the eastern Pacific basin. Conservation concerns for this species stem from historical overfishing, habitat loss, and life‐history traits such as slow growth and late sexual maturity. In this study, to aid conservation efforts, we assembled and characterized the complete mitochondrial genome of E. itajara. The mitochondrial genome of Epinephelus itajara is 16,561 bp long and comprises 13 protein‐coding genes (PCGs), two ribosomal RNA genes (12S and 16S rRNA), 22 transfer RNA (tRNA) genes, and an 856 bp control region. Gene order is identical to that reported for other congeneric species. The overall A + T content is 56%, and codon usage shows a preference for A + T‐rich codons. All PCGs were found to be under purifying selection, with variation in selective pressure among genes; cox1 and nad4 were under the strongest and weakest selection, respectively. Secondary structure analysis of the tRNA genes displayed typical cloverleaf secondary structures, except for trnS1, which lacked a complete D‐arm. Comparative analyses between MiTFi and RASP2 revealed that MiTFi provided more accurate predictions of tRNA secondary structures. The control region exhibited a high A + T content (69.9%), multiple microsatellite motifs, and one tandem repeat, along with hairpin secondary structures. These features mirror findings in closely related species. A maximum likelihood phylogenetic analysis based on translated PCGs did not support the monophyletic status of the genus Epinephelus and indicated a sister relationship between Epinephelus itajara and Epinephelus lanceolatus, another large‐bodied grouper from the Indo‐Pacific Ocean. The newly sequenced mitochondrial genome of Epinephelus itajara provides a new genomic resource that can support future conservation efforts. This study presents the complete mitochondrial genome of the critically endangered Goliath Grouper (Epinephelus itajara), totaling 16,561 bp and comprising 13 protein‐coding genes, 22 tRNAs, and two rRNAs. Genomic analysis revealed conserved gene order, A + T‐rich codon usage, and purifying selection across all protein‐coding genes, providing valuable resources for conservation genetics and species identification. Photograph by Albert Kok, used with permission.

Marine fish abundance and distribution often varies across spatial scales for a variety of reasons, and this variability has significant ecological and management consequences. We quantified the distribution of reef-associated fish species along the southeast United States Atlantic coast using underwater video survey samples (N = 4,855 in 2011-2014) to elucidate variability within species across space, depths, and habitats, as well as describe broad-scale patterns in species richness. Thirty-two species were seen at least 10 times on video, and the most commonly observed species were red porgy (Pagrus pagrus; 41.4% of videos), gray triggerfish (Balistes capriscus; 31.0%), black sea bass (Centropristis striata; 29.1%), vermilion snapper (Rhomboplites aurorubens; 27.7%), and red snapper (Lutjanus campechanus; 22.6%). Using generalized additive models, we found that most species were non-randomly distributed across space, depths, and habitats. Most rare species were observed along the continental shelf break, except for goliath grouper (Epinephelus itajara), which was found on the continental shelf in Florida and Georgia. We also observed higher numbers of species in shelf-break habitats from southern North Carolina to Georgia, and fewer in shallower water and at the northern and southern ends of the southeast United States Atlantic coast. Our study provides the first broad-scale description of the spatial distribution of reef fish in the region to be based on fishery-independent data, reinforces the utility of underwater video to survey reef fish, and can help improve the management of reef fish in the SEUS, for example, by improving indices of abundance.

The East Continental Shelf (ECS) of Brazil is a hotspot of endemism and biodiversity of reef biota in the South Atlantic, hosting a number of Marine Protected Areas (MPAs). Connectivity of MPAs through larval dispersal influences recruitment, population dynamics, genetic structure and biogeography in coral reef ecosystems. Connectivity of protected reef ecosystem in the ECS was investigated with a hydrodynamic model (ROMS) forcing an Individual Based Model (IBM-Ichthyop), and used groupers (genus Mycteroperca) as functional group. The hydrodynamic output from ROMS was compared with satellite data and showed good agreement with observed surface fields. Eggs were released, in IBM experiments, from April to September along six years (2002-2007) in five MPAs along the ECS. Intrannual variability in recruitment and self-recruitment of grouper larvae was observed, as well as a negative correlation of these population parameters with total Kinetic Energy (KE) used as a metric of the physical environment. Higher KE leads to increased offshore advection of larvae, reduced total recruitment and connectivity of MPAs. Our results indicate high and uni-directional connectivity between MPAs from north to south influenced by the Brazil Current flowing in the same direction. Results also showed that some MPAs act predominantly as \"sink\" while others are mainly \"source\" areas.

Rare species necessitate alternative survey techniques and, in the case of exploited resources, any attempt to monitor their abundance with a meaningful benchmark should also include local ecological knowledge (LEK) of local users. This study evaluates the status of Goliath grouper (Epinephelus itajara) in the Mexican Caribbean via LEK and also direct acquisition of data on habitat use of the species in Chetumal Bay, taking into account distribution by body size, site, and habitat. We interviewed 124 fishers about their knowledge and experience with Goliath grouper, comparing northern to southern Mexican Caribbean, as well as older vs. younger fishers. The species is a well-identified resource; fishers are able to describe many behavioral and habitat-use traits, but they find it difficult to discern males from females and juveniles from adults. The fishery is opportunistic and the capture is commercialized and consumed only locally. The species has declined over the last decades, the probable cause being the increase in the number of fishers and boats, as well as the use of harpoon by divers. In addition to the interviews, 54 specimens were recorded in Chetumal Bay, standard length 517–1613 mm. Goliath grouper preferred submerged sinkholes and caves, locally called “pozas,” with water temperature of 23–31 °C and salinity of 4.5–30.0 psu, 1.5–40.0 m deep. Although access to “pozas” can be dangerous—a fact that could favor viability of Goliath grouper—even in these sites, the fishery extracts young and subadult animals, probably affecting population dynamics.

The concentrations of mercury, lead, cadmium, and arsenic were evaluated in 96 samples, 12 by each one of the following eight fish species: snook (Centropomus undecimalis), crevalle jack (Caranx hippos), Serra Spanish mackerel (Scomberomorus brasiliensis), southern red snapper (Lutjanus purpureus), blue runner (Caranx crysos), Atlantic tarpon (Megalops atlanticus), ladyfish (Elops saurus), and Atlantic goliath grouper (Epinephelus itajara), which were collected during 1 year in the Atrato River Delta in the Gulf of Urabá, Colombian Caribbean. Three fish were caught from each of the following sites the community usually uses to catch them (known as fishing grounds): Bahía Candelaria, Bahía Marirrío, Bocas del Roto, and Bocas del Atrato. The quantification of metals was performed by microwave-induced plasma-optical emission spectrometry. The Pb concentration fluctuated from 0.672 to 3.110 mg kg−1, surpassing the maximum permissible limit (MPL = 0.3 mg kg−1) for human consumption for all species. The Hg concentration ranged between < Limit of detection and 6.303 mg kg−1, and in the crevalle jack and Atlantic tarpon, concentrations exceeded the MPL (0.5 mg kg−1). The levels of Cd and As were not significant in the studied species and did not exceed the MPL (0.05 mg kg−1).

The lack of data on the age, growth, and reproduction of the Atlantic Goliath Grouper Epinephelus itajara off the coasts of Florida (USA) makes it difficult to estimate the extent of their population recovery following the 1990 fishery closure, as well as the potential effects of the recent (2023) opening of a fishery for juveniles. Goliath Grouper from the Atlantic coast of Florida were non-lethally sampled for size (total length, TL), age (via fin rays), and sex and reproductive stage (via gonad biopsies, milt/egg expression, gonopores) from May to October 2010–2016. Of 653 unique fish captured (not including 118 recaptures), 257 (39.4%) were females (122–228 cm TL; 5–20 years old), 264 (40.0%) were males (104–225 cm TL; 4–22 years old), 100 (15.3%) were unsexed (82–211 cm TL; 3–15 years old), and 32 (4.9%) were protogynous hermaphrodites (108–209 cm TL; 5–20 years old). Protogyny was conclusively determined in two fish recaptured and re-biopsied that had transitioned from female to male. However, an overlap in the age and size of males and females, a 1:1 sex ratio, and the presence of relatively small, young, mature males, in combination with an apparently low functional sex change rate, all indicated that the sexual pattern of Goliath Grouper was functionally gonochoristic with the potential for diandric protogyny. Females > 10 years old were larger-at-age than males, and Goliath Grouper from the Atlantic coast were larger-at-age than fish from the Gulf of Mexico. These differences in age, growth, and reproductive strategy—as well as the nascent fishery for juveniles—need to be monitored closely so that the current and future reproductive capacity of the population continues to ensure growth and sustainability.