RESUMO
Marine debris is a persistent and pervasive threat worldwide including inside marine protected areas (MPAs). To assess marine debris accumulation rates and potential impacts, we counted and evaluated trap, non-trap fishing gear, and non-fishing debris in unprotected areas and MPAs with different management boundary regulations in the Florida Keys (USA). Analyses identified that neither MPA type nor size were strong drivers of debris density and that debris densities were not statistically different between unprotected areas and MPAs. Non-fishing and non-trap fishing gear debris densities were potentially related to unexplored local differences in human behavior, while trap debris density was likely associated with oceanographic forces that transported traps into the MPAs. Overall, our results suggested that the drivers of marine debris accumulation for each debris category were different and may vary with each individual MPA, and that marine debris is not constrained by MPA boundaries.
Assuntos
Conservação dos Recursos Naturais , Poluentes da Água , Animais , Ecossistema , Peixes , Florida , Humanos , Caça , OceanografiaRESUMO
The pathogenic virus Panulirus argus virus 1 (PaV1) was first discovered in Caribbean spiny lobsters Panulirus argus from the Florida Keys (USA) in 1999 and has since been reported in Belize, Mexico, and Cuba; its distribution in the wider Caribbean is unknown. We collected tissue samples from adult spiny lobsters from 30 locations in 14 countries bordering the Caribbean Sea and used molecular diagnostics to assay for the presence of PaV1. PaV1 occurred primarily in the northern areas of the Caribbean, where its prevalence was highest. The virus was not found in lobsters from the southeastern Caribbean, and its prevalence was lowest in the southwestern Caribbean. DNA sequence analysis was performed on a fragment of the viral DNA to examine the genetic diversity of PaV1 on a Caribbean-wide scale. Sequence variation in the viral DNA fragment was high, with 61 unique alleles identified from 9 areas. The sharing of viral alleles in lobsters from distant locations supports the hypothesis of a strong genetic connectivity among lobsters within the Caribbean, and further supports the hypothesis that postlarvae infected with PaV1 may serve to disperse the virus over long distances.
Assuntos
Vírus de DNA/genética , Vírus de DNA/isolamento & purificação , Palinuridae/virologia , Animais , Região do Caribe , Interações Hospedeiro-PatógenoRESUMO
Accurate age estimates for Panulirus argus, the commercially important Caribbean spiny lobster, would greatly enhance life history and population analyses. Most age approximations of P. argus are based on size and growth data, but size is generally considered a poor proxy for age of crustaceans in the field because of numerous environmental, density-dependent, and fishery-related factors. An established technique for aging crustaceans, employing histologically determined lipofuscin content in the nervous system, was investigated using known-age lobsters reared in the laboratory at ambient temperatures. We verified the presence of lipofuscin in eyestalk neural tissue by using autofluorescence and Sudan black staining and described its distribution in cell cluster A of the hemiellipsoid body. Neurolipofuscin accumulated with age; the overall trend was linear with indications of seasonal oscillation, whereas growth began to approach an asymptote after 3 years. Differences in the neurolipofuscin concentrations in the two eyestalks from the same animal were statistically insignificant. There was also no difference in the neurolipofuscin concentrations of males and females of the same age. The present data suggest a maximum potential lifespan for P. argus of about 20 years. These results also suggest that the neurolipofuscin technique will be valuable for estimating age of wild-caught specimens of P. argus.