Understanding patterns of connectivity among populations of marine organisms is essential for the development of realistic, spatially explicit models of population dynamics. Two approaches, empirical genetic patterns and oceanographic dispersal modelling, have been used to estimate levels of evolutionary connectivity among marine populations but rarely have their potentially complementary insights been combined. Here, a spatially realistic Lagrangian model of larval dispersal and a theoretical genetic model are integrated with the most extensive study of gene flow in a Caribbean marine organism. The 871 genets collected from 26 sites spread over the wider Caribbean subsampled 45.8% of the 1900 potential unique genets in the model. At a coarse scale, significant consensus between modelled estimates of genetic structure and empirical genetic data for populations of the reef-building coral Montastraea annularis is observed. However, modelled and empirical data differ in their estimates of connectivity among northern Mesoamerican reefs indicating that processes other than dispersal may dominate here. Further, the geographic location and porosity of the previously described east-west barrier to gene flow in the Caribbean is refined. A multi-prong approach, integrating genetic data and spatially realistic models of larval dispersal and genetic projection, provides complementary insights into the processes underpinning population connectivity in marine invertebrates on evolutionary timescales.

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Many large-bodied marine fishes that form spawning aggregations, such as the Nassau grouper (Epinephelus striatus), have suffered regional overfishing due to exploitation during spawning. In response, marine resource managers in many locations have established marine protected areas or seasonal closures to recover these overfished stocks. The challenge in assessing management effectiveness lies largely in the development of accurate estimates to track stock size through time. For the past 15 y, the Cayman Islands government has taken a series of management actions aimed at recovering collapsed stocks of Nassau grouper. Importantly, the government also partnered with academic and nonprofit organizations to establish a research and monitoring program (Grouper Moon) aimed at documenting the impacts of conservation action. Here, we develop an integrated population model of 2 Cayman Nassau grouper stocks based on both diver-collected mark-resight observations and video censuses. Using both data types across multiple years, we fit parameters for a state-space model for population growth. We show that over the last 15 y the Nassau grouper population on Little Cayman has more than tripled in response to conservation efforts. Census data from Cayman Brac, while more sparse, show a similar pattern. These findings demonstrate that spatial and seasonal closures aimed at rebuilding aggregationbased fisheries can foster conservation success.fish-spawning aggregation | Nassau grouper | integrated population model | mark-resight | tagging

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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. KEY WORDS: Spiny lobster · Disease · Epidemiology · ConnectivityResale or republication not permitted without written consent of the publisher Dis Aquat Org 104: 129-140, 2013 the commercial harvest of P. argus in Florida, USA, totaled 42 million kg, valued at US$365.3 million (Florida Wildlife and Conservation Commission 2012). In 2010, more than 35 000 metric tons (t) of P. argus were landed worldwide (FAO Fisheries and Aquaculture Information and Statistics Service). Countries with the highest landings include Brazil, the Bahamas, Cuba, Nicaragua, Honduras, the Dominican Republic, and the USA (Vondruska 2010).In 1999, a pathogenic virus, Panulirus argus virus 1 (PaV1), was discovered infecting spiny lobsters from the Florida Keys (Shields & Behringer 2004). Prevalence of PaV1 is highest in early benthic juveniles (EBJs) and lower among larger juveniles and adults (Shields & Behringer 2004, LozanoÁlvarez et al. 2008. Lobsters with clinical disease have chalky-white hemolymph and often have a discolored carapace with a pink hue. Heavily infected lobsters are typically lethargic, cease grooming and foraging, and have lower hemolymph serum protein values compared to uninfected lobsters . Histologically, signs of PaV1 infection include a depletion of the reserve inclusion cells, hemocyte infiltration into the intertubular spaces of the hepatopancreas, focal necrosis of the hepatopancreas, and the presence of infected hemocytes in the heart, gills, and connective tissues (Li et al. 2008).Since its initial discovery in Florida, infections have been confirmed in Belize (Huchin-Mian et al. 2009), Mexico , Cuba (Cruz Quintana et al. 2011), and the US Virgin Islands . Prevalence of PaV1 in juvenile lobsters in Florida is patchy, but has historically ranged from 5 to 8%, with some locations exceeding 60% (Behringer et al. 2011). While typ...