Notes on the Biology of Invasive Lionfish (Pterois sp.) from the Northcentral Gulf of Mexico

The first confirmed sightings of lionfish in the Gulf of Mexico occurred in 2010 (Schofield 2010), where they were reported in the southern GOM off the Yucatan Peninsula, Mexico (Aguilar-Perera and Tuz-Sulub 2010); in 2012 more than 1,500 lionfish were collected from northern GOM locations ranging from Florida to Texas (Fogg et al. 2013). However, other than visual observations (mostly from recreational divers), there is relatively little information on the biology and ecology of lionfish in the northern GOM. The life history of invasive species can vary as they colonize new habitats and areas (Bøhn et al. 2004); thus, biological parameters described for lionfish along the US southeast coast, the Bahamas, and the Caribbean may differ as the species invades the GOM. Recently, Fogg et al. (2013) provided information on length-weight and sex ratios of northern GOM lionfish. Here, we report biological data from 4 lionfish captured during fishery-independent sampling in nearshore GOM waters off Alabama in May 2012

Evaluating Management Actions for Spotted Seatrout, Cynoscion nebulosus, in Mississippi with an Age-Structured Projection Model

Spotted seatrout, Cynoscion nebulosus, is an important recreational fishery in the coastal waters of the Gulf of Mexico and is the most sought after gamefish in coastal Mississippi. The management of C. nebulosus is state-specific, and unlike other similarly managed species, data on both population structure and movement support the existence of local sub-stocks. It is important for each state to clearly examine its own sub-stock in the context of its own state fishery in order to properly manage for local sustainability. We used an age-structured assessment model to examine the status (1993–2005) of the Mississippi C. nebulosus population and to project forward several probable management actions (i.e., length limits) while also accounting for uncertainty in both fishing mortality and annual recruitment. Model results suggest annual fishing mortality for Mississippi C. nebulosus is close to Fmsy, but that spawning stock biomass (SSB) is not below SSBmsy. This suggests the sub-stock is currently stable, but with high fishing pressure and a high dependence on annual recruitment to the fishery. Projections suggest that when uncertainty in angler effort and annual recruitment are included in the analysis, more conservative management actions are warranted in order to achieve both higher fishery yield and stable SSB

Spatio-Temporal Distribution of Larval Gobiosoma Bosc in Waters Adjacent to Natural and Altered Marsh-Edge Habitats of Mississippi Coastal Waters

Larval naked gobies, Gobiosoma bose, were collected monthly from October 1995 to September 1997 by beam plankton trawl from waters adjacent to natural Juncus/Spartina marsh-edge, natural sandy beach and altered Juncus/Spartina marsh-edge habitats in Mississippi coastal waters. Altered marsh habitats consisted of two bulkheaded stations and one stretch of riprap. Abundances were significantly higher in waters adjacent to natural marsh-edge habitats than in those adjacent to altered habitats in year one (P = 0.011), suggesting that the physical nature of alteration may have caused reduced habitat suitability. Abundances also varied seasonally, with summer conditions of high water temperature, increasing tide height, intermediate depth, low dissolved oxygen, and clear skies being significantly related to high abundance of postflexion G, bose in each year (r(2) = 0.481 and 0.276, respectively). Year two abundances were lower than those of year one and not significantly different among habitats. There was also a noticeable shift in the reproductive strategy of G. bose from a bimodal pattern in year one to a single reproductive peak in year two. This study illustrates the importance of natural Juncus/Spartina marsh-edge habitat to G. bose reproduction/recruitment and by extension to the community structure of the Back Bay/Davis Bayou estuarine ecosystem

Movements of Spotted Seatrout (Cynoscion nebulosus) in Mississippi Coastal Waters Based on Tag–Recapture

Movement patterns of spotted seatrout (Cynoscion nebulosus) were evaluated in Mississippi coastal waters by an angler-based tagging study from 1995 through 1999. During this period, 505 anglers tagged 15,206 spotted seatrout, the majority of which (84%) did not meet the state\u27s legal minimum size limit of 14 inches (356 mm) total length. Overall, 408 (2.7%) tagged fish were recaptured and reported to project personnel. Over 90% of these recaptured fish moved less than 10 km from site of tagging to site of recapture (mean = 3.0 ± 0.41 km), and 82% moved less than 3 km. The greatest movement from tagging to recapture site by any fish was 60 km over a period of 200 d, and only three fish (0.7%) moved 50 km or more. Study results suggest that spotted seatrout in Mississippi waters comprise a nonmigratory fish stock, as has been found for this species in coastal waters of neighboring states along the U.S. Gulf of Mexico

Growth of Captive Juvenile Tripletail Lobotes surinamensis

Early-juvenile tripletail Lobotes surinamensis (n = 27; range 45–115 mm TL, 0 = 73.0 mm; range 3.2–34.7 g TW, 0 = 12.9 g) captured in pelagic Sargassum algae off coastal Mississippi in mid-July 1999 were reared in a recirculating seawater system for 210 days. Fish were maintained on a natural light-dark cycle and fed to satiation 3 times per day. Water temperature ranged from 25.2° to 29.0° C and salinity was 28.0‰. All fish were measured for length and weight on days 1, 60, 135 and 210 of the study. Between these dates, mean daily TL growth rates were 2.2 mm/day, 1.2 mm/day, and 1.0 mm/day, respectively, where as 0 daily TW growth rates were 2.9 g/day, 4.3 g/day, and 7.1 g/day. Over the entire study, 0 TL and TW growth rates were 1.4 mm/day and 4.9 g/day, respectively. There was a significant correlation between length and weight vs. date of measurement. At the end of the study, specimens ranged from 272–431 mm TL (0 = 359 mm) and from 443.9–2,380.0 g TW (0 = 1,012.5 g)

Monitoring 2019 Bonnet Carré Spillway Impacts - Final Report

Due to the multiple and extended openings of the Bonnet Carré Spillway in 2019, the University of Southern Mississippi (USM) was tasked by the Mississippi Department of Marine Resources to conduct ecological sampling in the Mississippi Sound and adjacent waters. in an effort to better understand the impacts of the extensive freshwater diversion of Bonnet Carré Spillway operations on Mississippi\u27s coastal and marine resources. The period of performance for this project was June 1, 2019, to August 31, 2019. This technical report summarizes the three months of weekly surveys and analyses, over June - August 2019, conducted by the University of Southern Mississippi\u27s research team

Habitat-Specific Growth, Survival and Diet of Late Juvenile Hatchery-Reared Spotted Seatrout (\u3ci\u3eCysnoscion nebulosus\u3c/i\u3e)

As a key recreational fishery species throughout the Gulf of Mexico, the spotted seatrout (Cynoscion nebulosus Cuvier) requires sound management practices (VanderKooy and Muller, 2003; Fulford and Hendon, 2010). Accordingly, it is imperative to fully understand the ecology of spotted seatrout (Lorio and Perret, 1978), especially factors affecting the successful recruitment of this estuarine-dependent carnivore. Considering the large gap in knowledge about the ecology of late juvenile stage spotted seatrout, as well as the need to evaluate current stock enhancement practices for this species, the objective of this study was to assess the growth, survival and diet of late juvenile hatchery-reared (HR) spotted seatrout within three prospective nursery habitats in a shallow bay system: submerged aquatic vegetation (SAV), non-vegetated shoreline (NVS), and non-vegetated open water (NVO). While caged under natural conditions for 4 weeks, relative growth was significantly greater for fish caged in SAV and NVS habitats compared to NVO habitat. Mortality was relatively high in the first week of the study during acclimation. Stomachs of HR fish contained prey, and the diet composition of HR fish included common prey types consumed by comparable sizes of wild fish. Findings indicate that habitats within or in close proximity to SAV or marsh shoreline offer more favorable conditions than deeper open water habitat for late juvenile HR spotted seatrout. Moreover, HR fish can acclimate to natural conditions and successfully transition to a natural diet, in the absence of predators and competitors

Growth, Mortality, and Movement of Cobia (\u3ci\u3eRachycentron canadum\u3c/i\u3e)

© 2017, National Marine Fisheries Service. All rights reserved. We describe the length-at-age relationship of cobia (\u3eRachycentron canadum) with the use of 3 nonlinear models, and examine both the movement patterns of cobia in the Gulf of Mexico and South Atlantic Ocean and the instantaneous total mortality rate (Z, per year) from tag-recovery models with data from the Sport Fish Tag and Release Program of the Universityof Southern Mississippi Gulf Coast Research Laboratory. The estimated mean asymptotic length (L∞) in this study (1172 mm in fork length [95% confidence interval (CI): 1151–1192]) was in the range of values reported for this species in the Gulf of Mexico and Atlantic Ocean, and the annual growth coefficient (k: 0.57 [95% CI: 0.52–0.61]) was greater than that reported for cobia elsewhere. Movements were reported between the 7Gulf of Mexico and the South Atantic Ocean and a statistically significant seasonal trend in recaptures was observed, both of which suggest that cobia inhabit the Florida Keys during the winter and the north central Gulf of Mexico during the summer. The most supported tag-recovery model included time-invariant survivorship and time-dependent recovery probability and the estimated Z was 0.59/year (95% CI: 0.55–0.63). This study provides a summary of a long-term cobia tagging program and information for future management of this species. We describe the lengthat-age relationship of cobia (Rachycentron canadum) with the use of 3 nonlinear models, and examine both the movement patterns of cobia in the Gulf of Mexico and South Atlantic Ocean and the instantaneous total mortality rate (Z, per year) from tag-recovery models with data from the Sport Fish Tag and Release Program of the University of Southern Mississippi Gulf Coast Research Laboratory. The estimated mean asymptotic length (L∞) in this study (1172 mm in fork length [95% confidence interval (CI): 1151-1192]) was in the range of values reported for this species in the Gulf of Mexico and Atlantic Ocean, and the annual growth coefficient (k: 0.57 [95% CI: 0.52-0.61]) was greater than that reported for cobia elsewhere. Movements were reported between the Gulf of Mexico and the South Atlantic Ocean and a statistically significant seasonal trend in recaptures was observed, both of which suggest that cobia inhabit the Florida Keys during the winter and the northcentral Gulf of Mexico during the summer. The most supported tag-recovery model included time-invariant survivorship and time-dependent recovery probability and the estimated Z was 0.59/year (95% CI: 0.55-0.63). This study provides a summary of a long-term cobia tagging program and information for future management of this species

Evaluation of the Stock Structure of Cobia (\u3ci\u3eRachycentron canadum\u3c/i\u3e) In the Southeastern United States By Using Dart-Tag and Genetics Data

Available tag-recapture and population genetics data for cobia (Rachycentron canadum) in the southeastern United States were evaluated to provide information on population structure and determine the geographic boundary between stocks in the Gulf of Mexico and the Atlantic Ocean. The movements of 1750 cobia were evaluated on the basis of assigned tagging and recapture zones. Genetic samples from an additional 2796 cobia collected during the presumed spawning season were genotyped at 10 microsatellite loci, and standard population genetic statistical analyses were applied to the resulting sample data set. Tag-recapture results indicate that cobia tagged south of Cape Canaveral, Florida, primarily move between that area and the Gulf of Mexico and that cobia tagged north of Georgia have little interaction with the area south of Cape Canaveral. Cobia tagged at Cape Canaveral distributed widely throughout the entire southeastern coast of the United States. Genetic analysis results agree, indicating separate stocks that occur from Texas through Hobe Sound on the east coast of Florida and from Savannah, Georgia, to the Chesapeake Bay in Virgina, with distinct genetic groupings within the Atlantic Ocean stock. The results indicate a transition area that occurs from Cape Canaveral through northern Georgia, and additional data from this region are necessary to further refine the stock boundary

Assessing Northshore Nekton Abundance, Substrate, and Environmental Conditions In the Northern Gulf of Mexico: Are There Differences Among Three Adjacent Coastal Areas and Have There Been Changes Over Three Decades (1986-2015)?

Fishery-independent data on fishes and crustaceans collected in spring and fall over three decades (1986–2015) from coastal areas of southeastern Louisiana, Mississippi, and Alabama were analyzed to determine if these areas differed in species composition and environmental conditions over this period. Multivariate community analyses revealed significant differences in species composition among the three areas in trawl collections for both spring (ANOSIM, R = 0.543, p \u3c 0.001) and fall (R = 0.722, p \u3c 0.001), while seine collections were not significantly different among the areas for either season (spring, R \u3c − 0.06, p = 0.61; fall, R \u3c 0.167, p = 0.14). The most important factor contributing to these differences was the presence of more shell substrate at the Louisiana sites (LINKTREE analysis, B% = 86, p \u3c 0.05). Abundance data for common species were used to test for changes over the three decades. Blue crabs (Callinectes sapidus) and least puffers (Sphoeroides parvus) experienced decreases in four of eight area–season–gear scenarios. Four species of flatfishes also experienced multiple declines. Salinity increased at the Louisiana trawl sites over the period in both spring (+ 2.92; ANOVA, p \u3c 0.001) and fall (+ 5.97; ANOVA, p = 0.001–0.002), while spring trawl sites became warmer in Mississippi (+ 2.15 °C; ANOVA, p = 0.001–0.002). Alabama trawl sites became warmer in both spring (+ 3.36 °C; ANOVA, p \u3c 0.001) and fall (+ 1.91 °C; ANOVA, p \u3c 0.001). With declines in species and changes in environmental conditions, this region faces multiple challenges in maintaining its estuarine fisheries