Age, growth, mortality, and radiometric age validation of gray snapper (Lutjanus griseus) from Louisiana

The gray snapper (Lutjanus griseus) is a temperate and tropical reef fish that is found along the Gulf of Mexico and Atlantic coasts of the southeastern United States. The recreational fishery for gray snapper has developed rapidly in south Louisiana with the advent of harvest and seasonal restrictions on the established red snapper (L. campechanus) fishery. We examined the age and growth of gray snapper in Louisiana with the use of cross-sectioned sagittae. A total of 833 specimens, (441 males, 387 females, and 5 of unknown sex) were opportunistically sampled from the recreational fishery from August 1998 to August 2002. Males ranged in size from 222 to 732 mm total length (TL) and from 280 g to 5700 g total weight (TW) and females ranged from 254 to 756 mm TL and from 340 g to 5800 g TW. Both edge analysis and bomb radiocarbon analyses were used to validate otolith-based age estimates. Ages were estimated for 718 individuals; both males and females ranged from 1 to 28 years. The von Bertalanffy growth models derived from TL at age were Lt = 655.4{1–e[–0.23(t)]} for males, Lt = 657.3{1–e[– 0.21(t)]} for females, and L t = 656.4{1–e[– 0.22 (t)]} for all specimens of known sex. Catch curves were used to produce a total mortality (Z) estimate of 0.17. Estimates of M calculated with various methods ranged from 0.15 to 0.50; however we felt that M= 0.15 was the most appropriate estimate based on our estimate of Z. Full recruitment to the gray snapper recreational fishery began at age 4, was completed by age 8, and there was no discernible peak in the catch curve dome

Guidelines for Ecotourism Operations in the Great Plains

The International Union for the Conservation of Nature defines ecotourism as: Environmentally responsible travel to natural areas, in order to enjoy and appreciate nature (and accompanying cultural features, both past and present) that promote conservation, have a low visitor impact and provide for beneficially active socioeconomic involvement of local peoples. Ecotourism has the potential to support communities and conservation efforts from revenue streams to parks and reserves in the Great Plains, while also contributing to a culture shift towards a conservation ethic. Recent surges in ecotourism have contributed to growth in the tourism sectors in Great Plains states, because these approaches to tourism can leverage the open spaces, natural landscapes, and culture and heritage of the region. Facilities, Food, Activities, Guest Care, and Environment Awareness-- This resource is designed to support the planning, growth, and development of ecotourism facilities that offer beds, activities, and food to guests. We selected five components of ecotourism for use in guidelines and evaluations for ecotourism operations: facilities, activities, food, guest care, and environmental awareness. Tourists vary in their expectations and needs, and ecotourism operations vary in their goals and investment potential. One path to business success is to meet expectations of guests. This publication provides rubrics that describe expectations for the five ecotourism components at each level (1-star to 5-star). Achievement of higher levels of guest expectations may require more design, planning, and investment, and clients may pay more for facilities that achieve higher levels. Each facilities’ goals should dictate the level at which they wish to operate. These evaluation guidelines were developed after considerable experience at domestic and international facilities

A new growth model for red drum (Sciaenops ocellatus) that accommodates seasonal and ontogenic changes in growth rates

The red drum (Sciaenops ocellatus) is a popular gamefish found throughout the coastal waters of the Gulf of Mexico and along the eastern seaboard as far north as Massachusetts. Juvenile red drum grow extremely rapidly, especially during the warmer months, but adults grow very little. In fact, the change in growth with age is so abrupt that the standard von Bertalanffy curve has proven inadequate— the predicted lengths of younger fish are generally too large and the predicted lengths of older fish too small (see Beckman et al., 1988; Murphy and Taylor, 1990)

Preliminary Evaluation of the Use of Phosphogypsum for Reef Substrate in the Gulf of Mexico

Phosphogypsum (PG), a solid by-product of phosphoric acid production in the fertilizer industry, contains radionuclides and trace metals in concentrations which are potentially hazardous to human health and to the environment. Due to the presence of these contaminants and to the lack of safe alternative uses for PG, the industry has necessarily resorted to on-site stockpiling as the primary disposal method. Thirty-three such stockpiles, totaling millions of tons of PG, are currently extant in the Gulf of Mexico region. The environmental and economic liabilities associated with PG stockpiling has prompted continuing research into alternative beneficial uses of this solid waste which will be protective of the public health. To investigate the efficacy of PG in the construction of artificial reefs, we conducted two preliminary studies which demonstrate that cement-consolidated PG may provide a suitable and safe substrate for artificial reef construction. The first, performed in the laboratory, examined the possibility of bioaccumulation of radium and six heavy metals over time when three levels (copepods, grass shrimp, and fishes) of an aquatic food chain experience both trophic and environmental exposure to PG. Other than higher radium levels in the experimental grass shrimp, little possible effect of PG exposure could be discerned. In all cases where increased metals concentrations were indicated within the experimental groups, roughly equivalent increases in metal concentrations also occurred in the control groups. The second, performed under natural conditions in four ¼-acre estuarine ponds, evaluated the effects of PG exposure on the community structures of marine meiofauna, macroinvertebrates, and fishes. Abundances of copepod species either were slightly increased in ponds with PG or were inconsistently affected. Diversity indices for macroinvertebrates and fishes showed modest but inconsistent variation among experimental and control ponds. Thus, no differences in community structure attributable to the presence of PG could be detected among benthic invertebrates, natant invertebrates, or fishes

Benzo-fused Lactams from a Diversity-oriented Synthesis (DOS) Library as Inhibitors of Scavenger Receptor BI (SR-BI)-mediated Lipid Uptake

We report a new series of 8-membered benzo-fused lactams that inhibit cellular lipid uptake from HDL particles mediated by Scavenger Receptor, Class B, Type I (SR-BI). The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR), measuring the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is part of a previously reported diversity-oriented synthesis (DOS) library prepared via a build-couple-pair approach. Detailed structure–activity relationship (SAR) studies were performed with a selection of the original library, as well as additional analogs prepared via solution phase synthesis. These studies demonstrate that the orientation of the substituents on the aliphatic ring have a critical effect on activity. Additionally, a lipophilic group is required at the western end of the molecule, and a northern hydroxyl group and a southern sulfonamide substituent also proved to be optimal. Compound 2p was found to possess a superior combination of potency (av IC50 = 0.10 μM) and solubility (79 μM in PBS), and it was designated as probe ML312

Discovery of Bisamide-heterocycles as Inhibitors of Scavenger Receptor BI (SR-BI)-mediated Lipid Uptake

A new series of potent inhibitors of cellular lipid uptake from HDL particles mediated by scavenger receptor, class B, type I (SR-BI) was identified. The series was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR) that measured the transfer of the fluorescent lipid DiI from HDL particles to CHO cells overexpressing SR-BI. The series is characterized by a linear peptidomimetic scaffold with two adjacent amide groups, as well as an aryl-substituted heterocycle. Analogs of the initial hit were rapidly prepared via Ugi 4-component reaction, and select enantiopure compounds were prepared via a stepwise sequence. Structure–activity relationship (SAR) studies suggest an oxygenated arene is preferred at the western end of the molecule, as well as highly lipophilic substituents on the central and eastern nitrogens. Compound 5e, with (R)-stereochemistry at the central carbon, was designated as probe ML279. Mechanistic studies indicate that ML279 stabilizes the interaction of HDL particles with SR-BI, and its effect is reversible. It shows good potency (IC50 = 17 nM), is non-toxic, plasma stable, and has improved solubility over our alternative probe ML278

Relativistic quasipotential equations with u-channel exchange interactions

Various quasipotential two-body scattering equations are studied at the one-loop level for the case of $t$- and $u$-channel exchange potentials. We find that the quasipotential equations devised to satisfy the one-body limit for the $t$-channel exchange potential can be in large disagreement with the field-theoretical prediction in the case of $u$-channel exchange interactions. Within the spectator model, the description of the $u$-channel case improves if another choice of the spectator particle is made. Since the appropriate choice of the spectator depends strongly on the type of interaction used, one faces a problem when both types of interaction are contained in the potential. Equal-time formulations are presented, which, in the light-heavy particle system corresponding to the mass situation of the $\pi N$ system, approximate in a reasonable way the field-theoretical result for both types of interactions.Comment: Revtex, 20 pages, 12 PostScript figures, to appear in Phys. Rev.

Indolinyl-Thiazole Based Inhibitors of Scavenger Receptor-BI (SR-BI)-Mediated Lipid Transport

A potent class of indolinyl-thiazole based inhibitors of cellular lipid uptake mediated by scavenger receptor, class B, type I (SR-BI) was identified via a high-throughput screen of the National Institutes of Health Molecular Libraries Small Molecule Repository (NIH MLSMR) in an assay measuring the uptake of the fluorescent lipid DiI from HDL particles. This class of compounds is represented by ML278 (17–11), a potent (average IC50 = 6 nM) and reversible inhibitor of lipid uptake via SR-BI. ML278 is a plasma-stable, noncytotoxic probe that exhibits moderate metabolic stability, thus displaying improved properties for in vitro and in vivo studies. Strikingly, ML278 and previously described inhibitors of lipid transport share the property of increasing the binding of HDL to SR-BI, rather than blocking it, suggesting there may be similarities in their mechanisms of action