Although coral declines have been reported from major reefs of the world, region-specific trends still remain unclear, particularly in areas with high diversity such as the Philippines. We assessed the temporal patterns of the magnitude and trajectory of coral cover change in the Philippines using survey data collected from 317 sites. We examined the rate of change in coral cover in relation to time, effects of bleaching and protection against fishing and assessed the efficacy of marine protected areas (MPAs) using meta-analysis. Results showed an overall increase in coral cover in the Philippines from 1981 to 2010. Protection from fishing contributed to the overall increase in the mean annual rate of change as the coral cover significantly increased within MPAs than outside. The significant differences in the rate of coral cover change through time were influenced by chronic anthropogenic stresses, coinciding with the timing of thermal stress and the establishment of MPAs. The rate of change in coral cover was independent of the level of protection and the age and size of MPA
Alterations in fish developmental trajectories occur in response to genetic and environmental changes, especially during sensitive periods of development (critical windows). Embryos and larvae of Atractosteus tropicus were used as a model to study fish survival, growth, and development as a function of temperature (28 °C control, 33 °C, and 36 °C), salinity (0.0 ppt control, 4.0 ppt, and 6.0 ppt), and air saturation (control ~95% air saturation, hypoxia ~30% air saturation, and hyperoxia ~117% air saturation) during three developmental periods: (1) fertilization to hatch, (2) day 1 to day 6 post hatch (dph), and (3) 7 to 12 dph. Elevated temperature, hypoxia, and hyperoxia decreased survival during incubation, and salinity at 2 and 3 dph. Growth increased in embryos incubated at elevated temperature, at higher salinity, and in hyperoxia but decreased in hypoxia. Changes in development occurred as alterations in the timing of hatching, yolk depletion, acceptance of exogenous feeding, free swimming, and snout shape change, especially at high temperature and hypoxia. Our results suggest identifiable critical windows of development in the early ontogeny of A. tropicus and contribute to the knowledge of fish larval ecology and the interactions of individuals × stressors × time of exposure.
Seismic profiles, well logs, biostratigraphic data, and cross section restorations were integrated to investigate the relationships between salt tectonics and sedimentation in northern Green Canyon, Ewing Bank, and southwestern Eugene Island. Preliminary results address three aspects of salt-sediment interaction.
First, minibasins have characteristic stratigraphic stacking patterns that evolve from ponded to bypass settings. The transition may occur entirely within the slope environment or be associated with shelf progradation through the minibasin. The shift can sometimes be related to salt evacuation, and in other cases to regional variations in the location and volume of clastic input.
Second, different types of salt bodies have varying bathymetric expressions that may affect sequence thicknesses and facies development: reactive diapirs are overlain by graben at the sea floor; passive diapirs usually create asymmetric highs, with smooth slopes on some flanks and steep scarps on others; and diapirs modified by contraction are marked by broad topographic highs.
Third, models of salt sheet emplacement by extrusion at the sea floor have important implications for the spatial and temporal shifting of sedimentation patterns. Salt bodies originally covered by condensed sections become major minibasins, while bathymetric lows that serve as turbidite conduits and depocenters may be overridden by allochthonous salt sheets.
Because complex salt/sediment geometries in any area are genetically linked to surrounding basins and salt bodies, the interactions between deformation and sedimentation can be understood only by reconstructing the regional evolution of both salt and sediments. Although a daunting task, such efforts will aid in the exploration for hydrocarbons, especially in the sub-salt province.
Tropical gar (Atractosteus tropicus) aquaculture is a potential economic activity in southeast Mexico. This study analyzed the economic profitability of tropical gar grow-out using two commercial feeds (Silver Cup ® and Super ®). The last one was designed based on the digestive physiology of the species. The experiment was conducted in six concrete ponds of 4 m 3 (two treatments with three replicates) for 210 days; in each experimental unit 40 juveniles were stocked with an initial average weight and a total length of 104 ± 10 g and 27.7 ± 0.88 cm, respectively. At the end of the grow-out, there were statistics differences (P < 0.05) among treatments, where fish fed with Silver Cup ® obtained the highest final average weight and total length (450.29 ± 5.36 g and 41.7 ± 1.81 cm, respectively), compared with fish fed Super ® , which obtained a final average weight and total length of 415.05 ± 5.38 g and 41.4 ± 1.57 cm. Proximal analysis indicated a better protein content and fewer lipids in fish fed with Super ®. The profitability analysis showed that fish fed with Silver Cup ® diet had the highest values, with a Net
This study was conducted to investigate the effects of dietary fructooligosaccharides (FOS) on the growth, survival rate, digestive enzyms activity, and the expression of intestinal barrier function genes in tropical gar (Atractosteus tropicus) larvae. A total of 960 larvae (0.030 ± 0.006 g) were fed three diets supplemented with increasing FOS concentrations (2.5, 5, and 7.5 g kg−1) and a control diet for 15 days. Results revealed that a 7.5 g kg−1 FOS supplementation improved weight gain, specific growth rate, and survival rate (p < 0.05). Furthermore, 5 g kg−1 FOS supplementation increased alkaline protease and amylase activities and induced an upregulation of the claudin-17 gene expression (p < 0.05). Meanwhile, the inclusion of 7.5 g kg−1 FOS induced the upregulation of mucin 2 (muc-2), and the tight junction genes zo-2 and claudin-3 (p < 0.05). In addition, 2.5, 5, and 7.5 g kg−1 FOS promoted the downregulation of the claudin-15 gene expression (p < 0.05). At the same time, FOS inclusion did not increase the pro-inflammatory cytokine il-8 expression. We can conclude that 7.5 g kg−1 FOS supplementation improves growth performance, survival rate, and digestive capacity, and could contribute to the reinforcement of the intestinal barrier function of Tropical gar larvae.
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