scholarly journals Spatial and temporal variability of red grouper holes within Steamboat Lumps Marine Reserve, Gulf of Mexico

2011 ◽  
Vol 431 ◽  
pp. 243-254 ◽  
Author(s):  
CC Wall ◽  
BT Donahue ◽  
DF Naar ◽  
DA Mann
Keyword(s):  
Gulf Of Mexico ◽  
Temporal Variability ◽  
Marine Reserve ◽  
Spatial And Temporal Variability ◽  
Red Grouper

scholarly journals Temporal variability of chlorophyll distribution in the Gulf of Mexico: bio-optical data from profiling floats

2017 ◽  
Author(s):  
Orens Pasqueron de Fommervault ◽  
Paula Perez-Brunius ◽  
Pierre Damien ◽  
Julio Sheinbaum
Keyword(s):  
Gulf Of Mexico ◽  
Mixed Layer ◽  
Temporal Variability ◽  
Mixed Layer Depth ◽  
Chlorophyll Concentration ◽  
Optical Data ◽  
Spatial And Temporal Variability ◽  
Layer Depth ◽  
In Situ Experiments ◽  
Surface Increase

Abstract. Chlorophyll concentration is a key oceanic biogeochemical variable. In the Gulf of Mexico (GOM), its distribution, which is mainly obtained from satellite surface observations and scarce in situ experiments, is still poorly understood. In 2011–2012, eight profiling floats equipped with biogeochemical sensors were deployed for the first time in the GOM and generated an unprecedented dataset that significantly increased the number of chlorophyll vertical distribution measurements in the region. The analysis of these data, once calibrated, permits us to reconsider the spatial and temporal variability of the chlorophyll concentration in the water column. At a seasonal scale, results confirm the surface signal seen by satellites, presenting maximum concentrations in winter and low values in summer. It is shown that the deepening of the mixed layer depth is the primary factor triggering the chlorophyll surface increase in winter. In the GOM, current belief is that this surface increase corresponds to a biomass increase. However, the present dataset reveals a vertically integrated content of chlorophyll which remains constant throughout the year, suggesting that the surface increase results from a vertical redistribution of subsurface chlorophyll or photoacclimation processes, rather than a net increase of primary productivity. One plausible explanation for this is the decoupling between the mixed layer depth and the deep nutrient reservoir since mixed layer depth only reaches the nitracline in sporadic events in the observations. Float measurements also provide evidence that the depth and the magnitude of the deep chlorophyll maximum is strongly controlled by the mesoscale variability, with higher chlorophyll biomass generally observed in cyclones rather than anticyclones.

Spatial and temporal variability of a coarse-sand anomaly on a sandy inner shelf, northeastern Gulf of Mexico

1996 ◽  
Vol 16 (3) ◽  
pp. 266-272 ◽  
Author(s):  
Peter Fleischer ◽  
William B. Sawyer ◽  
Hannelore Fiedler ◽  
Ingo H. Stender
Keyword(s):  
Gulf Of Mexico ◽  
Temporal Variability ◽  
Coarse Sand ◽  
Spatial And Temporal Variability ◽  
Inner Shelf ◽  
Northeastern Gulf Of Mexico

Isotopic characterization of lifetime movement by two demersal fishes from the northeastern Gulf of Mexico

2021 ◽  
Vol 657 ◽  
pp. 161-172
Author(s):  
JL Vecchio ◽  
JL Ostroff ◽  
EB Peebles
Keyword(s):  
Gulf Of Mexico ◽  
Continental Shelf ◽  
Life Histories ◽  
Linear Mixed Model ◽  
Trophic Position ◽  
Eye Lens ◽  
Outer Continental Shelf ◽  
Red Grouper ◽  
Lens Diameter ◽  
Isotopic Characterization

An understanding of lifetime trophic changes and ontogenetic habitat shifts is essential to the preservation of marine fish species. We used carbon and nitrogen stable isotope values (δ13C and δ15N) recorded within the laminar structure of fish eye lenses, reflecting both diet and location over time, to compare the lifetime trends of 2 demersal mesopredators. Tilefish Lopholatilus chamaeleonticeps inhabit burrows on the outer continental shelf, which results in exceptional site fidelity. Red grouper Epinephelus morio are spawned on the middle to outer continental shelf, move to the inner shelf for the juvenile period, and return offshore upon sexual maturity. Both species inhabit the eastern Gulf of Mexico, a region with a distinctive offshore-inshore gradient in background δ13C values. Within individual tilefish (n = 36), sequences of δ13C values and δ15N values had strong, positive correlations with eye-lens diameter, and strong correlations between the 2 isotopes (mean Spearman r = 0.86), reflecting an increase in trophic position with growth and little lifetime movement. In red grouper (n = 30), δ15N values positively correlated with eye-lens diameter, but correlations between δ15N and δ13C were weak (mean Spearman r = 0.29), suggesting cross-shelf ontogenetic movements. Linear mixed model results indicated strong relationships between δ15N and δ13C values in tilefish eye lenses but no convergence in the red grouper model. Collectively, these results are consistent with previously established differences in the life histories of the 2 species, demonstrating the potential utility of eye-lens isotope records, particularly for investigating the life histories of lesser-known species.

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