scholarly journals West Indian manatee movements reveal novel occupancy and distribution patterns in the northern Gulf of Mexico

2016 ◽  
Author(s):  
Allen Aven ◽  
Ruth H. Carmichael ◽  
Elizabeth E Hieb ◽  
Monica Ross
Keyword(s):  
Gulf Of Mexico ◽  
Spatial Ecology ◽  
Regional Scale ◽  
Satellite Telemetry ◽  
West Indian ◽  
Distribution Patterns ◽  
Habitat Associations ◽  
Movement Model ◽  
Functional Movement ◽  
Northern Gulf Of Mexico

Since the 1980s, West Indian manatees (Trichechus manatus) have been reported more frequently along the northern Gulf of Mexico (GOM) coast in areas that were recently considered to be outside the species' normal areas of occupancy. The ecological importance of the northern GOM region to manatees is currently unclear, but knowledge of the spatial ecology, population linkages, and habitat associations of individuals occupying the fringes of their known range is vital to bring context and improve understanding of demographic trends and potential threats to the species, rangewide. We tracked regional-scale movements of 13 manatees documented in Mobile Bay, AL using satellite telemetry and mark-recapture methods. We determined movement and occupancy patterns including origins, seasonal dispersal and site fidelity, and functional movement modes of those individuals during the tracking period. Focal manatees moved along the GOM coast between Tampa Bay, FL and Lake Pontchartrain, LA, and consistently returned to discrete locations in both the northern GOM and within the species' core range in peninsular FL. Functional movement model fits confirmed that most relatively long-range seasonal movements were migratory in nature, suggesting that consistently occupied migratory endpoints contain relatively important seasonal habitat for manatees and diminishing the possibility that tracked manatees were nomads or transient within the study area. These results provide evidence of shifting seasonal manatee distribution in the US, and highlight repeatedly used locations that may increase in importance to the species if manatee abundance in the northern GOM increases.

scholarly journals West Indian manatee movements reveal novel occupancy and distribution patterns in the northern Gulf of Mexico

2016 ◽  
Author(s):  
Allen Aven ◽  
Ruth H. Carmichael ◽  
Elizabeth E Hieb ◽  
Monica Ross
Keyword(s):  
Gulf Of Mexico ◽  
Spatial Ecology ◽  
Regional Scale ◽  
Satellite Telemetry ◽  
West Indian ◽  
Distribution Patterns ◽  
Habitat Associations ◽  
Movement Model ◽  
Functional Movement ◽  
Northern Gulf Of Mexico

Since the 1980s, West Indian manatees (Trichechus manatus) have been reported more frequently along the northern Gulf of Mexico (GOM) coast in areas that were recently considered to be outside the species' normal areas of occupancy. The ecological importance of the northern GOM region to manatees is currently unclear, but knowledge of the spatial ecology, population linkages, and habitat associations of individuals occupying the fringes of their known range is vital to bring context and improve understanding of demographic trends and potential threats to the species, rangewide. We tracked regional-scale movements of 13 manatees documented in Mobile Bay, AL using satellite telemetry and mark-recapture methods. We determined movement and occupancy patterns including origins, seasonal dispersal and site fidelity, and functional movement modes of those individuals during the tracking period. Focal manatees moved along the GOM coast between Tampa Bay, FL and Lake Pontchartrain, LA, and consistently returned to discrete locations in both the northern GOM and within the species' core range in peninsular FL. Functional movement model fits confirmed that most relatively long-range seasonal movements were migratory in nature, suggesting that consistently occupied migratory endpoints contain relatively important seasonal habitat for manatees and diminishing the possibility that tracked manatees were nomads or transient within the study area. These results provide evidence of shifting seasonal manatee distribution in the US, and highlight repeatedly used locations that may increase in importance to the species if manatee abundance in the northern GOM increases.

Beach vegetation and plant distribution patterns along the northern Gulf of Mexico

1987 ◽  
Vol 15 (2) ◽  
pp. 201-233 ◽  
Author(s):  
M.G. Barbour ◽  
M. Rejmanek ◽  
A. F. Johnson ◽  
B. M. Pavlik
Keyword(s):  
Gulf Of Mexico ◽  
Distribution Patterns ◽  
Plant Distribution ◽  
Northern Gulf Of Mexico ◽  
Beach Vegetation ◽  
Plant Distribution Patterns

scholarly journals Seasonal Mixing and Biological Controls of the Carbonate System in a River-Dominated Continental Shelf Subject to Eutrophication and Hypoxia in the Northern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei-Jen Huang ◽  
Wei-Jun Cai ◽  
Xinping Hu
Keyword(s):  
Gulf Of Mexico ◽  
Continental Shelf ◽  
Dissolved Inorganic Carbon ◽  
Time Lag ◽  
Distribution Patterns ◽  
Detailed Examination ◽  
Total Alkalinity ◽  
Dominant Factor ◽  
Near Surface ◽  
Northern Gulf Of Mexico

Large rivers export a large amount of dissolved inorganic carbon (DIC) and nutrients to continental shelves; and subsequent river-to-sea mixing, eutrophication, and seasonal hypoxia (dissolved oxygen < 2 mg⋅L–1) can further modify DIC and nutrient distributions and fluxes. However, quantitative studies of seasonal carbonate variations on shelves are still insufficient. We collected total alkalinity (TA), DIC, and NO3– data from nine cruises conducted between 2006 and 2010 on the northern Gulf of Mexico continental shelf, an area strongly influenced by the Mississippi and Atchafalaya Rivers. We applied a three-end-member model (based on salinity and potential alkalinity) to our data to remove the contribution of physical mixing to DIC and nitrate distribution patterns and to derive the net in situ removal of DIC and nitrate (ΔDIC and ΔNO3–, respectively). Systematic analyses demonstrated that the seasonal net DIC removal in the near-surface water was strong during summer and weak in winter. The peak in net DIC production in the near-bottom, subsurface waters of the inner and middle sections of the shelf occurred between July and September; it was coupled, but with a time lag, to the peak in the net DIC removal that occurred in the near-surface waters in June. A similar 2-month delay (i.e., January vs. November) could also be observed between their minima. A detailed examination of the relationship between ΔDIC and ΔNO3– demonstrates that net biological activity was the dominant factor of DIC removal and addition. Other effects, such as air–sea CO2 gas exchange, wetland exports, CaCO3 precipitation, and a regional variation of the Redfield ratio, were relatively minor. We suggest that the delayed coupling between eutrophic surface and hypoxic bottom waters reported here may also be seen in the carbon and nutrient cycles of other nutrient-rich, river-dominated ocean margins worldwide.

Taxonomic composition, abundance and habitat associations of squid paralarvae in the northern Gulf of Mexico

2021 ◽  
pp. 103572
Author(s):  
Michelle Zapp Sluis ◽  
Heather Judkins ◽  
Michael A. Dance ◽  
Michael Vecchione ◽  
Maëlle Cornic ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Taxonomic Composition ◽  
Habitat Associations ◽  
Northern Gulf Of Mexico

scholarly journals West Indian Manatees Use Partial Migration to Expand Their Geographic Range Into the Northern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Carl S. Cloyed ◽  
Elizabeth E. Hieb ◽  
Kayla DaCosta ◽  
Monica Ross ◽  
Ruth H. Carmichael
Keyword(s):  
Climate Change ◽  
Gulf Of Mexico ◽  
Range Expansion ◽  
West Indian ◽  
Geographic Range ◽  
Partial Migration ◽  
Geographic Ranges ◽  
Northern Gulf Of Mexico ◽  
Stopover Sites ◽  
Primary Habitat

Partial migration provides a mechanism for species to shift their geographic ranges into new, environmentally favorable regions but has been poorly studied as a means to alleviate effects of climate change. Populations at the edge of their geographic range are ideal to investigate how migratory behaviors may enable range expansion as adjacent areas become more climatically favorable. We determined the contribution of partial migration to the range expansion of West Indian manatees (Trichechus manatus) using GPS data from tagged individuals that migrated between the northern Gulf of Mexico (nGoM) and primary habitat in peninsular Florida. Most of these manatees migrated to the nGoM annually and exhibited high site fidelity among years. Many individuals spent cumulatively more time in the nGoM than in peninsular Florida, indicating the nGoM is a regular part of their geographic range, and they returned to peninsular Florida to meet temperature-related physiological needs for survival. Autumn migrations most frequently terminated at Crystal River, Florida, and manatees that commenced migration late in the season stopped less frequently and had more directed movements. Spring migrations most frequently terminated at Mobile Bay, Alabama, and several manatees quickly and directly migrated from Florida to nGoM stopover sites. Migrations ranged from 10 to 133 days in length, and variation in duration was primarily driven by use of stopover sites and directedness of travel. These data confirm partial migration as an important component of manatee migratory behavior that has already enabled range shifts for manatees on the U.S.A. Gulf of Mexico coast and has potential to facilitate future responses to climate change. As the most common type of migration across the animal kingdom, partial migration may provide a global mechanism for a diverse variety of species to resist the range limiting effects of climate change.

scholarly journals Assessment of Longitudinal Gradients in Nematode Communities in the Deep Northern Gulf of Mexico and Concordance with Benthic Taxa

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Jyotsna Sharma ◽  
Jeffrey G. Baguley ◽  
Paul A. Montagna ◽  
Gilbert T. Rowe
Keyword(s):  
Gulf Of Mexico ◽  
Mississippi River ◽  
Distribution Patterns ◽  
Nematode Communities ◽  
Northern Gulf Of Mexico ◽  
The North ◽  
Longitudinal Gradients ◽  
Harpacticoid Copepods ◽  
Significant Difference ◽  
Abundance And Diversity

Meiobenthic nematode assemblages were examined at 16 stations along two transects on the eastern and western boundaries of the deep northern Gulf of Mexico (dNGOM) at depths of 212–3000 m. The highest abundance (297 individuals 10 cm−2) and number of genera (71) occurred at stations near the Mississippi River delta. Number of genera decreased with increasing depth, and showed differences in community composition between the east and west regions. The dominant family, Comesomatidae, was represented by Sabatieria that was present at most shallow stations but absent at greater water depths. A significant difference in nematode feeding morphology was observed between depth groups but not between the two transects at different longitudes. Patterns of nematode community structure are congruent with harpacticoid copepods. Overall, the higher abundance and diversity of nematodes in the north-central Gulf of Mexico is consistent with findings of other benthic taxa and reflects organic material loading from the Mississippi River driving deep sea communities in the Gulf. The east-west gradient in composition of nematode communities suggests that nematode assemblages have well-defined distribution patterns similar to other meiobenthic taxa in the GOM but they are not aligned in the bathymetric zones observed in macrofauna, megafauna and demersal fishes.

scholarly journals Meta-analysis of Nekton Utilization of Coastal Habitats in the Northern Gulf of Mexico

2019 ◽  
Vol 43 (7) ◽  
pp. 1722-1745 ◽  
Author(s):  
Terill A. Hollweg ◽  
Mary C. Christman ◽  
Just Cebrian ◽  
Bryan P. Wallace ◽  
Scott L. Friedman ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Analytical Approach ◽  
Meta Analysis ◽  
Regional Scale ◽  
Open Water ◽  
Oyster Reefs ◽  
Habitat Types ◽  
Coastal Habitats ◽  
Northern Gulf Of Mexico ◽  
Community Assemblages

Abstract Estuaries in the northern Gulf of Mexico (GOM) provide habitat for many ecologically, commercially, and recreationally important fish and crustacean species (i.e., nekton), but patterns of nekton abundance and community assemblages across habitat types, salinity zones, and seasons have not been described region-wide. Recognizing the wealth of information collected from previous and ongoing field sampling efforts, we developed a meta-analytical approach to aggregate nekton density data from separate studies (using different gear types) that can be used to answer key research questions. We then applied this meta-analytical approach to separate nekton datasets from studies conducted in the Gulf of Mexico to summarize patterns in nekton density across and within several estuarine habitat types, including marsh, oyster reefs, submerged aquatic vegetation (SAV), and open-water non-vegetated bottom (NVB). The results of the meta-analysis highlighted several important patterns of nekton use associated with these habitat types. Nekton densities were higher in structured estuarine habitats (i.e., marsh, oyster reefs, SAV) than in open-water NVB habitat. Marsh and SAV community assemblages were relatively similar to each other, but different from those associated with open-water NVB and oyster habitats. Densities of commercially and recreationally important crustacean and fish species were highest in saline marshes, thus demonstrating the importance of this habitat in the northern GOM. The results of our meta-analysis are generally consistent with previous site-specific studies in the region (many of which were included in the meta-analysis) and provide further evidence for these patterns at a regional scale. This meta-analytical approach is easy to implement for diverse research and management purposes, and provides the opportunity to advance understanding of the value and role of coastal habitats to nekton communities.

scholarly journals Epibionts Reflect Spatial and Foraging Ecology of Gulf of Mexico Loggerhead Turtles (Caretta caretta)

2021 ◽  
Vol 9 ◽  
Author(s):  
Ian Silver-Gorges ◽  
Jeroen Ingels ◽  
Giovanni A. P. dos Santos ◽  
Yirina Valdes ◽  
Leticia P. Pontes ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Gulf Of Mexico ◽  
Habitat Use ◽  
Spatial Ecology ◽  
Foraging Ecology ◽  
Satellite Telemetry ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Loggerhead Turtles ◽  
Nesting Beaches

Sea turtles are exposed to numerous threats during migrations to their foraging grounds and at those locations. Therefore, information on sea turtle foraging and spatial ecology can guide conservation initiatives, yet it is difficult to directly observe migrating or foraging turtles. To gain insights into the foraging and spatial ecology of turtles, studies have increasingly analyzed epibionts of nesting turtles, as epibionts must overlap spatially and ecologically with their hosts to colonize successfully. Epibiont analysis may be integrated with stable isotope information to identify taxa that can serve as indicators of sea turtle foraging and spatial ecology, but few studies have pursued this. To determine if epibionts can serve as indicators of foraging and spatial ecology of loggerhead turtles nesting in the northern Gulf of Mexico we combined turtle stable isotope and taxonomic epibiont analysis. We sampled 22 individual turtles and identified over 120,000 epibiont individuals, belonging to 34 macrofauna taxa (>1 mm) and 22 meiofauna taxa (63 μm–1 mm), including 111 nematode genera. We quantified epidermis δ13C and δ15N, and used these to assign loggerhead turtles to broad foraging regions. The abundance and presence of macrofauna and nematodes did not differ between inferred foraging regions, but the presence of select meiofauna taxa differentiated between three inferred foraging regions. Further, dissimilarities in macrofauna, meiofauna, and nematode assemblages corresponded to dissimilarities in individual stable isotope values within inferred foraging regions. This suggests that certain epibiont taxa may be indicative of foraging regions used by loggerhead turtles in the Gulf of Mexico, and of individual turtle foraging and habitat use specialization within foraging regions. Continued sampling of epibionts at nesting beaches and foraging grounds in the Gulf of Mexico and globally, coupled with satellite telemetry and/or dietary studies, can expand upon our findings to develop epibionts as efficient indicators of sea turtle foraging and spatial ecology.

Effects of hypoxia on habitat quality of pelagic planktivorous fishes in the northern Gulf of Mexico

2014 ◽  
Vol 505 ◽  
pp. 209-226 ◽  
Author(s):  
H Zhang ◽  
DM Mason ◽  
CA Stow ◽  
AT Adamack ◽  
SB Brandt ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Habitat Quality ◽  
Northern Gulf Of Mexico
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