scholarly journals Kilometer-scale larval dispersal processes predict metapopulation connectivity pathways for Paramuricea biscaya in the northern Gulf of Mexico

2021 ◽  
Author(s):  
Guangpeng Liu ◽  
Annalisa Bracco ◽  
Andrea M. Quattrini ◽  
Santiago Herrera
Keyword(s):  
Gulf Of Mexico ◽  
Ocean Circulation ◽  
Larval Dispersal ◽  
Circulation Model ◽  
Physical Models ◽  
Genetic Connectivity ◽  
Connectivity Pattern ◽  
Dispersal Pattern ◽  
Long Distance ◽  
Northern Gulf Of Mexico

AbstractFine-scale larval dispersal and connectivity processes are key to species survival, growth, recovery and adaptation under rapidly changing disturbances. Quantifying both are required to develop any effective management strategy. In the present work, we examine the dispersal pattern and potential connectivity of a common deep-water coral, Paramuricea biscaya, found in the northern Gulf of Mexico by evaluating predictions of physical models with estimates of genetic connectivity. While genetic approaches provide estimates of realized connectivity, they do not provide information on the dispersal process. Physical circulation models can now achieve kilometer-scale resolution sufficient to provide detailed insight into the pathways and scales of larval dispersal. A high-resolution regional ocean circulation model is integrated for 2015 and its advective pathways are compared with the outcome of the genetic connectivity estimates of corals collected at six locations over the continental slope at depths comprised between 1000 and 3000 meters. Furthermore, the likely interannual variability is extrapolated using ocean hindcasts available for this basin. The general connectivity pattern exhibits a dispersal trend from east to west following 1000 to 2000-meter isobaths, corresponding to the overall westward near-bottom circulation. The connectivity networks predicted by our model were mostly congruent with the estimated genetic connectivity patterns. Our results show that although dispersal distances of 100 km or less are common, depth differences between tens to a few hundred meters can effectively limit larval dispersal. A probabilistic graphic model suggests that stepping-stone dispersal mediated by intermediate sites provides a likely mechanism for long-distance connectivity between the populations separated by distances of 300 km or greater, such as those found in the DeSoto and Keathley canyons.

scholarly journals Kilometer-Scale Larval Dispersal Processes Predict Metapopulation Connectivity Pathways for Paramuricea biscaya in the Northern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Guangpeng Liu ◽  
Annalisa Bracco ◽  
Andrea M. Quattrini ◽  
Santiago Herrera
Keyword(s):  
Gulf Of Mexico ◽  
Ocean Circulation ◽  
Larval Dispersal ◽  
Circulation Model ◽  
Physical Models ◽  
Genetic Connectivity ◽  
Connectivity Pattern ◽  
Dispersal Pattern ◽  
Long Distance ◽  
Northern Gulf Of Mexico

Fine-scale larval dispersal and connectivity processes are key to species survival, growth, recovery and adaptation under rapidly changing disturbances. Quantifying both are required to develop any effective management strategy. In the present work, we examine the dispersal pattern and potential connectivity of a common deep-water coral, Paramuricea biscaya, found in the northern Gulf of Mexico by evaluating predictions of physical models with estimates of genetic connectivity. While genetic approaches provide estimates of realized connectivity, they do not provide information on the dispersal process. Physical circulation models can now achieve kilometer-scale resolution sufficient to provide detailed insight into the pathways and scales of larval dispersal. A high-resolution regional ocean circulation model is integrated for 2015 and its advective pathways are compared with the outcome of the genetic connectivity estimates of corals collected at six locations over the continental slope at depths comprised between 1,000 and 3,000 m. Furthermore, the likely interannual variability is extrapolated using ocean hindcasts available for this basin. The general connectivity pattern exhibits a dispersal trend from east to west following 1,000 to 2,000-m isobaths, corresponding to the overall westward near-bottom circulation. The connectivity networks predicted by our model were mostly congruent with the estimated genetic connectivity patterns. Our results show that although dispersal distances of 100 km or less are common, depth differences between tens to a few hundred meters can effectively limit larval dispersal. A probabilistic graphic model suggests that stepping-stone dispersal mediated by intermediate sites provides a likely mechanism for long-distance connectivity between the populations separated by distances of 300 km or greater, such as those found in the DeSoto and Keathley canyons.

scholarly journals Seascape Genomics Reveals Metapopulation Connectivity Network of Paramuricea biscaya in the Northern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Matthew P. Galaska ◽  
Guangpeng Liu ◽  
Destiny West ◽  
Katie Erickson ◽  
Andrea M. Quattrini ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Oil Spill ◽  
Ocean Circulation ◽  
Deep Sea ◽  
Larval Dispersal ◽  
Spatial Diversity ◽  
Stepping Stones ◽  
Northern Gulf Of Mexico ◽  
Mississippi Canyon ◽  
Population Structuring

The degree of connectivity among populations influences their ability to respond to natural and anthropogenic stressors. In marine systems, determining the scale, rate, and directionality of larval dispersal is therefore, central to understanding how coral metapopulations are interconnected and the degree of resiliency in the event of a localized disturbance. Understanding these source-sink dynamics is essential to guide restoration efforts and for the study of ecology and evolution in the ocean. The patterns and mechanisms of connectivity in the deep-sea (>200 m deep) are largely understudied. In this study, we investigated the spatial diversity patterns and metapopulation connectivity of the octocoral Paramuricea biscaya throughout the northern Gulf of Mexico (GoM). Paramuricea biscaya is one of the most abundant corals on the lower continental slope (between 1,200 and 2,500 m) in the GoM. The 2010 Deepwater Horizon oil spill (DWH) directly impacted populations of this species and thus are considered primary targets for restoration. We used a combination of seascape genomic analyses, high-resolution ocean circulation modeling, and larval dispersal simulations to quantify the degree of population structuring and connectivity among P. biscaya populations. Evidence supports the hypotheses that the genetic diversity of P. biscaya is structured by depth, and that larval dispersal among connected populations is asymmetric due to dominant ocean circulation patterns. Our results suggest that there are intermediate unsampled populations in the central GoM that serve as stepping stones for dispersal. The data suggest that the DeSoto Canyon area, and possibly the West Florida Escarpment, critically act as sources of larvae for areas impacted by the DWH oil spill in the Mississippi Canyon. This work illustrates that the management of deep-sea marine protected areas should incorporate knowledge of connectivity networks and depth-dependent processes throughout the water column.

scholarly journals Seascape genomics reveals metapopulation connectivity network of Paramuricea biscaya in the northern Gulf of Mexico

2021 ◽  
Author(s):  
Matthew P. Galaska ◽  
Guangpeng Liu ◽  
Destiny West ◽  
Katie Erickson ◽  
Andrea Quattrini ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Oil Spill ◽  
Ocean Circulation ◽  
Deep Sea ◽  
Larval Dispersal ◽  
Spatial Diversity ◽  
Stepping Stones ◽  
Northern Gulf Of Mexico ◽  
Mississippi Canyon ◽  
Population Structuring

AbstractThe degree of connectivity among populations influences their ability to respond to natural and anthropogenic stressors. In marine systems, determining the scale, rate, and directionality of larval dispersal is therefore central to understanding how coral metapopulations are interconnected and the degree of resiliency in the event of a localized disturbance. Understanding these source-sink dynamics is essential to guide restoration efforts and for the study of ecology and evolution in the ocean. The patterns and mechanisms of connectivity in the deep-sea (> 200 meters deep) are largely understudied. In this study, we investigated the spatial diversity patterns and metapopulation connectivity of the octocoral Paramuricea biscaya throughout the northern Gulf of Mexico (GoM). Paramuricea biscaya is one of the most abundant corals on the lower continental slope (between 1200 and 2500 m) in the GoM. The 2010 Deepwater Horizon oil spill (DWH) directly impacted populations of this species and thus are considered primary targets for restoration. We used a combination of seascape genomic analyses, high-resolution ocean circulation modeling, and larval dispersal simulations to quantify the degree of population structuring and connectivity among P. biscaya populations. Evidence supports the hypotheses that the genetic diversity of P. biscaya is predominantly structured by depth, and that larval dispersal among connected populations is asymmetric due to dominant ocean circulation patterns. Our results suggest that there are intermediate unsampled populations in the central GoM that serve as stepping stones for dispersal. The data suggest that the DeSoto Canyon area, and possibly the West Florida Escarpment, critically act as sources of larvae for areas impacted by the DWH oil spill in the Mississippi Canyon. This work illustrates that the management of deep-sea marine protected areas should incorporate knowledge of connectivity networks and depth-dependent processes throughout the water column.

scholarly journals Simulating the effects of phosphorus limitation in the Mississippi and Atchafalaya River plumes

2012 ◽  
Vol 9 (11) ◽  
pp. 4707-4723 ◽  
Author(s):  
A. Laurent ◽  
K. Fennel ◽  
J. Hu ◽  
R. Hetland
Keyword(s):  
Gulf Of Mexico ◽  
Primary Production ◽  
Inorganic Nitrogen ◽  
Circulation Model ◽  
Phosphorus Limitation ◽  
Early Summer ◽  
Nitrogen And Phosphorus ◽  
River Plumes ◽  
Northern Gulf Of Mexico ◽  
Plume Region

Abstract. The continental shelf of the northern Gulf of Mexico receives high dissolved inorganic nitrogen and phosphorus loads from the Mississippi and Atchafalaya rivers. The nutrient load results in high primary production in the river plumes and contributes to the development of hypoxia on the Louisiana shelf in summer. While phytoplankton growth is considered to be typically nitrogen-limited in marine waters, phosphorus limitation has been observed in this region during periods of peak river discharge in spring and early summer. Here we investigate the presence, spatio-temporal distribution and implications of phosphorus limitation in the plume region using a circulation model of the northern Gulf of Mexico coupled to a multi-nutrient ecosystem model. Results from a 7-yr simulation (2001–2007) compare well with several sources of observations and suggest that phosphorus limitation develops every year between the Mississippi and Atchafalaya deltas. Model simulations show that phosphorus limitation results in a delay and westward shift of a fraction of river-stimulated primary production. The consequence is a reduced flux of particulate organic matter to the sediment near the Mississippi delta, but slightly enhanced fluxes west of Atchafalaya Bay. Simulations with altered river phosphate concentrations (±50%) show that significant variation in the spatial extent of phosphorus limitation (±40% in July) results from changes in phosphate load.

scholarly journals Simulating the effects of phosphorus limitation in the Mississippi and Atchafalaya River plumes

2012 ◽  
Vol 9 (5) ◽  
pp. 5625-5657 ◽  
Author(s):  
A. Laurent ◽  
K. Fennel ◽  
J. Hu ◽  
R. Hetland
Keyword(s):  
Gulf Of Mexico ◽  
Primary Production ◽  
Inorganic Nitrogen ◽  
Circulation Model ◽  
Phosphorus Limitation ◽  
Early Summer ◽  
Nitrogen And Phosphorus ◽  
River Plumes ◽  
Northern Gulf Of Mexico ◽  
Plume Region

Abstract. The continental shelf of the northern Gulf of Mexico receives high dissolved inorganic nitrogen and phosphorus loads from the Mississippi and Atchafalaya rivers. The nutrient load results in high primary production in the river plumes and contributes to the development of hypoxia on the Texas-Louisiana shelf in summer. While phytoplankton growth is considered to be typically nitrogen-limited, phosphorus limitation has been observed in this region during periods of peak river discharge in spring and early summer. Here we investigate the presence, spatio-temporal distribution and implications of phosphorus limitation in the plume region using a circulation model of the northern Gulf of Mexico coupled to a multi-nutrient ecosystem model. Results from a 7 yr simulation (2001–2007) compare well with available observations and suggest that phosphorus limitation develops every year between the Mississippi and Atchafalaya deltas. Model simulations show that phosphorus limitation results in a delay and westward shift of a fraction of river-stimulated primary production. The consequence is a reduced flux of particulate organic matter to the sediment near the Mississippi delta, but enhanced fluxes westward in the Atchafalaya and far-field regions. Two discharge scenarios with altered river phosphate concentrations (±50 %) reveal a significant variation (±40 % in July) in the spatial extent of phosphorus limitation with changes in phosphate load.

scholarly journals Modeling <i>p</i>CO<sub>2</sub> variability in the Gulf of Mexico

2016 ◽  
Vol 13 (15) ◽  
pp. 4359-4377 ◽  
Author(s):  
Zuo Xue ◽  
Ruoying He ◽  
Katja Fennel ◽  
Wei-Jun Cai ◽  
Steven Lohrenz ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Ocean Circulation ◽  
Inorganic Carbon ◽  
Circulation Model ◽  
Global Ocean ◽  
Open Boundary ◽  
Biogeochemical Model ◽  
Open Boundary Conditions ◽  
Model Simulations ◽  
Co2 Sink

Abstract. A three-dimensional coupled physical–biogeochemical model was used to simulate and examine temporal and spatial variability of sea surface pCO2 in the Gulf of Mexico (GoM). The model was driven by realistic atmospheric forcing, open boundary conditions from a data-assimilative global ocean circulation model, and observed freshwater and terrestrial nutrient and carbon input from major rivers. A 7-year model hindcast (2004–2010) was performed and validated against ship measurements. Model results revealed clear seasonality in surface pCO2 and were used to estimate carbon budgets in the Gulf. Based on the average of model simulations, the GoM was a net CO2 sink with a flux of 1.11 ± 0.84  ×  1012 mol C yr−1, which, together with the enormous fluvial inorganic carbon input, was comparable to the inorganic carbon export through the Loop Current. Two model sensitivity experiments were performed: one without biological sources and sinks and the other using river input from the 1904–1910 period as simulated by the Dynamic Land Ecosystem Model (DLEM). It was found that biological uptake was the primary driver making GoM an overall CO2 sink and that the carbon flux in the northern GoM was very susceptible to changes in river forcing. Large uncertainties in model simulations warrant further process-based investigations.

scholarly journals Deepwater Horizon oil spill impacts on sea turtles could span the Atlantic

2015 ◽  
Vol 11 (12) ◽  
pp. 20150596 ◽  
Author(s):  
Nathan F. Putman ◽  
F. Alberto Abreu-Grobois ◽  
Iñaky Iturbe-Darkistade ◽  
Emily M. Putman ◽  
Paul M. Richards ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Oil Spill ◽  
Ocean Circulation ◽  
Sea Turtles ◽  
Circulation Model ◽  
Deepwater Horizon ◽  
The United States ◽  
Deepwater Horizon Oil Spill ◽  
Spill Site ◽  
Kemp's Ridley

We investigated the extent that the 2010 Deepwater Horizon oil spill potentially affected oceanic-stage sea turtles from populations across the Atlantic. Within an ocean-circulation model, particles were backtracked from the Gulf of Mexico spill site to determine the probability of young turtles arriving in this area from major nesting beaches. The abundance of turtles in the vicinity of the oil spill was derived by forward-tracking particles from focal beaches and integrating population size, oceanic-stage duration and stage-specific survival rates. Simulations indicated that 321 401 (66 199–397 864) green ( Chelonia mydas ), loggerhead ( Caretta caretta ) and Kemp's ridley ( Lepidochelys kempii ) turtles were likely within the spill site. These predictions compared favourably with estimates from in-water observations recently made available to the public (though our initial predictions for Kemp's ridley were substantially lower than in-water estimates, better agreement was obtained with modifications to mimic behaviour of young Kemp's ridley turtles in the northern Gulf). Simulations predicted 75.2% (71.9–76.3%) of turtles came from Mexico, 14.8% (11–18%) from Costa Rica, 5.9% (4.8–7.9%) from countries in northern South America, 3.4% (2.4–3.5%) from the United States and 1.6% (0.6–2.0%) from West African countries. Thus, the spill's impacts may extend far beyond the current focus on the northern Gulf of Mexico.

scholarly journals Modeling ocean circulation and biogeochemical variability in the Gulf of Mexico

2013 ◽  
Vol 10 (11) ◽  
pp. 7219-7234 ◽  
Author(s):  
Z. Xue ◽  
R. He ◽  
K. Fennel ◽  
W.-J. Cai ◽  
S. Lohrenz ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Ocean Circulation ◽  
Function Analysis ◽  
Inorganic Nitrogen ◽  
Circulation Model ◽  
Deep Ocean ◽  
Global Ocean ◽  
Open Boundary ◽  
Biogeochemical Model ◽  
Open Boundary Conditions

Abstract. A three-dimensional coupled physical-biogeochemical model is applied to simulate and examine temporal and spatial variability of circulation and biogeochemical cycling in the Gulf of Mexico (GoM). The model is driven by realistic atmospheric forcing, open boundary conditions from a data assimilative global ocean circulation model, and observed freshwater and terrestrial nitrogen input from major rivers. A 7 yr model hindcast (2004–2010) was performed, and validated against satellite observed sea surface height, surface chlorophyll, and in situ observations including coastal sea level, ocean temperature, salinity, and dissolved inorganic nitrogen (DIN) concentration. The model hindcast revealed clear seasonality in DIN, phytoplankton and zooplankton distributions in the GoM. An empirical orthogonal function analysis indicated a phase-locked pattern among DIN, phytoplankton and zooplankton concentrations. The GoM shelf nitrogen budget was also quantified, revealing that on an annual basis the DIN input is largely balanced by the removal through denitrification (an equivalent of ~ 80% of DIN input) and offshore exports to the deep ocean (an equivalent of ~ 17% of DIN input).

scholarly journals Modeling ocean circulation and biogeochemical variability in the Gulf of Mexico

2013 ◽  
Vol 10 (5) ◽  
pp. 7785-7830 ◽  
Author(s):  
Z. Xue ◽  
R. He ◽  
K. Fennel ◽  
W.-J. Cai ◽  
S. Lohrenz ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Ocean Circulation ◽  
Function Analysis ◽  
Circulation Model ◽  
Deep Ocean ◽  
Global Ocean ◽  
Open Boundary ◽  
Biogeochemical Model ◽  
Open Boundary Conditions ◽  
Nutrient Input

Abstract. A three-dimensional coupled physical-biogeochemical model is applied to simulate and examine temporal and spatial variability of circulation and biogeochemical cycling in the Gulf of Mexico (GoM). The model is driven by realistic atmospheric forcing, open boundary conditions from a data assimilative global ocean circulation model, and observed freshwater and terrestrial nutrient input from major rivers. A 7 yr model hindcast (2004–2010) was performed, and validated against satellite observed sea surface height, surface chlorophyll, and in-situ observations including coastal sea-level, ocean temperature, salinity, and nutrient concentration. The model hindcast revealed clear seasonality in nutrient, phytoplankton and zooplankton distributions in the GoM. An Empirical Orthogonal Function analysis indicated a phase-locked pattern among nutrient, phytoplankton and zooplankton concentrations. The GoM shelf nutrient budget was also quantified, revealing that on an annual basis ~80% of nutrient input was denitrified on the shelf and ~17% was exported to the deep ocean.

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