565
32.4.2 Recovery
The trajectories of biomass recovery for fish guilds impacted by DWH are more
monotonic than those impacted by Ixtoc 1. Monotonic recovery of DWH may be
explained because oil mortality was much higher than predation mortality. The relatively quick release of oil contamination as a source of mortality enabled a quick
and relatively linear recovery. The more complex biomass recovery trajectories after
the Ixtoc 1 spill may be due to the relatively higher influence of predation mortality
after the oil mortality effect was removed. Predation mortalities in Atlantis exhibit
non-linearities typical of complex ecosystem dynamics, while oil mortality has a
more uniform effect across all functional groups. The complex biomass recovery
trajectories after the Ixtoc 1 oil spill could also explain the changes in fish assemblages composition reported by Amezcua-Linares et al. (2015).
32.4.3 Trophic Impacts
Ainsworth et al. (2018) concluded that a high degree of connectivity exists between
populations in the Gulf. The loss of grouper biomass in Campeche Bay in DWH
simulation, which was large and in the same order of magnitude as the Ixtoc 1 simulation, was communicated from over 1000 miles away. There is similar evidence
from the current study of strong connectivity over large spatial scales. However,
biomass decrease in the southern Gulf estimated by the DWH simulation was solely
due to trophic interactions, including starvation, as evidenced by a decrease in condition factor estimates. Whereas, the biomass decrease estimated by Ixtoc 1 simulations was due to oil mortality. This highlights the important role of starvation on
stock biomass decrease compared to direct oil mortality.
Acknowledgments Shaojie Sun provided GIS data of processed satellite images, and Francisco
Arreguín-Sánchez provided fisheries data for the southern Gulf. This research was made possible
by grants from the Gulf of Mexico Research Initiative through The Center for the Integrated
Modeling and Analysis of the Gulf Ecosystem (C-IMAGE). Atlantis model data are publicly available through the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC)
at https://data.gulfresearchinitiative.org (doi: 10.7266/N779435P; 10.7266/n7-24gt-6z95).
References
Ainsworth CH, Schirripa MJ, Morzaria Luna HN (eds) (2015) An Atlantis ecosystem model for the
northern Gulf of Mexico supporting integrated ecosystem management. U.S. Dept. Commer.,
NOAA Tech. Memo. NMFS-SEFSC-TM-676. https://doi.org/10.7289/V5X63JVH
Ainsworth CH, Paris CB, Perlin N, Dornberger LN, Patterson WF III, Chancellor E, Murawski S,
Hollander D, Daly K, Romero IC, Coleman F, Perryman H (2018) Impacts of the Deepwater
Horizon oil spill evaluated using an end-to-end ecosystem model. PLoS One 13(1):e0190840.
https://doi.org/10.1371/journal.pone.0190840
32 Comparing Ecosystem Model Outcomes Between Ixtoc 1 and Deepwater...
32.4.2 Recovery
The trajectories of biomass recovery for fish guilds impacted by DWH are more
monotonic than those impacted by Ixtoc 1. Monotonic recovery of DWH may be
explained because oil mortality was much higher than predation mortality. The relatively quick release of oil contamination as a source of mortality enabled a quick
and relatively linear recovery. The more complex biomass recovery trajectories after
the Ixtoc 1 spill may be due to the relatively higher influence of predation mortality
after the oil mortality effect was removed. Predation mortalities in Atlantis exhibit
non-linearities typical of complex ecosystem dynamics, while oil mortality has a
more uniform effect across all functional groups. The complex biomass recovery
trajectories after the Ixtoc 1 oil spill could also explain the changes in fish assemblages composition reported by Amezcua-Linares et al. (2015).
32.4.3 Trophic Impacts
Ainsworth et al. (2018) concluded that a high degree of connectivity exists between
populations in the Gulf. The loss of grouper biomass in Campeche Bay in DWH
simulation, which was large and in the same order of magnitude as the Ixtoc 1 simulation, was communicated from over 1000 miles away. There is similar evidence
from the current study of strong connectivity over large spatial scales. However,
biomass decrease in the southern Gulf estimated by the DWH simulation was solely
due to trophic interactions, including starvation, as evidenced by a decrease in condition factor estimates. Whereas, the biomass decrease estimated by Ixtoc 1 simulations was due to oil mortality. This highlights the important role of starvation on
stock biomass decrease compared to direct oil mortality.
Acknowledgments Shaojie Sun provided GIS data of processed satellite images, and Francisco
Arreguín-Sánchez provided fisheries data for the southern Gulf. This research was made possible
by grants from the Gulf of Mexico Research Initiative through The Center for the Integrated
Modeling and Analysis of the Gulf Ecosystem (C-IMAGE). Atlantis model data are publicly available through the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC)
at https://data.gulfresearchinitiative.org (doi: 10.7266/N779435P; 10.7266/n7-24gt-6z95).
References
Ainsworth CH, Schirripa MJ, Morzaria Luna HN (eds) (2015) An Atlantis ecosystem model for the
northern Gulf of Mexico supporting integrated ecosystem management. U.S. Dept. Commer.,
NOAA Tech. Memo. NMFS-SEFSC-TM-676. https://doi.org/10.7289/V5X63JVH
Ainsworth CH, Paris CB, Perlin N, Dornberger LN, Patterson WF III, Chancellor E, Murawski S,
Hollander D, Daly K, Romero IC, Coleman F, Perryman H (2018) Impacts of the Deepwater
Horizon oil spill evaluated using an end-to-end ecosystem model. PLoS One 13(1):e0190840.
https://doi.org/10.1371/journal.pone.0190840
32 Comparing Ecosystem Model Outcomes Between Ixtoc 1 and Deepwater...