395
impacts of the fishery closures and the impacts of oil on the major predators of eggs
and larvae could have contributed to the high catch rates in seagrass habitats in the
northern GoM during 2010. Some of the wetland areas included in this study were
considered minimally impacted (lightly oiled or no oil observed) based on oiling
surveys (Nixon et al. 2016), which could also explain the lack of changes in juvenile
fish assemblages and community composition in this area. A similar situation
occurred in the SGoM where no significant impacts on demersal fish communities
were reported as a result of the Ixtoc 1 oil spill (Yáñez-Arancibia 1986; YáñezArancibia et al. 1982). Although the oil spill spread along the SGoM reaching Texas
beaches potentially affecting extensive shorelines (1700–3000 km) (Tunnell Jr
2016; Sun et al. 2015), coastal areas were not uniformly heavy oiled (Anonymous
1980). The main nursery areas in the SGoM, like Términos Lagoon and nearby
offshore areas in proximity to Ixtoc 1, were not heavily affected due to natural barriers from current patterns and freshwater plumes.
Habitat usage and fish assemblages in oiled and unoiled salt marshes in Louisiana
in 2012 and 2013 were compared (Able et al. 2015). The study area spanned 90 km
along the LA coast, including 22 sites within Terrebonne, Caminada, and Barataria
Bays. There were no statistical differences in composition, abundance, size, or
assemblage composition of fundulids, cyprinodontid, or poeciliids between oiled
and unoiled sites in Barataria Bay. The inability to detect fish assemblage or abundance differences could be due to limitations related to statistical power, reference
site locations (e.g., unknown oiling of sites considered “controls”), and timing of
the fish collections. Conversely, a study conducted at similar sites within Barataria
Bay found lower abundances of Gulf killifish at oil-impacted sites in Barataria Bay
compared to reference or unoiled site located in Texas (Carr et al. 2018). Body
weight, standard length, and total length were all statistically lower in fish collected
at impacted sites versus the unimpacted, reference site. Remarkably, there were no
sexually mature F. grandis greater than 12 g collected at any of the 11 sites sampled
in Barataria Bay. The timing of these studies and the selection reference sites
between these two studies are obviously important in interpreting results. The study
by Carr et al. (2018) was conducted in 2010, whereas Able et al. (2015) conducted
their study 2–3 years post-DWH. This time lag could have allowed for a period of
recovery, particularly given the short life spans of the species involved. Also, Able
et al. (2015) selected a reference location within Barataria Bay. Within the last three
decades, at least nine major oil spills have occurred in coastal Louisiana, including
Barataria Bay. Identifying reference sites or unoiled marshes within Barataria Bay
might be challenging since Barataria Bay marsh sediments routinely receive input
of PAHs from petrogenic, pyrogenic, and biogenic sources (DeLaune et al. 1979;
Hester and Mendelssohn 2000; Dincer Kırman et al. 2016).
Time-series data and generalized additive models (GAM) were also used to characterize the patterns of abundance and habitat usage for large predatory pelagic
fishes in the northern GoM for the years 2007–2010 (Rooker et al. 2013). This study
examined the spatial extent of the DWH surface oil to determine whether habitat of
blackfin tuna, blue marlin, dolphinfish, and sailfish was exposed to oil. The spatial
distribution predications and impacts on suitable habitat in 2010, post-DWH, were
24 Chronic Sub-lethal Effects Observed in Wild-Caught Fishes Following Two Major…
impacts of the fishery closures and the impacts of oil on the major predators of eggs
and larvae could have contributed to the high catch rates in seagrass habitats in the
northern GoM during 2010. Some of the wetland areas included in this study were
considered minimally impacted (lightly oiled or no oil observed) based on oiling
surveys (Nixon et al. 2016), which could also explain the lack of changes in juvenile
fish assemblages and community composition in this area. A similar situation
occurred in the SGoM where no significant impacts on demersal fish communities
were reported as a result of the Ixtoc 1 oil spill (Yáñez-Arancibia 1986; YáñezArancibia et al. 1982). Although the oil spill spread along the SGoM reaching Texas
beaches potentially affecting extensive shorelines (1700–3000 km) (Tunnell Jr
2016; Sun et al. 2015), coastal areas were not uniformly heavy oiled (Anonymous
1980). The main nursery areas in the SGoM, like Términos Lagoon and nearby
offshore areas in proximity to Ixtoc 1, were not heavily affected due to natural barriers from current patterns and freshwater plumes.
Habitat usage and fish assemblages in oiled and unoiled salt marshes in Louisiana
in 2012 and 2013 were compared (Able et al. 2015). The study area spanned 90 km
along the LA coast, including 22 sites within Terrebonne, Caminada, and Barataria
Bays. There were no statistical differences in composition, abundance, size, or
assemblage composition of fundulids, cyprinodontid, or poeciliids between oiled
and unoiled sites in Barataria Bay. The inability to detect fish assemblage or abundance differences could be due to limitations related to statistical power, reference
site locations (e.g., unknown oiling of sites considered “controls”), and timing of
the fish collections. Conversely, a study conducted at similar sites within Barataria
Bay found lower abundances of Gulf killifish at oil-impacted sites in Barataria Bay
compared to reference or unoiled site located in Texas (Carr et al. 2018). Body
weight, standard length, and total length were all statistically lower in fish collected
at impacted sites versus the unimpacted, reference site. Remarkably, there were no
sexually mature F. grandis greater than 12 g collected at any of the 11 sites sampled
in Barataria Bay. The timing of these studies and the selection reference sites
between these two studies are obviously important in interpreting results. The study
by Carr et al. (2018) was conducted in 2010, whereas Able et al. (2015) conducted
their study 2–3 years post-DWH. This time lag could have allowed for a period of
recovery, particularly given the short life spans of the species involved. Also, Able
et al. (2015) selected a reference location within Barataria Bay. Within the last three
decades, at least nine major oil spills have occurred in coastal Louisiana, including
Barataria Bay. Identifying reference sites or unoiled marshes within Barataria Bay
might be challenging since Barataria Bay marsh sediments routinely receive input
of PAHs from petrogenic, pyrogenic, and biogenic sources (DeLaune et al. 1979;
Hester and Mendelssohn 2000; Dincer Kırman et al. 2016).
Time-series data and generalized additive models (GAM) were also used to characterize the patterns of abundance and habitat usage for large predatory pelagic
fishes in the northern GoM for the years 2007–2010 (Rooker et al. 2013). This study
examined the spatial extent of the DWH surface oil to determine whether habitat of
blackfin tuna, blue marlin, dolphinfish, and sailfish was exposed to oil. The spatial
distribution predications and impacts on suitable habitat in 2010, post-DWH, were
24 Chronic Sub-lethal Effects Observed in Wild-Caught Fishes Following Two Major…