Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event
In 2019, an unusual mortality event (UME) affected bottlenose dolphins (<i>Tursiops truncatus</i>) in the Mississippi Sound (MSS) following an extended dual opening of the Bonnet Carré Spillway (BCS), which prevents flooding in New Orleans. This resulted in low salinity, skin lesions, an...
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2025-06-01
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| author | Nelmarie Landrau-Giovannetti Ryanne Murray Stephen Reichley Debra Moore Theresa Madrigal Ashli Brown Ashley Meredith Christina Childers Darrell Sparks Moby Solangi Anna Linhoss Beth Peterman Mark Lawrence Barbara L. F. Kaplan |
| author_facet | Nelmarie Landrau-Giovannetti Ryanne Murray Stephen Reichley Debra Moore Theresa Madrigal Ashli Brown Ashley Meredith Christina Childers Darrell Sparks Moby Solangi Anna Linhoss Beth Peterman Mark Lawrence Barbara L. F. Kaplan |
| author_sort | Nelmarie Landrau-Giovannetti |
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| description | In 2019, an unusual mortality event (UME) affected bottlenose dolphins (<i>Tursiops truncatus</i>) in the Mississippi Sound (MSS) following an extended dual opening of the Bonnet Carré Spillway (BCS), which prevents flooding in New Orleans. This resulted in low salinity, skin lesions, and electrolyte imbalances in dolphins. Additionally, the influx likely altered the MSS’s environmental chemical composition, including levels of heavy metals and metalloids; thus, we quantified heavy metals, metalloids, and essential elements in the tissues of dolphins that stranded in the MSS before and after the 2019 UME. We hypothesized that levels of heavy metals and metalloids (such as mercury (Hg), arsenic (As), lead (Pb), and cadmium (Cd)) would not show significant changes post-UME. Indeed, we found no major changes associated with the UME in most metals; sodium (Na) and magnesium (Mg) levels were lower in several tissues after 2019, which correlated with the average yearly salinity measured from the MSS. Toxic metals and metalloids were detectable with some changes over time; however, the selenium (Se):Hg molar ratio increased in some tissues post-2019. Additionally, we confirmed that Hg can bioaccumulate, with positive correlations between Hg levels and dolphin size as assessed by straight length. Overall, our findings indicate that freshwater incursions into the MSS can alter dolphin exposure to essential and toxic elements. |
| format | Article |
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| institution | Kabale University |
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| language | English |
| publishDate | 2025-06-01 |
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| series | Toxics |
| spelling | doaj-art-9bd51dd1a36648bb9b35cc2f7ed6aa952025-08-20T03:29:43ZengMDPI AGToxics2305-63042025-06-0113651110.3390/toxics13060511Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality EventNelmarie Landrau-Giovannetti0Ryanne Murray1Stephen Reichley2Debra Moore3Theresa Madrigal4Ashli Brown5Ashley Meredith6Christina Childers7Darrell Sparks8Moby Solangi9Anna Linhoss10Beth Peterman11Mark Lawrence12Barbara L. F. Kaplan13Global Center for Aquatic Health and Food Security, Mississippi State University, Mississippi State, MS 39762, USAGlobal Center for Aquatic Health and Food Security, Mississippi State University, Mississippi State, MS 39762, USAGlobal Center for Aquatic Health and Food Security, Mississippi State University, Mississippi State, MS 39762, USAGlobal Center for Aquatic Health and Food Security, Mississippi State University, Mississippi State, MS 39762, USAInstitute for Marine Mammal Studies, Gulfport, MS 39503, USAMississippi State Chemical Laboratory, Mississippi State University, Mississippi State, MS 39762, USAMississippi State Chemical Laboratory, Mississippi State University, Mississippi State, MS 39762, USAMississippi State Chemical Laboratory, Mississippi State University, Mississippi State, MS 39762, USAMississippi State Chemical Laboratory, Mississippi State University, Mississippi State, MS 39762, USAInstitute for Marine Mammal Studies, Gulfport, MS 39503, USADepartment of Biosystems Engineering, Samuel Ginn College of Engineering, Auburn University, Auburn, AL 36849, USAGlobal Center for Aquatic Health and Food Security, Mississippi State University, Mississippi State, MS 39762, USAGlobal Center for Aquatic Health and Food Security, Mississippi State University, Mississippi State, MS 39762, USAGlobal Center for Aquatic Health and Food Security, Mississippi State University, Mississippi State, MS 39762, USAIn 2019, an unusual mortality event (UME) affected bottlenose dolphins (<i>Tursiops truncatus</i>) in the Mississippi Sound (MSS) following an extended dual opening of the Bonnet Carré Spillway (BCS), which prevents flooding in New Orleans. This resulted in low salinity, skin lesions, and electrolyte imbalances in dolphins. Additionally, the influx likely altered the MSS’s environmental chemical composition, including levels of heavy metals and metalloids; thus, we quantified heavy metals, metalloids, and essential elements in the tissues of dolphins that stranded in the MSS before and after the 2019 UME. We hypothesized that levels of heavy metals and metalloids (such as mercury (Hg), arsenic (As), lead (Pb), and cadmium (Cd)) would not show significant changes post-UME. Indeed, we found no major changes associated with the UME in most metals; sodium (Na) and magnesium (Mg) levels were lower in several tissues after 2019, which correlated with the average yearly salinity measured from the MSS. Toxic metals and metalloids were detectable with some changes over time; however, the selenium (Se):Hg molar ratio increased in some tissues post-2019. Additionally, we confirmed that Hg can bioaccumulate, with positive correlations between Hg levels and dolphin size as assessed by straight length. Overall, our findings indicate that freshwater incursions into the MSS can alter dolphin exposure to essential and toxic elements.https://www.mdpi.com/2305-6304/13/6/511dolphinsMississippi Soundmetalsunusual mortality eventBonnet Carré Spillway |
| spellingShingle | Nelmarie Landrau-Giovannetti Ryanne Murray Stephen Reichley Debra Moore Theresa Madrigal Ashli Brown Ashley Meredith Christina Childers Darrell Sparks Moby Solangi Anna Linhoss Beth Peterman Mark Lawrence Barbara L. F. Kaplan Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event Toxics dolphins Mississippi Sound metals unusual mortality event Bonnet Carré Spillway |
| title | Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event |
| title_full | Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event |
| title_fullStr | Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event |
| title_full_unstemmed | Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event |
| title_short | Tissue Element Levels and Heavy Metal Burdens in Bottlenose Dolphins That Stranded in the Mississippi Sound Surrounding the 2019 Unusual Mortality Event |
| title_sort | tissue element levels and heavy metal burdens in bottlenose dolphins that stranded in the mississippi sound surrounding the 2019 unusual mortality event |
| topic | dolphins Mississippi Sound metals unusual mortality event Bonnet Carré Spillway |
| url | https://www.mdpi.com/2305-6304/13/6/511 |
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