Marine mammals exhibit variation in diving behavior, with some species conducting short (less than 5 minutes) shallow dives to a few meters and others exhibiting long (over an hour) deep dives to thousands of meters. Many of these species show physiological adaptations to low oxygen conditions (hypoxia) during prolonged breath holds.

Hypoxia is important in human health as it occurs when tissues are deprived of an adequate oxygen supply and is highly relevant to human disease across multiple clinical settings, including heart attack, stroke, COVID-19 and cancer. However, the underlying cellular and molecular mechanisms that enable marine mammals to adapt to hypoxia and the differences in these adaptations across species remain largely unexplored.

The aim of this research was to identify the cellular and molecular mechanisms underlying marine mammal adaptations to hypoxia and to investigate the genetic differences within bottlenose dolphin populations that exhibit different diving patterns in the western North Atlantic Ocean. To address these questions, team members used cell cultures created from biopsy samples from a range of marine mammal species. In the laboratory, cells were placed into normoxic and hypoxic conditions, and a range of downstream analyses were conducted to identify candidate hypoxia genes.

Results showed significant cellular differences between marine and terrestrial mammals’ responses to hypoxic conditions, suggesting important adaptive differences in respiration, oxygen affinity and mitochondrial volume. Furthermore, genetically distinct groups were identified within bottlenose dolphin data by analyzing Single Nucleotide Polymorphisms across the genome, which can help inform management units and better understand these populations.

Ultimately, this team hopes that their work will contribute knowledge to how whales are adapted to diving whilst also identifying possible links to human health and hypoxia.

Timing

Summer 2023 – Spring 2024

Team Outputs

Learning From Whales (team website)

Learning from Whales: A Deep Dive in Marine Mammal Genetics (Poster presented at Fortin Foundation Bass Connections Showcase, April 17, 2024)

Examining Classification Frameworks: Bottlenose Dolphins, the ESA, and the MMPA (Poster presented at SEAMAMMS, Duke University Marine Lab, Beaufort, NC, April 2024)

Genomic Analysis of Stranded Atlantic Common Bottlenose Dolphins (Tursiops truncatus/T.erebennus) to Identify Genetically Distinct Groups (Poster presented at SEAMAMMS, Duke University Marine Lab, Beaufort, NC, April 2024)

A New Cell Culture System to Study Marine Mammal Hypoxia Adaptations Pinpoints Changes in Metabolic Activity and Oxygen Affinity (Poster presented at SEAMAMMS, Duke University Marine Lab, Beaufort, NC, April 2024)

Genomic Differentiation of Common Bottlenose Dolphins (Tursiops truncatus/T.erebennus) in the Western North Atlantic (Poster presented at SEAMAMMS, Duke University Marine Lab, Beaufort, NC, April 2024)

Investigating Genes Involved in Cellular Hypoxia Response in Common Bottlenose Dolphins (Tursiops truncates/T.erebennus) (Poster presented at SEAMAMMS, Duke University Marine Lab, Beaufort, NC, April 2024)

Regional Genetic Variation in Ecologically Important Genes in the Common Bottlenose Dolphin (Tursiops truncatus/T.erebennus) (Poster presented at SEAMAMMS, Duke University Marine Lab, Beaufort, NC, April 2024)

Population Genomic Analyses of Common Bottlenose Dolphins (Tursiops truncatus/T.erebennus) in the Western North Atlantic (Poster presented at SEAMAMMS, Duke University Marine Lab, Beaufort, NC, April 2024)

See related teams, Learning From Whales: Oxygen, Ecosystems and Human Health (2024-2025) and Learning from Whales: Oxygen, Ecosystems, and Human Health (2021-2022).