Impact of environmental pollutants on migration and breeding patterns of bottlenose dolphins (Tursiops truncatus) in coastal ecosystems: a multi-omics and field study

Project Abstract

Exposure to diverse environmental pollutants in coastal ecosystems can perturb the migratory routes, timing, and reproductive success of bottlenose dolphins (Tursiops truncatus), with cascading effects on population viability and ecosystem dynamics. This study integrates field observations, multi-omics analyses, and advanced pollutant profiling to elucidate the mechanistic links between contaminant exposure and dolphin migration and breeding patterns. Field components include longitudinal photo-identification, fine-scale telemetry using satellite-linked transmitters, passive acoustic monitoring, and biopsy sampling of skin/blubber for contaminant and genomic analyses, conducted across multiple coastal habitats with varying pollutant regimes. Chemical analyses quantify a broad suite of pollutants—persistent organic pollutants (POPs), heavy metals, and emerging contaminants (e.g., PFAS, microplastics-associated compounds)—to generate exposure indices at individual and population levels. Multi-omics approaches encompass transcriptomics, proteomics, and epigenomics (DNA methylation) to identify molecular signatures associated with pollutant burdens, stress response pathways, endocrine disruption, and reproductive physiology. Integrated data science pipelines will correlate exposure metrics with movement ecology metrics (migration corridors, seasonal residency, dive behaviour), reproductive indicators (reproductive hormones, sperm quality in males, calving intervals, uterine health in females), and offspring viability. The study also employs controlled modeling to predict how pollutant-induced physiological perturbations influence energy budgets, migratory timing, and breeding readiness under variable environmental conditions such as prey availability and sea surface temperature anomalies. We hypothesize that higher internal loads of organochlorines, heavy metals, and PFAS will correlate with altered hormone profiles and epigenetic modifications that disrupt gonad development and fecundity, while neurotoxicants may affect navigation cues and social coordination during group migrations. Expected outcomes include a risk matrix linking contaminant burdens to specific migratory deviations and reproductive impairments, identification of key molecular biomarkers predictive of sublethal effects, and a framework to forecast population-level impacts under future pollution scenarios. The research will contribute to conservation strategies by identifying critical habitats with elevated pollutant exposure, informing adaptive management decisions for marine protected areas, and guiding pollutant regulation to mitigate adverse behavioural and reproductive outcomes in bottlenose dolphins. Ethical considerations, including minimizing distress during handling and ensuring wildlife welfare, are integrated throughout the methodology. Potential limitations include variability in exposure measurement due to transient foraging patterns and genetic heterogeneity across populations, as well as challenges in disentangling pollutant effects from climate-driven ecological stressors. The study addresses a significant gap in understanding how coastal pollution reshapes key life-history traits in a sentinel marine species, providing actionable insights for policymakers, conservationists, and the scientific community.

Project Overview

What This Project Is About

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A straightforward look at how pollution in coastal waters may affect where bottlenose dolphins travel and how often they breed. The project combines simple field observations with basic biological data to see if pollutants are linked to changes in dolphin movement and reproduction.

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The Problem It Addresses

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Pollution can accumulate in coastal habitats used by dolphins. Little is known about how this exposure might disrupt their daily movements or breeding cycles. Understanding these links helps protect dolphins and coastal ecosystems, and informs pollution control decisions.

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Objectives of the Project

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1. Describe dolphin movement patterns in polluted vs. cleaner coastal areas.
2. Assess indicators of breeding activity in relation to pollutant levels.
3. Identify key pollutants that correlate with observed changes.
4. Provide practical recommendations for pollution management to protect dolphins.

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What You Will Do Step by Step

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1) Review basic literature on dolphins, pollution, and coastal ecosystems. 2) Collect simple field data on dolphin sightings and breeding indicators during planned surveys. 3) Gather water and sediment samples to measure common pollutants. 4) Compare movement and breeding signals with pollutant data using simple statistics. 5) Interpret results in plain language and discuss limitations. 6) Suggest actions for reducing pollution impacts.

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Expected Outcome

A concise set of findings showing whether and how coastal pollution relates to dolphin movement and breeding, plus clear recommendations for policy and conservation actions.