Forever chemicals found at unprecedented levels in marine animals

The ocean often seems timeless and undisturbed, with depths where marine animals can slip beyond human activity. New research reveals a far more urgent story.

PFAS compounds, built for endurance, now sit inside whales and dolphins across wide marine zones. Even animals diving into cold, dark layers carry heavy chemical burdens.

PFAS in marine environments

Research groups once believed deep divers lived with lighter contamination. Data now challenges that idea.

Dr. Katharina Peters is a marine ecologist and research leader of the University of Wollongong (UOW).

“Whales and dolphins are considered indicator species because they reflect their ecosystem,” said Dr. Peters.

“We expected that species feeding mainly in deep water, like sperm whales, would have lower PFAS contamination than coastal species like Hector’s dolphins, which are closer to pollution sources.”

“Our analyses show that this is not the case: there really seems to be no place to hide from PFAS.”

How PFAS reach the sea

Movement of contaminants through air, rain, rivers and currents pushes PFAS across wide marine regions.

Strong chemical bonds allow long survival. Many compounds attach to protein-rich tissue and accumulate across life stages.

PFAS also move with ease between water layers. Shifts in salinity, pH and mixing patterns shape dispersal across depth.

Long-chain PFAS show powerful accumulation in organ tissue. Such molecules resist decay and travel great distances across ocean basins.

Inputs from wastewater plants, coastal runoffs and atmospheric fallouts feed these compounds into open seas. Currents transport PFAS far offshore, touching zones once viewed as insulated.

Marine animals exposed to PFAS

The research team analyzed liver tissue from 127 stranded whales and dolphins. Samples covered 16 toothed species. Many species gained a first global PFAS assessment.

The animals represented neritic, mesopelagic, bathypelagic and polar ranges. PFAS profiles varied across families and diets.

Some groups carried high PFSA loads. Others held PFCA or precursor compounds. Predator diets push exposure upward. Species with slow clearance rates accumulate PFAS across long life spans.

Age shaped internal loads. Young animals often showed high values due to maternal transfer.

Adult males carried heavier burdens due to lifelong retention. Adult females often showed lower values due to offloading during nursing.

Such trends match patterns reported across global dolphin and porpoise studies and highlight complex physiological roles in contaminant storage.

No safe marine habitat

“Even offshore and deep-diving species are exposed to similar levels of PFAS, highlighting how widespread pollution, compounded by climate-driven stressors, poses a growing threat to marine biodiversity,” said study co-author Dr. Saltré.

Earlier views suggested coastal waters carried greater exposure. Current evidence disputes that view. Animals from deep trenches, mid-water zones and coastal areas all carried overlapping PFAS ranges.

Research models showed weak support for habitat as a main driver. Sex and age acted as stronger predictors.

Body size index, used as an age proxy, aligned well with PFAS variation. Young individuals showed rising PFAS due to active growth and diet changes.

Older animals often showed slower accumulation. Species clusters also produced distinct patterns linked to feeding style, movement patterns and prey choice.

Rising PFAS risks for marine animals

PFAS presence across many species signals deep ecological concern. The chemicals can disrupt immune function, hormone balance and reproductive health in marine mammals.

Concerns extend to human communities due to shared biological pathways. Marine mammals act as early warning indicators, revealing shifts in ocean quality long before surface level effects become clear.

New Zealand has no major PFAS production, yet PFAS still arrived in large amounts via global movement. Polar visitors carried high burdens, pointing to strong atmospheric pathways.

Climate change may shift current patterns and wind systems, raising exposure risk across many regions in coming years.

Global call for action

Combined data showed PFAS spread across habitats regardless of depth or distance. Marine ecosystems now carry compounds once assumed too remote or dilute to matter.

Life in deep zones now holds chemical footprints shaped by global industry, long range transport and persistent molecular design.

Policy shifts, tighter waste controls and improved global monitoring may slow future rises. Oceans once felt large enough to dilute human activity. New PFAS research reveals a new truth.

No zone lies beyond reach, and animals diving into silent blue layers now carry clear evidence inside their own bodies.

The study is published in the journal Science of The Total Environment. 

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