From Sand Tiger Sharks to Safe Waters: Why PFAS Oversight Matters for North Carolina’s Aquatic Ecosystems

Connecting Animal Care to Water Quality

The recent collaboration between the North Carolina Aquarium at Fort Fisher and the Georgia Aquarium to move two sand tiger sharks into a larger, more expansive habitat is more than a story of animal welfare—it is a vivid reminder of how dependent captive marine life is on the quality of the water that sustains them. The sharks have resided for nearly a decade in the 235,000‑gallon Cape Fear Shoals exhibit, a system that draws directly from the Cape Fear River basin. As an environmental scientist who has spent years investigating PFAS contamination in North Carolina’s waters, I see this move as an opportunity to reflect on the broader implications of water quality for both ecosystems and public health.

PFAS in the Cape Fear River Basin: A Persistent Challenge

The Cape Fear River has been a focal point of PFAS research since the discovery of GenX and other per‑ and polyfluoroalkyl substances in its watershed. Industrial discharges upstream, legacy use of fluorinated surfactants, and inadequate treatment have resulted in detectable PFAS concentrations throughout the river and its tributaries. While the exact levels vary by location and sampling campaign, the U.S. Environmental Protection Agency (EPA) has issued interim updated health advisories for two of the most studied PFAS: perfluorooctanoic acid (PFOA) at 0.004 parts per trillion (ppt) and perfluorooctane sulfonate (PFOS) at 0.02 ppt. These advisories, released in June 2022, reflect growing evidence that even trace amounts of these compounds can pose health risks.

North Carolina’s Department of Environmental Quality (DEQ) has responded by expanding monitoring programs, issuing fish consumption advisories where PFAS levels exceed state‑derived thresholds, and working with utilities to implement treatment technologies. The Cape Fear Public Utility Authority (CFPUA), for example, has deployed granular activated carbon (GAC) and ion exchange systems at its drinking‑water plants to reduce PFAS concentrations to below detectable limits for many compounds. These efforts are essential not only for protecting human consumers but also for safeguarding the aquatic organisms that rely on the same water sources.

Why Water Quality Matters for Captive Sharks

Sand tiger sharks (Carcharias taurus) are apex predators that, in the wild, bioaccumulate contaminants through their prey. In a controlled aquarium setting, water quality directly influences their health, behavior, and longevity. High PFAS concentrations can disrupt endocrine function, impair immune response, and potentially affect reproductive success—effects documented in various fish species and inferred for elasmobranchs through mechanistic toxicology. Although the Cape Fear Shoals exhibit employs sophisticated filtration, including mechanical, biological, and chemical stages, the source water’s PFAS burden remains a background stressor.

By moving the sharks to a larger habitat with upgraded life‑support systems—likely incorporating enhanced filtration, greater water turnover, and possibly advanced treatment such as reverse osmosis or advanced oxidation—the aquariums are reducing the sharks’ cumulative exposure to contaminants. This proactive step illustrates a best practice that should be emulated across facilities that source water from PFAS‑impacted watersheds.

Broader Policy Implications for North Carolina

The intersection of animal care, environmental protection, and public health underscores the need for coherent PFAS policy at the state level. North Carolina has taken several noteworthy steps:

1. Monitoring and Transparency – DEQ’s PFAS Monitoring Network provides publicly accessible data on surface water, groundwater, and drinking‑water sites. Continued funding for this network is essential to track trends and identify emerging hotspots.
2. Guideline Development – While the state has not yet promulgated enforceable maximum contaminant levels (MCLs) for PFAS in drinking water, it has adopted EPA’s health advisories as interim guidance. Aligning state standards with the EPA’s forthcoming MCLs—expected to set legally enforceable limits of 4 ppt for PFOA and PFOS—will provide clear regulatory targets for utilities and industry.
3. Source‑Water Protection – Initiatives such as the Cape Fear River Basin PFAS Action Plan aim to reduce industrial discharges, promote best‑management practices, and invest in watershed restoration. Strengthening these plans with enforceable discharge limits and incentives for PFAS‑free alternatives will curb contamination at its source.
4. Public Engagement and Education – Outreach programs that explain PFAS risks to communities, anglers, and aquarium visitors foster informed decision‑making and support for protective measures.

The relocation of the sand tiger sharks offers a tangible narrative to communicate these policy goals. When the public sees that even charismatic megafauna benefit from cleaner water, the abstract concept of PFAS regulation becomes concrete and relatable.

Looking Forward: Science‑Driven Solutions

As a researcher focused on PFAS destruction technologies—including hydrothermal liquefaction of municipal sludge and advanced oxidation for GenX—I am optimistic that innovative treatment methods will soon become more widely deployable. Pilot projects in North Carolina have demonstrated that hydrothermal processes can break down PFAS chains while converting sludge into usable bio‑crude, offering a dual benefit of waste reduction and contaminant destruction. Scaling such technologies, coupled with rigorous monitoring, will be key to achieving the EPA’s anticipated MCLs and ensuring that both human populations and aquatic ecosystems thrive.

In conclusion, the move of the sand tiger sharks to a larger home is more than an upgrade in animal husbandry; it is a catalyst for renewed attention to the water quality challenges facing the Cape Fear River basin. By linking animal welfare to PFAS science and policy, we can build a more resilient future where clean water supports both the marvels of our aquariums and the health of our communities. Let us seize this moment to advocate for evidence‑based standards, invest in cutting‑edge treatment, and protect the waters that sustain life in all its forms.