Five Billion Dead Sea Stars and the Push to Finally Manage Marine Diseases

More than five billion sea stars have died worldwide in recent years, with some species losing over 90% of their populations. In the Bering Sea, over 10 billion snow crabs starved between 2018 and 2021, shutting down one of America's most valuable fisheries for the first time. In Argentina, avian influenza killed 97% of elephant seal pups in a single colony in 2023.

These are not isolated catastrophes. They are symptoms of a growing problem that marine science has been slow to address: infectious disease in the ocean.

A field playing catch-up

Compared to terrestrial disease ecology, the study of marine diseases has historically lagged far behind. Resource managers have had limited tools to track, predict, or respond to outbreaks in the ocean. Few studies have proposed management solutions tailored to marine environments, where you cannot fence off a population, quarantine a reef, or vaccinate a school of fish.

That gap is starting to close. A new special edition of Philosophical Transactions of the Royal Society B, co-edited by researchers from Bigelow Laboratory for Ocean Sciences, Hakai Institute, and the USGS Western Fisheries Research Center, provides the first thorough collection of peer-reviewed studies focused specifically on disease management in marine wildlife.

The issue builds on a 2016 edition of the same journal that broadly surveyed marine disease ecology. This time, the focus is sharper: not just understanding marine diseases, but figuring out what to do about them.

New tools for an old problem

Several advances have accelerated the field in recent years. Genomic sequencing can now identify pathogens faster and more cheaply. Artificial intelligence tools help analyze surveillance data at scale. Advances in ocean modeling allow scientists to predict how diseases might spread through currents and temperature gradients.

The special issue showcases these approaches across a range of species and settings. Some studies examine threats to wild populations -- work that is logistically difficult and expensive in open ocean environments. Others focus on aquaculture, including a deadly virus that has plagued oyster farms across Europe. Still others look at ecosystem-level strategies, such as making coral reefs more resilient to disease outbreaks.

Species that matter economically, ecologically, and culturally

Many of the species examined carry weight beyond their biology. The American lobster supports coastal economies across New England. The sunflower sea star, a keystone predator in kelp forests, has been devastated by sea star wasting disease. Both are cases where disease has intersected with -- and sometimes compounded -- other stressors like warming oceans and changing salinity.

The southern New England lobster fishery offers a particularly sobering example. A shell-degrading disease emerged in the early 2000s just as the fishery collapsed. Disentangling disease from other factors like rising water temperatures remains an ongoing challenge, but the coincidence underscores how disease can amplify ecological crises already underway.

From discovery to practical management

The most important thread running through the special issue is the insistence on connecting science to action. Articles cover molecular tools for identifying new diseases, protocols for investigating outbreaks of unknown origin, modeling approaches for tracking disease drivers in remote ocean areas, and methods for evaluating whether to reintroduce species after an outbreak has subsided.

Common recommendations surface across multiple studies: the value of observer networks that can detect outbreaks early, efficient information sharing between researchers and managers, regular disease monitoring rather than reactive responses, and proactive screening before outbreaks escalate.

The funding and collaboration problem

There is an honest limitation underlying all of this work: it requires sustained investment. Marine disease surveillance is expensive, and the infrastructure for it remains underdeveloped compared to terrestrial and human health systems. Building relationships between management agencies and research institutions takes time and political commitment.

The editors acknowledge this directly. David Paez, a quantitative biologist with the USGS Western Fisheries Research Center and a co-editor, noted that while progress is real, the infrastructure to respond adequately to marine disease emergencies is still being built.

The special issue does not claim to have solved the problem of marine disease management. What it does is establish a foundation: a body of peer-reviewed evidence showing that management is possible, that new tools are making it more feasible, and that the consequences of inaction are measured in billions of dead animals and collapsed fisheries.