Report warns of invasive species risk from LNG carrier ballast water and biofouling

A report authored by US-based research and consulting firm Energy and Environmental Research Associates (EERA) has found that LNG carrier traffic associated with proposed LNG export projects on the Gulf of California could pose a serious risk to marine ecosystems.

Looking at the EERA findings in “The Impacts of Ballast Water from Projected LNG Vessel Traffic in the Gulf of California” (April 2026) an issue brief from maritime decarbonisation-focused non-profit Equal Routes said that LNG carrier traffic could disrupt marine life and activity across a highly biodiverse oceanscape.

"It supports extraordinary biodiversity, including 39% of all marine mammal species, eleven species of whales, 891 fish species, and five of the world’s seven sea turtle species. The GoC supports 57% of Mexico’s national marine fisheries production and sustains a thriving marine ecotourism sector valued at approximately $518 million USD annually," Equal Routes said.

The research indicates that the region currently experiences relatively low levels of commercial shipping, meaning a significant increase in LNG tanker traffic could alter existing patterns of marine activity.

The EERA report examines three proposed LNG export projects: Vista Pacifico LNG, Amigo LNG and Saguaro LNG. It estimates that LNG tanker operations could involve substantial volumes of ballast-water exchange, depending on vessel traffic and operating practices.

For Saguaro LNG Phase 3, the study estimates annual ballast-water exchange of approximately 12 million to 30 million tonnes, based on assumptions about vessel calls and the frequency of ballast-water exchange. 

Ballast water can contain organisms taken up in one port and subsequently discharged in another that can become invasive. If non-native organisms establish themselves in a new environment, they can compete with native species, alter habitats and food webs, and create economic impacts for fisheries and other marine-dependent activities.

"Invasive species are non-native organisms that are introduced and capable of establishing in environments where they do not naturally occur. When they become invasive, they can cause significant environmental, ecological, economic, and public health impacts," Equal Routes said. "

In new habitats, invasive species often lack the predators and ecological controls that limit them in their native ranges, allowing populations to expand rapidly. They can outcompete native species, alter habitat structures, disrupt food webs, and trigger cascading ecosystem effects threatening native and migratory species and creating risks for marine dependent coastal communities."

The brief also highlights the potential impacts on ecosystems from biofouling-based transfer, or the process by which organisms attached to ships’ hulls and other submerged surfaces can be transferred and become invasive. Equal Routes notes that the International Maritime Organization recognises biofouling as an important vector for invasive species, and that its regulations are less developed than those covering ballast water.

While Mexico is party to IMO’s Ballast Water Management Convention, which requires ships on international voyages to manage ballast water and meet biological discharge standards, Equal Routes argues that enforcement, monitoring and the effectiveness of treatment systems remain areas of concern.

"An introduction of LNG tanker traffic to the Gulf of California will increase the number of opportunities for non-native organisms to be released. Some fraction will survive and establish despite existing controls. Once established, marine invasions are rarely reversible and may persist for decades. The Gulf of California’s protected habitats, species, and the associated human activities and use in the area make the consequences of even a small increase in invasion probability disproportionately severe. Prevention is therefore the only reliable way to avoid long-term ecological harm," Equal Routes concluded.