Ammonia spills while used as a shipping fuel could negatively impact certain habitats and species more than others, a new study calling for a regulatory framework for suitable mitigation measures has found.
Ammonia produced with renewable energy is already projected as one of the possible main future fuels for shipping. However, its introduction creates new challenges related to safe fuel bunkering, storage, supply and consumption for different ship types, as ammonia is toxic if released into the environment.
The study by consulting firm Ricardo, on behalf of the Environmental Defense Fund (EDF), with support from Lloyd’s Register, into the potential marine environmental impacts from bunkering operations, ship collisions and sinkings found estuaries, mangroves and wetlands are particularly sensitive to potential ammonia fuel spills compared to the polar regions and deep sea.
We have to make sure we get it right from the very beginning
Within these habitats, it is typically fish and particularly ecosystems with less saline water and higher temperatures that are most sensitive to an ammonia spill, with birds and mammals to a lesser degree, the report said.
Lauren Dawson, senior consultant, water and environment practice at Ricardo, stated: “It is important to study the impact of ammonia carefully for particular regions where these habitats intersect with major shipping channels and ports, such as the Strait of Malacca. The findings of the report provide an excellent step forward in delivering a baseline upon which future assessments can be refined.”
The results were compared to previously studied habitat and species’ sensitivity to conventional oil-based fuels, showing a relatively smaller dispersion distance and lower persistence within the environment when compared to heavy fuel oil (HFO) and marine gas oil (MGO). Existing reports show that oil-based fuels have higher impacts on invertebrates and birds, compared with ammonia. Ammonia has a medium impact on all other ecological receptors, except bacteria, whereas oil-based fuels have medium impacts on plankton, fish, macrophytes, reptiles and marine mammals.
Still, the report warned that the potential toxicity of ammonia cannot be ignored and that without mitigation measures and solid spill management practices, an ammonia fuel spill could have negative impacts on aquatic environments.
“Greater clarity about the risks posed to marine ecosystems will allow industry stakeholders to make better informed decisions on the multiple transition pathways under consideration,” said Andy Franks, senior risk specialist at the LR Maritime Decarbonisation Hub.
This study is a first look at ammonia’s potential ecological impacts as a fuel and calls for further research to evaluate the full range of ecological and health implications, including the increased nitrogen deposition from chronic ammonia leakage and combustion by-products, to determine its safety.
“All future fuels come with specific challenges. We have been using oil to power ships for almost a century now and we had to learn how to do so in a safe way. We can’t go through the same process with ammonia,” said Marie Hubatova, director of global shipping for EDF’s global transport team. “We have to make sure we get it right from the very beginning. A robust regulatory framework and good management practices are essential for the safe use of ammonia.”