May 1 (UPI) -- To understand a problem, it's important to take stock of you know and what you don't: New research suggests there's an awful lot scientists don't know about discarded munitions and their impact on ocean environs.
Along the coasts of the Baltic and North seas, there are millions of discarded munitions, relics of World War II. The munitions include sea mines, aerial bombs, torpedo heads, grenades and ammunition -- some found in piles, others scattered across the seafloor, most of them dumped intentionally.
"Coastal regions of nearly every continent are impacted by underwater munitions," Aaron Beck, a scientist at the GEOMAR Helmholtz Center for Ocean Research Kiel, said in a news release.
In a new paper, published this week in the journal Frontiers in Marine Science, Beck and his colleagues compiled what is currently understood about the ecological effects of munitions-related chemicals.
"Although the underwater munitions problem is widespread globally, it has received surprisingly little attention," Beck said. "The approach thus far has primarily been 'out of sight, out of mind,' despite the occasional tragedy when munitions are encountered by beachgoers or fishermen."
As infrastructure, whether aquaculture, renewable energy construction or otherwise, makes inroads into coastal regions, researchers say it's important to know the hazards that await.
In the decades since they were discarded, many of the munitions are likely to have had their casings severely corroded, exposing their insides to the surrounding water. Many of the munitions house toxic chemicals, including carcinogenic, and cyto- and genotoxic chemicals. Previous studies have shown these chemicals to have measurable genetic and metabolic effects on marine species.
Less understood is how long these chemicals can persist in the environment and how they're carried by ocean currents. Researchers working on the UDEMM project are currently studying tests sites to measure the release, dispersion and migration patterns of munitions chemicals.
"In our study, we were able to show that there are still significant knowledge gaps about the global impact of old ammunition on marine ecosystems. We are in the process of closing some of them in the UDEMM project. But the ultimate goal must be to clear the seafloor of ammunition as well," said GEOMAR researcher Eric Achterberg. "And that's a mammoth task."