Offshore Seismic Testing for Oil and Gas Could Endanger Marine Food Chains

U.S. fossils are pushing back after research found that a common technique used in offshore oil and gas exploration endangers marine food chains by doubling to tripling the death rate of zooplankton at a distance of at least 1.2 kilometres (three-quarters of a mile)—much farther away than past reports have indicated.

“The world’s powerful offshore oil and gas industry has used seismic surveys for decades as the primary way to locate fossil fuels under the ocean floor,” DeSmog Blog reports, in a post republished by Resilience.org. The technique uses “an underwater air gun pulled behind a boat and fired at intervals, and as the shock waves bounce off the sea floor and return to sensors, they help reveal where oil and gas might be.”

Past reports had found impacts on zooplankton, an organism at the base of the marine food web, at distances up to 10 metres. The new paper in the journal Nature Ecology and Evolution, co-authored by marine scientists Dr. Robert McCauley of Australia’s Curtin University and Jayson Semmens of the University of Tasmania, tracked mortality at a far greater distance.

“Using sonar images, the study looked at the abundance of zooplankton after the air gun blasts and analyzed the organisms caught in nets, which revealed the increase in dead zooplankton,” DeSmog explains. “Semmens says there are many studies on the impacts of seismic surveys on fish and marine mammals, but there was almost no knowledge of how the exploration technique affected invertebrates.”

The Guardian reports that the American Petroleum Institute and the International Association of Geophysical Contractors have been working to discredit the research with U.S. authorities, with an IAGC spokesperson pointing to “small sample sizes, the large day-to-day variability in both the baseline and experimental data, and the large number of speculative conclusions that appear to be inconsistent with the data collected over a two-day period.”

McCauley, who’s been studying the impact of seismic surveys on marine life since the 1990s, accused the fossils of a “whole load of whitewash”, asserting that critics would “throw as much mud and confusion around to stall the process.”

Already, the research is producing tensions between fossils, regulators, and the fishing industry, DeSmog reports. Commercial fishers in the Australian states of Tasmania and Victoria are concerned that seismic testing could affect lobster, abalone, scallop, and crab populations, and the North Carolina Divisions of Coastal Management and Marine Fisheries have similar concerns.

“Based on the new studies, we believe the proposed seismic testing could severely impact North Carolina’s commercial and recreational fisheries, and we are requesting more information for review by state officials and the public,” Director Braxton Davis wrote last December.