{"id":2206523,"date":"2026-07-30T18:00:19","date_gmt":"2026-07-30T17:00:19","guid":{"rendered":"https:\/\/focusingonwildlife.com\/news\/?p=2206523"},"modified":"2026-07-24T14:51:27","modified_gmt":"2026-07-24T13:51:27","slug":"as-australia-expands-seismic-testing-experts-warn-of-profound-effects-on-sealife","status":"publish","type":"post","link":"https:\/\/focusingonwildlife.com\/news\/as-australia-expands-seismic-testing-experts-warn-of-profound-effects-on-sealife\/","title":{"rendered":"As Australia expands seismic testing, experts warn of profound effects on sealife"},"content":{"rendered":"

It was spring, 20 years ago now, but he remembers it clearly. On the deck of the\u00a0Geco Resolution<\/em>, wind tearing spray from the waves, Robert McCauley stood gazing out onto an ocean blackened by night.<\/p>\n

The ship had been firing seismic airguns all day, thunderous blasts punching through the water and into the seabed. Over time, the rhythmic boom reverberating through the hull had almost faded into the background.<\/p>\n

But then night fell, and the sound revealed itself.<\/p>\n

\u201cEvery time the airgun went off, the sea would light up,\u201d McCauley told Mongabay. Each blast was triggering a burst of bioluminescence \u2014 dinoflagellates and other microscopic life igniting in unison. \u201cA sheet of light would shoot out, like a wave traveling at the speed of sound. It went out for about a kilometer at least,\u201d he said.<\/p>\n

As Australia\u2019s leading expert in marine bioacoustics, McCauley, a research scientist at the Centre for Marine Science and Technology at Curtin University, was there to study how whales responded to the noise. But watching the bioluminescent glow pulse outward and fade, then pulse again, he found himself wondering less about whales and more about the tiny organisms that sustain them.<\/p>\n

\u201cIt made me think, what\u2019s happening to all those little animals? How are they being stimulated? And what happens if they\u2019re being stimulated every five or 10 seconds, repeatedly?\u201d McCauley wondered.<\/p>\n

For decades, marine seismic surveys have echoed through the world\u2019s oceans, largely in search of oil and gas. Research has shown the intense, impulsive underwater noise can disrupt communication, impair hearing and trigger stress responses in\u00a0marine mammals,\u00a0fish\u00a0and\u00a0penguins. Yet, marine scientists say major gaps remain in understanding how the effects of repeated airgun exposure may accumulate across ecosystems over time.<\/p>\n

Even so, the technology is becoming embedded in Australia\u2019s energy transition plans. Off the state of Western Australia\u2019s northwest coast, Australian petroleum production company Woodside Energy Ltd. is proposing vast new gas developments that would use seismic surveys not only to search for gas, but also to monitor offshore carbon storage sites.<\/p>\n

Under the proposal, carbon dioxide captured during gas production would be injected into rock formations deep beneath the seabed in a process known as carbon capture and storage. If approved, the project could mark a shift in the role of seismic surveys from a tool of resource exploration to a recurring feature of Australia\u2019s net-zero ambitions.<\/p>\n

\"Bioluminescence
Bioluminescence emitted by algae on the coast of Jervis Bay, Australia. Image Image by Trevor McKinnon via\u00a0Unsplash.<\/figcaption><\/figure>\n
\"The<\/a>
The\u00a0MV Geco Resolution\u00a0tows seismic arrays along the mid-Western Australian coast in 1996. Image courtesy of Robert McCauley.<\/figcaption><\/figure>\n

Widening circle of known effects<\/strong><\/h2>\n

Marine seismic surveys are designed to make the invisible visible. Survey vessels tow long arrays of acoustic receivers while firing continuous blasts of compressed air into the ocean. The returning echoes are then used to build three-dimensional maps of the geology beneath the seafloor.<\/p>\n

The sound blasts are intense, reaching 230-250 decibels \u2014 about as loud as some \u00a0underwater volcanic eruptions \u2014 and can be detected in the open ocean thousands of kilometers away.<\/p>\n

Traditionally, research into the ecological effects of seismic surveys in Australia focused largely on whales, because they are both legally protected and rely on sound to navigate.<\/p>\n

But in 2010, that focus shifted after scallop fishers in Bass Strait between the states of Victoria and Tasmania began hauling up\u00a0masses of dead and damaged shells\u00a0following two seismic surveys conducted in the same waters months earlier. At the time, operators\u00a0said<\/a>\u00a0there was no scientific evidence that seismic surveys harmed shellfish, but the scale of die-offs prompted urgent calls for investigation.<\/p>\n

Two years later Ryan Day, a marine animal physiologist at the Institute for Marine and Antarctic Studies at the University of Tasmania, led research to test that assumption, exposing scallops (Pecten fumatus<\/em>) and southern rock lobsters (Jasus edwardsii<\/em>) to varying pulses from a single seismic airgun.<\/p>\n

\u201cIt was the first big, well-done study [on invertebrates] that showed pretty substantial impacts following exposure,\u201d he told Mongabay. Scallops presented severe physiological stress and elevated mortality. Lobsters exhibited weakened immune responses and damage to sensory systems that affected their balance and ability to right themselves if toppled.<\/p>\n

\"A<\/a>
A southern rock lobster (Jasus edwardsii) in Tasmania. Experimental seismic blasts induced weakened immune responses and damage to sensory systems in the species, according to a scientific study. Image courtesy of Scott Bennett\/Great Southern Reef Foundation.<\/figcaption><\/figure>\n

\"Commercial<\/a>
A scallop (Pecten fumatus). Experimental exposure to seismic blasts induced severe physiological stress and elevated mortality in the species, a scientific study found. Image \u00a9 Tiffany Kosch via\u00a0iNaturalist\u00a0(CC BY-NC-SA 4.0).<\/figcaption><\/figure>
\nThe findings, published in\u00a02017\u00a0and\u00a02019, helped extend scientific attention beyond marine mammals.<\/p>\n

In 2017, McCauley published\u00a0research\u00a0with Day as a coauthor, examining the effects of seismic blasts on zooplankton \u2014 minute animals such as fish larvae and krill that underpin marine ecosystems. Until then, industry assumptions had held that impacts would be confined to within 10 meters (33 feet) of an airgun. Instead, McCauley\u2019s team recorded sharp declines in zooplankton abundance as far out as they sampled, up to 1.2 kilometers (0.75 miles) away. Mortality rates were two to three times higher in water samples exposed to an operating airgun than those not, and all krill larvae collected after exposure were dead.<\/p>\n

The results challenged long-held assumptions about the scale and reach of seismic impacts,\u00a0suggesting potentially significant disruption at the base of marine food webs and implications for cascading effects through entire ecosystems.<\/p>\n

Within days, the top national oil and gas lobby group, currently named Australian Energy Producers, commissioned scientists to model McCauley\u2019s results. The subsequent\u00a0report\u00a0projected substantial impacts within 15 km (9 mi) of a modeled survey area, but concluded these would not be detectable at the population level. Zooplankton, it suggested, would rebound quickly in the region, aided by rapid growth rates and ocean mixing.<\/p>\n

\u201cI get it. It\u2019s pretty hard to conceptually accept that you could depopulate zooplankton in a big enough area of ocean for it to matter,\u201d Day said. \u201cBut, you know, that\u2019s what we thought about fisheries for hundreds of years and look where we are now.\u201d<\/p>\n

\"Airguns<\/a>
Airguns (metal tubes) arranged in their tow configuration on the vessel MV Rig Seismic in 1998. The vessel was used for geophysical research by Geoscience Australia and its predecessor organization the Bureau of Mineral Resources. Image courtesy of Robert McCauley.<\/figcaption><\/figure>\n
\"An<\/a>
An airgun used in experimental seismic surveys. This air gun can emit underwater sounds at 206 dB re 1\u00b5Pa2.s (sound exposure level, an underwater measure of impulse sounds). It is loud enough to cause physiological damage to certain marine organisms more than 1 kilometer (0.6 miles) away, depending on the species and environment, a scientific study found. Image courtesy of Robert McCauley.<\/figcaption><\/figure>\n

Increasing seismic surveys<\/strong><\/h2>\n

Day pointed to a limitation in how the research is applied. Field experiments like the zooplankton study are typically based on a single survey line, but commercial surveys operate quite differently. They continue for weeks or months at a time, following grid or race-track patterns while airguns fire every few seconds. As vessels move between adjacent survey lines, the same marine life may be repeatedly exposed. \u201cAnd that\u2019s not something we\u2019ve studied at all yet,\u201d Day said.<\/p>\n

For McCauley, these knowledge gaps about cumulative effects are becoming more pressing.<\/p>\n

\u201cYou would think that, because oil and gas has become less in favour, the amount of seismic that they do would be going down,\u201d he said. \u201cBut it\u2019s actually the opposite.\u201d<\/p>\n

The reason lies partly in Australia\u2019s\u00a0Future Gas Strategy, a long-term plan that keeps gas in the energy mix through to the government\u2019s 2050 net zero target and beyond, assuming that gas emissions can be either offset through purchasing carbon credits or abated through carbon capture and storage (CCS).<\/p>\n

Last year, the federal government cleared a key hurdle for Woodside Energy\u2019s\u00a0proposed expansion\u00a0of offshore gas fields into the Browse Basin by\u00a0approving\u00a0the extension of its\u00a0North West Shelf Project\u00a0to 2070. Gas from Browse would feed into the aging Karratha Gas Plant, one of Australia\u2019s largest gas processing facilities, primarily for export.<\/p>\n

To meet emissions requirements associated with new gas production, Woodside has\u00a0committed\u00a0to incorporating CCS into the design. Under its proposal, Woodside would capture at least 85% of the carbon dioxide (CO\u2082) separated from extracted gas and inject it beneath the seafloor for intended permanent storage, rather than releasing it into the atmosphere as a planet-warming greenhouse gas.<\/p>\n

Seismic surveys will be central to that process, first to identify suitable rock formations for storing CO2<\/sub>\u00a0and then repeatedly after injection begins to monitor how the gas moves underground and ensure it remains contained.<\/p>\n

Woodside\u2019s CCS\u00a0plan\u00a0estimates that injecting around 4 million metric tons of CO\u2082 yearly could reduce the project\u2019s direct emissions by about 47%. This does not address emissions released when the exported gas is burned by customers \u2014 emissions\u00a0projected\u00a0to exceed 80 million metric tons of CO\u2082-equivalent each year, about\u00a0double\u00a0Norway\u2019s total annual CO2<\/sub>\u00a0emissions.<\/p>\n

The project would drill up to seven injection wells near Scott Reef, a remote and biodiverse coral system supporting seasonal whale migrations and a range of marine species, some found nowhere else on Earth.<\/p>\n

\"Australian<\/a>
Australian petroleum production company Woodside Energy\u2019s Karratha Gas Plant in Western Australia. Gas from Woodside\u2019s proposed gas field in the offshore Browse Basin would be sent here for processing then exported. Image courtesy of Woodside Energy Ltd.<\/figcaption><\/figure>\n

Expanding CCS<\/strong><\/h2>\n

CCS technology itself is not new. Since the 1970s, captured CO2\u00a0<\/sub>has been injected into oil reservoirs to improve extraction rates, a practice known as enhanced oil recovery. Most CCS projects worldwide are still tied to oil production in this way. Only in more recent years have dedicated carbon storage projects begun to emerge, using the technology to reduce emissions rather than increase fossil fuel production.<\/p>\n

Supporters of CCS argue it enables emissions reductions in sectors that are near-impossible to fully electrify. Geologist Peter Cook, an advisor at the Peter Cook Centre for CCS Research at the University of Melbourne and pioneer of CCS research in Australia, said it is indispensable.<\/p>\n

\u201cI don\u2019t see any other way we can get to net zero without including CCS in the equation,\u201d he told Mongabay.<\/p>\n

But the economics and performance hurdles remain challenging, experts say.<\/p>\n

The only CCS project currently operating at a scale comparable to Woodside\u2019s proposal is also the world\u2019s largest. The Chevron-owned Gorgon project in Australia has consistently fallen short of sequestration targets, storing just 25% of the CO\u2082 separated during gas processing last year \u2014 its lowest performance to date and well below its targeted 80%. The facility\u2019s ongoing inefficiency has reportedly driven costs to nearly\u00a0four times original estimates, according to the Institute for Energy Economics and Financial Analysis.<\/p>\n

CCS also carries a growing offshore industrial footprint. In 2024, Australia\u2019s Minister for Resources, Madeleine King, granted 10 new greenhouse gas storage assessment permits and committed AUD$3.4 billion ($2.36 billion) to \u201ccomprehensively map our natural resources and renewable energy potential, including the geological suitability for CCS,\u201d she said in a\u00a0speech.<\/p>\n

Cook said monitoring technology is becoming more sophisticated, which could reduce the need for frequent seismic surveys in the future. Still, under Woodside\u2019s proposal, seismic surveys would be conducted every five years or so to monitor storage sites.<\/p>\n

\"Phytoplankton<\/a>
Phytoplankton blooming in Bass Strait, between mainland Australia and Tasmania, on Nov. 5, 2024. A mass die-off of scallops occurred in Bass Strait in 2010 following seismic testing. Image by\u00a0NASA Ocean Color.<\/figcaption><\/figure>
\nThe scale of that activity could expand further in coming decades if Australia moves ahead with ambitions to become a regional carbon storage hub. Under its\u00a0Net Zero Plan, the federal government flagged the country\u2019s potential to store captured CO\u2082 from overseas as part of emerging \u201ctransboundary CCS\u201d partnerships across the Asia-Pacific region.<\/p>\n

Cook said several companies are already exploring the idea, particularly in the North West Shelf and Timor Sea regions, where geological formations may be able to store large volumes of carbon. In theory, he said, liquified natural gas exported to countries such as Japan or South Korea could be paired with return shipments of CO\u2082 captured upon burning the gas, creating a circular carbon system.<\/p>\n

\u201cSo, it\u2019s a business opportunity, but it\u2019s also an environmental opportunity,\u201d Cook said.<\/p>\n

Persisting unknowns<\/strong><\/h2>\n

If this comes to fruition, seismic surveys may no longer be sporadic exploration tools, but a routine feature of offshore development, returning to the same marine systems every few years for decades to come, while the science on their impacts catches up.<\/p>\n

Twenty years after watching airgun pulses ignite the sea, McCauley said many of the fundamental questions they raised remain unanswered.<\/p>\n

\u201cThe impacts of seismic noise on marine fauna have been barely studied, despite what industry tells everyone,\u201d he said. \u201cWe\u2019re only just scratching the surface of understanding what\u2019s going on.\u201d<\/p>\n

Citations:<\/strong><\/h2>\n

Day,\u00a0R.\u00a0D., McCauley,\u00a0R.\u00a0D., Fitzgibbon,\u00a0Q.\u00a0P., Hartmann,\u00a0K., & Semmens,\u00a0J.\u00a0M. (2017). Exposure to seismic air gun signals causes physiological harm and alters behavior in the scallop\u00a0Pecten fumatus<\/em>.\u00a0Proceedings of the National Academy of Sciences<\/em>,\u00a0114<\/em>(40). doi:10.1073\/pnas.1700564114<\/a><\/p>\n

Day,\u00a0R.\u00a0D., McCauley,\u00a0R.\u00a0D., Fitzgibbon,\u00a0Q.\u00a0P., Hartmann,\u00a0K., & Semmens,\u00a0J.\u00a0M. (2019). Seismic air guns damage rock lobster mechanosensory organs and impair righting reflex.\u00a0Proceedings of the Royal Society B: Biological Sciences<\/em>,\u00a0286<\/em>(1907), 20191424. doi:10.1098\/rspb.2019.1424<\/a><\/p>\n

Maciel, I., Tardin, R., Moreira, S. C., Melo-Santos, G., Maricato, G., & Alves, M. A. S. (2026). Cetaceans Change Their Acoustic Behavior During the Airgun Noise of Seismic Surveys.\u00a0Journal of Marine Science and Engineering<\/em>,\u00a014<\/em>(2), 181. doi:10.3390\/jmse14020181<\/a><\/p>\n

McCauley,\u00a0R.\u00a0D., Day,\u00a0R.\u00a0D., Swadling,\u00a0K.\u00a0M., Fitzgibbon,\u00a0Q.\u00a0P., Watson,\u00a0R.\u00a0A., & Semmens,\u00a0J.\u00a0M. (2017). Widely used marine seismic survey air gun operations negatively impact zooplankton.\u00a0Nature Ecology & Evolution<\/em>,\u00a01<\/em>(7). doi:10.1038\/s41559-017-0195<\/a><\/p>\n

McCauley,\u00a0R.\u00a0D., Fewtrell,\u00a0J., & Popper,\u00a0A.\u00a0N. (2003). High intensity anthropogenic sound damages fish ears.\u00a0The Journal of the Acoustical Society of America<\/em>,\u00a0113<\/em>(1), 638-642. doi:10.1121\/1.1527962<\/a><\/p>\n

Pichegru,\u00a0L., Nyengera,\u00a0R., McInnes,\u00a0A.\u00a0M., & Pistorius,\u00a0P. (2017). Avoidance of seismic survey activities by penguins.\u00a0Scientific Reports<\/em>,\u00a07<\/em>(1). doi:10.1038\/s41598-017-16569-x<\/a><\/p>\n

This article <\/a>by Theon\u00e9 van der Merwe was first published by Mongabay on 22 July 2026. Lead Image: Southern humpback whales, including a calf (Megaptera novaeangliae ssp. australis). The animals in the photo are in Tonga; the species also inhabits Australian waters. Image \u00a9 Wayne and Pam Osborn via iNaturalist (CC BY-NC 4.0).<\/em><\/p>\n

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