Non-native marine species and pollution pose a real threat to Antarctica’s delicate ecosystems, reveals a recent research. The new oceanographic modelling reveals that these threats may be more pervasive than previously understood, as floating debris can now reach Antarctica from a broader range of sources.
The study published in Global Change Biology by researchers from UNSW Sydney, ANU, the University of Otago, and the University of South Florida highlights how marine pollution and non-native species could endanger Antarctica’s unique environments. The study, led by Dr. Hannah Dawson, used oceanographic models to track how floating objects, including plastics and natural debris, can traverse from various Southern Hemisphere landmasses to Antarctica.
UNEXPECTED PATHWAYS OF MARINE DEBRIS
Dr. Dawson, who completed this research during her PhD at UNSW and now works at the University of Tasmania, explains that the study shows floating debris can originate from far beyond previously known sources. Non-native species, such as small marine invertebrates, can hitch rides on floating kelp, driftwood, pumice, and plastic, making their way to Antarctica from continents including South America, New Zealand, Australia, and South Africa.
IMPACT OF KELP ON ANTARCTIC ECOSYSTEMS
Professor Crid Fraser from the University of Otago points out that kelp poses a particular risk due to its size and ecological role. Southern bull kelp and giant kelp, which can grow over 10 meters long, create habitat for numerous small marine animals. If these kelps establish themselves in Antarctic waters, they could drastically alter local marine ecosystems.
MODELLING OCEAN CURRENTS TO TRACK DEBRIS
The research team used oceanographic models to simulate the movement of floating debris from various Southern Hemisphere sources to Antarctica. By analyzing surface current and wave data from 1997 to 2015, they tracked how often and along what pathways debris reaches the Antarctic coastline.
THE RESULTS OF THE SIMULATION
Dr. Adele Morrison from ANU explains that the simulations demonstrated that debris consistently reaches the Antarctic coastline each year. The models showed a range of travel times, with the fastest objects arriving from Macquarie Island in just under nine months, while those from South America took the longest.
ROLE OF SEA ICE IN CONTAINING NON-NATIVE SPECIES
The study also highlights which regions of Antarctica are most vulnerable to invasions by non-native species. The Antarctic Peninsula, with its relatively warmer ocean temperatures and often ice-free conditions, is identified as a high-risk area. The recent dramatic reduction in sea ice further exacerbates this risk by making it easier for floating organisms to reach and establish themselves in Antarctic waters.
IMPLICATIONS FOR ANTARCTIC ECOSYSTEMS
Dr. Dawson emphasizes that the decline in sea ice could significantly impact Antarctic ecosystems. Sea ice previously acted as a barrier to non-native species, but as it decreases, the likelihood of these species successfully colonizing Antarctica increases, potentially disrupting local marine life.
FUTURE RESEARCH AND CONSERVATION EFFORTS
The findings underscore the need for ongoing research and conservation efforts to monitor and protect Antarctica’s unique ecosystems. Understanding the pathways and impacts of non-native species and pollution will be crucial in developing strategies to mitigate these threats.
As climate change accelerates and human-made debris continues to infiltrate the oceans, protecting Antarctica’s fragile ecosystems becomes increasingly challenging. This research highlights the urgent need for global efforts to reduce marine pollution and manage the risks posed by non-native species, ensuring the preservation of Antarctica’s unparalleled natural environments.