Climate change, invasive species pose a significant threat to the Pacific’s biodiversity

Three out of  thirty-five of the world’s most diverse ecosystems are housed in the Pacific region. However, the ecological structure of the Pacific is being directly affected by changes to climate, habitats, and the introduction of non-native species, all of which imperil the Pacific’s unique wildlife. The changes to the environment threaten the biodiversity of the Pacific’s organisms, as well as the identities and lives of people within its countries and territories.

            Climate change is one reason for the decline in biodiversity. The effects of climate change can be seen in rising sea levels, which threaten to flood and erode low-lying islands. When coastal regions flood, Pacific birds, plants, and numerous others are at risk of losing their habitats or being forced to move inland. The increase in sea temperature is leading to the loss of habitat for marine life, and ocean acidification is eating away at coral, which provides a breeding ground for millions of marine species. Severe change in weather is also a result of climate change. According to the Woods Hole Oceanographic Institute’s Coastal Systems Group, “changing climate circulation patterns affects the strength, duration, and paths of storms and precipitation events in the Pacific Ocean,” which can be linked to severe weather like storm surges, heatwaves, and decreased rainfall. Volatile weather can contribute to the destruction of habitat areas and even create vulnerability to parasitic infection or disease.

Despite the extensive impact of climate change, invasive species continue to be the most significant threat to the Pacific’s distinct wildlife. According to the International Union for the Conservation of Nature (IUCN): “The spread of invasive species can be facilitated by increasing trade, travel, and the transport of goods through the movement of, for example, ships, containers, cars, and soil.” Despite formal efforts to manage invasive species by implementing laws and action plans, non-native populations remain difficult to control due to a need for “constant vigilance, partnerships with host and destination countries, and resourcing of biosecurity measures”

One case of a non-native species wreaking havoc on the Pacific is the brown tree snake, which is native to Australia, Indonesia, Papua New Guinea. It was introduced to Guam during the 1950s and became responsible for the near-extinction of the endemic Ko‘ko‘ bird, also known as the Guam Rail. The sharp decline of the Ko‘ko‘ population led to an increase in spider populations and to a decrease in native plants, which relied on the birds to spread their seeds. The brown tree snake had similarly devastating effects on nine other Pacific bird species and endangered several bats, lizards, and other birds. The introduction of just one invasive species can both directly, and indirectly devastate a large portion of the native wildlife in Pacific island countries and territories. The IUCN explains that the sustained “management of one invasive species…has far-ranging benefits for the surrounding habitats as well as for other species,” and that successful management can ultimately prevent further decline to the Pacific’s biodiversity.

The loss of biological variety could spell disaster for the identities, traditions, and wellbeing of Pacific islanders. Increased awareness and continued invasive species mitigation strategies could prove to be the most beneficial approaches for maintaining the diversity of the Pacific’s ecosystems.

By Suzanna DeCosta

Gender and Cimate Journalist Intern
Pacific Environment Weekly

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