One key finding is just how disproportionate the impacts are. Between 1980 and 2019, invasive species caused more than $11.7 billion in damages across US and US-affiliated islands. When adjusted for land area, that’s five times higher per square kilometer than on the US continent. Islands import most of their food and goods, rely heavily on tourism and military transport, and often have limited resources to respond when new pests arrive.

But the paper also shows that the biggest challenges are not about a lack of tools or knowledge. This research, led by Pacific RISA PI Laura Brewington as part of her service on the US Invasive Species Advisory Committee, identifies three lessons that apply not only to US islands, but to island nations around the world. First, local capacity and trust determine whether efforts succeed. Programs that invest in local jobs, training, and community engagement are more likely to detect invasions early, while long-term support of island-led research, workforce development, and implementation supports sustained management as climate extremes intensify. Second, prevention at ports of entry matters. Airports, seaports, and shipping routes are the main gateways for invasive species. When inspections are inconsistent or under-resourced, new pests slip through—and the costs multiply later. Third, long-term control tools are essential but often underused. Islands have successfully applied biological control, targeted chemical treatments, and ecosystem restoration, but these approaches are frequently limited by short-term funding or regulatory delays. Expanding access to conservation-relevant tools and investing in restoration infrastructure also both increase ecosystem resilience following disturbance.

“In many cases, the science exists and the solutions are known,” says lead author Laura Brewington. “The real challenge is making sure systems are in place to prevent invasions in the first place and to act quickly and effectively when they occur.”

The paper also highlights promising examples, from interagency agreements in the Pacific to biofouling controls in Australia and community-driven biosecurity efforts in Mexico. These cases show that coordination and sustained investment can make a real difference. Islands are often described as “sentinels” for environmental change. But in the case of invasive species, they are also shields—protecting surrounding regions from further spread. Strengthening island biosecurity isn’t just an island issue. It’s a global one. Download the paper here.

Featured image: Sunset over Tumon Bay, Guam. Credit: Laura Brewington

]]> 7326 https://www.pacificrisa.org/2022/10/27/invasive-species-and-climate-change/ Thu, 27 Oct 2022 20:31:59 +0000 https://www.pacificrisa.org/?p=5749 Read More]]> Over 100 representatives from across the Pacific region met at the inaugural Pacific Ecological Security Conference (PESC) that took place in Palau from 3–5 October. Hosted by the Government of Palau, the East-West Center, the Pacific Community (SPC), the Global Environment Facility, the Nature Conservancy, the US Office of Insular Affairs, and the US Forest Service, biosecurity experts, development partners, regional organizations, agricultural and natural resource managers, researchers, and government came together to identify and discuss how to address the critical threat of invasive species.

Conference organizer and Pacific RISA co-lead investigator Laura Brewington described the profound impacts of invasive species on the Pacific Islands region, while pointing to the need for regional collaboration to address the issue. “This first PESC has reminded us that invasive species impact every aspect of Pacific Island life and security. While we have many of the tools we need for their prevention, control, and eradication, we also recognize that no country can do it alone,” said Dr. Brewington.

Participants shared stories from across the region about the multi-faceted and devastating impacts of invasive species on climate resilience, food security, and ecosystem sustainability. Dr. Brewington, as a co-founder of the Pacific Regional Invasive Species and Climate Change management network, gave a keynote presentation focusing on three main interactions between climate change and invasive species in Pacific Islands:

• Climate change is expected to alter mechanisms for invasive species transport and introduction, by creating new tourism or shipping opportunities, or by increasing the frequency and intensity of extreme events like storms and flooding.
• Climate change will alter the distributions of invasive species that already exist on islands, allowing them to spread into new areas, especially under warmer conditions.
• Climate change will alter the effectiveness of our current methods of controlling invasive species, so much so that restoration may not even be possible under new climate regimes and conservation strategies will have to be dynamic.

High-level conference outcomes

• Participants at the PESC acknowledged the importance of invasive species work to building and maintaining the climate resilience and adaptability of Pacific Island ecosystems, as well as food security, biodiversity, sustainable livelihoods, and the protection of native traditions and cultural resources.
• Participants developed three Strategic Action Plans to address the issues of coconut rhinoceros beetles, invasive ants, and biocontrol needs. The Plans are living documents that are intended to be modified as milestones are achieved and new needs are identified.
• Statements, backed by conference, recommended that the Pacific Community (SPC) and the Secretariat of the Pacific Regional Environment Programme (SPREP) collaboratively take on the PESC outcomes, and the issue of invasive species itself, as a joint effort.
• A second PESC must be convened in two years to address other critical invasive species issues, such as biosecurity, invasive vertebrates, and marine invasive species, as well as to report on progress in implementing Plans from the first PESC.

Momentum initiated at the PESC has already been translated into concrete legislative outcomes: At the Association of Pacific Island Leaders (APIL) meeting in mid-October, Resolution 39-GA-15 was passed to endorse and support invasive species management, control, and eradication in Micronesia. For more information about the PESC, conference resources, and outcomes documents, please stay tuned to the Conference Website!