Quantifying reviewer declines in scientific publishing: twenty-one years of data from biological invasions 2002–2024

Abstract The peer review process has been fundamental to scientific publishing since the mid-twentieth century because it helps to ensure scientific rigor and integrity. However, as fewer scientists seem willing to undertake manuscript review and the number of papers submitted keeps climbing, the peer-review process has become increasingly fraught. In recent years, a “reviewer crisis” has emerged seemingly owing to reviewer fatigue, inequitable workloads, and relentless critics on social media platforms that castigate large publishing houses for exploiting unpaid labor. This study investigates trends in reviewer engagement at the journal Biological Invasions using editorial data from 2003 to 2024. We examined trends in reviewer acceptance and decline rates, differences by career stage, and global variation in review completion rates. Our results show that reviewer acceptance rates have dropped steadily over the past two decades, converging with increasing decline rates. Early-career researchers had the highest acceptance and lowest decline rates, while senior scholars were least likely to accept review invitations. Geographic analysis revealed uneven reviewer follow-through across countries, with some lower-income nations outperforming high-income countries. These findings highlight the need for structural reform in the peer review process. Potential solutions include targeted incentives, expanded reviewer training, equitable invitation practices, compensation, and formal recognition of reviewer contributions. Without such measures, the current system—reliant on altruism and strained by increasing publication volume—risks becoming unsustainable. Our analysis provides empirical insight into the dynamics of reviewer participation and suggests steps to support a more sustainable peer review ecosystem.