Resilience of the sea urchin Arbacia dufresnii to a shrimp wastewater spill: Recovery after a disease outbreak

Abstract

In the summer of 2023, Arbacia dufresnii populations in Golfo Nuevo, Patagonia, faced a significant environmental stressor due to a wastewater spill from local fishing industry operations. This study explores the resilience of sea urchins to this stressor and their recovery following a disease outbreak linked to the spill. Prior to the spill, sea urchin densities varied across different sites with no signs of infection. However, following the spill, over 90 % of the sea urchins at the affected site exhibited symptoms such as severe epidermal damage and bacterial infections. Remarkably, within less than a year, the populations demonstrated considerable resilience; disease rates plummeted, and population density returned to pre-spill levels without significant changes in size distribution. This recovery, primarily through the migration of mature individuals rather than juvenile recruitment, underscores the profound impact of chemical pollutants in triggering marine diseases. Furthermore, this study serves as a significant example of how population density and health estimates can be effectively conducted through a non-lethal research approach, adhering to ethical standards, and ensuring the well-being of the sea urchins. These findings highlight the necessity of continuous environmental monitoring to effectively manage and mitigate the impacts of such stressors.