Why are sub-lethal impacts of oil exposure often more problematic in oil spill risk assessments than lethal impacts?

Sub-lethal impacts of oil exposure are often more problematic in oil spill risk assessments because they are harder to detect and track. Unlike lethal impacts, which can be straightforward to measure—such as counting dead organisms—sub-lethal effects can manifest as changes in behavior, reproduction, growth, or health that may not be immediately observable. These effects can occur at individual and population levels and might take time to become apparent, making them challenging to quantify in the short term following an oil spill.

Additionally, sub-lethal effects may not always result in immediate mortality, but they can significantly affect the overall health and sustainability of populations over time. This delayed recognition can lead to underestimating the long-term ecological consequences of oil spills, complicating risk assessments and response strategies. Understanding the underlying sub-lethal impacts is crucial for accurately predicting the broader ecological implications and ensuring effective management and remediation efforts.