Gene-to-Population Level Responses to Multiple Stressors on the Rocky Shore

Area of Science:

• Marine ecology
• Ecotoxicology
• Environmental science

Background:

• Coastal ecosystems face multiple stressors, including global warming and local pollution.
• Interactions between these stressors are complex and rarely studied across biological scales.

Purpose of the Study:

• To investigate the independent and interactive effects of warming and sewage pollution on coastal ecosystems.
• To analyze stressor impacts from the genetic to population levels in intertidal organisms.

Main Methods:

• An in situ warming experiment using settlement plates at polluted and non-polluted rocky shore sites.
• Monitoring temporal dynamics of intertidal taxa, barnacle physiology (size, isotopes, RNA sequencing), and microphytobenthos.
• Quantifying responses across genes, individuals, and populations.

Main Results:

• Pollution increased invertebrate and macroalgal abundance, while warming decreased barnacle abundance and late-season macroalgal cover.
• Warming and pollution synergistically affected barnacle abundance, with pollution being the dominant stressor.
• Pollution altered barnacle stable isotopes and gene expression related to protein turnover, with warming intensifying these effects.

Conclusions:

• Sewage pollution can overwhelm and reshape the impacts of ocean warming in coastal ecosystems over time and across biological levels.
• The study demonstrates a link between community-level responses and molecular-level changes under multiple stressors.
• The experimental approach provides a model for future multi-stressor marine research.