Artificial Light at Night (ALAN) causes size-dependent effects on intertidal fish decision-making

Area of Science:

• Marine Biology
• Behavioral Ecology
• Environmental Science

Background:

• Artificial Light at Night (ALAN) disrupts natural diel cycles.
• Altered light cycles can impact wildlife behavior and decision-making.
• Intertidal species face unique challenges in anthropogenically lit environments.

Purpose of the Study:

• To investigate the effect of ALAN on the decision-making processes of the intertidal rockfish, Girella laevisifrons.
• To determine if prior exposure to ALAN influences directional swimming behavior in Y-maze experiments.
• To assess the impact of ALAN on the rockfish's preference for dark versus lit environments.

Main Methods:

• Utilized a Y-maze apparatus to test rockfish behavior.
• Exposed fish to either natural day/night cycles or ALAN conditions for one week.
• Quantified visits and time spent in dark, lit, and non-decision areas of the maze.

Main Results:

• Rockfish under natural light conditions showed a preference for the dark arm.
• Fish exposed to ALAN spent more time in the non-decision area.
• ALAN exposure affected rockfish behavior in a size-dependent manner, reducing their ability to select dark areas.

Conclusions:

• Prior exposure to Artificial Light at Night may disorient rockfish.
• ALAN exposure appears to reduce the rockfish's capacity to choose dark, presumably safer, conditions.
• The findings highlight potential behavioral disruptions in intertidal species due to light pollution.