Elevated CO2 affects embryonic development and larval phototaxis in a temperate marine fish

Area of Science:

• Marine Biology
• Ecology
• Climate Change Research

Background:

• Anthropogenic CO2 emissions are altering ocean chemistry, leading to ocean acidification.
• Previous studies on ocean acidification effects have primarily focused on tropical reef fish.
• The impact on temperate marine species, particularly their reproductive and developmental stages, remains less understood.

Purpose of the Study:

• To investigate the effects of elevated CO2 on the reproduction and early life history of a temperate coastal goby.
• To assess the impact of ocean acidification on embryonic development and larval behavior, specifically phototaxis.

Main Methods:

• Goby pairs were induced to reproduce in controlled aquarium conditions.
• Experimental groups were exposed to either elevated CO2 (approx. 1400 μatm) or control seawater (approx. 370 μatm).
• Spawning occurrence, clutch size, embryonic abnormalities, egg loss, and larval phototactic response were monitored.

Main Results:

• Elevated CO2 did not influence spawning frequency or clutch size.
• A significant increase in embryonic abnormalities and egg loss was observed under elevated CO2 conditions.
• Newly hatched larvae exposed to elevated CO2 exhibited significantly altered phototactic responses.

Conclusions:

• Ocean acidification negatively affects embryonic development and increases mortality in temperate goby early life stages.
• Elevated CO2 impairs sensory responses, such as phototaxis, in temperate fish larvae.
• These findings highlight potential risks of ocean acidification to fish recruitment in temperate coastal ecosystems.