Effects of dissolved oxygen stress on larval Haminoea vesicula survivorship and growth

Abstract

Dissolved oxygen in coastal marine systems is projected to become more variable and is on the average declining in coastal systems. As surface temperatures and eutrophication continue to increase with climate change and anthropogenic inputs into marine systems, benthic marine invertebrates are expected to experience delayed development and reduced survival to metamorphosis. This study assesses the effect of dissolved oxygen (DO) stress on recently hatched Haminoea vesicula for the first 4 days of development as a planktotrophic veliger. Larvae survivorship and growth were compared between a reduced (~4.8 mg/L) and saturated DO (~8 mg/L) treatment. Dissolved oxygen stress did not significantly affect survivorship or any of the shell metrics measured. There was considerable variation in initial shell size (maximum shell dimension) which alone could not explain variance in growth rates within and among replicates and treatments. Given the small sample size, it is possible that limited statistical power precluded detection of an effect of DO on larval growth and survivorship. However, further research is needed to determine whether Haminoea vesicula, which experience DO stress during encapsulated embryonic development, are robust to DO stress. Additionally, studies should investigate if early exposure to DO stress post-hatching could have lasting effects via affecting time to competency, success at settlement, and juvenile performance