July 25, 2019 — The following was released by the The Princeton Environmental Institute:
Phytoplankton forms the base of the food chain in marine environments, transforming solar energy into plant matter. Their blooms provide vital nourishment to animals further up the food chain, including the larval stages of many fish species.
The researchers recently reported in the journal Global Change Biology that as Earth’s climate continues to warm, the occurrence of phytoplankton blooms have shifted from historic timelines, occurring earlier than normal. Supported by the Princeton Environmental Institute (PEI), the scientists found that phytoplankton blooms could start approximately two to four weeks earlier in temperate and polar ecosystems under climate change. This could create hardships for developing fish as they struggle to find the phytoplankton they need to fuel their growth and survive into adulthood.
“Once fish larvae utilize all of the yolk that they received from their parents, they must learn how to hunt quickly — otherwise they risk starvation,” said first author Rebecca Asch, an assistant professor of biology at East Carolina University who began the work as a postdoctoral researcher in Princeton’s Program in Atmospheric and Oceanic Sciences.
“Larvae that do not starve are slow to capture food and also likely to have lower survival because slower-growing fish are more likely to be eaten by predators,” explained Asch, who conducted the research with PEI associated faculty member Jorge Sarmiento, Princeton’s George J. Magee Professor of Geoscienceand Geological Engineering, Emeritus, and Charles Stock, a researcher at the NOAA Geophysical Fluid Dynamics Laboratory located on Princeton’s Forrestal Campus.
Fish develop in annual “classes,” with individuals reaching maturity and breeding age at roughly the same time. If enough larvae of a certain year class fail to make it to adulthood, that can affect the species’ future reproductive rates as there are fewer adults available to breed. Successive years of low adult populations could result in tighter fishing quotas that could create food shortages and economic hardship in communities that rely on fishing.