Exploring the Connection Between Weather and Plankton

By Olivia Heric

Everyday, billions of microscopic organisms drift through global waters. Though nearly invisible to the naked eye, these tiny plankton have a profound impact on marine ecosystems throughout the world, supporting every organism from small fish to large whales. Understanding what influences their populations can help scientists better understand the health of our oceans.

I had an opportunity to study these organisms through my nine-month internship at the Ocean Institute in Dana Point, California. Working aboard the RVSE (Research Vessel Sea Explorer), I was able to design my own research project. 

Every Sunday, I boarded the RVSE during the public whale-watching cruise, and became interested in understanding how changing weather conditions influenced plankton populations. While assisting and interacting with guests, I spent time collecting plankton samples from two offshore sites, measured water quality including temperature, pH, and salinity, and kept a weather log. 

On the boat, there was a lab where I used a microscope to analyze the plankton samples, estimated the total plankton abundance, and compared it to the weather data and water quality samples, searching for a relationship between the two.

The main finding I came across was that wind appeared to have the largest influence on plankton populations. Moderate winds likely create favorable conditions for plankton growth and survival. However, stronger winds showed a decline in plankton abundance possible due to the fact that it creates an excess amount of nutrient mixing between water layers, and disperses plankton, making it more difficult to survive.

Another finding of mine was that temperature did not have a significant impact on abundance. This could be because temperature has a greater influence on plankton populations long term. Because California does not experience large temperature fluctuations and this study was done over a shorter period of time, the small changes in temperature won't show much of an impact on population sizes. 

Although this project focused on a microscopic organism, its findings have a broader value for the local community. Plankton is often overlooked due to its small size, however it plays a huge role in the health of marine ecosystems. By investigating the ways in which these organisms are affected, and the environmental factors that have the greatest impact, we gain a better understanding of what these organisms need to survive, and could possibly give insight into how they might respond to climate change issues.

Presenting my findings with Ocean Institute guests, staff, and other people in my community, allowed me to to raise awareness of the necessary part plankton plays in supporting marine health and encourage greater appreciation for marine science. In addition, this project could also serve as a baseline for future researchers. By comparing future observations with these findings, could help determine long term patterns within Dana Point’s waters, and improve our understanding of marine health.