Meet Désirée Tommasi: Pioneer in new field of fish forecasting

Long known for weather forecasting and climate prediction, NOAA is pioneering a new type of forecasting -- fish forecasting.  Meet Désirée Tommasi, Ph.D., a young oceanographer working at  NOAA’s Geophysical Fluid Dynamics Laboratory in Princeton, N.J. who has just published research about forecasting the Pacific sardine, one of the nation’s most storied fish, made famous by John Steinbeck’s Cannery Row.

How did you get interested in forecasting fisheries?

Growing up in Italy, spending my summers by the sea, I knew I wanted to be an oceanographer. When my family moved to British Columbia, Canada, my high school had a salmon hatchery where we learned about salmon biology. For my master’s and Ph.D. research,  I worked closely with First Nation people researching sockeye salmon.  I could see that climate was affecting fish and the people who depend on them. Now I’m working to integrate climate information with fisheries biology to improve how we manage fisheries.

How does fish forecasting work for the Pacific sardine?

Advances in climate modeling now allow us to predict ocean conditions such as sea surface temperatures down to a regional level for an upcoming season.  In our research, we take a global climate model developed by NOAA, plug in current conditions of sea surface temperatures and the physics of the ocean and make monthly temperature predictions for the California current off southern California. We test how accurate our model can predict temperature by comparing its predictions for each month from 1982 to 2009 with actual conditions that occurred. We demonstrate that the model can effectively predict sea surface temperature four months in advance with a high level of skill.

Why is predicting sea surface temperature so important to understanding how abundant the Pacific sardine will be?

Scientists have shown a strong connection between the abundance or biomass of Pacific sardines and the temperature and currents when sardines spawn in spring. Adult sardines spawn best in temperatures around 60 degrees Fahrenheit, producing more young. At around 60 degrees the young sardines are also better able to survive than in waters that are too cold or too warm.  Colder temperatures mean there’s a strong upwelling of deep waters. The strong upwelling pushes young sardines or larvae out to sea where there is less food and it’s harder to survive.  In waters warmer than 60 degrees, fish must expend more energy to metabolize their food, which can also hamper growth and survival.

How can your research be used to help fishing and those who depend on fishing for their livelihoods?

Our research suggests that forecasting the abundance of sardines may enable managers to proactively adjust catch limits. In times of favorable conditions, sardine catch levels may be set higher. When forecasts warn of difficulties due to ocean conditions, managers can reduce catch levels. Our research shows that over the long-term, setting catch levels based on forecasts can result in greater average catches and a more sustainable sardine population.  

Can this type of fish forecasting be applied to other fish? 

The Pacific sardine is one of the few fisheries where we have such a long-term robust understanding of how sea surface temperature affects its population. So it makes sense to start fish forecasting here. But there are opportunities with other fisheries as we develop greater understanding of climate effects on fisheries. Such improvements are priorities of the NOAA Fisheries Climate Science Strategy.

What are the next steps for the Pacific sardine? 

Before fish forecasting can be integrated into a fishery management plan, we need to carefully test our forecasts. I’ll soon be working at the University of California Santa Cruz and be based at NOAA Fisheries Southwest Fisheries Science Center where my job will be to assess management strategies for fisheries, including sardines.

To read Tomassi’s research on fish forecasting in Ecological Applications: http://onlinelibrary.wiley.com/doi/10.1002/eap.1458/full

For more on the Pacific sardine: http://www.fishwatch.gov/profiles/pacific-sardine

For more research on the Pacific sardine: https://swfsc.noaa.gov/news.aspx?ParentMenuId=39&id=22407

For more information please contact Monica Allen, director of public affairs at NOAA Research, at 301-734-1123 or by email at monica.allen@noaa.gov