New Tool for Assessing Fish Vulnerability to Climate Change

By MarEx 2014-03-04 17:38:00

A new web portal is helping NOAA Fisheries Service with its assessment of how vulnerable fish stocks are to climate change. The Ocean Climate Change Web Portal is an online system that provides an easy way to display maps of climate data, such as ocean temperature and salinity, over portions of the globe. For example, it can allow a user to view how the temperature in the North Atlantic would change in the 21st century as compared with the 20th century. Users can zoom in and create plots for any region of interest on the planet.

“There are tools that show temperature and precipitation over the U.S., but our portal is more comprehensive because it includes ocean-specific information like sea surface temperature and salinity, and also provides more statistical options,” says Mike Alexander, research meteorologist at NOAA’s Earth System Research Lab in Boulder, Colorado who is one of the project collaborators with NOAA Fisheries. 

The tool is designed for scientists, resource managers, educators and the general public. It will provide fisheries scientists and managers with easy access to existing projections of changes in climate and ocean conditions for all U.S. marine regions and world-wide to help them assess, prepare for and respond to possible future impacts on marine ecosystems and fisheries. 

This information is used in the new methodology used to assess the vulnerability of U.S. fish stocks to a changing climate. It will also be useful in more detailed assessments of future conditions and possible management options to address specific issues through the NOAA Integrated Ecosystem Assessment Program. The program is developing a suite of indicators that managers can use to make decisions about fish stocks. The goal is to use a more holistic approach that includes information such as interactions through the food web, climate change and societal needs.

A map created with NOAA's Ocean Climate Change Portal shows changes in the mean sea surface temperature for the latter half of the 21st century as compared to the latter half of the 20th century that indicate that ocean warming will be greatest in the northern hemisphere where changes are more than 3 degrees Celsius. Less intense warming is predicted in the North Atlantic and the Southern Ocean.

Alexander describes the design of the portal: “We began by obtaining a large volume of climate data and model output from centers around the world. The data then had to be put on the same grid. In other words, points on a map had to be translated into similar locations. Once the data were on a common grid, monthly climate model output was then distilled into seasonal and annual mean statistics. The most difficult part is the software programming, which tells the computer where to grab the data and how to map the information. The design of the underlying software allows the portal to work properly and display the data in an easy to read manner.”

The information comes from climate models and Earth system models of more than 20 centers around the world. Climate models simulate how the global state of the atmosphere, oceans, sea ice, and land change over time; for example they simulate the winds in the jet stream, precipitation over the United States, ocean and land temperatures, and sea ice coverage. Earth system models include these physical variables plus ocean chemical and biological processes that alter the carbon cycle.