DDT Advisory For You and Your Seafood

Caught a fish off the coast of Southern California? Fill in the required fields below to understand the DDT levels in your seafood and receive serving size recommendations based on DDT, Mercury, and PCB advisories.

Disclaimer: This research project was designed for educational purposes. The information provided here does not come from any public agency and we are not making health recommendations.
Step 1: Click the location on the map where your fish was caught within the study area (outlined in blue)

Step 2: Please select your catch species in the dropdown below the map

Click through map layers to gather more information
Privacy Statement: No data shared with us will be given to third parties or stored in any way. Your data will never be used by us for any purpose other than DDT concentration predictions.
Need help identifying your catch? Check out this resource!

Image of Species
DDT Prediction Results *

OEHHA Health Advisory **
Follow the lower recommendation for number of servings per week.

Fish Hand Image

Source: OEHHA

* A serving size is defined by the OEHHA as an 8oz skinless fillet
** This advisory was provided from the OEHHA Fish Advisory webpage

Dashboard User Manual

Welcome to the Fish DDT Concentration Prediction Dashboard! This user-friendly tool is designed to assist fishermen and environmental researchers by predicting DDT concentrations in various fish species based on their geographic catch location and catch species. This manual will guide you through initial setup, application operation, and understanding your results.

Getting Started

Navigate through the application using the tabs to the left of the dashboard.

Initial Setup: Begin by identifying your fish species in the 'Fish Identification' tab under 'Resources'. This platform provides detailed information about a wide range of California marine species.

Have a good idea of where the fish was caught. Accurately entering the catch location enhances the prediction accuracy. This study focuses on a particular area with defined bounds so be sure that your location falls within the specified study area for the app to work effectively.

Running The Application

To estimate the DDT concentration:
  1. Navigate to the 'Toxin Tracker' tab.
  2. Use the interactive map to select your fish catch location by placing a marker. This helps in providing the most accurate predictions. Your location must be within the highlighted study area in order to receive a prediction.
  3. Select a fish species from the dropdown menu.
  4. Click the 'Predict DDT' button to receive the forecast.
  5. Results will be displayed below the map.

How To Interpret The Output

The output displays the estimated DDT concentration in the fish species at your specified location. This measurement is shown in ng/g units, which reflects the DDT levels typically found in the tissue of the species based on the entered parameters. Along with the DDT concentration, a recommended serving size and relevant Mercury/PCB advisories are also outputted. Understanding these results can help in assessing potential health risks and making informed decisions. These results do not come from any federal agency and should be used in conjunction with advisories provided by the California Office of Environmental Health Hazard Assessment, the Food and Drug Administration, and the Fish Contamination Education Collaborative. These are NOT FDA sectioned advisories. For women and children related advice refer to this link: https://oehha.ca.gov/fish/women-and-children


Potential Map Display Errors

Symptom: Map does not load or markers do not appear.

Possible Causes: Browser cache issues, network issues, or compatibility issues on specific devices.

Resolution: Refresh the page to clear the cache. Check your internet connection. If the issue persists on a specific device, try accessing the dashboard from a different device or browser as a temporary workaround. If the problem continues, please contact the support team for further assistance.

Note: Compatible browsers for the leaflet package include:
- Desktop: Chrome, Firefox, Safari 5+, Opera 12+, IE 9-11, Edge
- Mobile: Safari for iOS 7+, Chrome for mobile, Firefox for mobile, IE10+ for Win8 devices

Potential Data Errors

Symptom: Incorrect or no inputs displayed after inputting location and species.

Possible Causes: Misidentification of species, incorrect location coordinates, network issues, server-side problems.

Resolution: Ensure that the fish species and location details are correctly entered. Verify that the location is geographically plausible for the selected species and study area. Check your internet connection. If the problem continues, please contact the support team for further assistance.

Note: Some potential server-side problems include high load, misconfiguration, crashes, or maintenance downtime.

Error Messages

Location Error Message: We’re sorry, but we are not able to make predictions for that location. We can only make valid predictions for the area outlined on the map."
- Indicates that the location selected is not a valid location and no prediction will be made until a valid location is selected.

Fish Error Message: "Please select a fish species before pressing the Predict button."
- Triggered when a user clicks the predict button without first selecting a fish species. No prediction will be made until a species is selected.

Advisory Error Message: "No other advisories found for your species at your location."
- Specifies that there are no current Mercury/PCB advisories for that specific species of fish in the selected location.

Having trouble identifying your fish?

Use the link below to access the California Marine Species Portal, where you can find detailed information about various fish species. This resource may assist you in identifying the fish species by their common names, scientific names, and visual characteristics.

Visit the California Marine Species Portal


  1. Use the search bar to enter the common name or scientific name of the fish.
  2. Use the filters on the left to narrow down by category, group, region, or gear type.
  3. Click on any fish entry to get more detailed information including photos and distinctive features.

These features will help you to effectively identify the fish species you encounter.

For additional assistance, please refer to the tutorial videos and FAQs on the portal.

Still having trouble? Contact our support team for personalized help.

Email Support

The Broader Picture

Further research and educational collaborators, working to understand the human and ecological impacts of the recently discovered DDT dumpsite, will be highlighted here. We aim to provide a platform that enables researchers to connect with communities in a meaningful way.