Gina Solomon’s Blog
Gulf Shrimp Testing: Is a Dozen Samples in 5000 Square Miles Enough to Reassure You?
Posted September 2, 2010 in Health and the Environment
Today, NOAA reopened 5,130 square miles of Gulf waters to shrimping and fishing. I took a look at the data on which NOAA based their decision and was surprised to find that their data included only 12 samples of shrimp, consisting of a grand total of 73 individual shrimp, caught from an area about the size of the State of Connecticut.
Does that reassure you that they've really found whatever contamination might be out there?
After all of the calls to do more and better testing of Gulf seafood, I am presenting to you below the grand total of publicly-available testing data on Gulf shrimp. After you look at the data below, I'm wondering if you will be confident that it's adequate. In a previous blog, I raised some concerns about the way the FDA was determining the 'safe' levels of contaminants in Gulf seafood. I also raised some general concerns in another blog about the very limited data available on what's actually in the seafood. In this blog, I've summarized all of the data that have been made publicly available to-date on chemical testing of Gulf shrimp.
The bottom line is this, as of September 2nd:
- FDA has released data on a total of 42 shrimp samples from Louisiana, 12 from Florida, 7 from Alabama, and 6 from Mississippi. Each sample contained an average of between 1 and 7 shrimp,
- NOAA has released data on chemical testing of a total of 17 shrimp samples from offshore Gulf waters, containing an average of 6 shrimp each.
Here's a question: Is a total of six samples, containing a total of 21 individual shrimp, enough data on which to base a decision to reopen all of Mississippi's territorial waters to shrimping? Some Mississippi fishermen don't think so, especially since they're still seeing oil in the water. You could ask the same question about each of the other Gulf states.
Even in Louisiana, where more testing has been done, there are still questions: A total of 53 shrimp from Louisiana waters have been chemically analyzed and the levels reported as low. If those 53 shrimp really represent the full extent of the open territory, maybe that's OK, but this oil spill has lots of variability, with pockets of contamination appearing in many locations. As a scientist, I would feel better if I knew there was a robust sampling strategy to address this variability and to take enough samples - maybe several hundred - to assure that if there were contaminated shrimp out there, they would be detected. I'll be meeting with officials from NOAA and FDA on Tuesday and you'd better believe I'll be asking them some questions about their scanty sampling!
Shrimp Sampling in the Gulf Reported by FDA
Louisiana:
Date Tested
# of Shrimp Tested
# of analysis performed (composite samples)
7/22/10
14
14
7/29/10
9
5
8/2/10
13
6
8/11/10
4
4
8/12/10
6
6
8/12/10
7
7
Mississippi:
Date Tested
# of Shrimp Tested
# of analysis performed (composite samples)
7/30/10
9
4
8/2/10
12
2
Alabama:
Date Tested
# of Shrimp Tested
# of analysis performed (composite samples)
8/5/10
26
4
8/13/10
16
3
Florida:
Date Tested
# of Shrimp Tested
# of analysis performed (composite samples)
7/30/10
3
3
8/13/10
39
9
NOAA Shrimp Sampling
Chemical analysis of 5 composite samples were reported as of August 27th, they consisted of the following:
Sample #1: 12 shrimp
Sample #2: 2 shrimp
Sample #3: 7 shrimp
Sample #4: 2 shrimp
Sample #5: 4 shrimp
Sampling was not reported by state.
Today, September 2nd, NOAA released results of 12 more composite samples of shrimp. Here's how many were tested in each sample:
Sample 1: 5 shrimp
Sample 2: 1 shrimp
Sample 3: 1 shrimp
Sample 4: 3 shrimp
Sample 5: 2 shrimp
Sample 6: 9 shrimp
Sample 7: 9 shrimp
Sample 8: 9 shrimp
Sample 9: 9 shrimp
Sample 10: 1 shrimp
Sample 11: 1 shrimp
Sample 12: 23 shrimp
What do you think? Is it enough?
