The secret lives of mercury testers

I just wanted to contribute to this discussion as I think it is very important and one of those ‘bury our heads in the sand and hope for the best’ issues. For a little background, I should say that I work for one of the agencies that collect fish tissue for Hg analysis around the state and I in fact used to sample fish being brought back to the docks. Given my experience, I have followed the data from collection, to analysis, to reporting and know of glaring gaps in the process, particularly the reporting. I have spoken to people at the various agencies involved to get more information on the analysis, process and reporting.

Here is how mercury testing is done for saltwater fish. Biologists collect fish tissue from around the state according to protocol and list of target species. Samples are processed and sent to FDEP for analysis. There is (or was when I was collecting fish tissue a few years ago) such a bottleneck at the analysis level mainly due to staff shortage that they can’t handle too many samples. There are field labs and personnel around the entire state so essentially all areas get sampled, some more than others, some species more than others. A species needs to have at least 20 samples processed in an area to get analyzed and reported and then an average of the Hg in the tissue is analyzed against the legal standard. Having looked at the data, not the raw data, but a summary of the data, the range of mercury in any one given sample can have a pretty large range and may differ in the various regions throughout the state. Generally, the Everglades and Florida Bay have higher mercury levels.

Some other points of interest:
· If you go out and catch a spotted seatrout, for instance, there is no real way to know how much mercury is in it since the range is so large. However, generally, the bigger the fish the more mercury it likely has accumulated. So even though a fish has a lower advisory level, the individual fish may have very little Hg or way over the ‘safe’ limits.

· Just because a fish isn’t on the ‘advisory’ list, it doesn’t necessarily mean that that species is low in mercury. It requires the minimum 20 samples (which can be accumulated since 1989). In other words, an advisory may be based on older data from the 1990s solely or in part. However, since the late 1990s, mercury sampling throughout the state has been ramped up and most of the Hg analysis is based on more recent fish. But there are or have been fish left off the state advisory list that in all likelihood should be there. For instance, swordfish are notorious for their high mercury levels but are (or were in 2005) left off the states’ list. This is simply because there weren’t enough samples to analyze. This is frustrating to me on a personal level since I actually sampled over 20 swordfish from one commercial boat but those samples got lost in the shipping (I won’t condemn the company here!).

· Mercury bioaccumulates in fish tissue and other seafood like blue crab, and stays in our bodies when we consume fish with mercury for some time. However, we can expel the mercury through excretion and sweat. So if you eat a fish with Hg and do not consume any more Hg for ~2 months, that Hg should have left your body. The problem becomes when the intake becomes or remains higher than the output. So our family (mother of child-bearing age and an almost-3- year old) closely monitors our intake of fish in our diets, pay particular attention to what species, try not to eat fish if we don’t know what it is.

· Fish that are imported are not sampled for mercury, at least not to my knowledge. Not only is it very difficult for the consumer to determine 1) where their meal at a restaurant is from, 2) if it was farmed, 3) what the actual species is, 4) how much Hg, and whatever else is in it. There are growing incidents in Florida , and here in Tallahassee , where DNA tests from fish on the menu are not actually what they say they are. An article in the St Pete Times a few years ago showed that about 50% of the sampled snapper from about 15 area restaurants (in Tampa ) were not snapper. The good news is that most of the fish sold as snapper or grouper, if it is not actually that species, it is probably farm raised tilapia – much lower in Hg but if it is farm-raised probably has a whole suite of other chemicals.

· It has been claimed that the half of the mercury in our local and state waters comes from across the globe. However long and far Hg travels and gets deposited, it is clear that it just doesn’t get deposited locally. So coal plants in our area will not only affect our waters, but waters downwind. (Even though I am ~45 miles from the Perry paper plant, on some days in the morning I can smell the poisoned air flowing. Generally on cold winter mornings).

· There is wealth of information online from the federal governments (EPA, FDA, etc), scientific reports, etc that claim that some, even high, Hg levels in our body (for male adults, females not bearing children) are not that bad for us and that the health benefits for eating fish tissue (omega-3 fatty acids) far outweigh the consequences of consuming Hg. However, some fish species should be avoided all together (shark, swordfish, kingfish (king mackerel), Spanish mackerel, tuna, etc). Whether this information is put out there to confuse the public, to not create a panic about Hg, or whatever I am not sure. Some of it is misleading but I still wonder what the effects of eating too much Hg for the average male adult is compared to the gain in eating fish. It is too bad that we have to make that sort of risk-benefit analysis when we know that if we quit polluting the earth with Hg, we wouldn’t have to make that decision. In my opinion, putting that kind of risk-benefit out there just skirts around the problem of input into the environment.

· A Chicago Tribune investigative report of a few years ago showed that mercury levels sold in fish at restaurants throughout the country had exceeded the EPA limits. They also found that basically all canned tuna products have the same high levels of Hg and even though one is supposed to be lower in Hg due to the species it really is not.

· ‘head in the sand, hope for the best’ – a game of hot potato is played by the state agencies on Hg levels. FWC collects the fish tissue and turns it over to the FDEP. FWC doesn’t want to acknowledge mercury levels in all of the regulated fish species are on the advisory list and some very important species shouldn’t be eaten at all by anyone (e.g., king mackerel). FDEP tests and analyzes the data and passes the info to FDOH. DOH creates the advisories based on their level of acceptance. DEP and DOH takes no ownership of the Hg in fish tissue, they just are the messenger, FWC just samples the fish. No one wants to take ownership, acknowledge the widespread problem, work on lowering mercury levels, truly inform anglers and consumers about Hg in fish, regulate fish species based on mercury content, allow imported fish to be sold and consumed untested. There is some minimal effort to prosecute violators who do not label or market the fish species correctly, but much more needs to be done (this could be argued for many reasons.

· I think it is up to the consumers (anglers, people who eat/but retail fish products, environmentalists, etc) to unite and force the government to beef up its testing and reporting. At the very least, consumers should be provided with fact sheets on mercury anywhere fish are available for retail or consumption. It should be included in angling guides, through state fish regulation publications, etc. If we don’t demand it, it won’t happen because that will just allow the heads to be stuck in the sand.

Chad