The following is a post from John Leek, an activist scuba-diver who uses the Children's Pool in La Jolla to access the rich kelp beds and of the reserve. There is no reason that people can't share the beach with our harbor seals, but irrational animal activists are pushing for a political and judicial closure of the Children's pool.
Looking forward to the 3rs at Children's Pool and environs this Saturday, I set out to assess the danger of exposure to seal bacteria at Children's Pool. On one Thursday while on video I took standard 100 ml sample bottles out into the Pool. I followed Health Department protocol and packed 4 separate samples in ice to go to a lab the next morning. County Health has not tested Children's Pool water in years.
Beach testing is done for 2 indicator bacteria. Coliform (E Coli) and Enterococcus. Before 2004, coliform was the usual "indicator bacteria". That term is very important. Both bugs are resident in mammals, and so in the absence of another mammal concentration, it can be assumed their presence at a beach indicates a sewage spill possibly containing human pathogens which could include giardia, hepatitis, cholera, Gawd-knows-what. Enterococcus became preferred because it lives much longer in salt water. But since 2004, a beach cannot be closed for non-human levels, only posted advisory, because sea gulls or such can trip the tests. In 1999, DNA tests had shown such bacteria at Children's Pool was seal originated, not indicative of a sewage spill
I had read statements on Divebums by divers who said they would not enter Children's Pool because they heard of the contamination, yet divers disport themselves in the equivalent of space suits, and often sign legal waivers stating "I know diving is dangerous and if I die it will have been my own fault". Can risk level values be determined?
The lab tests would tell the current level of 2 bacteria, but not about any virulent other life forms it was, or was not indicating. Nor would it indicate if bacteria or viruses from a seal could "hop" to a human like swine flue or salmonella from chickens. For that there was needed human systems regularly exposed to seal water. I found 4 swimmers who said they each swam in Children's Pool over 200 times/year. None could recall ever getting sick. Encouraging. The last test would have to be a human guinea pig exposed to high levels to measure any reaction. I filled another sample bottle and with the camera running, I drank it. Then we found the camera had not been on properly so I did it again. The next day was Friday. I turned the samples in to the lab in the morning and went back that evening to fill another sample bottle and drank it on camera. Science.
Saturday, I sought out the park ranger and with him in the camera field I asked him if he had seen me capture a sample just then and what diseases he was told might be resident, "Some sort of gastroenteritis, I should think" he said. "Good guess", said I and quaffed it. Still nothing. Sunday I found somebody to film me collecting 2 samples in the Pool, with seals swimming around me. I stood by the ranger again and downed both samples. Six bottles in 4 days documented. Enough. The lab results would be ready the next day.
The lab samples had been at a very high tide. Anything on the sand had been exposed to the water. Almost all coliform had tested to be E Coli, no surprise. 7 to8 hundred MPN/100ml. (MPN = Most Probable Number of colonies) . EPA standards are statistical. 235 MPN/100ml predicts 8 in 1000 swimmers will become ill, which is considered an acceptable level, but it is preferred water be below 126 (4 swimmers/1000) 400MPN/100ml is considered not good. But I was not just in it - I swallowed around 5000 colonies in 4 days. The Enterococcus level was 140, 4 times over "acceptable". Yet I was unaffected with 600ml ingested, = over 1000 colonies.
Dr. Dezfulian, director of EEL Analytical Laboratory, was kind enough take time to answer some questions.
Q: Is it surprising I did not get sick?
A: No, the standards are statistical. A population contains infants, very old people, people with AIDS or other immune deficiencies. A diver is typically of a healthy population. Your digestive system destroys most bacteria immediately, though had you had a peptic ulcer you could have had serious problems. The only thing you know is you met a high load of INDICATOR bacteria. They are not normally virulent, but varieties can be opportunistic in the event of open wounds or immunodeficiencies.
Q: If the water had been 4 times less populated, the water would have been as safe as a normal beach?
A: There is no safe level. Somebody somewhere can get sick in any water. There are thousands of kinds of bacteria in sea water. A common native ocean bacteria is vibrio vulnificus, a cousin of cholera. (Cholera is also found in recreational water in "acceptable levels") Vibrio wulnificus is concentrated in filter feeders and causes 95% of seafood related deaths. (raw oysters) If it settles into an open wound, there can be sepsis the next day.
Q: How many indicator bacteria do you have inside you right now?
A: On the order of a billion. A digestive system depends on them.
Q: So did I prove anything?
A: Not really. Now if you want to contract for daily measurements for a year with temperature, salinity, tide, time entries, you could nail something down. You just need a grant.
