San Pablo Dam

There are new guidelines regarding eating fish caught in the San Pablo Reservoir...............
State issues new safe eating guidelines for fish from San Pablo Reservoir
By Alice Crane
CONTRA COSTA TIMES
Posted: 02/27/2009 04:07:06 PM PST
Updated: 02/28/2009 07:17:38 AM PST


State officials today released new safety guidelines for eating fish caught in the San Pablo Reservoir.

The report from the state Office of Environmental Health Hazard Assessment relied on studies by the California Department of Fish and Game and the East Bay Municipal Utility District, and replace previous guidelines issued by Contra Costa County.

The new guidelines recommend that women from age 18 to 45 and children can eat five servings per week of rainbow trout or up to two servings per week of black crappie. Men over 17 and women over 45 can eat five servings per week of black crappie or trout or one serving per week of largemouth, smallmouth or spotted bass.

All people should avoid eating catfish and carp from the reservoir, and woman 18 to 45 and children should not eat bass.

Fish taken from the reservoir contain some mercury, most of the form of methylmercury. High exposures to methylmercury can affect the nervous system in children and harm learning ability, language skills, and memory.

Samples from fish in the reservoir also contain other contaminants, including dieldrin and polychlorinated biphenyls (PCBs). Dieldrin and PCBs have been found to cause cancer in animals and PCBs may harm the nervous system in children similar to methylmercury. Although both chemicals are no longer used, they can persist in the environment and are still found in some fish.



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....harm learning ability, language skills, and memory. ...

 

( shaking my head while thinking "what the hell are we doing to ourselves")

Surely thousands of people drink the water from that reservoir every single day?

Plus; the catfish are stocked, how the hell do they accumulate Bad Stuff. If people aren't supposed to eat them, WTH are they being stocked for?

Phil, I think the fish do accumulate chemicals from the reservoirs, especially the bottom dwellers like catfish. Trout & other fish accumulate from eating other little beasties that pick stuff up from the sediment. Going on this premise, a recently planted fish shouldn't have too many toxins.

My understanding is that the water from these res's is tested and treated for chemical & bacterial content, so it reaches households nice & clean (all relative, I guess). I think the deal is that most of the contamination is held in the sediment, so a lot of the junk doesn't flow into the main water supply. South Bay res's are known to have a lot of mercury due to the mining that took place before. I don't know if they are able to filter it out or if it mostly just stays on the bottom. The res's that hold pristine water don't allow other activities on the water so it doesn't get contaminated.

Anyone please correct or amend any of this. I've read bits & pieces on this over the years but don't have the whole scoop.

Wow! I was even thinking of kayak fishing that lake when it opens. I guess I could
still go for some CP&R. Thanks for the heads up.

Jedmo

OK, here's a snippet I found from a quick search. Pretty much as I said above; the contaminants bind & absorb into the sediment and bioaccumulate in fish that eat other fish & organisms (beasties, in my speak). Believe or not at your own discretion! None of this is new, though. Most Bay Area water utilities always get high marks for drinking water quality. Also, I think signs are posted at all affected res's regarding eating the fish.

If contamination was found in fish, is the drinking water also contaminated?
The drinking water is not contaminated. “Although these chemicals have been found in fish, they do
not concentrate in the water,” said Bruce Wolfe, Executive Director of the San Francisco Bay
Regional Water Quality Control Board. “Bay Area drinking water utilities regularly monitor their water
supplies, and treated water supplied from these reservoirs is safe for drinking and other domestic
uses.”
How can fish be contaminated but not the water?
These contaminants do not concentrate in water as they do in fish. The contaminants tend to bind
with or adsorb onto sediment, where they can enter the aquatic food chain. The chemicals
accumulate over long periods of time in the sediment and enter organisms eaten by fish that live in or
on the sediment. The chemicals build up in fish that eat other fish because their bodies eliminate
these chemicals very slowly. In this process, known as bioaccumulation, the fish that derive their food
from the sediment and the most active predators accumulate the most contaminant, which can be
amplified by up to one million times as it moves up the food chain.

Link to article:  http://209.85.173.132/search?q=cache:B8JwQoxgNGUJ:www.co.marin.ca.us/depts/hh/main/hs/PublicHealth/Fish/pdf/FishFAQs101404.pdf+Bay+Area+Reservoirs+contamination&hl=en&ct=clnk&cd=3&gl=us&client=firefox-a

Here's a link to health advisories for fish consumption from 9 Bay Area reservoirs:
http://oehha.ca.gov/fish/so_cal/bayareares.html

This is really nothing new.  In  fact, I believe the new guidelines are less restrictive than the previous ones.  It's still a great place to fish for trout in a kayak.  Last year, I caught lots of good size trout, trolling Rapalas along the dam.  If you catch and release, the guidelines don't matter anyway.  If the hours are the similar to last season, there are a few days a week when no PBs are allowed on the lake other than the few rentals.  Many times, I had the place to myself other than those fishing from the shore.  If you get the inspection done at the main gate, you can leave the facility and reenter down by the dam and launch from the beach.  The goose "deposits" on the sand are a little messy but this way you don't have to paddle the length of the reservoir to fish the dam area.
Martin

The mercury is there by one  of two ways, naturally and from mining years back.  My GF is an enviormental toxicoligists and she was telling me about it.