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green lake dirty or not ?!

Posted: Thu Feb 26, 2009 7:14 am
by driftercn83
is green lake in seattle dirty? no actual it gets its name from the large blloms of mill foil that grows during the summer giving it a green tint. the lake its self is actually ver clean cleaner the lake washington host a large ecosytem. I found this out when I attended roosevelt highschool from 1999 to 2002 fished the lake every day and did some scince projects on the the water quality I am now a fish biologist as well as a hatchery tech and gone back and done pro water samples on the lake and it is still quite clean. the only warning I give ist to make sure you cook your carp well and same with any crayfish. anyways how many beilive its clean or dirty just a interest.

RE:green lake dirty or not ?!

Posted: Thu Feb 26, 2009 7:34 am
by urbanangler
I had thought it was not so clean, but you have me convinced otherwise. I live close to Roosevelt High, and fish Green Lake a fair amount. I have seen recent state warnings about eating cutthroats and perch out of Lake Washington. No wanrings for Green Lake. We must just assume the urban runoff, and lack of a big streams going in or out, make for a polluted lake. Thank you for the facts!!

RE:green lake dirty or not ?!

Posted: Thu Feb 26, 2009 8:13 am
by racfish
I used to fish Greenlake all the time.I rowed on the Greenlake rowing club.I still fish Greenlake.Its a great lake to take innercity kids fishing.Its close to home but if you go on a weekend go early for good parking.Greenlake is not a man made lake as some would suggest.I've seen pictures of it from the very early 1900's.I'm sure it gets a good runoff from the streets but the lake itself I imagine is clean.I wouldnt swim in it.

RE:green lake dirty or not ?!

Posted: Thu Feb 26, 2009 10:42 am
by swedefish4life1
Every road dumps that lake in the highly populated area fertlizer, oils and everything else goes into her each and every rain how often does it Rain:-$ in Seattle#-o :-({|= lol

RE:green lake dirty or not ?!

Posted: Thu Feb 26, 2009 4:14 pm
by Bro-Rando
I'm inclined to agree with Swede. First of all, Green Lake is not named for its milfoil. Eurasian milfoil is a recent (relatively speaking) addition to our waters. Natuarl blooms of pelagic algae that stain the water column green are where the name comes from. It's not a very helpful quetsion to simply ask "is Green Lake clean" or to compare it to Lake Washington since they are two very different hydrological regimes. It's more helpful to ask questions about specific contaminants and ecological conditions. For example, it's undeniable that Green Lake has become increasingly eutrophic with input of nutrients from lawns, pet waste, nitrogen deposited from automobile exhaust, etc. The result has been swimming closures due to toxic blue-green algae blooms which occured in the early 2000s. Does this mean it's not clean? Nothing discussed here is "unatural" in the system, becaue phosphorous and nitrogen are natuarlly occuring, we just add a bunch more of this stuff and those toxic algae go crazy.

In response to this Green lake has recieved an alum treatmen. Aluminum phosphate bonds with the nutrients and causes them to sink to the bottom, thus preventing pelagic algae from using them. However, the prolific population of non-native common carp root about in the sediments and resuspend a great deal of these nutrients. These carp have also been listed as a fish that should not be eaten by anyone by the WDFW. Due to their bottom feeding habits they absorb all the toxins that i assure you permeate the sediments for Green Lake.

Consider This: Green Lake has no outlet anymore aside from storm drains that dump its overflow in Lake Union. It's been estimated that the water that runs off of our streets, lawns, etc. spends a minimum of two years in the lake. This is untreated stormwater mind you, the same stuff that is causing orcas in the Puget Sound to turn up as the most toxic animals on the planet.

Back to the milfoil, have you ever heard of swimmer's itch? I'm forget about the details, but there's some kind of aquatic parasite that hatches from eggs in duck poop and incubates on amongst the milfoil. It then hatches an burries itself in your skin when you go for a swim in Green Lake, thus the icth.


All this is to say that there are many different ways to decide whether or not a body of water is clean. I'll say this, I swim in Lake Washington every day in the summer, but I won't put my toe in Green Lake. Are you safe eating a trout out of the lake? I'd say probably. They're stocked fish anyway, so they likely haven't spent a ton of time in the lake. If you happen to find a muskie still swimming about I'd probably think twice about eating it. Being a big carnivore they tend to accumulate all the toxins that work their way up the food chain.

Moral of the story? Based on a number of factors I would call Green Lake dirty. While on any given day (a bunch of them this winter in fact) the water is clear enough to see to the bottom even in the deepest parts of the lake, that is a farily superficial way to judge water quality. To do the tests for heavy metals, pcbs, etc. would cost thousands of dollars and I don't think anyone has really done them. I would encourage anyone with the time/interest/equipment to test the water quality after a big rain and see what they come up with. I can promise you it will be interesting.