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Hi Dusan & All, Jan 7, 2015
A sewer outfall might generate some anoxic zones (perhaps) but surely
not all of Halifax Harbour. The feeding to which I refer would be on
suspended particles (mostly live or dead bacteria I would expect) and of
course in an aerated volume wherever that might be.
Yt, DW, Kentville
----- Original Message -----
From: "Nicholas Hill" <fernhillns@gmail.com>
To: <naturens@chebucto.ns.ca>
Sent: Wednesday, January 07, 2015 6:51 AM
Subject: Re: [NatureNS] Sewer Strolls: Before and After Harbour Cleanup ?
> not ragworms? Some can handle anoxic conditions...defies biochem maybe
>
>
> On Tue, Jan 6, 2015 at 9:52 PM, Dusan Soudek <soudekd@ns.sympatico.ca>
> wrote:
>> I can see that a well-deigned and properly maintained (i.e., mechanically
>> aerated) sewage lagoon or engineered marsh can support a highly diverse
>> and
>> productive ecosystem. But not if the decomposing sewage makes the water
>> column anoxic. Nothing but anaerobic bacteria survive there...
>> Dusan Soudek
>>
>>
>> From: David & Alison Webster
>> Sent: Tuesday, January 06, 2015 8:19 PM
>> To: naturens@chebucto.ns.ca
>> Subject: Re: [NatureNS] Sewer Strolls: Before and After Harbour Cleanup ?
>>
>> Hello:
>> Would not many forms of zooplankton species
>> Feed directly on soup that is made out of feces ?
>> And thus form a meal for the next larger size
>> Until some can be seen using unaided eyes.
>> Yt, DW, Kentville
>>
>> ----- Original Message -----
>> From: Dusan Soudek
>> To: naturens@chebucto.ns.ca
>> Sent: Tuesday, January 06, 2015 6:59 PM
>> Subject: RE: [NatureNS] Sewer Strolls: Before and After Harbour Cleanup ?
>>
>> These are interesting observations. I can see how fertilizing a harbour
>> with
>> sewage will increase its primary production and shift if from attached
>> plants (kelp, eelgrass, etc.) to phytoplankton. But I doubt that the
>> unmentionables we flush down our toilets are directly available to
>> seabirds
>> and seals as food. The stuff forms local sewage upwellings (sewage is
>> warm),
>> is dispersed by tidal currents, and broken down by decomposers, which
>> eventually liberate the phosphates and nitrates...
>> Dusan Soudek
>>
>> On January 6, 2015 at 12:40 PM jen cooper <iffercooper@hotmail.com>
>> wrote:
>>
>> Hello all,
>>
>> I can't speak to Halifax Harbour but for comparison...
>> The Sydney side of Sydney harbour was fitted with wastewater
>> infrastructure
>> within the last ten years. Since the diversion of wastewater the clusters
>> of
>> diving ducks and seals, have either left or are very obviously not as
>> plentiful as they used to be. On the west side of the harbour where
>> infrastructure is yet to come (but on the way!) ducks still frequent the
>> outfalls.
>>
>> My two cents on why, are these:
>>
>> Wastewater does cause eutrophication, fertilizing plants and algae (an
>> onwards up the web). Food availability would definatley be different at
>> outfalls than where there are none.
>>
>> Often times, here, the warmer water at outfalls causes openings in the
>> ice.
>> In some areas these are the only access points to the water.
>>
>> :) Jen
>>
>>
>> ________________________________
>> From: soudekd@ns.sympatico.ca
>> To: naturens@chebucto.ns.ca
>> Subject: Re: [NatureNS] Sewer Strolls: Before and After Harbour Cleanup ?
>> Date: Sun, 4 Jan 2015 18:21:18 -0400
>>
>> Joanne,
>> an excellent question. A broader one is what is it that attracts birds
>> to
>> the outfalls? The warm temperature of the discharge? it seems that a lot
>> of
>> the herring and great black-backed gulls that used to frequent the Point
>> Pleasant Park outfalls were just bathing. Lots of preening, wind
>> fluttering,
>> etc. is the attraction the fish that are themselves attracted to this
>> warm
>> water? The sewage itself?
>> Dusan Soudek
>> From: Joanne Cook
>> Sent: Sunday, January 04, 2015 5:44 PM
>> To: naturens@chebucto.ns.ca
>> Subject: Re: [NatureNS] Sewer Strolls: Before and After Harbour Cleanup ?
>> Dusan,
>>
>> I was wondering the same thing yesterday, and also wondering about the
>> temperature of the current effluent, and what effects it has - if any -
>> where it emerges.
>>
>> cheers,
>> Joanne
>>
>>
>>
>> ____________________________________
>> Do not meddle with the Forces of Nature, for you are small,
>> insignificant,
>> and biodegradable.
>> ____________________________________
>> On Sun, Jan 4, 2015 at 5:25 PM, Dusan Soudek <soudekd@ns.sympatico.ca>
>> wrote:
>>
>> Just curious: Have there been any noticeable changes in the numbers
>> and
>> species of waterfowl associated with Halifax Harbour sewer outlets since
>> the
>> Harbour Solutions project was completed? Only a small percentage of the
>> city’s raw sewage gets dumped into the harbour these days, more so after
>> periods of heavy rainfall when the sewage plants are overwhelmed by
>> discharge from combined sewers...
>> Dusan Soudek
>>
>>
>>
>>
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 2015.0.5577 / Virus Database: 4257/8882 - Release Date: 01/06/15
>
>
> -----
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> Checked by AVG - www.avg.com
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