Effects of post-event event effluent on sea fishing

[Grumpy Grandpa]

I'd briefly mentioned this on the thread about fly fishing and was rightly reminded that it should really have a separate thread...

So - I live on the North Ayrshire coast and I've considered that seafood would be an ideal source of food for anyone living in this area and in others but there is a question about sea fishing post event that's been worrying me.

Post a large event, I'm sure that the under or unmanning, or failures in maintenance in treatment stations, would result in an increased volume of effluent entering the coastal waters that we would be harvesting from.

Does anyone have any information on whether this would pose any significantly increased heath risk?

[Lightspeed]

Agreed GG

Maybe a few interconnected scenarios to consider:

Failure of Water treatment ( sewerage) works allowing raw effluent to flow in rivers and to direct sea outlets

But maybe reduced flow of effluents into those treatment plants due to failure of pumped water.

Longer term reduced generation of effluent due to reduced population

Possible contamination of sea based food chain from large numbers of bodies floating out to sea from major rivers ( those big rivers generally have large cities along their course.


Implications for seashore harvesters and foragers:

Bivalves, and in particular Mussels will be filter feeding on organic matter ( effluent and pathogens) in suspension in the water.

Crabs, shrimps,whelks, and some fish ( especially eels) will actively scavenge on any corpse that they encounter.

Both the bivalves and the scavengers will be actively taking up and condensing pathogens.

The normal rule when consuming sea-food that has been foraged is to only harvest live and healthy specimens. After event I would not eat anything raw unless as a last resort. Everything must be cooked thoroughly.

[Highlander]

I dont think it would be a problem, because I dont think it would reach the sea, if your sewage system wasn't working it would just block up and wouldn't go anywhere,...if waste got as far as the treatment centers then it would be treated and water cleaned.

.... but lets say it did get to the sea, fish wouldn't swim in unfit water, you would either see dead fish, or no fish...and what little fish might feel they could deal with would be filter through their gills,.... I dont think it would effect the fish you could catch

[Lightspeed]

HL,

many many hours spent fishing on a coastline with a notorious near shore unprocessed sewer outlet tell me otherwise.

Especially with regards to bivalve filter feeders.

Fish, and in particular eels take up and retain in their systems all manner of nasties.

See:

http://www.ingentaconnect.com/content/ia...0/art00039
Abstract:
In this study we analyzed the pattern of copper (Cu), cadmium (Cd), lead (Pb), and mercury (Hg) accumulation in liver (as a detoxifying organ) and muscle (as the most important tissue for human consumption) of brown trout (Salmo trutta) and European eel (Anguilla anguilla) caught in two wild Spanish rivers where both species are usually angled for human consumption. Cd, Pb, and Cu accumulated preferentially in the liver of both species. Hg accumulated both in the liver and muscle in brown trout, whereas it accumulated preferentially in muscle in European eel. Both high metal content and preferential accumulation of Hg in muscle suggest that European eel is more harmful than brown trout for human consumption.



Document Type: Short Communication

Affiliations: 1: Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil 2: Departamento de Biología Funcional, Area de Genética, Facultad de Medicina, C/ Julián Clavería s/n, 33006 Oviedo, Spain

Publication date: 2004-10-01

[Binnie]

Agree with HL

before sewage systems, the effluent was discharged without being treated, people still ate the fish, and generally didn't die on contact with a fish supper.

lol maybe an overexaggeration, but unless the water was completely foul, i'd probably still fish it and eat said fish.

[Skean Dhude]

Interesting thought.

At the worst we would have to go further out to sea to fish. It wouldn't be a continual feed because if the works were malfunctioning because they were unmanned then that implies more has happened and so I would guess less waste is being produced.

Inland however while it all arrives at the waste station will be interesting. Houses nearer will have backflow as waste from higher ground comes in. Eventually it will disappear but disease will follow.

[I-K-E]

one question would be assuming that the effluent did make it out to sea then how long would it be before it breaks down or it is that dispersed that it becomes less off an issue.

tides and currents will have a big impact on any area and I think that you could put a time on the breakdown but this would vary depending on the time of year (temperature).

[Grumpy Grandpa]

In my own situation, I may be limited to the shoreline - beach casting and collecting shellfish. It's the shellfish that concern me most, I think. They're susceptible to algal blooms for example, aren't they? During such times do they not become a wee bit dangerous to eat?

As for effluent, I never did get round to studying shit in detail but surely there must be some toxins or other unpleasantness involved that could be retained by shellfish?

I suppose it's the uncertainty that's the real problem...

---

Doh! (Best Homer voice again.) Environmental Health Officer...

[Geordie_Rob]

(1 October 2013, 16:12)Grumpy Grandpa Wrote: In my own situation, I may be limited to the shoreline - beach casting and collecting shellfish. It's the shellfish that concern me most, I think. They're susceptible to algal blooms for example, aren't they? During such times do they not become a wee bit dangerous to eat?

As for effluent, I never did get round to studying shit in detail but surely there must be some toxins or other unpleasantness involved that could be retained by shellfish?

I suppose it's the uncertainty that's the real problem...

---

Doh! (Best Homer voice again.) Environmental Health Officer...

My thoughts would be avoid the shellfish unless a last resort. If after an initial "messy" period has passed, I would go against traditional advice & only go for the smaller ones that haven't been alive as long to suck up the shite. Avoid estuary areas & only collect from the open seashore.

[Scythe13]

I've been thinking of this recently, possibly to the point where it's an unhealthy level of consideration.

There are a few things I'd like to put out and get feedback on.

1. Fish poo, and it's a natural part of the sea cycle. What's to say our poo will be that different?
2. What breaks down fish poo at the moment? Bottom feeders (pardon the pun). Won't they become more plentiful with the increase of effluence? Thus the breakdown of the matter should increase in speed, due to more bottom feeders present. More food means more bottom feeders, means more fish that prey on them, etc.
3. How will the effluent get into the sea? Treatment plants shut down, so are people going to be pooing in rivers or directly into the sea? For me this makes the idea of canals more dangerous than the sea. Not many major cities will be hosting beach poo parties. More likely people will be pooing in the city rivers etc.
4. No running water, so no toilets will be flushing, so why would a shutdown sanitation centre be an issue? No running water means there will be no waste getting to the sewers anyway, so no crap at the sewer centre.
5. People will be more likely to poo in woods, fields etc, than into a stretch of running water, or in the sea. This is a bigger issue in my opinion.
6. Bodies...these will be the bigger problem if there's a major die off. Bodies will be put into stretches of running water and disposed of that way. Many will be burned and buried, but some will be 'flushed' down a river and into the sea. But these bodies will end up no different from the carcass of a whale. Only thing that would concern me then would be AID and HIV in the fish swimming around in the water.

These are my thoughts. I'd love a bit of feedback on this.