Jump to content


Releasing native fish back into waterways is not okay


14 replies to this topic

#1 Guest_EricaWieser_*

Guest_EricaWieser_*
  • Guests

Posted 22 April 2011 - 09:52 AM

I was researching how to raise lepomis fry for another of the topics on this forum and I encountered this article: http://www.aquariuml...ive-fish/69.asp in which the author says the sentences,

Throughout the summer of 1992 I collected several green sunfish for my aquarium. Some had to be returned to their original body of water due to conflicts with the other sunfish already in the tank.

There is no way to contact the author, but I wanted to find them and let them know that that is not okay. It is not acceptable aquarist behavior to contaminate the local water bodies with anything from your aquarium, even a fish that came from the local water body. The reason is, once that fish has come into contact with the water from your tank, then they have also come into contact with any pathogen present.

Many pathogens remain dormant for long periods of time, only expressing themselves when the fish has a lowered immune system. These "opportunistic" pathogens are riders, and will ride from one fish to another without you even knowing it was there. They would ride from the aquarium water to the native fish and back into the native ecosystem, infecting it and tainting it.

For this reason, it is not okay to release anything back into the water once it has contacted your tank. Even fish that originally came from that water may not be released back in. Find somewhere else to get rid of your pet. You can sell it on aquabid, you can give it away on craigslist, heck, I'd prefer to see a person kill that individual fish and toss it in the trash before I see them put it back in the local water body.

If anyone knows how to contact this Peter R. Rollo person so I can tell them that, I'd greatly appreciate it.

Edit: I wish I could change the title of this topic to add "once they've been introduced to a tank". Hmm. Whoops.

Edited by EricaWieser, 22 April 2011 - 09:57 AM.


#2 Guest_Ramiro_*

Guest_Ramiro_*
  • Guests

Posted 22 April 2011 - 11:39 AM

I was researching how to raise lepomis fry for another of the topics on this forum and I encountered this article: http://www.aquariuml...ive-fish/69.asp in which the author says the sentences,

There is no way to contact the author, but I wanted to find them and let them know that that is not okay. It is not acceptable aquarist behavior to contaminate the local water bodies with anything from your aquarium, even a fish that came from the local water body. The reason is, once that fish has come into contact with the water from your tank, then they have also come into contact with any pathogen present.

Many pathogens remain dormant for long periods of time, only expressing themselves when the fish has a lowered immune system. These "opportunistic" pathogens are riders, and will ride from one fish to another without you even knowing it was there. They would ride from the aquarium water to the native fish and back into the native ecosystem, infecting it and tainting it.

For this reason, it is not okay to release anything back into the water once it has contacted your tank. Even fish that originally came from that water may not be released back in. Find somewhere else to get rid of your pet. You can sell it on aquabid, you can give it away on craigslist, heck, I'd prefer to see a person kill that individual fish and toss it in the trash before I see them put it back in the local water body.

If anyone knows how to contact this Peter R. Rollo person so I can tell them that, I'd greatly appreciate it.

Edit: I wish I could change the title of this topic to add "once they've been introduced to a tank". Hmm. Whoops.

I totally agree, under no circumstances can you release a fish that you've kept for any length of time. If you can't sell or give them away, the only responsible thing to do is destroy them, unfortunately. I have some tanks with pond water from a pond next to my house and I often go in there to scoop up some life with a brine shrimp net to throw in my tanks, yet it would still be irresponsible to release fish I took out of that pond originally because while in captivity I exposed the fish to all sorts of pathogens from my other tropicals and even the live blackworms and other live foods I had used. Fortunately the people on this site tend to be pretty knowledgeable about fishkeeping and natives.

#3 Guest_gerald_*

Guest_gerald_*
  • Guests

Posted 22 April 2011 - 12:09 PM

Sorry if I'm adding to your worries, but our local wastewater treatment plants don't exactly sterilize all that aquarium water and fish poop we pour down the drain. And seafood markets and restaurants import fish from around the world and wash guts down the drain. WWTPs do kill a lot of bacteria, but not all, and the only micro-orgs they normally sample are fecal coliforms. Loads of viable bacteria, eggs of parasitic worms, and other potential pathogens probably slip right the through our WWTPs and out into local rivers.

#4 Guest_Skipjack_*

Guest_Skipjack_*
  • Guests

Posted 22 April 2011 - 07:33 PM

This is not okay, and is fully against NANFA ethics. But also realistically every pond owner in this country with a short spillway, is stocking their pond, and inadvertently releasing captive fish into waterways. NANFA members are the least of this problem. No easy answer.

#5 Guest_Irate Mormon_*

Guest_Irate Mormon_*
  • Guests

Posted 22 April 2011 - 11:15 PM

Peter Rollo was a NANFA member many years back. In the 60's and 70's it was well understood that no fish should be released into a foreign body of water. The idea that a fish once caught should never be released, ever, under any circumstances, period, is a relatively new philosophy. While there can be debate on the subject, it is official NANFA policy today. This wasn't always the case. The article is almost 20 years old.

#6 Guest_mywan_*

Guest_mywan_*
  • Guests

Posted 23 April 2011 - 03:14 AM

Even though wastewater should get far more scrutiny there remains a lot of good reasons for this policy, and release practices can add a whole new range of potential pathogen issues that wastewater cannot. Not to say wastewater does not have its share. But many pathogens require live host, or requires live host to enter an infectious stage with a mechanism described below. Perhaps going through some of the basic mechanisms triggering these bacteria would be helpful in making it easier to understand why transferring infected fish to an environment already infected by the same bacteria is so bad.

The environment is full of pathogenic bacteria which essentially everything is exposed to at some levels. You are carrying cold viruses for colds you do not have or ever had. The ones you have had you will never get sick from again. The dormancy Erica spoke of is not a dormancy in the normal sense of the word. The bacteria remains active even when not effectively pathogenic at the time. The mechanism behind this is called quorum sensing, which is a kind of language much like ants have. All bacteria not only have a language, they have two! One language speaks only to members of the same species while the other speaks to all species of bacteria, like a universal bacteria language. A host with a normal infection tends to have infections from a wide variety of pathogens to no ill effect. We need these exposures to stay healthy for the following reasons. Due to the quorum sensing mechanism when a particular species of bacteria gains a foothold on the host where they outnumber competing bacteria they sense this and switch strategies or modes. Where before they acted as bunch of solitary individual bacteria they now start tightly congregating. This triggers the infectious mode that makes you feel so bad when you get a cold. This congregation behavior is also why many drugs that look promising in the lab do not often work so well in practice. The drug simply cannot penetrate all but the outer portion of these congregations.

Now when you put a fish from some habitat into the different environmental conditions of your tank, often these different conditions are enough to give an infection the fish, and all the fish in the original habitat, a foothold in that host they otherwise would not have. Since, like the fact that you never get the same cold twice, the fishes immune system is geared to protect from infections likely to get a foothold in the environment it came from. Not the environment you provided it for some length of time. Now when you return this fish with a bacteria that now in infectious mode looking to expand its colony none of the fish in that habitat have an immune system geared to protecting from that infection that was so unlikely to go into infectious mode in that environment.

So it has nothing to do with introducing pathogens to any environment that does not already posses those pathogens. It has to do with providing pathogens with a lifecycle stage they would not have entered in that environment, and because those pathogens are so unlikely to enter that lifecycle in that environment none of the fishes immune systems are primed to deal with it when you introduce pathogens in that lifecycle.

I hope that clears up the, "but I have no diseases in my tank", or, "it was where it came from", because the disease is everywhere, in your tank, on you and your food, and in the original environment the fish came from as well as all fish there. You did not introduce the pathogen, you provided the pathogen the lifecycle stage it needed to potentially kill a lot of natives.

#7 Guest_pylodictis_*

Guest_pylodictis_*
  • Guests

Posted 01 May 2011 - 06:59 PM

Sorry if I'm adding to your worries, but our local wastewater treatment plants don't exactly sterilize all that aquarium water and fish poop we pour down the drain. And seafood markets and restaurants import fish from around the world and wash guts down the drain. WWTPs do kill a lot of bacteria, but not all, and the only micro-orgs they normally sample are fecal coliforms. Loads of viable bacteria, eggs of parasitic worms, and other potential pathogens probably slip right the through our WWTPs and out into local rivers.



True, but I wonder if the overuse of commercial antibiotics for this purpose has or would have the same effect as the use of antibiotics as medications breeding "superbugs". Does anyone have any insight on this?

#8 Guest_EricaWieser_*

Guest_EricaWieser_*
  • Guests

Posted 01 May 2011 - 07:17 PM

True, but I wonder if the overuse of commercial antibiotics for this purpose has or would have the same effect as the use of antibiotics as medications breeding "superbugs". Does anyone have any insight on this?

I think Gerald's term "WWTPs" was referring to Waste Water Treatment Plants.
Waste water treatment plants don't use antibiotic medications to kill bacteria; they use processes that are at conditions that bacteria can't survive. Bacteria die because of extended anaerobic conditions, extreme values of pH, and the use of chlorine compounds.

This water resource department cites the use of sodium hypochlorite to kill bacteria: http://www.mwra.stat...tml/sewditp.htm

Disinfection
After passing through primary and secondary treatment, wastewater is disinfected with sodium hypochlorite to kill bacteria. There are two disinfection basins, each approximately 500 feet long with a capacity of 4 million gallons, in which the effluent is mixed with sodium hypochlorite. Finally, sodium bisulfite is added to dechlorinate the water, so that chlorine levels in the ultimate discharge will not threaten marine organisms.


Edited by EricaWieser, 01 May 2011 - 07:21 PM.


#9 Guest_pylodictis_*

Guest_pylodictis_*
  • Guests

Posted 02 May 2011 - 02:58 PM

I think Gerald's term "WWTPs" was referring to Waste Water Treatment Plants.
Waste water treatment plants don't use antibiotic medications to kill bacteria; they use processes that are at conditions that bacteria can't survive. Bacteria die because of extended anaerobic conditions, extreme values of pH, and the use of chlorine compounds.

This water resource department cites the use of sodium hypochlorite to kill bacteria: http://www.mwra.stat...tml/sewditp.htm




I understand that, what I'm pointing out it that if you kill bacteria using any method you are artificially selecting the individuals in the population that can survive such conditions, therefore in the future you will need stronger and stronger antibiotics(antibiotic meaning anything that kills bacteria).

#10 Guest_mywan_*

Guest_mywan_*
  • Guests

Posted 02 May 2011 - 10:02 PM

I understand that, what I'm pointing out it that if you kill bacteria using any method you are artificially selecting the individuals in the population that can survive such conditions, therefore in the future you will need stronger and stronger antibiotics(antibiotic meaning anything that kills bacteria).

Yes, in principle some species may find some survival strategy for chlorine disinfectants etc. Bacteria evolve survival strategies constantly with or without us. Certain things, like fire, they will never evolve to survive. For disinfectants that simply kill any living thing they may evolve some tiny resistance if lucky enough to only to escape a big dose, but there are too many killing vectors to evolve a defense for all of them. So as long as WWTPs are not using antibiotic, but rather disinfectants, it is not a real issue for at least a few tens of thousands of years.

For antibiotics the situation is quiet different. Antibiotics need to target certain bacteria while remaining harmless for most bacteria and living lings. That means its killing vector is highly limited and easy to evolve a strategy to get around. Or else it would not be so harmless to everything else, or harmless enough for you to take in a pill. It is a numbers game, just like evolution is. If there are natural environments which nothing lives in then you can bet that nothing will evolve a way to live in it anytime soon since nothing has in 4 billion years.

Your best long term defense again bacteria is to maintain a healthy colony of the bacteria we all carry. It is this competition between bacteria that prevents almost all infections, where no one gets a big advantage over any other. Many of the bacteria you carry you could not live without for a whole range of reasons. Antibiotics and disinfectants are not the same thing.

#11 Guest_EricaWieser_*

Guest_EricaWieser_*
  • Guests

Posted 02 May 2011 - 10:13 PM

Antibiotics and disinfectants are not the same thing.

Very true.
Pylodictis, if a pressure on a population kills a large fraction of it, for example 90%, then the 10% that survive produce a second generation that is more likely to survive the pressure in the future. But if the pressure kills 100% of the population, then a second generation doesn't happen, and a mechanism of resistance cannot possibly arise. The issue in medicine is that we sometimes only kill 99.999%, which leaves 0.001% to survive and reproduce. But with something like chlorine, if the dose is high enough, you get 'em all. It's very harsh stuff.
Chlorine isn't like an antibiotic, which blocks one pathway or a single protein. It's just plain poison.

Of course, then you have your hydrogen sulfide caves and the deep ocean vents, where a constant poison pressure exists for thousands of years. In those sorts of circumstances you get all sorts of weird life forms. For example, the technique of PCR employs high temperature proteins from a special strain of bacteria that evolved to live in hot temperature springs. Given enough millenia, life seems to always find a way. :D Of course, waste water treatment plants only exist for a couple decades or so, which isn't nearly long enough or constant enough to get its own special chlorine-resistant life forms. And if it did we'd probably switch chemicals. :)

Edited by EricaWieser, 02 May 2011 - 10:21 PM.


#12 Guest_Irate Mormon_*

Guest_Irate Mormon_*
  • Guests

Posted 02 May 2011 - 10:24 PM

Given enough millenia, life seems to always find a way. :D



I've said that before (I think it was WRT triploid grass carp) and was roundly pooh-poohed for it. Welcome to the vocal minority!

#13 Guest_fundulus_*

Guest_fundulus_*
  • Guests

Posted 02 May 2011 - 11:01 PM

I think that triploid carps are always created, and guaranteed, by people who got C's in Aquaculture classes.

#14 Guest_mywan_*

Guest_mywan_*
  • Guests

Posted 02 May 2011 - 11:08 PM

There are situations life can never evolve to survive, but the first time you try to claim this is one of those situation some life will come along and prove you wrong.

#15 Guest_pylodictis_*

Guest_pylodictis_*
  • Guests

Posted 07 May 2011 - 04:47 PM

Very true.
Pylodictis, if a pressure on a population kills a large fraction of it, for example 90%, then the 10% that survive produce a second generation that is more likely to survive the pressure in the future. But if the pressure kills 100% of the population, then a second generation doesn't happen, and a mechanism of resistance cannot possibly arise. The issue in medicine is that we sometimes only kill 99.999%, which leaves 0.001% to survive and reproduce. But with something like chlorine, if the dose is high enough, you get 'em all. It's very harsh stuff.
Chlorine isn't like an antibiotic, which blocks one pathway or a single protein. It's just plain poison.

Of course, then you have your hydrogen sulfide caves and the deep ocean vents, where a constant poison pressure exists for thousands of years. In those sorts of circumstances you get all sorts of weird life forms. For example, the technique of PCR employs high temperature proteins from a special strain of bacteria that evolved to live in hot temperature springs. Given enough millenia, life seems to always find a way. :D Of course, waste water treatment plants only exist for a couple decades or so, which isn't nearly long enough or constant enough to get its own special chlorine-resistant life forms. And if it did we'd probably switch chemicals. :)


Okay, I understand. My delima was I couldn't find the correct verbalization.





Reply to this topic



  


0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users