Releasing Native Fish

[Terryz_]

Was having a discussion with a fellow reefer on the debate of releasing a native fish that was caught from local water and releasing them back after keeping for sometime..

Was thinking it might be fine as it is native fish and caught from local water but he was against it as it would spread pathogen and upset the local ecosystem.. Because isnt animal rehab center doing this with other injured animals and marine mammals?

Just wanna have some feedback and views on this? If possible any expert feedback on this?

 

[leveldrummer]

would you be keeping said fish along with imported species from other enviroments? that in my opinion makes all the difference

 

[Terryz_]

would you be keeping said fish along with imported species from other enviroments? that in my opinion makes all the difference

Yes, I believe they are being kept with other fishes from other countries.. And it is not me keeping the fishes...

 

[MikeyUU]

if the fish has been housed with imported fish I would not release it back for fear of introducing new disease to the area. smallpox.

 

[Derikku]

You also want to keep in might, depending on location, it may be illegal to release native fish back into wild without a permit. Even if it was kept in quarantine or local only water/species.

 

[billsreef]

Yes, I believe they are being kept with other fishes from other countries..

That right there is sufficient by itself to make any release a bad idea, and quite likely illegal in most coastal states.

 

[Terryz_]

But what are the chance of it being a pathogen carrier and they can be carrier and survive well? Just wanna clarify it so can learn more about this issue, not being doubtful here...

 

[GratefulReef]

I would think that the species will not be able to adapt to the ecosystem when reintroduced. As far as the pathogen issue Im not really sure, but I would assume there are things in our tanks that arent in the wild and vice/versa. I think the wildlife rehabs have special permits, and go through special regulations for doing so. Im taking environmental regulations in college, so next class I will ask my professor is she knows anything about it. =)

 

[billsreef]

But what are the chance of it being a pathogen carrier and they can be carrier and survive well? Just wanna clarify it so can learn more about this issue, not being doubtful here...

Any chance, even a small one, is too much of a chance. For a little perspective, genetic examination of lionfish in the tropical Atlantic shows that the huge quantities of this invasive species started out as all of 6 introduced specimens. It just doesn't take much to become a huge problem.

 

[Terryz_]

I would think that the species will not be able to adapt to the ecosystem when reintroduced. As far as the pathogen issue Im not really sure, but I would assume there are things in our tanks that arent in the wild and vice/versa. I think the wildlife rehabs have special permits, and go through special regulations for doing so. Im taking environmental regulations in college, so next class I will ask my professor is she knows anything about it. =)

Yup, I know that Wild Caught Seahorse cannot be kept with Captive Bred ones, as they might cross infect each other but havent heard of it in fishes yet or I have not experienced it as of yet...

I know the wildlife rehabs have stringent regulations and experienced vet to make sure the animals are healthy..

That is a cool "subject" that you are taking, Hope to hear some info from you..

 

[Terryz_]

Any chance, even a small one, is too much of a chance. For a little perspective, genetic examination of lionfish in the tropical Atlantic shows that the huge quantities of this invasive species started out as all of 6 introduced specimens. It just doesn't take much to become a huge problem.

I have heard about the invasive lionfish issue to a point, where they are out of control. But isnt this, the issue of releasing foreign species in a different habitat? We also have a lot of issue here in our freshwater catchment areas, where there a lot foreign species which are carnivorus and prey on our small native species to a point of being endangered. I know this will be a problem to the ecosystem..

So it is possible that pathogen could kill off the whole population even in the sea with so large space, volume and "circulation"?

 

[SSprince]

I would think that a fish that has been captive would have adaptation problems going back to the wild. (hunting, survival, etc..) Not sure about the other issues.......

 

[Derikku]

But what are the chance of it being a pathogen carrier and they can be carrier and survive well? Just wanna clarify it so can learn more about this issue, not being doubtful here...

I'm not 100% sure about pathogens, but in relation to parasites if the function in any similar way, even through a 90day quarantine it may not actually mean the fish would be "clean" of all parasites, but it just would show no significant signs of it. It's quite possible to have strong fish that can tolerate low levels of Ich or similar parasite for example. They might seem perfectly healthy because they fight off most of the Ich or heal well, but there is still enough of them to reproduce in a tank. So when you add the new fish into the tank they might be infected and survive the same way because they eat well and are healthy. But, the day that a not so strong fish is placed in the mix, it'll get sick and the Ich will start to reproduce.

So what might appear as a healthy fish being released, might just be one tolerant or immune to whatever it might be carrying, but in reality you might be releasing something potentially contagious. Any like it was started earlier, any risk is too high a risk.

 

[Derikku]

I have heard about the invasive lionfish issue to a point, where they are out of control. But isnt this, the issue of releasing foreign species in a different habitat? We also have a lot of issue here in our freshwater catchment areas, where there a lot foreign species which are carnivorus and prey on our small native species to a point of being endangered. I know this will be a problem to the ecosystem..

So it is possible that pathogen could kill off the whole population even in the sea with so large space, volume and "circulation"?

Technically a pathogen wouldn't have to kill off a whole population to cause its demise. It would only need to do enough damage to collapse the food web around it. Much like foreign species of fish causing native ones to go endangered. Maybe they only eat the young of a certain species of fish, or only the young in a very specific area. That impact would lead to a chain reaction that five years from now could mean that there are fewer adults, thus less total young, but still a large population of non native predators, leading the even less surviving young the next generation.

A pathogen could do the same with only killing a portion of a population. If you have half as many fish but the same number of predator fish, then it's possible the populations of the victim fish would dwindle even faster before the predator fish started to lose numbers, which would leave an opening for a different fish that the predator fish would normally eat to increase in number. If those other fish competed for the same food as the infected fish, then their battle becomes even more uphill. That is to say if only that one species was effected by the pathogen. If more species got infected than the situation just compounds itself.

Sorry if I am making overly detailed posts, I just had some free time and thought it might be a helpful to try and see the bigger picture of why native release is so risky.

 

[billsreef]

I have heard about the invasive lionfish issue to a point, where they are out of control. But isnt this, the issue of releasing foreign species in a different habitat? We also have a lot of issue here in our freshwater catchment areas, where there a lot foreign species which are carnivorus and prey on our small native species to a point of being endangered. I know this will be a problem to the ecosystem..

So it is possible that pathogen could kill off the whole population even in the sea with so large space, volume and "circulation"?

Pathogens are just another species. Just not large and charismatic like a lionfish. Other than than, there is no difference.

In regards to pathogens, many states do not allow fish caught in one part of the state to be transported and released or used as bait in another part of the state or different body of water than where that fish was caught, for just that reason of the possibility of spread of disease.

 

[Terryz_]

Thanks for all the answers and replies on this issue.. The informations are detail and informative compared to what I received from the fellow reefers.. who state the pathogen will infect every single fish and the fish will die and wipe out a whole population of fishes in that area.. sounds like pathogen will kill everything in its way. Now I understand more about the risk that releasing a native fish, will do not directly but indirectly in a long term effect by disrupting the food chain thus causing a unbalanced..

 

[KafudaFish]

Even if you are trying to repopulate a species in a freshwater system your source fish are going to be from the same river basin as to where you plan to repopulate regardless if the project is a captive breeding one or a simple collection and release effort.

Why? Genetics.

For example, even within a river system you can have 3 populations with "identically" looking fish, though there maybe some variation in color or lateral line scale counts but if you look at the genetic composition those 3 populations are independent of one another and the question is then raised:

How many species are present?

Here is an example of something simple having a major impact:

http://www.invasivespeciesinfo.gov/aquatics/didymo.shtml

In some areas felt boot waders are no longer allowed because it has been proposed that if one picks it up in one affected stream and fishes in another unaffected one it can spread.

 

[lil urchin]

leave it to the professionals

leave it to the professionals

i'd sell the fish in question to another aquarist. this keeps one less fish from being collected from the wild.
leave restocking to the professionals.

---------------------------------------------------------------
good intentions and paving materials...
:furious:

 

[billsreef]

Even if you are trying to repopulate a species in a freshwater system your source fish are going to be from the same river basin as to where you plan to repopulate regardless if the project is a captive breeding one or a simple collection and release effort.

Why? Genetics.

For example, even within a river system you can have 3 populations with "identically" looking fish, though there maybe some variation in color or lateral line scale counts but if you look at the genetic composition those 3 populations are independent of one another and the question is then raised:

How many species are present?

Here is an example of something simple having a major impact:

http://www.invasivespeciesinfo.gov/aquatics/didymo.shtml

In some areas felt boot waders are no longer allowed because it has been proposed that if one picks it up in one affected stream and fishes in another unaffected one it can spread.

Indeed. I was so focused on the pathogen issue, that I forgot about this point.

 

[KafudaFish]

:beer:

I'll buy the first round.