Invasive Species or Native Species for human sustenance in degraded water bodies

I would like to start a diverse discussion on a potential problem in the future of degraded water systems. I read this interesting paper on small scale fisheries in east Asia, http://pacificscienc...ew-67-3-1a.pdf. One quote really stood out to me,
"At the global scale, small-scale fisheries account for most of the livelihoods associated with fisheries (Berkes et al. 2001). Estimates from the UN Food and Agriculture Organization, for example, suggest these fisheries employ more than 90 percent of the world’s capture fishers (FAO 2012a)."
This causes me to pose this next question that I would love to hear everyone's opinion on.

What is your opinion of replacing native fish species with invasive fish species in a degraded system that otherwise could no longer support the native species, where the primary goal is to support local small scale fisheries and sustenance fisheries? Hypothetically we will say that the water system would take a minimum of a century of extreme recovery efforts to support native fish species again and that the invasives would thrive enough in this degraded system to support the fisheries and sustenance demand.

What is the prevalence of "local small scale fisheries and sustenance fisheries" on the North American continent that are threatened due to degraded aquatic systems ? (Not including over-fishing. Also not including degradation due to chemical/industrial pollution that will move up the foodchain, even if you swap out native species for invasives.) It's not obvious to amateur me that this is problem really needing to be solved, here.

But if small scale sustenance fisheries are a need, it's also not clear that introducing invasives would be a better idea than high-density, tank-based aquaculturing of say tilapia. It's not easy keeping species picked due to their invasive skills and ability to survive in degraded waters from moving into all the connected waters, even the ones that are not degraded.

So right off the bat I'm rather sceptical of the concept, but that's not to say that someone couldn't come up with a viable plan for some specific location & need.

You have some more specific ideas ?

You are quite right that this is not a problem In North America. I was thinking of more in context of eastern asia. Citing this article, http://www.greenfact...consumption.htm, Of the 107 million tonnes available for human consumption in 2005,consumption was lowest in Africa (7.6 million tonnes, with 8.3 kg per capita), while Asia accounted for two-thirds of total consumption, of which 36.9 million tonnes were consumed outside China (13.9 kg per capita), with 33.6 million tonnes in China alone (26.1 kg per capita)." China has a huge demand for fish and many rural parts of the country still live by subsistence and sustenance fisheries. There degraded systems are extremely overfished. What would be the best possible way to convert the degraded system and exhausted fishery to a usable fishery for subsistence families?

I know zero subsistence farmers and fishers, and I think most of the other NANFA members have similar experience. Perhaps you could get in touch with the Alaska department of fish and game? Alaska has the closest subsistence fishing population that I can think of.
http://www.adfg.alas...ubsistence.main

Personally I'm against stocking invasive species in general, and I'm against subsistence living as an economic model because it leads to a just terrible quality of life. That's why we don't do it here: it's not good times. You'll find a lot of plans online published by government agencies and NGOs for converting people who are currently subsistence living to some other lifestyle.

Subsistence farming does not provide a quality life when in close proximity to industrialized populations. There examples or least there used to be where quality of life was pretty good. Introductions should be avoided if they risk persistant populations or the ability to spread out side area of use. I do not know why this font problem is persisting.

Edited by centrarchid, 10 October 2013 - 11:55 AM.

I'm not certain subsistence living is "terrible". I think most people are just too lazy to pull it off. I think if done properly it would be a wonderful way to live.

This being said, my issue with the plan would be the use of the degraded waters for any fishery. If the water is degraded to the point where native species can no longer exist then it is likely also hazardous for whatever fish may be there, exotic or native, to be consumed by humans. You would in essence be trading one issue, lack of adequate proteins, for another.

A friend of mine working in China performed a fish survey on a reach of river that was extremely overfished and for two weeks a sampling gill net sat out and they caught nothing. When they asked all the local subsistence fishermen why they used 1/2" mesh, a fisherman replied (in chinese of course) "to catch the big fish". I totally agree that using a degraded system for a fishery is a terrible way to live but subsistence fisherman (especially poor families) already fish and continue to fish degraded systems because of financial, housing, equipment, cultural, etc. issues. From what my friend said, the government was supposed to provide a stipend for the families during a newly enacted closed fishing season (to help increase fish size). But the stipends never came and the families kept fishing and some were fined heavily for "poaching". Of course restoration efforts would be ideal but we all know that they are extremely expensive and long term (which is an understatement for China). A short term solution would be ideal for the subsistence fisherman so I hypothesized a tolerant r-selected predator could be utilized to help the subsistence farmers. But the unlimited ethical and economic issues that go with it, is why this discussion was formed. By the way, great comments from everyone!

I see your point and understand the logic. I don't, however, believe the introduction of exotic predators will prove useful. At some point the forage fish will also be depleted and that will lead to a dead system. Also, I would hope that one day, these systems may be considered for restoration and once the cat is out of the bag in the form of an exotic, it may impossible to achieve this. What about utilizing aquaculture processes in landlocked ponds?

I'm not certain subsistence living is "terrible". I think most people are just too lazy to pull it off. I think if done properly it would be a wonderful way to live.

Yup, they're super lazy. That's why they starve and their malnourished babies die. If only they were more motivated.

Nothing about this sounds like a fun way to live. http://www.ruralpove...me/tags/nigeria

The long and the short of it is: Subsistence farming and fishing aren't good for people, and they aren't good for their environment. People don't eat every last fish in a place because they delight in extinct species and empty rivers. They do it because if they don't, they'll starve. That's why the best solution is not to call them lazy, but instead to give people the ability to move away from subsistence practices. How to do that is up for debate. Adding an invasive fish species has already been tried, in Lake Victoria: http://www.cichlid-f...ctoria_sick.php

You got me Erica. I'm the insensitive type.

I should have qualified my response. I was solely commenting on the choice of Americans to eat and drink whatever chemical and preservative filled food stuff is cheapest and most easily obtained. I applaud folks like Matt who very nearly do live off of what they grow, both produce and protein. It is by no means comparable to someone that is living a truly subsistent life.

I will say, though, that I am not sure ushering away people that have lived for generations off of the land and waters is the best practice. This is what they know. What is better? Moving them into slums in the larger cities and having them work 16 hours a day in unsafe and unsanitary conditions in order to earn a pittance? And still they starve and their malnourished babies die? But maybe it would be more fun.

You got me Erica. I'm the insensitive type.

I should have qualified my response. I was solely commenting on the choice of Americans to eat and drink whatever chemical and preservative filled food stuff is cheapest and most easily obtained. I applaud folks like Matt who very nearly do live off of what they grow, both produce and protein. It is by no means comparable to someone that is living a truly subsistent life.

I will say, though, that I am not sure ushering away people that have lived for generations off of the land and waters is the best practice. This is what they know. What is better? Moving them into slums in the larger cities and having them work 16 hours a day in unsafe and unsanitary conditions in order to earn a pittance? And still they starve and their malnourished babies die? But maybe it would be more fun.

I know you're not insensitive, and I wasn't trying to offend you. Honestly this all is why I'm not an economist or in charge of people in any way. Economics hurts my brain. I'm just a death researcher, and that's what I'll stick with. Pathology is the life for me. Gotta love an obvious villain.

We're not so different then. I run a forensic tox lab....

I just finished reading "Julie of the Wolves" and its sequel "Julie" with my son (by Jean C. George). An enlightening and thought-provoking exploration of what us "developed" (lazy?) people call "subsistence" living. I understood what you meant right away Dustin.

Many countries especially in Asia and Africa have already spread easy-to-grow and/or pollution tolerant fish all over the place to feed the poor in rural areas (carp, snakehead, giant gourami, tilapia, nile perch, bluegill, channel catfish, etc). They're gonna keep doing it whether or not we have a philosophical discussion about the ecological ethics of it on NANFA.

I believe aquaculture systems were being started but they were run by the government poorly.

Is there no native species in the area that can be cultured in the unpleasant waters? For example, bullheads and green sunfish here in North America can grow to extreme densities in nasty waters, and need not be introduced. Sure, they stunt if they reach high enough concentrations, but in a subsistence situation I imagine they would be harvested at a rate that would work against this factor. The bioaccumulation also concerns me as it does others but even if we ignore that, there are other questions to be answered. It reminds me of a debate I once heard over bananas and paw-paws. I think many factors need to be examined before one can make a decision that could potentially impact future ecosystems and livelihoods of those in the area.

Is there no native species in the area that can be cultured in the unpleasant waters? For example, bullheads and green sunfish here in North America can grow to extreme densities in nasty waters, and need not be introduced. Sure, they stunt if they reach high enough concentrations, but in a subsistence situation I imagine they would be harvested at a rate that would work against this factor. The bioaccumulation also concerns me as it does others but even if we ignore that, there are other questions to be answered. It reminds me of a debate I once heard over bananas and paw-paws. I think many factors need to be examined before one can make a decision that could potentially impact future ecosystems and livelihoods of those in the area.

I agree with this. If I had my way, research would focus more on developing such species best suited for degraded / early successional habitats that can be consumed in their entirety and controlled by simply allowing habits to recover to natural state where production occurs.

And I would be your half example of a subsistence farmer. I am yet to starve, and I believe my family eats healthier than most. We eat fish from our pond, beef from our cattle herd, goats and milk from our dairy herd, chicken, eggs, and turkey, then there is the garden. Once all big bills are gone, house paid off(3-5 years) I hope to be a full subsistence farmer.Not thinking it is that bad of a way to live.

What size is your homestead, Matt?

I own only 2.5 acres, but lease about 70.

Could you meet your nutritional needs off just 2.5 acres? I assume the leased ground is used primarily for animal protein, especially for grazers.

I keep contemplating the setup of a small sustainable fishery based on a multivoltine low trophic level species where the entire animal can be consumed. Pounds per harvest would not be as high but harvest frequency would be higher and inputs such as feed would be much lower to near zero.

Edited by centrarchid, 14 October 2013 - 09:09 AM.