Drought

[AbbeysDad]

And Then There Was Drought

 

[The Lumpfish Guy]

It is an interesting article.
The only issue I have with it is that breakdown of proteins creates nitrogenous waste, the breakdown of starches does not. So the logic of that point is the other way around, high fishmeal diets (High protein) will cause more nitrogenous waste.

While there would be more carbohydrates/ starches in your aquarium they contain no nitrogen thus no Ammonia (Starch is (C6H10O5)n +(H2O)). Their breakdown results in H2O and C02.
Not sure what the effect of increase sugars would be? might help the plants?

 

[AbbeysDad]

It is an interesting article.
The only issue I have with it is that breakdown of proteins creates nitrogenous waste, the breakdown of starches does not. So the logic of that point is the other way around, high fishmeal diets (High protein) will cause more nitrogenous waste.

While there would be more carbohydrates/ starches in your aquarium they contain no nitrogen thus no Ammonia (Starch is (C6H10O5)n +(H2O)). Their breakdown results in H2O and C02.
Not sure what the effect of increase sugars would be? might help the plants?

Many years ago, I switched to higher quality commercial foods and noticed a significant reduction in fish waste. The fish no longer swam around with long trailing excrement. In the old days, fishmeal used in fish foods was a very low quality, so an excess of grains and grain starch was used as binder/filler. In some fish food products, grain was the first ingredient listed! This grain/grain starch passes through as excess waste, and I believe that this excess waste does pollute the water. Higher quality fishmeal made from whole fish, requires less grain/grain starch, resulting in far less fish waste. Fish food manufacturers agree (see Commercial Fish Foods) and strive for reductions in grain binders.

 

[The Lumpfish Guy]

Many years ago, I switched to higher quality commercial foods and noticed a significant reduction in fish waste. The fish no longer swam around with long trailing excrement. In the old days, fishmeal used in fish foods was a very low quality, so an excess of grains and grain starch was used as binder/filler. In some fish food products, grain was the first ingredient listed! This grain/grain starch passes through as excess waste, and I believe that this excess waste does pollute the water. Higher quality fishmeal made from whole fish, requires less grain/grain starch, resulting in far less fish waste. Fish food manufacturers agree (see Commercial Fish Foods) and strive for reductions in grain binders.

1) See most fish have some ability to digest plant bases proteins within grains, Tilapia are a good example of this which can utilise may different plant based dietary sources of food up to 100% inclusion in some cases (El-Sayed. 1999), even carnivorous Atlantic salmon can utilise pea meal inclusion up to 33% of the diet with no effect on growth, feed conversion, or digestibility (Carter and Hauler. 2000).

As for the starches, there is evidence that some fish are able to utilise some carbohydrates within the diet (Stone. 2003), however you are right most are not able to utilise great deals of carbohydrates. this will result in waste being produced. Even so Carbohydrates have been shown to be able to be utilised as "free energy" in many fish species and digestibility ( amount which can be used in a diet) can range from 70% (goldfish ) to 50% moonlight Gourami (Sales. 2007).

2) So excess carbs (Starch) will result in excess waste, however as I said above carbohydrates do not produce nitrogenous waste (Ammonia), upon metabolism, I will assume by other things in the tank, they produce H2O and CO2.
Whether increase sugars within the tank will have effects on anything, I have no idea, I imagine they will somewhere, but I cannot find any resources describing the effect in any recirculating system.

3) There is this huge cult following of high fishmeal diets being objectively good for ornamental fish, however this is a myth that the aquaculture industry has dispelled for some time and have moved on to inclusions from farm waste (Bone meal, blood meal, alage meal ect, (Kaushik. 1990), plant based proteins (El-Sayed. 1999,Carter and Hauler. 2000) and other sources of feeds, this has seen the use of fishmeal decline across the board with little effects on digestibility (Hardy. 2006).
The use of fishmeal is highly unsustainable (Hall. 2011) and there is great pressure for lower inclusions in fish diets. While the Ornamental market is comparably small, when compared to aquaculture, it is still an issue of sustainability.

The issue comes with ornamentals Is there is such a large range of species, often kept together that it is almost impossible to document their requirements to the degree that aquaculture has. However even in these less studied species, effective replacement of fish meal (with little digestibility effects) have been shown in tinfoil barb (Elangovan and Shim. 1997) up to 33% inclusion of soybean meal.
And this also depends on the life stage, inclusion of overall protein in goldfish is 53% of larvae, dropping to 29% for juveniles (Lochman and Phillips. 1994, Fiogbé and Kestemont. 1995).

At the end of the day there is little evidence in most species that inclusion of "lower quality" protein sources, carbohydrate inclusion or grains are any worse than "high quality" fishmeal diets. when formulated for individual species .

REF:
El-Sayed, A. F. M. (1999). Alternative dietary protein sources for farmed tilapia, Oreochromis spp. Aquaculture, 179(1-4), 149-168.
Carter, C. G., & Hauler, R. C. (2000). Fish meal replacement by plant meals in extruded feeds for Atlantic salmon, Salmo salar L. Aquaculture, 185(3-4), 299-311.
Stone, D. A. (2003). Dietary carbohydrate utilization by fish. Reviews in Fisheries Science, 11(4), 337-369.
Sales, J. (2003). Nutrient requirements of ornamental fish. Aquatic Living Resources, 16(6), 533-540.
Kaushik, S. J. (1990). Use of alternative protein sources for the intensive rearing of carnivorous fish. Mediterranean aquaculture, 125-138.
Hardy, R. W. (2006). Worldwide fish meal production outlook and the use of alternative protein meals for aquaculture. Avances en Nutrición Acuicola.
Hall, G. M. (2011). Fishmeal production and sustainability. Fish processing–Sustainability and new opportunity. Blackwell Publishing Ltd., UK, 207-235.
Elangovan, A., Shim, K.F., 1997. Growth response of juvenile Barbodes altus fed isocaloric diets with variable protein levels. Aquaculture 158, 321–329.
Lochmann, R.T., Phillips, H., 1994. Dietary protein requirement of juvenile golden shiners (Notemigonus crysoleucas) and goldfish (Carassius auratus) in aquaria. Aquaculture 128, 277–285.
Fiogbé, E.D., Kestemont, P., 1995. An assessment of the protein and amino acid requirement in goldfish (Carassius auratus) larvae. J. Appl. Ichthyol. 11, 282–289

 

[Retired Viking]

Interesting article, I have the opposite to deal with too much water. Lake Michigan water levels are so high most beaches are under water. The river by me is over it's banks and flooding low lying areas and we have flood warnings every time it rains.

 

[itiwhetu]

1) See most fish have some ability to digest plant bases proteins within grains, Tilapia are a good example of this which can utilise may different plant based dietary sources of food up to 100% inclusion in some cases (El-Sayed. 1999), even carnivorous Atlantic salmon can utilise pea meal inclusion up to 33% of the diet with no effect on growth, feed conversion, or digestibility (Carter and Hauler. 2000).

As for the starches, there is evidence that some fish are able to utilise some carbohydrates within the diet (Stone. 2003), however you are right most are not able to utilise great deals of carbohydrates. this will result in waste being produced. Even so Carbohydrates have been shown to be able to be utilised as "free energy" in many fish species and digestibility ( amount which can be used in a diet) can range from 70% (goldfish ) to 50% moonlight Gourami (Sales. 2007).

2) So excess carbs (Starch) will result in excess waste, however as I said above carbohydrates do not produce nitrogenous waste (Ammonia), upon metabolism, I will assume by other things in the tank, they produce H2O and CO2.
Whether increase sugars within the tank will have effects on anything, I have no idea, I imagine they will somewhere, but I cannot find any resources describing the effect in any recirculating system.

3) There is this huge cult following of high fishmeal diets being objectively good for ornamental fish, however this is a myth that the aquaculture industry has dispelled for some time and have moved on to inclusions from farm waste (Bone meal, blood meal, alage meal ect, (Kaushik. 1990), plant based proteins (El-Sayed. 1999,Carter and Hauler. 2000) and other sources of feeds, this has seen the use of fishmeal decline across the board with little effects on digestibility (Hardy. 2006).
The use of fishmeal is highly unsustainable (Hall. 2011) and there is great pressure for lower inclusions in fish diets. While the Ornamental market is comparably small, when compared to aquaculture, it is still an issue of sustainability.

The issue comes with ornamentals Is there is such a large range of species, often kept together that it is almost impossible to document their requirements to the degree that aquaculture has. However even in these less studied species, effective replacement of fish meal (with little digestibility effects) have been shown in tinfoil barb (Elangovan and Shim. 1997) up to 33% inclusion of soybean meal.
And this also depends on the life stage, inclusion of overall protein in goldfish is 53% of larvae, dropping to 29% for juveniles (Lochman and Phillips. 1994, Fiogbé and Kestemont. 1995).

At the end of the day there is little evidence in most species that inclusion of "lower quality" protein sources, carbohydrate inclusion or grains are any worse than "high quality" fishmeal diets. when formulated for individual species .

REF:
El-Sayed, A. F. M. (1999). Alternative dietary protein sources for farmed tilapia, Oreochromis spp. Aquaculture, 179(1-4), 149-168.
Carter, C. G., & Hauler, R. C. (2000). Fish meal replacement by plant meals in extruded feeds for Atlantic salmon, Salmo salar L. Aquaculture, 185(3-4), 299-311.
Stone, D. A. (2003). Dietary carbohydrate utilization by fish. Reviews in Fisheries Science, 11(4), 337-369.
Sales, J. (2003). Nutrient requirements of ornamental fish. Aquatic Living Resources, 16(6), 533-540.
Kaushik, S. J. (1990). Use of alternative protein sources for the intensive rearing of carnivorous fish. Mediterranean aquaculture, 125-138.
Hardy, R. W. (2006). Worldwide fish meal production outlook and the use of alternative protein meals for aquaculture. Avances en Nutrición Acuicola.
Hall, G. M. (2011). Fishmeal production and sustainability. Fish processing–Sustainability and new opportunity. Blackwell Publishing Ltd., UK, 207-235.
Elangovan, A., Shim, K.F., 1997. Growth response of juvenile Barbodes altus fed isocaloric diets with variable protein levels. Aquaculture 158, 321–329.
Lochmann, R.T., Phillips, H., 1994. Dietary protein requirement of juvenile golden shiners (Notemigonus crysoleucas) and goldfish (Carassius auratus) in aquaria. Aquaculture 128, 277–285.
Fiogbé, E.D., Kestemont, P., 1995. An assessment of the protein and amino acid requirement in goldfish (Carassius auratus) larvae. J. Appl. Ichthyol. 11, 282–289

Great stuff, very interesting. Use to raise goldfish partly on soya flour, it was just what you did!!. Mainly because of its high protein content and fine particle size.