How many fish will survive after stocking fingerlings
A popular question, "If I put fingerlings in my dam, how many will survive ?
Link to related questions -
There is no simple answer to this question.
There are too many variables.
Essentially you need to assess this for yourself.
The way to do this is to ask yourself some questions, and this is where is gets foggy.
Most people don’t know what questions to ask, so I will cover the most common questions below.
Other factors may still impact survival of stocked fish, but I will cover the most common impacts to fish stocking on this page.
Can I legally stock my dam?
Be sure to check regulations before stocking any fingerlings in dams anywhere in Australia
Are cane toad tadpoles a threat to my fingerlings - find out here
What is the water quality?
The next thing to do is look at any special requirements for the species you intend to stock.
Some of the information you will find here
Best temperature range 23C and 28C.(WATER TEMPERATURE, NOT AIR TEMPERATURE.)
They will tolerate as low as 2C, and as high as 37C.
They will grow well at temperatures above 15c.
When you take the water temperature of your dam, it should be taken at least 1.5 meters from the surface, and not in direct sunlight. (The deeper the better.)
Your thermometer should be attached to a long string to do this.
Best pH range between 6.5 and 9.
Tolerate pH levels between 5 and 10
Salt Salinity levels of 5 grams per litre are very safe.
These are questions you need to answer for yourself.
When you take the water temperature of your dam, it should be taken at least 1.5 meters from the surface, and not in direct sunlight. (The deeper the better.)
If there are already small fish in your dam, then you can probably ignore most of these questions.
Silver perch are very hardy, so if there are other fish surviving happily in you dam, then you can reasonably assume that silver perch will be just as happy.
PLUS, as bonus silver perch can be fed pellets which will greatly speed up their growth.
Feeding should be done in an appropriate location to avoid predation. More here
Predation?
Has your dam been stocked in the past with predatory species like barramundi, golden perch, or Australian bass?
If the answer is yes, you will experience losses of new fingerlings due to those previous stockings of predatory fish feeding on the small fingerlings.
To reduce this as much as possible release your new fingerlings in an area where they can hide quickly after being released.
However, consider this, predatory species will quite likely be lurking amongst the shelter you choose.
In the picture above you can see a considerable difference between those two dams.
One has a large amount of weed which will provide hiding places for fingerlings after they are released.
The larger dam at the top, has less hiding places for fingerlings.
(The angle of the picture does not show the size difference.
The dam at the top is about five times bigger than the dam at the bottom of the picture.)
Also remember, you should not release new fingerlings in shallow water which may be quite hot.
Silver perch are not considered to be a predatory species, so if you have only stocked silver perch, predation is not really an issue.
Large silver perchusually won't bother chasing a fast healthy fingerling unless it is sick, or stressed from the trip to your dam.
One of the biggest predation issues are cormorants, sometimes called shags.
There are several species. Pictured here are the most common.
They are often seen drying themselves on the banks of dams or in trees near the dam.
These water birds essentially "fly" underwater and are expert fish hunters.
The one pictured below is one of the larger types capable of catching and eating quite large fish.
The most common is the little black cormorant, pictured below.
The best defence against these predators is a lot of underwater structure that the fish can use to escape from these efficient fish eaters.
This structure should be placed in the right place, not in shallow or even very deep water.
Select an area where the water quality is ideal for the species.
If you choose the correct location and the fish accept the structure, they will make it their home.
For those with a very large dam/lake to stock I can visit your site and offer advice based on decades of experience.
See this page.
Escape
Virtually all dams overflow at some time.
The principle job of a dam is to catch overland water flows and store it for future use.
Fish are designed to make sure the species will survive.
One way they do this is to move about when water is flowing.
Even your big adult fish will move when water is flowing.
Usually perch will go upstream but some will move downstream.
This way they can populate areas that may have been in drought conditions, as is often the case in Australia.
This is an easy fix.
If you dam does not overflow a lot you might get away with a gravel screen across the overflow of the dam.
See this example that I used for decades on a small dam that had almost no catchment and only overflowed very slowly.
You can see the fish trying to get out of the dam but the fence is working perfectly.
This is my favourite video.
Food
Does you dam have enough natural resources for the fish species you will stock?
If not you may need to feed them, or stock less fish.
If you are stocking silver perch this is easily solved because silver perch can be fed aquaculture pellets.
My fish are already converted to aquaculture feed.
Silver perch definitely are NOT vegetarian, they are in fact omnivores.
However they are generally not considered to be predatory.
They will eat almost anything, animal or vegetable!
They will eat worms and most other aquatic life including weeds.
Should you add fingerlings in the future the older fish are very unlikely to eat the new fingerlings.
They readily take artificial food, such as aquaculture pellets, chook pellets or bread.
Bread or chook foods are not the best of diets for fish but will do in small quantities.
Aquaculture pellets are a properly balanced diet and fish will thrive on these commercially available foods.
You can also use the website search tool at the bottom of each page
OTHER SPECIES
Click the picture for video - Low altitude passes over Barcoo River - with surprise ending
Click the picture below to see some of the birds and other wild life I filmed while collecting jade perch and golden perch breeders
