You may want to catch a freshwater shrimp, but you don't want to do it with your bare hands. Don't worry, there are many methods to build a trap and in this article you will find instructions for making a simple but effective one. To get started, you need two two-liter plastic bottles.
Steps
Part 1 of 4: Cutting the Bottles
Step 1. Find two two-liter soda bottles
The brand is not important, but make sure the containers are clean and intact. Rinse the bottles in the sink or with a garden hose before using them. Remove any labels that have come loose in contact with water.
If you do not rinse the containers or remove the adhesives, you risk contaminating the watercourse or pond where you want to put the traps
Step 2. Cut the first bottle in half
Use a pair of scissors or a sharp knife to make an incision around the circumference, 1 cm above the midpoint. Make sure the edge is completely even and smooth.
Step 3. Cut the second bottle
This time the incision should be a few inches higher than the one you made on the first bottle. The two containers must fit together, so check that the edges are clean.
Step 4. Assemble the bottles
Build some sort of funnel trap to allow the shrimp to enter. First, unscrew the cap of the smaller top portion and slide the smaller top portion into the open end of the larger top portion of the other bottle. In doing so, you believe that there is ample access for the crayfish that can enter from the "base" of the trap, but which will then not be able to find their way out.
Part 2 of 4: Connecting the Bottles
Step 1. Drill five holes along the base of the trap
They are used to tie the inner and outer bottle together and thus create the trap. Check that the two elements are well secured. The holes in the outer bottle should line up with those on the inner bottle. You can use a drill, awl, or other safe drilling tool for this.
- Pierce the plastic very carefully. Make sure the bottles don't slip, or the holes will not line up.
- Be cautious when using the knife or awl. It's not easy to drill a hole straight through a two-liter bottle, let alone through two! The surface of the material is slippery and the knife loses its grip easily. If possible, try to use a drill.
Step 2. Drill five more holes above the first five
Each of them should be one centimeter above the corresponding one. You will need to thread the string or string through the top and bottom openings to tie the bottles together.
Alternatively, you can use only the first set of holes. In this case, use zip ties and secure them to the outside of the bottle along the edge
Step 3. Join the holes with the zip ties
Thread one from the outside through a bottom hole. Then pass it through the upper adjacent hole. Lock the strap so that the parts of the trap stay together. Repeat this process until you have inserted the five zip ties around the circumference of the trap. There should be no gaps between the two pieces and they shouldn't move.
Step 4. Cut the zip ties
Use a pair of scissors to remove the excess. This step is not essential, but it makes the trap more tidy and sturdy. Mud, algae and other dirt could get stuck on the excess ends of the zip ties.
Part 3 of 4: Ballasting the Trap and Adding the Bait
Step 1. Place a weight on the bottom of the bottle
Freshwater shrimp have a tendency to spend a lot of time on the bottom of shallow rivers and streams. The sinker allows the trap to stay at the bottom to increase the chances of crustaceans entering it. Make a small hole in the base of the tool and hook a fishing sinker with a small strap.
You will have to try different weights before you find the right one that keeps the trap on the bottom; however, a weight between 500g and 2.5kg should be sufficient
Step 2. Attach a weight to the top of the bottle
Use ballast identical to the one you put on the base or slightly lighter. By doing so, the trap remains balanced on the bottom of the stream. If you only ballast the bottom, the opening of the bottles could get clogged with mud.
Step 3. Insert a bait
Unscrew the top cap and drop a bait into the trap chamber. Then screw the cap back on, so that the shrimp can't escape. To do this, use a fish that is part of the freshwater shrimp diet. Many Swedish fishermen use sunfish, small cyprinids or herring, while Cajun fishermen traditionally prefer dorosoma and sparidae; finally, fishermen on the west coast of North America use salmon heads and other fatty fish. If possible, use a fresh bait caught in the same waters you want to catch the shrimp in.
If you don't have any fish to use as bait, you can take some raw meat - a piece of bacon, chicken, or hot dog is fine. However, don't expect this type of bait to be as effective as fish
Part 4 of 4: Using the Trap
Step 1. Tie a thin string or strong string to the trap
You can attach it under the cap or to one of the zip ties. Consider making two more small holes in which to thread this rope, which you will need to prevent the trap from being swept away by the current. You will only use it to change the position of the trap and retrieve it.
Step 2. Install the trap
First, tie the rope to a tree, pole, or other sturdy object so the device doesn't get lost in the river. Afterwards, throw the trap into the water a meter or so from the shore, making sure it goes to the bottom. Check the rope to make sure it is sturdy and leave the trap in place overnight. Shrimp are more active in dark than in daylight.
- Ideally, crustaceans should smell the bait and climb inside the trap through the cap opening. Once inside, they are no longer able to find their way out.
- If you wait only a few hours or all night, the shrimp will survive until the moment you withdraw the trap. If you wait more than a day or two, your prey will starve. Remember that shrimp are unable to breathe.
Step 3. Check the trap
Return to the river the next day and pull the trap out of the water by pulling the rope. If it feels heavier than usual, it may be full of shrimp or it may have run aground in the mud of the bottom. Take it out of the water and check your loot!
To empty the trap, simply unscrew the outer cap and transfer the shrimp to a bucket or net
Advice
- If you leave the trap in place overnight, you are more likely to catch a large number of prey, as they forage for food when it gets dark.
- If you use a 3 liter bottle of apple juice with a large access hole, you will have a better fit between the two parts of the trap. A wider entrance allows you to catch larger shrimp.
- Try to use a bottle with a large cap to make it easier to get the fish out.
- It may be easier to attach the rope to the bottom, so all you have to do is pull it.
Warnings
- Don't expect to only catch shrimp. In the trap you will also find several small fish.
- Be careful when using the drill. It is a power tool and can be dangerous. If you don't have one available, you can use an awl.
