10 Things to Check Before Using Your Plankton Nets for Field Work

Plankton nets are essential tools for studying the ocean's biological diversity. They capture plankton, microscopic organisms that form the base of the ocean's food chain. These organisms are crucial for understanding the health and function of marine ecosystems.

To avoid inconvenience during your research, it is essential to ensure that your plankton nets are in good condition before leaving for field work. Here are ten things to check before using your plankton nets for field work.

1. Net Material

Check that the material used to make your plankton net is durable and resistant to seawater. A damaged net can lead to inaccurate results and may negatively affect your research.

Nylon and polyester are materials commonly used to make plankton nets. Nylon is strong, durable, and resistant to most chemicals, making it the most common option. Polyester is lightweight and easy to handle. 

2. Net Dimensions (Mouth Diameter and Length)

Choose the size of your plankton net based on your research objectives. A larger net may capture more organisms, but it may also be more challenging to handle and create drag.

The standard size for plankton nets is 0.5 to 1 meter in diameter. However, the size can vary depending on your research objectives. For example, if you are doing research based on a prior study, then you will need to acquire gear that has the same specifications as what was used in the study.

Custom nets can vary from 20cm diameter to 100cm with a ratio of 1:3 up to 1:7.

3. Net Mesh Size

The mesh size of your plankton net will determine the size of the organisms that you will capture. Check that the mesh size is appropriate for your research objectives. You should always aim for a mesh size slightly smaller than what you are trying to catch.

The mesh size can vary from 1 micron to 5000 microns. The smaller the mesh size, the smaller the organisms that will be captured. However, a smaller mesh size can also lead to excessive drag and reduced flow rate. Choose the mesh size based on the size of the organisms you want to capture and the required flow rate for your research.

4. Net Rigging

Check that the ropes and knots of your plankton net are securely tied and that the net is properly attached to the frame.Make sure that all your hardware is properly installed and is free of corrosion. Check all attachment points for weakness or damage. 

The rigging of the net determines its shape and stability. Ensure that the net is taut and free of any wrinkles or folds. Securely tie the knots and ropes to prevent any damage or detachment during towing. Make sure you are using marine grade shackles and hardware.

5. Ring Material

The frame of your plankton net should be made of durable and corrosion-resistant material. Check that the frame is in good condition and that there are no cracks or damages. The frame provides support and stability during towing. Aluminum and stainless steel are the most common materials used for frames. Aluminum is lightweight and easy to handle, but it can corrode in seawater if not properly maintained and is more complicated to fix when at sea as it requires advanced soldering skill and equipment. Stainless steel is more durable and corrosion-resistant, but it is heavier and more expensive. Stainless steel should be your preferred choice. 

6. Frame Size

Choose the size of your plankton net frame based on your research objectives and the mouth of your net. A larger frame may capture more organisms, but it may also require more effort to handle.

Choose the size based on the towing capacity of your vessel, the opening of your net and your research objectives. A larger frame can allow a better flow of water, but it can also be more challenging to handle, especially in rough sea conditions.

7. Collection Bottle (Cod End)

Check that the collection bottle is clean and has no cracks or damages and that the filtering mesh is properly attached and sealed.

The collection bottle is where the captured organisms are stored for further analysis. It should be made of clear and durable material, such as ABS. Clean the bottle before and after use to prevent contamination.

8.Transport Gear Replacement Gear

There is nothing more annoying than having to stop your project mid-run because of damage to your gear. Always make sure that you have ample replacement gear to prevent any interruption in your research. You should always have one or two replacement nets and cod ends. 

Also, plankton nets are very high quality, yet they are still made of fabric. The moment they are the most prone to damage is during transport. This is why it’s always important to purchase transport bags for your nets to minimize the chances of damage during transport.

9. Towing Speed

Check that the towing speed of your plankton net is appropriate for your research objectives and within the recommended range.

The towing speed can affect the size and quantity of organisms captured, as well as the quality of the sample. The recommended towing speed for plankton nets is between 1 and 3 knots. Monitor the towing speed during towing and adjust it if necessary to maintain a consistent flow rate.

10. Safety Equipment

Ensure that you have all necessary safety equipment, such as life jackets, first-aid kits, and communication devices.

Field work can be unpredictable and hazardous, especially when working on the ocean. The necessary safety equipment helps prevent accidents and respond to emergencies. Check the safety equipment before use to ensure that it is in good condition and functioning properly.

Conclusion

In conclusion, checking your plankton nets before using them for field work is crucial for the success of your research. By ensuring the net, rigging, frame, collection bottle, and safety equipment are in good condition, you can ensure that your research is more productive, safe, and accurate. Proper maintenance and care of your plankton nets will not only improve the quality of your research but also prolong the life of your equipment. Happy sampling!