Hi all,
I'm wondering what the best method is for ensuring the twine used on the spools is sterile? Can I soak the whole spool in a weak bleach solution and then neutralised sterile freshwater afterwards or will the twine retain the bleach somehow?
Thanks, Beth
@beth_marshall17 @michelle_stephens could you share more about the process that GreenWave has used to pre-treat seedstring in the past?
@beth_marshall17
Hello Beth:
I grow around 30,000 m of seed line per year and we no longer sterilize the seed line. The PVC pipes we wrap the seed line around do need to be sterilized, we clean them of surface debris with hot water (60 C) and then soak them for 15 minutes in a hot water (60 C) and 10% bleach solution.
If you wanted to bleach the seed line you could, as long as the seed line was rinsed and left out for 6-12 hours the bleach should be all but gone in a 1:10 water/bleach solution (commercial bleach is about 10% sodium hypochlorite). If you are using commercial bleach from the store and not just sodium hypochlorite, do not use the "splash-less" or "easy pour" formulas as they contain detergents that are difficult to wash off and leave residues on the seed pipes and string. Heating the seed pipes can cause them to distort as the schedule 80 PVC is not recommended for temperatures above 71 C so we have not tried autoclaving the seed string and pipes.
We are careful to handle the seed line and the seed pipes only while wearing nitrile gloves to prevent contamination and adding oils from skin to the pipes as this can deter meiospore recruitment.
I hope this helps,
Lexa
Hatchery Manger, Alaska Ocean Farms, Kodiak, AK
@lexa_meyer99 Hi Lexa, thank you for your detailed reply. When you say 1:10 solution this is with 10% bleach so the solution is 1% bleach in total?
@lexa_meyer99 Hi Lexa, thank you for your detailed reply. When you say 1:10 solution this is with 10% bleach so the solution is 1% bleach in total?
@beth_marshall17 Hello, yes, the total solution would be only 1% sodium hypochlorite. If you are using commercial laundry or disinfecting bleach from the store those solutions are around 10% sodium hypochlorite definitely check the labels and they often contain things like sodium lauryl sulfate that can leave residue on things. The highest concentration I have seen for sale is 12.5% sodium hypochlorite from a cleaning chemicals company.
@beth_marshall17 What we've done with seedstring in the past is soak the wrapped spools in distilled/DI water for at least 24 hours to leach out anything that might be on the string. Before using the spools we rinse them with sterilized sea water to rid it of any lingering fresh water.