NCMA’s cull policy for algal strains

NCMA’s cull policy for algal strains

The Provasoli-Guillard National Center for Marine Algae and Microbiota (NCMA) has developed a cull policy to help reduce strain redundancy in their current collection, develop better cost efficiency, and allow room for more diverse and scientifically interesting strains to be accessed. The broad actions of the cull process are to remove from the collection those algal strains that have been deposited but for one reason or another have not garnered much or any scientific interest, and to remove those strains that are of such poor quality that they are not beneficial to the algal community.

The NCMA (formerly CCMP) has not considered an organized culling of the phytoplankton collection in over 25 years. With this decision comes an opportunity for the public to review the cull list and “Adopt-a-Strain” for anyone who feels strongly about saving it. However, unhealthy strains are not available to adopt.

NCMA will not cull strains that have had their genome sequenced, type strains, authentic strains, or strains with a large publication record. Strains will only be culled from the live collection. No strains in NCMA’s current cryopreserved collection will be culled (50% of their strains are known to survive cryopreservation).

The following selection criteria will be considered to choose cull strains; at least 3 of these criteria must apply before a strain is culled:

  1. Multiple strains of same species, especially those that were collected at the same time from the same place and are rarely ordered (within the last 5 years).
  2. Multiple isolates of the same strain from same location and are rarely ordered (within the last 5 years).
  3. Strains growing so poorly that NCMA cannot distribute them reliably without excessive time and effort.
  4. Strains contaminated with fungi that NCMA has been unable to re-isolate.
  5. Rarely ordered strains (never been ordered, or no requests for that strain in the last 5 years).
  6. No publication record for the strain.
  7. The strain is held by another collection.
  8. Marine strains will take priority (for saving) over freshwater strains.
  9. No cryopreserved strains will be culled.

Using these criteria and the decision-making flow chart, NCMA estimates they can cull at least 20% (500 – 600 strains) of the algal collection without loss of any taxonomic diversity, geographical/ecological range, or scientific relevance – freeing up capacity by the curators to actively access new and potentially interesting strains.

NCMA will inform the original depositors of their intension to cull a strain. A cull list will be posted on NCMA’s website giving at least 30 days notice prior to initiation of the cull process for strains on that list. They will reconsider a specific strain(s) cull if either the depositor, or the wider academic and/or business communities present convincing reasons to the head curator.

These strains are available to purchase for a reduced rate of $50 (plus S&H) before November 22, 2015 by emailing