List of non-toxigenic marine microalgal species associated with animal kills or health impairment

Version: 1.1, November 2024

This list includes species not known to produce toxins that have been associated with mortality or damage to marine organisms. The list is meant to complement the IOC list of harmful species that produce toxic substances, with no overlap between the two lists. Therefore known toxigenic species are not included in this list, even in case the damage they caused was not due to their known toxins (e.g., they caused anoxia).

Non-toxigenic species causing harm other than to marine organisms' health, e.g., to recreational use of the sea, tourism, or other economic activities related to the sea (e.g. seawead cultivation) are not included and will be part of another list (in preparation).

The list only includes species responsible for traceable cases, i.e., harmful events reported in the literature (based on a non-exhaustive search) or in the IOC-ICES-PICES Harmful Event Database (HAEDAT).

The species reported to produce fish kills were the most abundant but not the only species found at the time of the event. Therefore, there is no certainty that those species were actually responsible for the animal kill. Exceptions are the repeated cases of mortalities associated with physical damage caused by spines, barbs, mucus or other specific mechanisms.


In addition to the 'Read me' and 'Quality Flag' explanation, the file includes two main sheets:

  1. A list of species not known to produce toxins but reported to have caused damage to marine organisms
  2. A list of events that support the inclusion of a species in the list in sheet 1. The list of events is not exhaustive, nor tells how frequent the events attributed to one species were. In some cases, multiple events are listed, to provide some indications on the spatial and temporal incidence.


Suggestions for correction or addition to the list can be addressed to Adriana Zingone (adriana.zingone@szn.it) and Laura Escalera (laura.escalera@ieo.csic.es). Changes and additions will be accepted if accompanied by a published paper or a HAEDAT reference code.