Rapid Risk Assessment: What is the risk from microcystins in the edible flesh of fish caught from Lough Neagh?
Statement of Purpose - Microcystins in Fish
Northern Ireland specific
The aim of the risk assessment is to establish whether there is a risk to health from the consumption of fish caught from Lough Neagh, Northern Ireland, which has been affected by a cyanobacteria bloom.
Following testing of samples of water from the Lough and of eels, roach, perch, pollan and bream, a number of cyanobacterial toxins were not detected in either the water or fish (nodularins, anatoxin, cylindrospermopsin and saxitoxin). However, microcystins were detected in water samples and in various parts of viscera in fish, though not in the edible flesh. This risk assessment has been produced to consider the risks from eating the edible flesh of fish.
It has been assumed that:
- Cyanobacterial toxins which were tested for but not detected in any sample of fish, nor in water samples from the Lough which were contaminated by cyanobacteria, were not present at any levels in fish flesh
- Microcystins, which were measured in water samples from the Lough, and in fish viscera samples but were not detected in edible fish flesh, may be present in fish flesh at levels below the limit of detection of the analytical method
- The concentrations of microcystins present in samples of fish taken in Autumn 2023 are reflective of long-term levels in fish flesh and therefore long-term dietary exposure
This risk assessment also includes a consideration of the potential risks if evisceration of fish is inadequate or incomplete.