den Hartog, C. 1989 Letter to D. Seaward.
The letter refers to a specimen of Z. angustifolia,
which D. Seaward sent to den Hartog for analysis
of disease. den Hartog mentions that Z. angustifolia
is thought to be an ecological variant of Zostera
marina. The specimen from the Fleet was diseased,
with Labyrinthula lesions. This disease had
been recorded from specimens from the Fleet on other
occasions and in 1934 and the 1970=s.
Wasting disease (caused by Labyrinthula)
has been found in eelgrass not subject to an epidemic
of the disease, and it is thought that an epidemic
could be caused by stress to the plants, such as
too little light or too high temperatures.