Jackson Estuarine Laboratory


Labyrinthula zosterae is clearly shown to be a primary pathogen of eelgrass Zostera marina L., not merely a secondary infection of senescent leaves or an indication of decomposition. The results of this investigation using a Diving-PAM fluorometer indicate that the regions of tissue photosynthetically compromised by Labyrinthula are substantially larger than previously thought. Labyrinthula moves through Zostera marina tissue at a rate of up to 0.8 mm h–1 during daylight periods. The photosynthetic efficiency of apparently healthy green leaf tissue can be reduced by almost 50% in areas up to 3 mm from a necrotic region infected with Labyrinthula. Once a necrotic spot expands to bisect the eelgrass leaf, the condition of all acropetal tissue is diminished; leaf tissue up to 5 cm away has severely reduced photosynthetic activity.

Publication Date


Journal Title

Marine Ecology Progress Series


Inter-Research Science Publisher

Document Type



This is an article published by Inter-Research Science Center in Marine Ecology Progress Series, in 1991, available online: https://www.int-res.com/articles/meps/226/m226p265.pdf