Degradation of Laminaria saccharina by Saprobic Fungi

Abstract

Eighteen fungi were found on stipe tissue of attached and detached Laminaria saccharina. Healthy stipes and others infected by Phycomelaina laminariae were placed in separate mesh bags, suspended in the water column and examined at three-month intervals for nine months. The species included an oomycete, Petersenia sp. or Atkinsiella sp., a parasite or the ascomata of Phycomelaina laminariae, Bartalinia robillardoides, a coelomycete new to North America and not previously observed from a marine substratum; Zalerion maritimum, a common marine saprobe not previously described from an algal substratum, and Dendryphiella salina, the most commonn fungal invader of macro-algae. The carbon level of detached, suspended stipe tissue increased during the first six months in infected tissues, while the levels in healthy (uninfected) tissues decreased in the first three-month interval and increased during the second three months. Carbon levels decreased in infected and healthy detrital tissues during the last three-month period. Nitrogen increased in infected and healthy detrital tissues during the first six months but decreased during the last three-month period.