title: Seasonal changes in zooplanktonic alkaline phosphatase activity in Toulon Bay (France): the role of Cypris larvae.
abstract: We studied zooplankton contribution to the total particulate phosphatase activity, the kinetics of this activity, the relation to the different taxonomic groups and the role of particle-bound bacteria. The activity of total particulate material collected from a liter of seawater was more elevated in May, June and August than during the rest of the year. These high activities resulted from a high contribution of the >90 microm fraction which account then for more than 60% of the total particulate activity. Two Michaelian processes with high and low V(max) were disclosed on this fraction. The high V(max) component was responsible for the high summer activities. During these periods, high densities of cirriped Cypris were found which were statistically correlated with this high V(max) component as with its specific activity. Moreover, the contribution of attached bacteria to these high activities was low. In return, this contribution was predominant during the periods of low activity. A simple method was developed to characterise this bacterial activity.
authors.affiliation: Département de Génie Biologique, Laboratoire des Echanges Particulaires aux Interfaces UPRES EA 1723, Université de Toulon et Var, BP 132, 83957 La Garde cedex, France.
authors.forename: Natacha
authors.initials: N
authors.lastname: Jean
authors.forename: Gérard
authors.initials: G
authors.lastname: Bogé
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Jamet
authors.forename: Simone
authors.initials: S
authors.lastname: Richard
authors.forename: Dominique
authors.initials: D
authors.lastname: Jamet
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis / Q000494:pharmacology*; D000818:Animals; D001419:Bacteria; D003445:Crustacea; D004784:Environmental Monitoring; D007700:Kinetics; D007814:Larva; D012621:Seasons; D015048:Zooplankton
chemical_list: D000469:Alkaline Phosphatase