Total suspended particulate matter concentration and grain size spectra, total and living particulate carbon, and dissolved nitrogen and carbon were measured at stations along the length of Petpeswick Inlet and over several tidal cycles. Distinct particle populations were associated with the water at the head and at the mouth of the inlet. Mixing of water masses and temporal periodicities cause variance in particle concentration and spectral shape which correspond to seasonal, tidal, and seiche variations. To explain the last, a process of transformation of organic matter between dissolved and particulate states by aggregate formation and breakup in response to turbulent changes is proposed.Key words: Petpeswick Inlet, Nova Scotia, particulates