Characterizing estuarine plume discharge into the coastal ocean using fatty acid biomarkers and pigment analysis.
The transformation of estuaries by human activities continues to alter the biogeochemical balance of the coastal ocean. The disruption of this balance can negatively impact the provision of goods and services, including fisheries, commerce and transportation, recreation and esthetic enjoyment. Here we examine a link, between the Elkhorn Slough and the coastal ocean in Monterey Bay, California (USA) using a novel application of fatty acid and pigment analysis. Fatty acid analysis of filtered water samples showed biologically distinct water types between the Elkhorn Slough plume and the receiving waters of the coastal ocean. A remarkable feature of the biological content of the plume entering the coastal ocean was the abundance of bacteria-specific fatty acids, which correlated well with concentrations of colored dissolved organic matter (CDOM). Pigment analysis showed that plume waters contained higher concentrations of diatoms and cryptophytes, while the coastal ocean waters showed higher relative concentrations of dinoflagellates. Bacteria and cryptophytes can provide a source of labile, energy-rich organic matter that may be locally important as a source of food for pelagic and benthic communities. Surface and depth surveys of the plume show that the biogeochemical constituents of the slough waters are injected into the coastal waters and become entrained in the northward flowing, nearshore current of Monterey Bay. Transport of these materials to the northern portion of the bay can fuel a bloom incubator, which exists in this region. This study shows that fatty acid markers can reveal the biogeochemical interactions between estuaries and the coastal ocean and highlights how man-made changes have the potential to influence coastal ecological change.
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA; National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Australian Maritime College, Launceston, TAS 7250, Australia. Electronic address: amf26@cornell.edu.
Andrew M
AM
Fischer
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA. Electronic address: ryjo@mbari.org.
John P
JP
Ryan
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA; John Abbot College, 21 275 Lakeshore Road, Sainte-Anne-de-Bellevue, Québec H9X 3L9, Canada. Electronic address: chris.levesque@johnabbott.qc.ca.
Christian
C
Levesque
Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA. Electronic address: welschmeyer@mlml.calstate.edu.
Nicholas
N
Welschmeyer
D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis*; D002140:California; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D017377:Diatoms / Q000502:physiology*; D004141:Dinoflagellida / Q000502:physiology*; D063366:Estuaries; D005227:Fatty Acids / Q000032:analysis; D005618:Fresh Water / Q000737:chemistry*; D064307:Microbiota / Q000502:physiology*; D010140:Pacific Ocean; D010860:Pigments, Biological / Q000032:analysis; D013045:Species Specificity; D014872:Water Movements
D015415:Biomarkers; D005227:Fatty Acids; D010860:Pigments, Biological
Bacteria; Coastal zone; Ecosystem change; Estuaries; Fatty acid markers; Phytoplankton; Pigment analysis