Documenting variable oceanic influence on water properties and plankton as a possible stressor on biological communities of the Inland Sea

Jan Newton, Washington State Department of Ecology
2002: $57,885 2003: $40,000

Several studies have established that water properties such as temperature, salinity, oxygen, nutrient, and plankton concentrations show considerable variation interannually in the Strait of Juan de Fuca and that a significant source of this variation is related to climate and associated ocean changes. Variation in nutrient availability and primary production can have wide-ranging effects on marine systems, since this is food at the base of the food web. This project was designed to document variability in levels of oxygen, nutrients, and plankton within the incoming oceanic waters at the boundary of the Inland Sea by maintaining a database of time-series of these observations from three stations in the eastern Strait of Juan de Fuca. Our first hypothesis was that a large portion of the observed variation in water properties and plankton in the Inland Sea is related to variability in climatic and/or oceanic forcing, which will be assessed. Secondarily, we hypothesized that the variation in water properties and plankton is important to the success of populations of other marine organisms in the Inland Sea, due to stresses such as the availability of food, low oxygen that affect communities in addition to other stressors such as habitat loss and chemical contamination.  Documenting the variability in water properties and plankton and understanding the degree variation is influenced by external forces (ocean, climate) is critical to interpreting success or failure of marine organisms and to evaluating the efficacy of MPAs and other conservation approaches. At the start of this project there were no long-term, ongoing, time-series of water property measurements or of plankton in these Straits. Virtually nothing was known about how the variability in zooplankton species in time and space relates to the fish and other higher organisms that feed on them. For some dwindling salmon stocks, gaining an understanding of what affects them during their residence in nearshore marine waters may be particularly critical. Not only are plankton species assessments essential for trophic-linkage implications, but exotic zooplankton species are just beginning to appear in this area and it is important to know when and if new species become established, given the profound ecosystem-level effects of planktonic invaders elsewhere in the world and the region.
 
Results from this work have helped to advance the understanding of ecosystem health of the inland marine waters of Washington State and British Columbia by providing a record of the strong variation in water properties and plankton in the Strait of Juan de Fuca and how these link to climate or other drivers.  Water properties readily vary due to cycles and variability in weather, ocean circulation, and river flow.The data from this and other studies have established that water properties such as temperature, salinity, oxygen, nutrient, and plankton concentrations show considerable interannual variation in the Strait of Juan de Fuca and that a significant source of this variation is related to climate and associated ocean changes.  The resulting marine conditions set the baseline on which other human-caused stresses, such as chemical contamination, habitat loss, invasive species competition, are added. Effects of cumulative stresses must be assessed in any complex environment, such as coastal waters where a variety of human activities and natural processes occur. Prior to this work, no program had been monitoring this variation over time.We sought support to sustain a newly established observational program (JEMS; Joint Effort to Monitor the Strait) to measure variation in water properties, to assess the drivers of the observed variation, and to make the data and information available for application toward evaluation of organism health and MPA design.
Publications resulting from this research

Newton, Jan A., Eric Siegel and Skip L. Albertson. 2003. Oceanographic Changes in Puget Sound and the Strait of Juan de Fuca During the 2000–01 Drought. Canadian Water Resources Journal 28(4): 715-728. (PDF)

Presentations resulting from this research
Newton, J. 2003. Changes in the Strait of Juan de Fuca and Puget Sound During the 2000 Drought. Georgia Basin-Puget Sound Research Conference 2003:  Mar-April 2003, Vancouver, BC.
 
Newton, J. 2003. Variation in water properties of the Strait of Juan de Fuca as revealed by the Joint Effort to Monitor the Strait. Friday Harbor Labs Associates Meeting:  November 2003, Friday Harbor, WA.
 
Newton and Albertson. 2004. The Effect of Drought Conditions on Physical Properties and Oxygen Concentrations in Puget Sound and the Strait of Juan de Fuca. Ocean Sciences Meeting:  January 2004, Portland, OR.
 
Newton, J. 2004. Changes in the Strait of Juan de Fuca and Puget Sound during the 2000-01 drought. Pacific Estuarine Research Society Meeting April 2004.
 
Newton, Van Voorhis, Bos, Albertson. 2004. Climate-related variation in Puget Sound density and oxygen. Eastern Pacific Ocean Conference October 2004, Sidney, B.C.
 
Friday Harbor Marine Resource Committee meeting:  November 2004, Friday Harbor, WA, “San Juan County Marine Water Quality: local and external effects,” Newton
 
Newton, Albertson, Bos. 2005. Climate-related variation in Puget Sound. Puget Sound-Georgia Basin Research Conference 2005:  March 2005, Seattle, WA.  

Management outcomes

The objective of the proposed work was to assess the variability in physical water properties (T, S, light), oxygen, nutrients, and plankton within the waters at the boundary of the Puget Sound-Georgia Basin by maintaining a database of time-series observations from three stations in the eastern Strait of Juan de Fuca. 
 
This objective was met, as the project allowed the documentation of water properties via the Joint Effort to Monitor the Strait of Juan de Fuca (JEMS) and posting of those data to the public via the Washington State Department of Ecology website.  Plankton was assessed via chlorophyll (phytoplankton) and net biomass (zooplankton). The chlorophyll is part of the data available through the Ecology website. A database of zooplankton resides with Dr. Jeff Cordell (UW, SAFS). 
 
Our first hypothesis was that a large portion of the observed variation in water properties and plankton in the Inland Sea would be related to variability in climatic (e.g., precipitation, winds, sunlight) and/or oceanic forcing (e.g., ENSO status, upwelling strength, offshore thermocline depth), and, that this influence can be revealed by time-series measurements from the Strait of Juan de Fuca. 
 
Considerable variation was in fact observed in the JEMS time-series for water properties and was related to climate and ocean influences. ENSO variation could be clearly seen in the record and the drought during 2000-2001 showed a considerable effect on the exchange velocity time through Strait (Newton et al., 2003). See implications of this variation for ecosystems discussed in Newton et al. (2003). JEMS has proven to be an important time-series at a critical environment for the Puget Sound-Georgia Basin region, for several reasons, as discussed below. The zooplankton data proved to be highly variable, and multivariate statistical analysis is recommended but was not budgeted for in this project.
 
Our second hypothesis was that the variation in water properties and plankton is important to the success of other marine organisms in the Puget Sound-Georgia Basin.  We did not have the level of data anticipated from other investigators with which to test this hypothesis, but the degree of variation in water properties and plankton was established such that these data can be used in models such as PRISM or EcoPath to investigate this in the future.  We recommend that a directed focused group of regional scientists would be needed to assess this food-web issue.