Methods:

Based on the physical characteristics of the San Juan Island archipelago, different methods of data collection were required. Since the methods of data collection are often the same from site to site, we have included a general methods page, that provides a description of all methods used in our study. Listed below are the methods that were used specifically at the San Juan Island stations.

A total of four stations were chosen off of San Juan Island for water sampling.  Each station was assigned a number: Strait of Juan de Fuca was station 1, north San Juan Channel was station 2, Friday Harbor was station 3, and south San Juan Channel was station 4.  The sampling was done by the using several types instruments.  The first instrument used was the secchi, which is a 30 cm round disc that has two distinctive colors of black and white.  The secchi was used to measure the turbidity in the water. 

The second instrument used was the zooplankton closed net, which is a 20 µm mesh net filtered into a cone shape, with a collection bottle at its end.  The net was used to extract plankton samples near the bottom of the sea floor.  The next instrument used was the phytoplankton net which is was a ¾ meter long net with a mesh of 153 µm.  The phytoplankton net was used to sample from the surface of each station. 

The next instrument used is called a rosette which is a metal structure that encases ten Niskin bottles along with a CTD, which is used to identify and measure water characteristics.  The Niskin bottles collected samples from three different depths: the bottom, the surface, and the thermocline. Samples collected at each level were later analyzed at the lab for chlorophyll, nutrients, and dissolved oxygen and later compared with the CTD results.