Project – Prince William Sound Sentinel Observations


The purpose of this project is to maintain long-term observations of meteorological and oceanographic conditions established as part of the Prince William Sound Ocean Observing System.


When the Alaska Ocean Observing System (AOOS) was being formed it was decided to use Prince William Sound (PWS) as a pilot location for the system.  In partnership with the Oil Spill Recovery Institute (OSRI) a number of models and observation systems were established to demonstrate the value of an ocean observing system in the region.  Included in the observations were several meteorological stations to improve observations for boaters and modelers.  More recently, an acoustic tracking system was established that allows for observations of tagged fish passing in and out of PWS, and a conductivity sensor was added to the tide station in Cordova to provide a measure of salinity to go with the temperature data being collected there.

Snowpack Telemetry (SNOTEL) meteorological stations, set up in partnership with the Natural Resources Conservation Service (NRCS) and the Oil Spill Recovery Institute (OSRI), measure precipitation from snow and rain throughout the year and are needed to establish the freshwater budget. Since the summer of 2005, six SNOTEL stations have been deployed at sea level in PWS, and two stations at alpine elevations.  Each station in PWS measures temperature, wind speed and direction, precipitation, and solar radiation.  With several years of data now available, we are able to more quantitatively test our understanding of freshwater input into PWS.  The weather measurements are also important for oil spill trajectory modeling. Understanding the circulation of Prince William Sound requires accurate measurements of wind fields and precipitation.  Snowmelt runoff and rainfall creates a freshwater layer that sets up aspects of the surface circulation.  Wind stress then modifies the circulation creating local and seasonal circulation patterns.  By understanding the basic meteorological conditions, including precipitation, we hope to improve our ability to model the hydrology of Prince William Sound, improve our understanding of the forces driving seasonal changes in circulation, and provide oil spill response organizations with necessary data.  The array provides a much broader network of weather observations for boaters as well.

In 2013 a Sea-Bird Microcat conductivity sensor was added to the tide station in Cordova.  The data is transmitted through the NOAA tide observation system and the sensor is maintained by the Prince William Sound Science Center (PWSSC).  The conductivity data is combined with temperature information to provide salinity data.  There are very few observations of salinity around Alaska.  By working with NOAA we are able to provide reliable observations at low cost.

In addition to physical observations we will collect observations of tagged fish and mammals.  In spring 2013, the Dalhousie University’s Ocean Tracking Network (OTN) installed 6 acoustic arrays across the major entrances to Prince William Sound (Hinchinbrook Entrance, Montague Strait, and the 4 Southwest Passages) to document the movements and survival of marine animals carrying acoustic tags and how both are influenced by oceanographic conditions. With data available within a year of uploading, OTN maintains a database for the repository for all globally collected OTN tracking data. PWSSC has a collaborative agreement with Dalhousie University to operate and maintain the Prince William Sound arrays. Current AOOS funding provides ship time to service the array and download data. Funding for the OTN expires in February 2017.  On an annual basis, the VR2w arrays in the Southwest Passages are maintained (batteries replaced/data uploaded) while at Montague Strait and Hinchinbrook Entrance arrays the data is uploaded remotely from VR4 receivers.  Batteries in the VR4 receiver arrays at Hinchinbrook Entrance and Montague Strait will expire ~January 2020, at which time they can be retrieved, refurbished and redeployed.  Refurbishment will extend the life of these important arrays for another 7 years.


  1. Provide accurate and real-time observations to be used by boaters and ocean forecasters in Prince William Sound; and,
  2. Meet short-term and long-term fisheries and ecosystem-based management needs by maintaining intensive sentinel monitoring in Prince William Sound.


  1. Contract with Natural Resources Conservation Service (NRCS) to maintain the most critical SnoTel stations in PWS and Cook Inlet providing real-time web accessible data. We will continue to assess the value of each of these stations, and focus our funding efforts on those with the broadest use.
  2. Support maintenance (vessel charters and personnel time to retrieve and download electronic data) of the biological monitoring network operated by Ocean Tracking Network (OTN) that uses acoustic monitoring equipment at entrances to PWS to identify tags on cod, salmon, sharks, whales, and other organisms that pass through PWS.
  3. Maintain the conductivity sensor at the Cordova tide station and evaluate the potential for possible expansion to other locations.

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