SEAFOOD WASTEPILE MONITORING SURVEY-DUTCH HARBOR, AK 


Studies have been conducted in Alaskan waters over the 
last decade to quantify wastepiles produced from seafood 
processing plants. Alaska seafood processors have 
historically contracted divers to perform wastepile 
monitoring required for NPDES permits, including 
measurements to calculate wastepile volume, aerial extent, 
and thickness. Much of the data collection through the use 
of divers was manual, subjective, and often not georeferenced. 


SCOPE AND APPROACH 

EHI proposed a scientific, methodical approach using 
established remote sensing technologies in combination 
with ground-truth sampling techniques to assess the 
wastepile. Key elements of the program were positioning, 
precision, records, and repeatability. A RTK-DGPS was 
used for controlled positioning. Acoustic equipment was 
used to gather a dense data grid and provide 3D imagery 
of the seafloor and wastepile. Underwater video was taken 
of the seafloor to document the outfalls, wastepile, and 
marine life. Sediment cores were collected to correlate the 
acoustic data and past diver surveys. The cores provided 
direct measurements of seafood waste over the native 
sediments. 

Side-scan imagery mosaic with 
bathymetry overlay. 


RESULTS 

The acoustic method for assessing the wastepile proved a 
viable alternative to the dive surveys. The primary reason 
was the extended area capable of being surveyed using 
acoustic methods over diver methods. In addition, the 
number of data points used to calculate volume, area, and 
thickness is ten-fold over diver survey data and 
comprehensibly delineated the seafood byproduct 
wastepile. Determination of the native seabed below the 
wastepile created a baseline by which the present and 
future surveys can determine change in wastepile volume. 
The methods established minimize subjective interpretation 
of wastepile aerial extent, which was very problematic in 
previous diver surveys 

Client Reference 

Mr. Joe Frazier 
UniSea 


(425) 861-5310 
joe.frazier@unisea.com 
Project Timeframe 

April – December 2007