Sep 2 2010

Sardine Research Update – Northern California Report

Weather continued to play a confounding role in Northern California, but we managed to find enough reasonably clear days to complete one full set of 66 aerial transects coast-wide, from Cape Flattery WA south past Catalina Island in S.CA,. and nearly finished set #2 by the last weekend in August.

Three planes participated, with pilots flying at 4,000 feet altitude along predetermined straight line transects from shore out 35 miles. Transects were spaced at 15 mile intervals along the coast. Cameras mounted in the planes continuously photographed a swath of ocean approximately one mile wide along each transect path. Photo analysts will later examine the thousands of photos to identify sardine schools.

Three (replicates) is the charm that will help lower the coefficient of variation fraction applied to the estimate of biomass derived from photo analysis. Remember, last year’s survey completed only 41 of the scheduled 52 transects — with only one replicate.

This year, our target is 66 transects times 3 replicates. We’re nearly two-thirds of the way done with two weeks remaining. Finishing the third replicate should be doable.

The next challenge is landing acceptable point sets, and we’re making steady headway on that front as well.

In Monterey, while planes have been able to conduct aerial transects in the north, the combo of fish location (all piled up on the beach) and persistent marine layer offshore have precluded starting point sets in Monterey — until now.

Anthony and Andy Russo, Frank Aliotti, and now Neil Guglielmo, one of our southern research boats, who ventured up to Monterey, are standing at the ready to help initiate point sets in the northern region. One of our northern pilots, Geno Zandona, spotted fish at Soquel Hole, which means sardines may now be returning to the bay, as the abundance typically increases in September.

We’re hopeful the fish schools will spread out so we can conduct point sets in a broad area, as recommended by scientists.

Doyle Hanan advised the boats to prepare to go fishing on Tuesday, Aug. 31. Geno prepared to set the boats while the second pilot, and Allen Hewitt flies the twin engine Seminole to Crescent City to begin the third set of transects.

Although fog did not lift sufficiently in the Bay to fish on Aug. 31, we’re expecting a fair weather break for the next several days, and we should be able to make “hay” while the sun shines. Keep your fingers crossed!

This research project is likely to go down to the wire. We have until September 14 to wrap up the summer project. Then we’ll jump-start planning for our fall pilot project in Southern California, where we’ll evaluate three different techniques for measuring fish, all deployed at a time when sardines are abundant in California.
•  Daylight vs. night time photography
•  LIDAR (Light Detection and Ranging): an optical remote sensing technology that measures properties of scattered light to find range and/or other information of a distant target, which can “see” 50 meters underwater
•  Hydroacoustics: utilizing SONAR technology, hydroacoustics is most commonly used for detection, assessment, and monitoring of underwater physical and biological characteristics

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