July 11, 2008 – After returning from the Acoustics 08 conference in Paris, we heard the great news that Paul Roberts won first prize in the student poster contest for his poster entitled “Application of multiple-angle acoustic scatter to remote fish classification.” The poster investigates how certain key parameters in a multiple-angle system (such as array aperture and signal bandwidth) effect the ability of the system to classify fish of different size, shape, and species.
December 4, 2007 – The FAD Sonar just returned from a month long deployment on board of the R/P Flip. It was used as a supplemental instrument to measure fish and plankton aggregating around Flip during the FLIP07 SCORE experiment conducted by John Hildebrand and Elizabeth Henderson. We’d like to thank Liz for an outstanding job of running the system throughout the 30 day deployment and recording 30 Gigabytes of data that we can’t wait to analyze!
This week we are being featured on an internationally syndicated radio show: Pulse of the Planet. The audio describes our work in testing a new idea related to measuring the microbial environment and hence the viscosity of the ocean. If you would like to listen, please go to the following link and check out the archives from August 14, 15, and 20th and October 9th.
We just returned from our spring cruise to Dabob Bay in the state of Washington. The purpose of our cruise was to explore a hypothesis that has to do with the foraging behavior of zooplankton, the small (1-4 mm) animals that live in the sea. Every night they make a big trip to the surface waters from the deeper parts of the ocean to forage on plants (phytoplankton). Once there, do they eat, turn around, go back down? or: Do they eat and keep eating up in the surface waters? Our new imaging system is a bispectral (two wavelength) method which records not only the green reflected light from their outsides (carapace) but also their insides (the phytoplankton) that they ate that fluoresces in the red. Together, the green reflected light and the red light from their insides tells us which animals they are and how recently they ate. We spent about 8 days on the U. of Washington ship the Tommy Thompson in Dabob Bay and worked almost all night to see these little guys make a living. We returned, tired but happy with lots of great data that will help us try and unravel how these animals, probably the most numerous multicellular animal on the planet, make a living.
The goal of our most recent cruise was to deploy our FIDO vehicle in various configurations to observe particle size spectra and also time varying scatter of light in the ocean. Leaving from San Diego we over-nighted off Catalina (up and back) on the way to the Channel Islands. The cruise went extremely well. We profiled with the FIDO – PHI configuration for 4 nights and then switched over to observe time varying scatter by suspending a small disk from FIDO with the laser incident on it from one direction and the camera imaging from the other. We saw some amazing radial spokes of light emanating from the center of the scattered light patterns that we believe have never been seen before!!….What could they be from? We are currently figuring out what we got, what to do with it and what it will tell us about oceanic micro structure and the propagation of light the ocean. Stay tuned for more.
We now have a link to the Science article: “Swimming Against the Flow: A Mechanism of Zooplankton Aggregation”. Please refer to the Articles page for the link.
April 27, 2005 – The article on Fish T.V. will be appearing in the May 4th issue of Science.
Successful deployment of the Autonomous Underwater Explorer (AUE).