Showing posts with label dive. Show all posts
Showing posts with label dive. Show all posts

Thursday, December 27, 2007

Betty - December 27

Three months ago, Betty and son Big Al were released into the Gulf of Mexico from the "Tomcat". After a sojourn through most of the Gulf of Mexico, Betty seems have settled on her current location, on the edge of the continental shelf west of Key West, as an acceptable location for conducting Grampus business. She has spent the past month in this general location, making occasional dives to 800-1,000 m, and staying down for 11-15 min at times. Over the past week, she has made 6 of
these impressively deep dives, but the vast majority of her dives continue to be to less than 50 m. Her deepest and longest dives occurred during the 6-hour period of "Dusk", providing additional support to the findings from Clyde that Grampus are crepuscular animals, most active at Dawn and/or Dusk.

We had hoped for 60 days of tracking, and have now exceeded 90 days. Her tag has made 24,832 transmissions. The specifications for the battery called for an expectation of 25,000 transmissions. The battery voltage on the tag continues to be in a good range, so we can hope for continued data.

Tuesday, December 18, 2007

Betty - December 18

Betty remains in the same area she has for more than 3 weeks, near the 1,000 m contour at the edge of the shelf. She has made one dive to 800-1,000 m - the deepest dive ever documented for this species (perhaps approaching the sea floor on this occasion), and double the deepest dive recorded for Clyde. Most of her dives continue to be to depths less than 50 m. One dive lasted 11-15 min, but most contrinue to be less than 4 min in duration. After more than 19,000 transmissions, battery voltage still looks good.

Monday, November 12, 2007

Betty - November 12

Betty has moved offshore a bit, south of Louisiana, to waters about 2000 m deep. She has been making a few dives to 300-500 m, but the vast majority of dives continue to be to less than 50 m. Over the past few days, she has made dives lasting as long as 9-10 min, but mostly they are 3-4 min or less. She has sent nearly 11,000 transmissions (of 25,000 projected total) and battery voltage continues to be strong.