Sargassum galore!

Blog posted for Jeff Plumlee:

Howdy from the Blazing Seven!

Today was another rousing success with an early 500-m midwater trawl at 04:00 followed by our 13^th station at N 27 W 89 36' at 06:00. Our midwater trawl consisted of shrimp, squid, jellyfish, and of course, lanternfishes (Myctophidae). It was another beautiful day with clear blue water, a gentle breeze, and 1 - 2 foot seas. We progressed through twelve stations today and continued to have Sargassum at every one. However, with Sargassum, comes abundant diversity, including filefishes (Monacanthidae), triggerfishes (Balistidae), Sargassum fish (Antennariidae), flyingfishes (Exocoetidae), dolphifishes (Coryphaenidae) and others, along with shrimp and crabs. We also found several billfish and flyingfish larvae as well in our neuston and bongo nets.

  juvenile flying fish 

One of our primary objectives on this cruise is to collect ichthyoplankton, primarily billfishes of the families Istiophoridae and Xiphiidae, tunas of the family Scombridae, dolphinfishes (Coryphaenidae) and flyingfishes (Exocoetidae). Dr. Jay Rooker from Texas A&M University at Galveston and many of his students utilize larvae and samples collected from these trips to create a better understanding of these pelagic fishes. Through the utilization of techniques such as otolith chemistry and genetics, along with the collection of oceanographic parameters, researchers can understand in detail the life history of these fishes as well as habitat preference, spawning locations, and population structure. Continued quantitative sampling using multiple gear types, with replicated sampling, allows detailed analysis over seasons and years, revealing long-term trends which are crucial to understanding pelagic ecosystem patterns.

Tonight we are making the trip from N 27 to N28 to begin our second leg of the trip, the westward transect back towards Port Fourchon. We have finished our last midwater trawl so sampling begins tomorrow at 06:00 with neuston and bongo net tows, so stay tuned for more updates!

Jeff