Sunset on Shark Season 2019

We had our last day sharking on this past Sunday, but no weekend sharks were to be found. So as we pack up the totes of line, buoys and gear— it looks like it’s a wrap for shark season 2019!

And what a season it was!  

Our team spent over 30 days on the water this summer. While there were a few days where we caught nothing,

Taking a break during the ‘doldrums’–a week of not catching any sharks

and a few where we only caught the wrong thing

in the end we caught 14 sharks this year! We know from our spaghetti tags that we did not re-capture any animals, so combined with the 9 sharks we caught in 2018, it brings us to 23 sharks total! (One of those was brought to the surface but got off the hook before we were able to handle him/her, so really we have 22 sharks we brought up for research).

Spaghetti tags–thin nylon or wire tags attached to the shark–have unique numbers on them to let us know if we re-catch a shark we’ve already worked with.

Operation Sleeper Keeper

The most exciting achievement this year was the two sharks that were small enough for Taylor to conduct multiple respirometry sessions on (our ‘sleeper keepers’).

If you remember, we only caught big sharks last year, so seeing this part of our project come together was really amazing. Even better was that other than the two animals we were able to keep at the ASLC for a short time, there were two additional sharks that were potentially small enough to bring in, but both were caught when we were not ready to receive them (one while we had the first one in residence). This does mean with a reasonable effort we can still plan on getting more keepers if we find a way to continue next year!

The team getting our first sleeper keeper ready for release

Contributing to Discovery

These 22 sharks have contributed incredible information for our understanding of the health (blood samples), genetics (skin samples), and physiology (muscle enzyme analyses) of Pacific sleeper sharks.

Taylor preparing to take a small skin sample from the shark.

We also tagged 10 sharks with satellite tags, including the two ‘keepers’ when they were released back into the wild. The good news is that so far the tags from the keepers have not reported, indicating that most likely, they are still alive and survived the capture, transport, temporary residence at the ASLC, re-transport and release! We have a few more months to wait until the tags release as part of their programming and start transmitting their data back to our research crew.

This season marked the end of the field part of the project funded through the North Pacific Research Board and we expect to wrap up some of the analyses this winter.  However, our team is excited about our successes and ready to pursue funding opportunities to continue this research next summer!

Written by: Dr. Markus Horning & Dr. Amy Bishop

This project is led by Dr. Markus Horning (ASLC) and Dr. Chris Lowe (California State University, Long Beach); together with graduate student Taylor Smith (CSULB), and Co-Investigators, Dr. Amy Bishop, Richard Hocking, and Jared Guthridge (ASLC).

This project is funded by the North Pacific Research Board (NPRB). The project is permitted by ASLC’s institutional ethics committee (AUP # R19-05-05) and by the Alaska Department of Fish & Game (CF-19-085).

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