Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Colorful squid jigs.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. High flyers, buoys, and floats attached to longline.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Dr. Rich Brill fishing for specimens for scientific experimentation.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Pacific lancetfish.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Pacific lancetfish caught on longline placed in specimen bucket.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Dusky shark being weighed.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Pacific lancetfish.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Head of Pacific lancetfish.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Blue shark with disgorged stomach on deck. Attempting to remove circle hook.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Measuring a juvenile swordfish.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Weighing a juvenile swordfish.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Crew watching retrieval of longline wondering what will come up next.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Attempting to remove circle hook from blue shark.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Skipjack on top (note horizontal lines); juvenile yellowfin tuna.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Retrieving live juvenile yellowfin tuna for experimentation.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Live juvenile yellowfin tuna showing true coloration and vertical stripes.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Live juvenile yellowfin tuna having hearing tested (really!)

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Live juvenile yellowfin tuna having hearing tested (really!). Tube in mouth is sends water through gills for breathing while fish is secured .

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Live juvenile yellowfin tuna having hearing tested (really!). Tube in mouth is sends water through gills for breathing while fish is secured .

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Longline gangions and circle hooks.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. NOAA divers checking hull of ship.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Juvenile wahoo. Note vertical stripes and blue coloration on top.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Head of juvenile wahoo. Note blue coloration.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Weighing juvenile wahoo.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Retrieving a HARP buoy anchored on Cross Seamount which is used to record whale vocalizations.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Closeup of HARP buoy on deck.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Tale of recently caught mahi mahi showing live coloration.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Head of recently caught mahi mahi showing live coloration.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. A large mahi mahi caught by rod and reel for experimentation.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Mako shark on deck.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Mako shark on deck with swallowed hook. Note small do-like sensory organs on head. These are called ampullae of lorenzini. They are electroreceptors that help sense the proximity of potential prey.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Mako shark on deck.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Head of barracuda.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Large barracuda on deck. Note vertical striping.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Attempting to remove circle hook from blue shark.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Bigeye tuna being brought on deck.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Blue shark with disgorged stomach on deck. Removing circle hook.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Deploying HARP buoy on Cross Seamount.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Deploying HARP buoy on Cross Seamount.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Deploying HARP buoy on Cross Seamount.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Bringing up small tuna.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. High flyers marking end of longline.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Unhooking gangion from longline.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Bigeye tuna.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Head of bigeye tuna.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Sawing head off bigeye tuna for scientific study.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Sawing head off bigeye tuna for scientific study.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Big thresher shark on longline.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Bigeye tuna on deck.

Longline fishing research on the NOAA Ship OSCAR ELTON SETTE. Chief scientist Mike Musyl taking bigeye tuna for further study.