Friday, May 31, 2013

New paper

One quick note on a separate subject. Our lab recently published a paper led by Max Kaplan.
The paper documents the effects of ocean acidification (OA) on squid development and early life. It shows that these keystone and commercially vital taxa can be impacted but high CO2 levels. Ocean acidification is the change in seawater chemistry as excess, largely human-produced CO2 is absorbed into the ocean. In squid, OA affects time until hatching, hatching size and sensitive statoliths. 

Wrap up

The end of this trip brought some very successful days. In the last four days we placed out 10 dtags, 7 on spotted dolphins and 3 on pilot whales.  This provided us some great baseline data as well as the soundscape of spotteds around fishing boats (the spotteds are often associated with tuna and other commercial important gamefish). We also had multiple DAWG and/or towfish deployments in these situations. All in all, unique, exciting acoustic behavior sets.

Aran and Aliza are now in Honolulu at some meetings, in part attending the false killer whale take reduction team meeting. This involves discussion on direct management of this now endangered population of false killer whales in Hawaii.

Tuesday, May 28, 2013

Another crazy day!


The last few days have been a whirlwind. 10 tags on in the last two days including 3 pilot whales and 7 spotted dolphins. We've also deployed the towfish and the DAWG (Digital Acoustic Wideband Gizmo), our drifting acoustic recorder. These two devices complement the DTAGs by gathering sounds of the group (as opposed to the tag, which records sounds of individuals). So it's been pretty amazing the past few days, and it's going to take a while to sort through all these data!
Daniel Webster placing the DTAG on a spotted dolphin (Photo: A. Mooney, NMFS permit # 15530 to CRC).

Spotted dolphin with a suction-cup DTAG attached (Photo: A. Mooney, NMFS permit # 15530 to CRC).
Max recovering the DAWG acoustic drifter after a deployment around spotted dolphins.

Today was particularly interesting. Several hours out of the harbor we met up with a huge group of pilot whales. We'd take photo id's, then leave a subgroup and 1 km later, we'd find another subgroup. They just kept on coming. Finally, we headed out of them towards some fishing boats. Sure enough, they were fishing around spotted dolphins. We spent most of the day with these spotteds, putting out 4 tags. Most of the tags attached great (thanks to Daniel Webster's great tagging, and Robin Baird's great driving). But the last tag didn't release when it was supposed to. We stayed with the group for several extra hours, but the tag still didn't pop off the animal. So, nearing the end of the day, we headed in. Fortunately, Aliza was on land and could track the VHF radiobeacon on the DTAG from the Big Island mountainside. She told us when it was at the surface. Unfortunately, we were nearly back in the harbor and running low on fuel. That's when we called in reinforcements in the name of Daron Verbeck (of Wild Hawaii Ocean Adventures). Daron was amazing! He took Daniel and Aran out on his boat (which is a retired Navy Seal RHIB and travels at 40 knots). We made the trip back to the tag (about 50 km away from the harbor) and found the tag in the dark. All in all, a productive and exciting day.


Speeding on the Wild Hawaii boat, out to save a DTAG adrift.


Daron's Navy Seal boat back at the harbor after retrieving tag 4, and a long, long, day.