Chris Sanborn: 2 Days Shark Tagging, July 15, 2015


NOAA Teacher at Sea
Christopher Sanborn
Aboard SRV C.E Stillwell
July 13 – 17, 2015

Mission: Cooperative Atlantic States Shark Pupping and Nursery (COASTSPAN) survey
Geographical area of cruise: Delaware Bay
Date: July 15, 2015

Weather

Day 1 weather was mostly overcast 5-10 mph wind with 2-3 ft seas though the swells were larger according to the other individuals on the boat.

Day 2 was forecasted for chance of storms with 10-15 mph winds with 2-3 ft seas..

Science and Technology log

We just finished day two of our shark tagging survey in the Delaware Bay aboard the C.E. Stillwell, a 21 ft. Boston Whaler center console.  The boat seems extremely small at times with 4 people and lots of gear on board.  The crew that I am aboard ship with are Nathan Keith, Natural Resource Management Specialist, Ben Church, Boat Captain for this shark survey, and Matt Pezzullo,Chief Scientist for this shark survey.  Our boat is docked at the University of Delaware Marine Operations pier located in Lewes, DE.  Day 1 of our tagging was mostly spent on the New Jersey side of Delaware Bay.  We left port at 6:00 a.m. and steamed roughly 14 miles across the bay to make our first set. The seas were fairly rough which made for a bumpy ride.

Center Console C.E Stillwell. Photo courtesy of Nathan Keith

Center Console C.E Stillwell. Photo courtesy of Nathan Keith

Sets are either made with 25 large circle hooks or 50 small circle hooks on a gangion extending from the mainline which is weighted to the bottom.  The mainline is 1000 ft long, plus buoy line which extends from beyond the last hook up to the marker buoy on either end of the line. Our first day on the water we did 4 large sets and 3 small sets.  A large set is 25 large hooks that soak for 2 hours while a small set is 50 smaller hooks that soak for 30 min. We arrived back at port at 7:00 p.m. Day 2 we did 3 large sets and 4 small sets leaving port at 6:00 a.m and arriving back in port at about 5:30 p.m.  All hooks are baited with mackerel as seen on the large hooks in the following video.

Nathan Keith baiting smaller hooks.

Nathan Keith baiting smaller hooks.

The long line is retrieved by hand,  Sharks 130 cm and below are brought on board the boat for biological workup which includes fork length, pelvic and dorsal girth, sex, weight (if conditions allow) and then tagged.

Ben and I working up a shark on board the boat. Photo courtesy of Nathan Keith.

Ben and I working up a shark on board the boat. Photo courtesy of Nathan Keith.

Ben Church holding a Sandbar Shark that had been bit by a Sand Tiger Shark while on the line, while I read the weight. Photo courtesy of Nathan Keith.

Ben Church holding a shark while I read the weight. Photo courtesy of Nathan Keith.

Sharks greater than 130 cm get the full biological workup except weights.  These sharks are tail roped and cleated to the side of the vessel.

Me Dart Tagging a Sand Tiger Shark while Matt Pezzullo looks on. Photo courtesy of Nathan Keith.

Me Dart Tagging a Sand Tiger Shark while Matt Pezzullo looks on. Photo courtesy of Nathan Keith.

All sharks under 100 cm receive a roto tag in the dorsal fin while sharks over 100 cm receive the dart tag seen in the picture.

 Day 1 Sharks:

    58 Total Sharks tagged

        45 Sandbar Sharks (Carcharhinus plumbeus)

        11 Sand Tiger Sharks (Carcharias taurus)

        1 Blacktip Shark  (Carcharhinus limbatus)

        1 Atlantic Sharpnose  (Rhizoprionodon terraenovae)

Day 2 Sharks:

    44 Total Sharks tagged

        43 Sandbar Sharks  (Carcharhinus plumbeus)

        1 Sand Tiger Shark (Carcharias taurus)

We also had some bycatch with a number of rays.  The largest ray was 176 cm across which had an enormous amount of power.  All rays are measured across the disk width and sexed.  We caught Bullnose (Myliobatis freminvillii) , Bluntnose (Dasyatis say), Southern Sting Ray (Dasyatis americana), and Spiny Butterfly (Gymnura altavela).  We also caught on line a Clearnose Skate (Raja eglanteria) and a Weakfish (Cynoscion regalis).

 

Personal Blog:

Besides the beating we take in a 21 ft. center console motoring miles between sets, back and forth, the extreme physical toll of pulling in a long line is very taxing.  Day 1 of our survey was exciting as we caught numerous large Sandbar and Sand Tiger sharks.  Although it was an adrenaline filled experience I can say I was extremely spent at the end of the day!  Day 2 we only caught a few sharks that we were unable to bring on board the boat.  The biggest problem with day 2 was the ever-changing weather.  Some of the day was even spent in the pouring rain.  Boat operator Ben Church and Chief Scientist Matt Pezzullo were constantly aware of weather conditions for safety as well as assuring that setting and hauling of gear could be set and hauled safely and in a timely manner. Sharks that are brought on board are secured just underneath the jaw as you can seen in many of the pictures. The skin of the shark is very similar to sandpaper for anyone that has felt a shark or dissected one in my class.  The skin on my hands has worn away and new skin has been exposed.

Day 3 starts early in the morning so I am headed to bed!

 

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