|
|
 |
 |
Little did Bill Chaprales know
when he began tagging free swimming bluefin tuna for National Marine
Fisheries Service (NMFS) in 1976, using a heavy, modified harpoon
pole, crude bronze dart, and trailing bright orange banner, how
technology would evolve. It was a modestly (at best) successful
program designed to track bluefin movement, relying on another
fisherman somewhere to catch that fish and return the tag and
location information to NMFS. There were a few returned and that
information was recorded, but most of the tags probably did not stay
on the fish. It was primitive methodology, but it was a beginning.
 |
|
Capt.
Bill Chaprales & Greg Skomal |
Nearly 30 years later, and
after refining the equipment while participating in several highly
successful bluefin tagging/tracking programs over the years, most
notably under the direction of Dr. Molly Lutcavage of the New
England Aquarium, Bill finds himself on the cutting edge of
technology once again. Currently working with the team of Dr. Greg
Skomal (Division of Marine Fisheries for the State of Massachusetts)
and the lab of Dr. Steve Zeeman (New England University), Bill is
currently tagging basking sharks from his fishing vessel EZYDUZIT,
carefully applying archival satellite pop-up tags for the purpose of
collecting data on the movements and habitat of the second largest
fish in the world. The pop-up tags are designed to release at a
specific time, pre-programmed into the device, then transmit data on
all its movement over that period to a satellite, which in turn
relays that information to Dr. Skomal. Another device being used is
a tethered "floating tag", which begins transmitting
immediately to give scientists precise, current tracks as that
animal swims at the surface.
|
|
 |
| PATtag |
 The
methodology is quite simple and effective. A single engine airplane
flown by Tim Voorheis is used to locate and direct the tagging
vessel to the target basking shark. Each fish is carefully analyzed
to determine if it meets the criteria for tagging. It is important to target sharks near
or at the surface to properly implant the tag. The shark is
approached very quietly from behind while being photographically
recorded from both the airplane and the vessel. This allows
Chaprales to precisely place the specially designed dart tethered to
the tag at the base of the dorsal fin, using a light-weight tagging
pole. The animal swims away, often not knowing what has happened,
and is often seen again in the area as we continue to tag others.
Unlike other fish tagging programs, which rely on animals to be
caught by rod and reel or net, putting them under great stress and
separating them from others of their species, the tagging of
free-swimming fish provides better science because the animals are
not being removed from or disturbed in their natural
environment.
To date Dr. Skomal's
tagging team, Chaprales, crewman Eli Lott, and Voorheis have
successfully tagged 22 basking sharks, 6 of which are currently
transmitting data from floating tags, the rest scheduled to release
at different times in the upcoming months.
 |
|
 |
|
select
image for greater detail |
|
select
image for greater detail |
This program has been a
remarkable example of commercial fisherman, spotter pilot, and
researcher coming together to advance the cause of science and
knowledge. Funded by The Massachusetts Environmental Trust and a
NASA grant, the project is ongoing at this date and we will post
results of this on this website on a timely basis as information
becomes available.
 |
 |
 |
Select
Charts for more detail
|
If
you are interested in using one of our photos for research,
education or publication purposes, please contact
us.
 |
Name
of Basko Study Article sent by Greg Skomal
date of article
Author information |
| |
|
|
DMF News
2nd Quarter 2004 / 3rd Quarter 2004
Volume 25
Basking Sharks May Help Identify Unknown Right Whale Habitats
Marine Fisheries shark and whale experts collaborate in tagging study
by Gregory Skomal, Shark Specialist and Ed Lyman, Protected Species Specialist
|
| |
|
|
DMF News
4th Quarter 2004 / 1st Quarter 2005
Volume 25
Basking
Shark Tagging Update
by Gregory Skomal
|
The
above reports require Adobe Acrobat Reader.
Click here to download a FREE copy of the program directly from Adobe.com.
|
