preventing spinal injuries

RECFISHING RESEARCH NEWS ITEM
PREVENTING SPINAL INJURIES
Figure 1 Pic courtesy of Jamin Forbes
When Elvis sang “Hold me tender”, who would have thought he was talking
about a fish? Ok so he sang love me tender, but he may still have been thinking
about a fish. Unlikely though...
Anyway, some recent research has confirmed what many anglers have
suspected for some time – holding fish vertically can cause them damage.
To anyone who hasn’t used them, lip grippers are a handy little tool which use
a pincer-like gripping movement to hold onto the lip of a captured fish. This
can make it easy to remove a hook with minimal fuss prior to release, and can
also reduce the need to have the fish come in contact with other surfaces
(which can help protect their slime coating, scales and skin). So effective are
these devices at holding fish securely, that some anglers have taken to using
them as a handle; lifting their fish up by the lip, to bring fish into the boat and
take photos, before release.
A little while back a fisheries researcher from the Northern Territory, Alf Hogan
was moving barramundi broodstock between tanks, lifting each one by its lower
jaw as he did so. He was later concerned to note that all of the broodstock
lifted in this manner subsequently died. A detailed follow up study was later
conducted by some researchers from the (now) Department of Primary
Industries, Fisheries and Resources in NT, to look more closely at the effect of
lifting barramundi using ‘lip grippers’.
Last Updated February 2008
RECFISHING RESEARCH NEWS ITEM
PREVENTING SPINAL INJURIES
Figure 2 Lip grippers can be a great way of handling big fish safely when used correctly (Pic courtesy
of Jamin Forbes)
The researchers ‘exercised’ barramundi (basically, chased around a tank until
they were tired) to simulate capture with rod and line, before attaching a lip
gripper to the lower jaw of 21 fish. Ten of those fish were then held out of the
water using just the lip gripper for 20 seconds. The remaining 11 fish were
lifted with the lip gripper, but with a hand supporting the fish at its midsection
in a horizontal position. They then compared the survival and injury levels
between these fish, and another 10 barramundi which had been held out of the
water in a landing net for the same length of time (with no handling using lip
grippers). Whilst only 2 fish died (it doesn’t look like these deaths were related
to the different handling approaches), X-rays showed that lifting fish with lip
grippers shifted the alignment of the fishes’ vertebrae, which did not return to
normal after three weeks.
Figure 3 X-ray of a barramundi showing the natural curvature of the first four vertebrae and the
locations where distances between vertebrae were measured (source: Gould and Grace 2009).
Last Updated February 2008
RECFISHING RESEARCH NEWS ITEM
PREVENTING SPINAL INJURIES
The researchers suggested that the injuries received by fish being lifted using
lip grippers might have resulted in deaths if they had used larger fish (the fish
they used were between 53cm and 102cm in size). It is also possible that the
shift in spinal alignment may have resulted in reduced health issues which
played out beyond the duration of the study.
Figure 4 Holding fish using lip grippers whilst still in the water is a great way to keep them calm and
healthy, maximising their chance of survival (Pic courtesy of Jamin Forbes)
Whilst this study focussed on barramundi, it is likely that other species like
Murray cod, big threadfin salmon, and jewfish also don’t handle being lifted up
by their jaw (would you!?), What’s more, these findings also raise some
concerns at potential impacts of grabbing fish by their tail and lifting them up
(which anglers do from time to time with tunas, mackerels and a host of other
species).
So in short, if you’re using a lip gripper, keep the fish in the water if possible
(through look out for crocs up north). If you must take the fish out of the
water, make sure you give it plenty of support at the fish’s mid-section. This
will help to minimise the stress on its operculum and spine, and make sure it
swims away to fight again another day.
Last Updated February 2008