Consequently they are of low value and
generally not retained.
Nonetheless, substantial progress has
been made in reducing shark bycatch in
the Hawaii longline fishery (Walsh et al.
2009). Shark finning was banned in this
fishery in 2000. Sets of shark fins must
now be landed with corresponding
carcasses (NMFS 2009). This and other
changes in the fishery (switching from
squid to mackerel-type bait for sword-
fish) have resulted in the substantial
reduction of the shark mortality rate
by 89% in the swordfish fishery and by
94% in the tuna fishery in Hawaii (Walsh
et al. 2009). Blue sharks dominate the
incidental shark catch in the fishery.
The percentage of blue sharks caught
and released alive is very high (94-96%).
The blue shark appears to tolerate
capture and handling stress and the
survival rate after release is thought
to be high (Moyes et al. 2006).
Hawaii longline fisheries interact with
seabirds. The U.S. Fish and Wildlife
Service (USFWS) prepared Biological
Opinions in 2002 and again in 2004
under Section 7 of the Endangered
Species Act on the effects of the Hawaii
longline fishery on the short tailed
USFWS concluded that due to the low
interaction rate the fishery is not likely
to jeopardize the species’ continued
existence (USFWS 2002; USFWS 2004).
The fishery has
developed and implemented measures
that have significantly reduced seabird
bycatch (Gilman et al. 2007a; Gilman et
al. 2008). These include requirements
for carrying line clippers, dip nets
and de-hookers for safe handling of
seabirds (NMFS 2009). Other measures
control the attractiveness of and access
to the baited hooks. Side-setting
(opposed to stern-stetting) longline
gear is one practical way to be certain
the baited hooks sink safely beyond
the reach of seabirds. Bird-scaring
curtains are also used to keep diving
seabirds away from baited hooks.
If side-setting is not used, there is an
alternative set of conservation measures
that focus on distracting seabirds away
from baited hooks by strategically
discharging fish offal, dying baits blue
to make them less attractive to birds
and setting the baited hooks during
dark hours to limit the visibility of
the baits. Seabird bycatch reduction
measures implemented in June 2001
reduced the bycatch rate by 96%
(Van Fossen 2007).
Sea turtles can become hooked and
or entangled in pelagic longline fishing
gear. These accidental sea turtle
captures are extremely rare events in
the Hawaii fishery (Gilman et al. 2007b).
NOAA prepared Biological Opinions
in 2004 and 2008 and concluded that
the anticipated impacts of the Hawaii
longline fisheries on sea turtles was
not likely to jeopardize the continued
existence of these species.
Protecting sea turtles.
longline fishery has greatly reduced sea
turtle bycatch by about 90% (Boggs et al.
2009; Gilman et al. 2007b). The only
reliable way to document this requires
a high level of monitoring by impartial
fishery observers. At-sea fishery
observers are deployed on Hawaii
longliners targeting swordfish (100%
trip coverage) and bigeye tuna (>20%
trip coverage). They monitor fishing
activities and document protected
species interactions. The swordfish
sector operates within a hard cap sea
turtles captures (17 loggerheads or
16 leatherbacks). These interactions
range from lethal to harmless entangle-
ments with live release, so that captures
do not equal mortalities. If either cap is
reached, the swordfish fishery is closed
immediately in real time and vessels
must return to port. No other longline
fleet in the Pacific operates under a
hard cap to protect sea turtles. NOAA
PIRO maintains an updated tally list of
sea turtle interactions in the Hawaii
swordfish (shallow-set) segment of the
longline fishery. The cap has only been
reached once since it was implemented
NOAA observer with red-footed booby
ON THE WEB:
Loggerhead Turtle Interactions in
the Shallow-set Component of the
Hawaii-based Longline Fishery [NOAA].
Photo: NOAA Observer Program