contributing to post-release predation in an attempt to unlock
mitigation strategies. To accomplish this we conducted a study in
a tidal creek in Eleuthera to compare the swimming capabilities
and predation rates of bonefish immediately after their release
compared to those retained in a ‘recovery bag’ for 15 minutes
prior to release. To assess swimming capabilities we tagged
bonefish with accelerometers and tracked them for 30 minutes
post-release to visually monitor behaviour, survival, and remove
the tags to retrieve the data. We found that bonefish were much
more vigorous after being retained in recovery bags, and
exhibited significantly improved swimming capabilities within the
first 5 minutes post-release; this period is the most critical time
for post-angling bonefish survival, as this is when most post-
release predation typically occurs. Additionally, we found that
bonefish retained for a short period also spent more time in
shallower water, close to mangrove and rocky structures, while
immediately released fish swam into the main creek channel
more often, which is where one immediately released fish was
attacked by a large great barracuda. Collectively these results
suggest that retaining bonefish for a short period in a recovery
bag has strong potential to reduce post-release behavioural
impairment and predation rates of angled bonefish in regions
where predator burden and predation risk is high.
The Take-Home Message
Bonefish populations are currently faced with numerous threats
to their sustainability, sparking concerns about their
conservations from anglers and scientists alike. We now have
insight into the daily patterns of bonefish swimming and foraging
behaviours, and perhaps more importantly, we have developed
methods capable of measuring bonefish foraging in the wild to
determine key feeding locations. These data could go a long way
for understanding and protecting key bonefish habitats. Further,
recovery bags appear to be a promising tool for anglers, allowing
them to retain bonefish for a short period to improve post-release
survival in situations where predation risk is high. While more
research must be done to address these questions, with
continued support from enthusiastic anglers and organizations
like Bonefish and Tarpon Trust, we are opportunistic about the
future of bonefish research and conservation.
Research has found post-release predation rates of up
to 40% in some regions...retaining bonefish for a short
period in a recovery bag has strong potential to reduce
post-release behavioural impairment and predation
rates of angled bonefish in regions where predator
burden and predation risk is high.
New Tech—
Accelerometers measure fish
behaviour on a finer scale
Most of us carry an accelerometer with us nearly all
the time. They’re a component of all smartphones,
used primarily to measure movement and changes
in orientation to alter screen rotation. Because of
this functionality, accelerometers are also very
useful for studying fish behaviour. When placed on a
fish as a compact tagging package, this technology
provides extremely fine-scale (up to hundreds of
samples per second) information about the fish’s
movement and body posture. Every tail beat and
body turn is measured in acceleration forces,
documenting each movement that the fish makes,
which is useful for studying behaviours such as
swimming, spawning, or feeding.
Recovery bagAccelerometer