Release Recovery
BY RYAN K. LOGAN, M.S.
RELEASE RECOVERY
Tracking the time it takes billfish to recover after release
Considered by many to be ultimate gamefish, blue marlin and sailfish are found worldwide in both tropical and subtropical waters. Noted for their high-speed runs, strong fights, and aerial acrobatics, these are some of the most sought-after fish in offshore angling. Recreational fishing for these charismatic species continues to increase around the world, providing considerable economic benefit, and prompting many countries to mandate catch-and-release practices for perceived conservation.
For the angler, a fight with a billfish consists of a fast-paced, high-energy battle of wills that hopefully culminates in a safe release, some high-fives, and a quick redeployment of the spread for the next one. But for the fish, this is a fight for its life. It uses a tremendous amount of energy doing so, and it is precisely those high-speed runs and aerial acrobatics that beg the question: How long does it take them to physically recover from that fight after being released?
SURVIVAL OF THE FITTEST
Previous research into the survival of several billfish, depending on the species, has shown that approximately 86 percent survive to fight another day after being released. This is good news for anglers, and suggests that recreational catch-and-release is—and continues to be—a successful management practice to conserve billfish populations. However, how the behavior of the billfish changes and how long it takes for the fish to recover have received far less attention, and could have important implications.
For example, if many fish are caught during a spawning aggregation but then fail to spawn after being released, that would greatly reduce the reproductive output of that population. Reproductive output is an important term for estimating population sizes, and previous studies examining recovery times have produced surprisingly different results (a few hours versus several weeks), depending on the post-release tracking method used. With robust information on what the fish do after release, what temperatures and oxygen levels they need to recover, and accurate information on their recovery dynamics, it might be possible to predict how many fish will not survive a fight with a fisherman based on the environmental conditions of where they are caught. Therefore, understanding how fish behave and how long it actually takes them to recover will add an important component…
