Stop cuddling the marlin!

With the marlin snapping right along the Queensland coast and now ranging into NSW, not to mention the hot WA bites, The Billfish Foundation (TBF) has issued a precautionary warning to anglers to help maximise the survival rates of these amazing sportsfish.

The Foundation says on its website that removing a billfish from the water not only causes unnecessary harm to the fish, but in many cases, it will kill the fish.

For those lucky enough to have caught a marlin, sailfish, or swordfish, the memory of the first billfish is perhaps one of the most coveted experiences for any angler.

Although it's a memory that will last forever, many anglers want a photo with their first billfish. Pulling billfish out of the water is illegal in U.S. Atlantic waters unless the fish is going to be harvested. Unfortunately, more and more photos of people holding up sailfish or small marlin or stretching them across the covering boards are posted on websites, sent via social media and published in fishing magazines.

However, removing billfish from the water puts additional stress on their body after the initial stress caused by the fight. Contact with the fish removes the slime that protects it from parasites and infections. Just like a person whose immune system is weakened after a hectic or traumatic experience, billfish are more susceptible to infections or diseases when stressed.

A billfish’s skeleton is designed for buoyant conditions of the ocean, so when removed from the water the skeleton and internal organs come under the strain of gravity, which can cause serious harm to the fish. While some research is complete on the effects non-offset circle hooks have in reducing billfish post-release mortality, less research is complete on assessing effects of fight times and other fishing stressors.

In studies by students at the Virginia Institute of Marine Science (VIMS) 22 pop-up satellite archival tags (PSATs) were deployed on white marlin caught using circle hooks. As part of the study, blood samples were taken from the fish requiring removal of the marlin from the water. Data from the PSATs indicated that 21 per cent of those white marlin died immediately after release. In a separate, similar study also conducted by VIMS, 30 white marlin were tagged without being removed from the water and resulted in only two per cent post-release mortality.

It was hypothesised that the significantly different mortality rates could be due to the additional stress put on the white marlin when removed from the water. It’s also interesting to note that the white marlin that did not survive, did not experience the longest fight times.

Researchers hypothesise that a short fight time before being removed from the water for blood samples may be equivalent to a human sprinting for as long and hard as possible, then being forced to hold their breath! Results from PSAT studies also show that it can take billfish as long as 14 days to recover and resume normal behaviour.

It is well known that stress caused by fight time makes a fish more vulnerable to predation and commercial fishing pressure. Anglers should strive to keep the billfish from getting injured, especially when deploying a $4000 PSAT, to gather valuable data. The scientists took every precaution during the research to ensure the survival of the fish, but even so some died, perhaps due to the additional stress from being hauled aboard a boat, being deprived of oxygen and having blood taken.

For anglers, the condition of the hooked billfish should be a priority. Injury can be mitigated by using non-offset, circle hooks with all natural baits, proper hook removal, and using tackle to match the size of your quarry. Taking the time to rig baits, spectacular boat handling, and world-class angling is all for nothing if the fish is pulled from the water and injured.

If an angler wants a photo with his or her fish, TBF recommends safe handling practices be followed. Once the fish is alongside the boat, keep it in gear with the fish’s lower jaw in the water to ensure oxygenated water passes over the gills. Then the angler can lean over the gunnel while someone snaps photos.

TBF says that taking the time to ensure a safe release is the mark of a real sportsman, not just the number of flags flying from outriggers, or pictures on a wall. The next time someone wants to pull a billfish out of the water for a photo, ask that person if the photo is worth the life of the fish. A photo may be worth a thousand words, but it is not worth killing a billfish.

Opening shot of a small black marlin kept in the water by David Lockwood. Second shot of a striped marlin.