Wednesday, August 24, 2011

Catching a Shark: marine laboratory to study effects of catch-and-release

In many parts of the world sportfishing is big business - there's no getting around it. And so whether you support or are opposed to the practice, it will probably be around for some time as long as there is money to made.

But it can be altered to provide for greater survivability of the fish through catch-and-release techniques. For conservationists, this isn't an ideal solution by any means. Dr. Sylvia Earle refers to catch-and-release as "torture and release" and to a large extant she has a point. Catching any fish by hook causes stress on the animal. After all, it was swimming and feeding one moment and the next, it's in complete survival mode fighting against some unknown force and slowly reaching a state of total exhaustion before being momentarily manhandled and then once again free to roam.

So, one way to look at catch-and-release is that it is an incremental step, one foot forward towards a greater awareness as to the sustainability and current dwindling populations of, in particular, large species like billfish and sharks. That is part of the philosophy behind the Shark Free Marinas Initiative (SFMI), supported by The Humane Society of America and the Guy Harvey Ocean Foundation. This organization gets sportfishing marinas to sign up to be "shark free" - meaning no sharks can be brought in to their docks for weighing, trophy photos, butchering, anything. No sharks, period.

Sure, to us hard core conservationists it would be great if all sportfishermen abandoned their rods and reels but, again, the economic underpinnings make it very unlikely that state or local governments will pass the required regulations that would effectively outlaw the sport. In California, legislation to prohibit the possession, trade, and distribution of shark fins is preparing for a final vote in the state senate. Those who oppose the legislation, AB 376, are pushing their campaign for a series of crippling amendments not because they hate sharks or love shark finning but because they see considerable dollars and many jobs that will be lost with its passage. Those who favor the legislation must carefully hone their argument and keep in mind that it is not the moral position or even the environmental position that will likely sway the politicians; it will be the economic rationale. And in today's current economic mess, any talk of lost revenue or jobs will certainly catch a politician's interest.

But I digress. . .

If we concede that catch-and-release is at least one step back from the brink of destruction of a fish, it's not an unreasonable question to ask just how much of a step it really is. Just how traumatic is catch-and-release on, say, a shark? Are there any long-term effects? Does the animal survive for the moment but die some days or even weeks later due to complications?

To better understand the lingering effects of catch-and-release techniques, Florida's Mote Marine Laboratory will begin a one-year study on sharks, aided by a $192 million grant from the National Oceanic and Atmospheric Administration (NOAA). Assisted by the Florida Aquarium's Center for Conservation and the Massachusetts Division of Marine Fisheries, the study will enlist the services of several sportfishing charter boats and will focus primarily on the blacktip shark, a popular species for shark fishermen because it is known to put up a good fight and often leap out of the water - some of the same criteria that make billfish like marlin popular among sportfishermen.

“For the first time, we’ll take a magnifying glass to sharks’ behavior after release — for instance, we’ll look at how strongly they’re swimming after capture and whether they’re rolling or listing,” said project leader Dr. Nick Whitney, a staff scientist in Mote’s Center for Shark Research. “These measurements go way beyond ‘dead or alive.’ The vast majority of sharks may survive, but it’s important to know if their recovery time varies with different kinds of fishing gear. Our technique will yield new, hard data comparing standard J-hooks with circle hooks, which are designed to be safer for sharks.”

Scientists will enlist the use of accelerometers - the same little electrical devices that sense movement in your smartphone or handheld video game player - along with small data recorders to record the movements of a shark as it is released following a catch-and-release episode. Every flick of the shark's tail or tilt of its dorsal fin will be recorded. The devices will fall off the shark after a period of time and will be retrieved and analyzed to determine the shark's behavior after being caught. By understanding what is being inflicted upon the shark, either temporary or long-lasting, wildlife management agencies can then better determine how best to minimize the effects through regulations and the use of various types of fishing gear.

“The goal will be for the charter captains to use the same practices and gear that Florida anglers normally would, so we can compare the two hooks in a real-world setting and look at how they perform in relation to shark survival and behavior,” Whitney said.

Personally, I choose not to fish. As a diver I stopped spearfishing or taking game like lobster or abalone many, many years ago. But I realize that sportfishing is a popular activity and thriving business in areas like Florida, and that overly-efficient, but indiscriminate, commercial fishing probably poses a much greater threat to overall survivability for many ocean species. So, if I want to sit down with a sportfisherman and have a go at changing his mindset and his hobby, having the scientific facts, as this Mote Marine Laboratory study hopes to obtain, will give me some heft to my argument - and could just maybe help prevent me from getting punched in the nose.

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