A recently published review and synthesis of the scientific literature suggests that venting (deflating) the swim bladders of released fish has no affect on survival of marine or freshwater species.Last May, I assembled published papers, reports, and other materials that compared survival rates of fishes that had been vented (or fizzed) with survival rates of fishes that were not vented. Once these studies were assembled, I performed a meta-analysis to determine the overall benefit of venting to fish that show signs of barotrauma.
The results of that study were published in the January 2009 issue of Fisheries (published by the American Fisheries Society). In a nutshell, there is very little evidence that venting fish has any positive affect on survival. In fact, the available evidence suggests that venting may be harmful for fish captured from deep water.
A copy of my paper can be viewed here.
As work progressed, I learned that the NOAA National Marine Fisheries Service had published a rule that required anglers fishing offshore in the Gulf of Mexico have in their possession devices for venting captured fishes. The rule, which also requires use of non-stainless steel circle hooks, and use of hook-removal devices.
The rationale for the rule is, “… to reduce the red snapper catch, bycatch, and discard mortality in the directed commercial and recreational fisheries, as well as in the shrimp fishery. These regulations are designed to ensure a reasonable probability of ending red snapper overfishing by 2010 and rebuild the stock by 2032.”
A similar rule is being considered for anglers fishing in the South Atlantic. Comments on the proposed rule are being accepted through 23 February 2009.
In both cases, the rule is well intended, but venting has not been shown to reduce “discard” mortality and there is reason to ask if this requirement ensures a "reasonable probability of ending red snapper overfishing by 2010."
Thanks to Bill Sawnok at Infofish Services for the photograph of a coral trout being vented.
Venting can also be harmful if not done correctly. I have seen the 'hands' of a party boat just blindly stab at the fish until they vent. Many times they go back in worse condition than a full air bladder.
ReplyDeleteYour links do not go where they are supposed to or the article is taken down for some strange reason. I can only speculate that what your paper states is that there is no safe way to release a deep water fish and that we should keep it regardless of size limit restricitons? Or is your approach exact science? What was the focus of your study and just how accurate is it? Is it non-biased? Of course there has been mistakes made on party boats and what not, but I have to question just how even us fishermen know if the fish actually lives to fight another day or ultimately meets its demise an hour; maybe a day later? I sure wish I could read the report, may shed some light on my questins. However, until then, I have to listen to people who have and I must say, sure has some in an uproar...
ReplyDeleteWhat's the latest word on this topic?
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