The Gulf of Mexico Fishery Management Council recently modified its Reef
Fish Fishery Management Plan to require that non-stainless steel circle
hooks be used when fishing for reef fish using natural baits. Although the
Council was primarily concerned with reducing red snapper discard mortality,
the rule, which took effect June 1, 2008, was applied to all reef fish
fishing. For purposes on analyzing the proposed action, the amendment
assumed that circle hooks could reduce discard mortality by up to ten
percent. Based on public comments, that may be a conservative estimate.
The following rationale and references are out of Reef Fish Amendment 27
(the amendment is available on the library section of the Council website,
- For many species, circle hooks reduce hooking mortality rates more than
J-style hooks (Cooke and Suski 2004).
- Reduction in release mortality associated with the use of circle hooks
results primarily from the tendency of circle hooks to jaw-hook fish (Cooke
and Suski 2004).
- Some studies indicate catch rates and mean length at capture for red
snapper are greater for circle hooks compared to J-hooks (Sullivan et al.
1999; Henwood et al. 2006); however, Powers and Shipp (personal
communication.), found similar mean length at capture, but lower catch rates
for red snapper caught with circle hooks compared to Jhooks.
- More red snapper caught with rod-and-reel gear die from hook mortality
caused by Jhooks
than all other causes combined, including depth, stress, and handling (Burns
et al. 2002). Additionally, Burns (personal communication.) has shown tag
return rates for red snapper caught on circle hooks to be greater than
- Preliminary data suggest that venting increases survival in red snapper
caught in deep water (Burns and Porch, personal communication).
- Ease of hook removal is a major contributor to release survival (Cooke and
- Venting, when properly executed, increases survival of released fish.
- Large hooks in general result in some size selectivity towards larger
fish; however, they do hook smaller fish as well (Cooke and Suski 2004).
You might also check the following references that are available online (do
a google search on the title to find them):
World Wildlife Organization. 2005. Year-long Study Shows Circle Hooks Help
Save Sea Turtles
Ng, A. and A. Ng. 2003. Effects of hook treatment and water depth in a
commercial hook-and-linr grouper fishery, Onslow Bay, NC
Bacheler, N.M. and J.A. Buckel. 2004. Does hook type influence the catch
rate, size, and injury of grouper in a North Carolina commercial fishery?
(only abstract is online for free - full article can be purchased from
There's lots more references on the subject, but these are some that I know
of that are available online.
Population Dynamics Statistician
Gulf of Mexico Fishery Management Council
(Sorry for the delay in replying, but the Fish-Sci listserv for some reason
will not accept e-mail sent from my web based e-mail client.)