Did this bad boy for my Quantitative Business Analysis MBA class and thought I would share.
Performance of circle hooks relative to traditional ‘J’ hooks in survival of billfish species relative to the recreational and commercial fisheries.
A L E C B R E A U D
BUS540
Abstract
There is a lot of commotion for fisherman across the country now that circle hooks have been mandated for natural baits during tournaments starting in 2008. So much so, that the decision to implement this plan was pushed back from 2007 until the upcoming year. That may have delayed the inevitable, but fishermen (both recreational and commercial) need to understand how important the circle hook is in conservation. The goal of this paper is to prove the benefits of circle hooks when compared to ‘J’ hooks when used to catch offshore fish (namely, billfish).
Circle Hooks vs. ‘J’ hooks in the Commercial and Recreational Sectors
The upcoming 2008 fishing season ushers in a new era for recreational anglers: the age of the circle hook. Benefits of using such have been widely proven, yet some fishermen are wary about their use. Most likely, this resistance to change relies in a deep-rooted sense of pride when out on the deep blue sea. We use what our fathers used and have built upon that knowledge over the years, fine-tuning our practices. Now the NMFS wants to take it all away with regard to tournament fishing and trolling natural baits, dead or alive, skirted or not. While this may pose a problem in the short run, the naysayers should look at it as an opportunity to save the sport we all love so much, and as a means to discover new methods of fishing. Change is not necessarily a bad thing, despite the old adage, “Never leave fish to find fish.”
It is a well known fact throughout the fishing community that billfish are experiencing declining stocks. Some species face possible endangerment. Most of us in the recreational sector choose to blame the commercial harvest and pelagic long lining for the decline, but we also share in the responsibility. Since our resources are shared, it is in the best interest for both parties to conserve. However, “maximizing [recreational] catch rates and maximizing [commercial] sustainable harvest are competing objectives.” (Goodyear 2007)
The solution is clear and simple: conservation is key. The commercial fleet is not going to stop their fishing and neither are we. As an added downfall, the National Marine Fisheries Service seems to favor the commercial guys, and some of the leading advocates out there will swing either way depending on who is signing his or her check. Despite those conflicts, it is up to the individual to make a difference. Keeping only what you can eat should always be practiced, as showing up at the dock loaded down with fish destined for the dumpster seems simply cruel. Catch-and-release is always a good option, and one I practice most of the time. Following that ideal requires more care in handling the fish, especially with the hookup. The angler must be cautious as to how well the fish can survive post-release. The best method for doing so is using circle hooks.
Not only should the recreational anglers stick to circles when fishing for pure fun, but the commercial sector needs to take heed. They are responsible for a lot of by catch. Many different types of sea creatures are killed in their long lining gear or nets each year, so they should change as well. This also requires some effort to adjust the gear, but again the benefits greatly outweigh the costs.
Numerous studies have been conducted on both sport fishing and long lining vessels with regard to the percent mortality of billfish species when using circle and the traditional ‘J’ hook. Circle hooks, divided into two categories (offset and non offset shank), are defined as “having a point angled perpendicular to the main hook shank.” (Prince
et al 2007) The design of the hook allows it to rotate freely while in the mouth of the fish, and when pulled at an angle it is more likely to set in the external portion of the jaw rather than internally (Kerstetter
et al 2006). Offset circle hooks, while more likely to set in the mouth than ‘J’ hooks, may still result in internal injuries. The traditional ‘J’ hook, which has been mostly used for decades in both recreational and commercial sectors, will often times gut hook a fish and reduce its chance for post release survival. So far, the results have been staggering for the long lining fleet. One study of sailfish mortality off the coast of Brazil resulted in far fewer dead specimens with circle hooks versus ‘J’ hooks (33.3% and 73.1%, respectively) on commercial gear (Kerstetter
et al 2006). Another sailfish study resulted in 61.1% live released fish at the time of gear haulback in the Gulf of Mexico (Kerstetter and Graves 2006).
For the recreational anglers, a group of scientists and conservationists accompanied four charter captains from the area surrounding Palm Beach and Miami to determine the benefits of circle hooks versus ‘J’ hooks when releasing sailfish. Not surprisingly, the results were that the fish were much more likely to be released in ‘desirable’ condition when using the circle hooks. ‘Desirable’ was defined as having a high chance of post release survival, while undesirable meant that any amount of blood was present during the catch process. The proportion of undesirable releases for the circle hooks ranged from 0.39 to 0.47 (with a standard deviation of 0.04), and 0.49 to 0.79 (standard deviation of 0.14) for ‘J’ hooks (Prince
et al 2007).
While commercial fishermen do catch much grief from the recreational anglers, not much can be done to sway the opinion of the NMFS with regard to that category. Therefore, since we cannot change them, it is time for us to take the action. Many proposals have been given to NMFS for revision of the pelagic long lining rules, most of which are rejected. For example, one alternative recently not selected were measures to rig the long lines so that the hooks are fished deeper in the water column (NMFS.noaa.gov). According to a recent study of catenary geometry in estimating long line depths of commercial fishermen in the Windward Passage between Haiti and Cuba by Rice
et al (2007), most vessels were using a system of baskets that included four hooks between the two floats. The hooks closest to the floats would be closest to the surface since there was no drop in the line, while the middle two would drop down further. The distance from the float to the main line connecting the drops was 10 fathoms (60 feet), the length of the fishing line was 11 fathoms (66 feet), and the leader measured 1 fathom (6 feet). Therefore, the total depth of the lines highest in the water column was 132 feet. The plan not selected by the NMFS was to mandate hook sets could be no closer to the nearest float than 240 feet. The farther the hook is away from the float, the farther down it goes due to the sag present in the main line. As a result, more species that exist higher in the water column such as sea turtles, etc, would not be affected as much by the gear. An interesting study by Horodysky
et al (2007) shows that White Marlin (
Tetrapturus albidus) spend most of their time in this higher column. In fact, the probability of this species being present in waters above 40 meters (131 feet) is a staggering 78%. According to that figure, long liners should stick to deeper water if they want to reduce their billfish by catch. However, Horodysky
et al (2007) also states, “While higher billfish catches have been noted in shallow-set research on long line deployments, the historical shift to deeper fishing long lines has not always resulted in reduced billfish catch rates. In fact, recent billfish catch rates on Japanese deep-set long lines occasionally exceeded those on shallow-set long lines.” The commercial sector has much to learn about reducing by catch, which is why the recreational fishermen must do what has been proven to work in order to keep our oceans filled with these creatures.
Since this article is targeted to the recreational angler, from here on I will focus on what we can do to help these species stay alive. The biggest step in conservation is the new circle-hook rule for tournaments. However, tournaments are not enough to keep the fisheries sustained. Anglers need to follow these practices more often in order to make a difference. Circle hooks have been proven to reduce mortality rates in billfish due to less of a chance of “gut-hooking” the fish. The use of prior and posterior probabilities assists in explaining these benefits. Using data collected by Prince
et al (2007) in a recent study of hook types and drop back times with sailfish (
Istiophorus platypterus) in south Florida, I constructed tables to show various probabilities for hook type success and the probability of an undesirable hooking location.
Four studies were conducted by Prince
et al (2007) with regard to drop back times and hook types. The first circle hook used was an Eagle Claw L2004 8/0 of standard design. The second was an Owner 5179 7/0 circle hook that differed from the first hook by three factors: a straight shank instead of curved, wider gap between the hook point and the shank, and a smaller hook point. The third hook in the study was a Mustad 10829 6/0 ‘J’ hook. The three hooks were then divided into the four studies regarding drop back time: 0-5 s, 6-10 s, 11-15 s, and 15+ s. While the results differed slightly between the four studies, I chose to average the group in order to continue with my probability analysis. The only hook that stood out from the norm was the Owner 5179. It showed a much higher catch success when using the 15+ second drop back time.
Adding the total fish caught between the four studies yields 698 sailfish. 272 of which were caught on the first circle hook (Eagle Claw), 179 were from the Owner hook, and the Mustad ‘J’ hook landed 247 specimens. The percentage of the total for each types is 0.39, 0.26, and 0.35 respectively. The first area I wanted to tackle was the probability of success given a certain hook type. The probabilities for success given a certain hook type were also given by Prince
et al (2007) via sets of ranges. For the purposes of this paper I have averaged them for easier manipulation. The following table illustrates the results of this study:
Table One
The probabilities of success given a certain hook type are very important to the recreational angler. Most notable is the fact that the traditional ‘J’ hook prevailed in this study. On average, it had an 81% chance of hooking the target fish. However, this particular study did not account for the possibility that the fish was hooked in an unfavorable location. The other outstanding factor was the unsteady ranges for the Owner hook. The high range of .94 was due to the longer drop back period. While the ‘J’ hook was most successful in this case, the circle hooks trailed behind closely. The probability for overall successful hookup (P(S) when using one of these three hooks) stands at nearly 74%. The next factor, the chance that a given hook was used given a successful hookup, evens the playing field. Each was nearly as likely to be used if a fish hookup was successful. What this means for anglers is that circle hooks (when pitch baiting sailfish) are nearly just as successful, but their significance in conservation is explained in the next section.
The next set of probabilities I calculated dealt with the chance of a certain type of hook resulting in an unfavorable hooking location in the fish. ‘J’ hooks have been notorious with regard to gut hooking fish, which is why so many are landed and kept using them (since they are seriously injured or even dead by the time they get to the boat). Again, the probabilities were given in ranges by Prince
et al (2007), and I averaged them for ease of use. The results of this study are found below:
TableTwo
In this case, the ‘J’ hook had a significantly higher chance of unfavorably hooking a fish (40%). Further solidifying that fact is the joint probability of having both an unfavorable hookup and the use of the ’J’ hook (14%). Compared to both circle hooks which stood at a quarter of that figure each, the traditional hook is clearly more unsafe to the fish. The probability of the ‘J’ hook being used given an unfavorable hook location was also high at 68%. In all, the overall chance of unfavorably hooking a fish was low (20%), but this figure was diluted due to the better performance of the circle hook. Looking at the big picture, circle hooks again have proven to be the preferred alternative for anglers wanting to safely release their catch.
Conclusion
While recreational fishermen have had a difficult time integrating circle hooks into their tackle boxes when big-game fishing, the benefits of their use has clearly outweighed the downfalls of tackle reorganization and adjusting fishing techniques. The safer hook may not have a proven track record like the older, traditional ‘J’ hook, anglers can rest assured that they have given the released fish more of a chance for survival. That is important in billfishing since the catch is not retained in most cases (except for the occasional weigh-in at tournaments or keeping a specimen that may be a potential record). Bottom fishermen (those targeting snapper, amberjack, grouper, etc.) have accepted and gladly used circle hooks in their preferred arsenal, so the next logical step was to apply their use to the big-game crowd. With their approval and the increasing use of circle hooks in the long line and commercial industry (which is steadily rising because of reduced by catch and the fines associated with such), the future of fish stocks may be sustainable for future generations. Most will gladly agree that fact is the most important factor, because no one wants to be responsible for our children not being able to enjoy the same resources and sports we have been so privileged to partake in.
Acknowledgments
Much thanks is extended to all those who have helped me locate the sources and materials used in this study. Peter Chaibonsai, Science Specialist, at The Billfish Foundation (
http://www.billfish.org) was the first to respond with numerous articles pertaining to circle hook use. The Billfish Foundation is the leading conservation agency protecting billfish stocks around the globe. Most of the articles used were written by their own team of scientists located worldwide. Other thanks go to Jason Schratwieser of the International Game Fish Association. He actually took part in the recreational sailfish study that provided most facts and figures in this paper, as well as forwarding me many other articles. He is currently the Conservation Director at the IGFA and teaches their Certified Observer program. The IGFA is the worldwide authority for fish records and rule setting, and their policies and procedures have affected every person that has fished since their inception. Also, thanks to the many scientists that spent their valuable time collecting and analyzing fish stocks so that this paper was possible. Not surprisingly, the National Marine Fisheries Service failed to respond.
References
Goodyear, C.P. (2007) Recreational catch and release: Resource allocation between commercial and recreational fishermen.
North Atlantic Journal of Fisheries Management 27: 1189-1194
Horodysky, A.Z., Kerstetter, D.W., Latour, R.J., and Graves, J.E. (2007) Habitat utilization and vertical movements of white marlin (
Tetrapturus albidius) released from commercial and recreational fishing gears in the western North Atlantic Ocean: inferences from short duration pop-up archival satellite tags.
Fisheries Oceanography 16:3. 240-256
Kerstetter, D.W., and Graves, J.E. (2006) Post-release survival of Sailfish (
Istiophorus platypterus) captured on commercial pelagic long line gear in the southern Gulf of Mexico. Standing Committee on Research and Statistics for the ICCAT: 149
Kerstetter, D.W., Pacheco, J.C., Hazin, F.H., Travassos, P.E., and Graves, J.E. (2006) Preliminary results of circle and J-style hook comparisons in the Brazilian pelagic long line fishery. Standing Committee on Research and Statistics for the ICCAT: 150
National Marine Fisheries Service. “2.0 Alternatives.” <
http://www.nmfs.noaa.gov/sfa/hms/FSE...ection%202.pdf> Retrieved December 3, 2006.
Prince, E.D., Snodgrass, D., Orbesen, E.S., Hoolihan, J.P., Serafy, J.E., and Schratwieser, J.E. (2007) Circle hooks, ‘J’ hooks and drop-back time: a hook performance study of the south Florida recreational live-bait fishery for sailfish,
Istiophorus platypterus.
Fisheries Management and Ecology 14: 173-182
Rice, P.H., Goodyear, C.P., Prince, E.D., Snodgrass, D., and Serafy, J.E. (2007) Use of catenary geometry to estimate hook depth during near-surface pelagic long line fishing: Theory versus practice.
North American Journal of Fisheries Management 27: 1148-1161
Circle Vs J Hook paper 
