RE:Addressing Hook Mortality IS Important
Been a while since I've been around, however, I seem to remember posting about this issue a couple of months ago - specifically the paper by Diodati and Richards, which is what I believe was used to set the recreational figure at 8%. I would imagine that the statistical analysis performed was some sort of logistic regression and that is why you may have skewed confidence intervals (3-26%), while the mean may be closer to the lower boundary. The 50% figure was from a study in Maryland if I remember correctly - and that was strongly influenced by water temperature. Additionally, they moved the fish from a saline environment to a more freshwater system to hold them for mortality - stripers don't do as well mortality wise in the freshwater as compared to saltwater - which may have artificially inflated those figures. Massachusetts has the highest recreational mortality because more people fish for them here - and as a result more are landed - I think it is proportional to the pressure. Here are some papers that people may want to dig up at the local university or try a few search engines like Web of Science on the web - <a href="http://webofscience.com/CIW.cgi" target="_blank"><!--auto-->http://webofscience.com/CIW.cgi</a><!--auto-->
Here is the paper I was referring to (got this off Web of Science - search topic-striped and bass and mortality):
Mortality of striped bass hooked and released in salt water
Diodati PJ, Richards RA
TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY
125: (2) 300-307 MAR 1996
Document type: Article Language: English Cited References: 22 Times Cited: 1
Despite the importance of the recreational fishery for striped bass Morone saxatilis along the eastern coast of the United States, little is known about the survival rates of caught and released striped bass. We predicted long-term (58-d) hooking mortality of striped bass after catch and release in saltwater using a logistic regression model. Experimental fishing was conducted on fish (27-57 cm) in a 2-ha saltwater impoundment in Salem, Massachusetts. Depth of hook pen etration in the oral cavity, anatomical site of hooking, gear type (treble or single hooks), and angler experience were significantly related to mortality (P < 0.05). The logistic regression model was developed with backwards stepwise selection to predict probability of death from hooking. The final model included depth of hook penetration, gear type, and angler experience as predictor variables. Predicted mortality ranged from 3% under the most favorable conditions to 26% for the worst set of conditions. Predicted as well as observed mortality for the entire experimental group was 9% which is generally much lower than reported in striped bass hooking mortality studies conducted in freshwater. At the end of the experiment, condition factors were significantly lower for surviving hooked fish than for fish that had not been hooked.
Diodati PJ, MASSACHUSETTS DIV MARINE FISHERIES, CAT COVE MARINE LAB, SALEM, MA 01970.
NATL MARINE FISHERIES SERV, NE FISHERIES SCI CTR, WOODS HOLE, MA 02543.
AMER FISHERIES SOC, BETHESDA
Here are a few more citations that people find interesting:
Bettoli, P. W. and R. S. Osborne. 1998. Hooking mortality and behavior of striped bass following catch and release angling. North American Journal of Fisheries Management 18: 609-615.
Dorazio, R. M. 1995. Mortality estimates of striped bass caught in Albemarle Sound and Roanoke River, North Carolina. North American Journal of Fisheries Management 15: 290-299.
Henderson-Arzapalo, A., P. Rago, J. Skjeveland, M. Mangold, P. Washington, J. Howe and T. King. 1999. An evaluation of six internal anchor tags for tagging juvenile striped bass. North American Journal of Fisheries Management 19: 482-493.
Nelson, K. L. 1998. Catch-and-release mortality of striped bass in the Roanoke River, North Carolina. North American Journal of Fisheries Management 18: 25-30.
Tomasso, A. O. and J. J. Isely. 1996. Physiological responses and mortality of striped bass angled in freshwater. Transactions of the American Fisheries Society 125: 321-325.
The tagging one is a little off the topic, however the mortality rates are eye-opening and leads me to really discourage recreational angler tagging operations, such as those run by the American Littoral Society (ALS). On the topic of angler tagging info - American Fisheries Society publishes Fisheries a magazine with some good scientific content and they had several articles on this topic in the last issue, specifically looking at the attitude of states in allowing or discouraging the practice.
If you guys want to really know what is going on - then I cannot stress how much a SW license would benefit the agencies that deal with these issues. We have IMO weak data on angler participation and pressure on the resource - a license would bring in the needed revenue stream to carry out some projects - until then it is pretty much a caretaker role.