Skip to Search
Skip to Navigation
Skip to Content


A New Status Quo in the Catch-and-Release Era


By: Mauri Liberati & Jan-Michael Hessenauer



Globally, fishing remains a subsistence activity. Fish are a food staple for many communities, therefore, fishermen and women keep what they catch. However, increasing food security has changed the fate fish in many developed nations.

The use of non-market fisheries in the United States have been undergoing a transformation - from subsistence to recreation. Over the past century, recreational fishing for some species has increasingly shifted to catch-and-release dominated practices. The release of fish has implicitly been viewed as beneficial because the fish (especially sport fish) are returned and available to be captured again. WFCC Directory Dr. Jason Vokoun and former student Dr. Jan-Michael Hessenauer designed a study to evaluate the effects of recreational angling on Largemouth Bass populations.

Largemouth Bass (Micropterus salmoides) are among the most popular sportfish in the United States and Connecticut. Connecticut is uniquely situated to evaluate the effects of recreational angling because, in addition to having heavily utilized populations, it also has several large waterbodies that have been completely protected from angling. These unique unfished populations provide a ‘control’ or reference to evaluate the effects of recreational angling. In collaboration with the Connecticut Department of Energy and Environmental Protection (DEEP) Inland Fisheries Division, Vokoun and Hessenauer’s research was able to take advantage of this natural angling experiment by comparing individuals from unfished populations to individuals from fished populations.

To date, these comparison have revealed that unfished populations have higher densities of large fish, but have similar body conditions to fished population. They also determined that unfished populations have higher abundances of individuals with high metabolic rates. Metabolic rates are linked to angling vulnerability, so fish with high metabolic rates are more likely to be caught and may be removed from fished populations through a process known as fisheries induced evolution. The project also found that fish from fished lakes that had never experienced angling learned to avoid lures faster than fish from unfished lakes.  A field trial of individuals from unfished populations stocked into these lakes revealed that these naive fish were captured at very high rates by small club tournaments.


Ultimately, the goal of this research is to improve recreational fisheries management in Connecticut. This is particularly important given the new status quo, where for some populations every fish may be caught three or more times each summer.


The next phase of this research project will be evaluating whether unfished individuals can breed successfully in wild fished lakes. If they can breed successful, they could provided fisheries managers with a way to infuse high metabolic rate characteristic (therefore, easier to catch fish) back into these waterbodies.




Publications resulting from this research:


Hessenauer, J.M., J. Vokoun, J. Davis, R. Jacobs, and E. O’Donnell. 2016. Loss of Naivety to Angling at Different Rates in Fished and Unfished Populations of Largemouth Bass. Transactions of the American Fisheries Society 145: 1068-1076.


Hessenauer, J.M., J. Vokoun, C. Suski, J. Davis, R. Jacobs, and E. O’Donnell. 2015. Differences in the metabolic rates of exploited and unexploited fish populations: a signature of recreational fisheries induced evolution? Public Library of Science One 10(6): e0128336. DOI: 10.1371/journal.pone.0128336


Hessenauer, J.M., J. Vokoun, J.P. Davis, R.P. Jacobs, E.B. O’Donnell. 2014. Population characteristics of historically unexploited largemouth bass in southern New England water suplly reservoirsJournal of Freshwater Ecology 29(3): 429-439. DOI: 10.1080/02705060.2014.910147




Research in the news:


CBC Quirks & Quarks - June 13, 2015 - "Sport fishing makes fish harder to catch"


WNPR - June 16, 2015 - "Connecituct study says recreational angling may influence how fish evolve"


Inside Science - June 15, 2015 - "Sports fishing opens evolutionary can of worms: a study of lakes in Connecticut reveals that recreational agnling pushes largmouth bass to evolve"


Bangor Daily News - June 14, 2015 - "Can't catch any largemouth bass? It may not be bad luck. Researchers think the fish are evolving."


The Waterbury Replican American - June 9, 2015 - "Survival of the fattest: while highly strung fish end up on the line"


Fishsens Magazine - June 5, 2015 - "Recreational fishing may harm fish species in the long term"


AAAS EurekAlert! - June 3, 2015 - "Differences in metabolic rates of exploited and unexploited fish populations"


Science Daily - June 3, 2015 - "Differences in metabolic rates of exploited, unexploited fish populations"


UConn Today - June 3, 2015 - "Study points to human impact on evolution of freshwater fish"


Wildlife and Fisheries Conservation Center
Department of Natural Resources and the Environment
University of Connecticut
1376 Storrs Road, Unit 4087