@article{jiang_pollock_brownie_hightower_hoenig_hearn_2007, title={Age-dependent tag return models for estimating fishing mortality, natural mortality, and selectivity}, volume={12}, ISSN={["1537-2693"]}, DOI={10.1198/108571107x197382}, abstractNote={Tag return studies play an important role in providing estimates of mortality rates needed for management of many fisheries, but current methods of estimation do not allow age dependence of instantaneous mortality rates. We present models that allow age-dependent fishing and natural mortality rates, an important advance, because there is often substantial variation in age (and size) of fish at tagging. Age dependence of fishing mortality is modeled by assuming that availability to the fishery, that is, selectivity, depends on age but is constant over years. We assume that all age classes are tagged each year, and allow for incomplete mixing of newly tagged fish and for fisheries that are year-long or limited to a fishing season. We investigate parameter redundancy and estimator performance using analytic and simulation methods, and show that estimator properties are poor if the tag reporting rate is estimated (without auxiliary data such as planted tags). We analyzed multiple age class tag return data from a 13-year study on striped bass (Morone saxatilis) and saw clear evidence that selectivity increases with age. Assuming that the tag reporting rate is constant and known, results also demonstrate age dependence of natural mortality rates, and an increase in natural mortality rates from about 1999 coinciding with observation of a bacterial disease in the fish.}, number={2}, journal={JOURNAL OF AGRICULTURAL BIOLOGICAL AND ENVIRONMENTAL STATISTICS}, author={Jiang, Honghua and Pollock, Kenneth H. and Brownie, Cavell and Hightower, Joseph E. and Hoenig, John M. and Hearn, William S.}, year={2007}, month={Jun}, pages={177–194} }
 @article{jiang_brownie_hightower_pollock_2007, title={Estimating fishing mortality, natural mortality, and selectivity using recoveries from tagging young fish}, volume={27}, ISSN={["0275-5947"]}, DOI={10.1577/M06-127.1}, abstractNote={Abstract Current methods for estimation of age- and year-specific instantaneous mortality rates based on multiyear, multiple-age tagging studies assume that it is feasible to tag fish in a wide range of ages. For some species, however, only the youngest one or two age-classes are readily available for tagging. Given the practical advantages of tagging young fish only, an important question is whether such studies would provide the information needed for estimation of age-dependent mortality rates. We investigated three designs: tagging only the youngest available age-class, tagging the two youngest age-classes, and tagging the first five age-classes. We carried out simulation studies to assess estimator performance under these three designs, in each case assuming the same total number of tagged fish. Data were generated assuming fishing mortality rates to be age and year dependent and natural mortality rates to be constant or with limited age dependence. Estimator performance is best when fish are tagged ...}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Jiang, Honghua and Brownie, Cavell and Hightower, Joseph E. and Pollock, Kenneth H.}, year={2007}, month={Aug}, pages={773–781} }
 @article{jiang_pollock_brownie_hoenig_latour_wells_hightower_2007, title={Tag return models allowing for harvest and catch and release: Evidence of environmental and management impacts on striped bass fishing and natural mortality rates}, volume={27}, ISSN={["0275-5947"]}, DOI={10.1577/M06-089.1}, abstractNote={Abstract Catch-and-release fisheries have become very important in the management of overexploited recreational fish stocks. Tag return studies, where the tag is removed regardless of fish disposition, have been used to assess the effectiveness of restoration efforts for these fisheries. We extend the instantaneous rate formulation of tag return models to allow for catch and release as well as harvest. The key point of our methods is that, given an estimate of the tag reporting rate, the fishing mortality rate (F) is separated into two components: the mortality on harvested fish and the “mortality” on tags (because the tags are removed) of fish released alive. The total fishing mortality rate for untagged fish is the sum of the Fs due to harvest and hooking mortality suffered by fish released alive. Natural mortality rates can also be estimated. Both age-independent models and age-dependent models are constructed, and the age-dependent models are illustrated by application to data from a study of striped ...}, number={2}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Jiang, Honghua and Pollock, Kenneth H. and Brownie, Cavell and Hoenig, John M. and Latour, Robert J. and Wells, Brian K. and Hightower, Joseph E.}, year={2007}, month={May}, pages={387–396} }
 @article{pollock_jiang_hightower_2004, title={Combining telemetry and fisheries tagging models to estimate fishing and natural mortality rates}, volume={133}, ISSN={["1548-8659"]}, DOI={10.1577/T03-029.1}, abstractNote={Abstract The traditional multiple-year tag return method is a fundamental approach to estimating fishing and natural mortality rates in fisheries. It can provide reliable and precise estimation of the parameters when the tag reporting rate, λ, is known. However, it is often difficult to estimate λ accurately. An additional disadvantage is that this method has to estimate natural mortality indirectly because natural deaths are not observable. Recently, fisheries biologists have begun to implement telemetry methods to estimate fishing and natural mortality. The advantage of a telemetry method is that it contains direct information about natural mortality and survival. A shortcoming is that there is no direct information on fishing deaths. In this paper, we combine the two methods, using direct information about both fishing and natural mortality to obtain more precise and effectively unbiased parameter estimates, including reporting rate estimates for the regular tags. Using simulation when the telemetry ta...}, number={3}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Pollock, KH and Jiang, HH and Hightower, JE}, year={2004}, month={May}, pages={639–648} }