| UW / NWFSC / AFSC |
| Mini-Workshops |
| The mini-workshop series is a collaboration between fisheries stock assessment researchers at the University of Washington’s School of Aquatic & Fishery Sciences and the NMFS Northwest and Alaska Fisheries Science Centers. |
| For more information, email series coordinator Jason Cope at jcope@u.washington.edu |
| View the Spring 2003 schedule here. |
| Next Workshop: |
| Thursday, 12th June, 2003 |
| 9:30am-11:30am |
| UW Fishery Sciences Building, room 203 |
| Andre E. Punt |
| (School of Aquatic & Fishery Sciences, UW) |
| & Richard D. Methot |
| (NOAA Fisheries, Northwest Fisheries Science Center) |
| "The Impact of Recruitment Projection Methods on Forecasts of Rebuilding Rates for Overfished Marine Resources" |
| Abstract |
| Under the U.S. Sustainable Fisheries Act, Rebuilding Plans have to be developed for fish stocks that are determined to be overfished, i.e. are found to be below the Minimum Stock Size Threshold, irrespective of whether they are data-rich or data-poor. Rebuilding Plans have to include analyses to determine the minimum time, TMIN, to recover to a BMSY proxy and the target level of fishing mortality, FREC, that is consistent with recovery to this proxy within a pre-specified timeframe and with an agreed probability. Key factors that determine TMIN and FREC are the methods used to forecast future recruitment and to estimate the size of the unfished reproductive output of the population. Several approaches to modeling future recruitment are available. For example, Monte Carlo draws from previous recruitments, from previous recruits per spawner, and from a parametric probability distribution around an estimated stock-recruitment relationship have been used for groundfish resources off the U.S. west coast. The results of rebuilding analyses are sensitive to this choice of modeling approach. The performance of alternative approaches to modeling future recruitment, in terms of providing unbiased and precise estimates of TMIN and FREC, are explored by means of simulation. [The impacts of uncertainty in the estimates of historical recruitment and spawning stock size, and of the number of years for which stock and recruitment data are available on the ability to make reliable predictions of the quantities required by the Sustainable Fisheries Act are quantified. The results of these analyses are used to identify the most robust approaches for predicting future recruitment in data-rich and data-poor situations.] |
| Click here to link to previous quarter's workshop schedules. |
| MPAM Group website |