Comparison of two approaches for estimating natural mortality based on longevity

Vetter (1988) noted that her review of the estimation of the instantaneous natural mortality rate (M) was initiated by a discussion among colleagues that identified M as the single most impor ta nt but least well-estimated parameter in fishery models. A lthough much has been accomplished in the inter vening years, M remains one of the most difficult parameters to estimate in fishery stock assessments. A number of novel approaches using tagging and telemetry data provide promise for making reliable direct estimates of M for a given stock (Hearn et al., 1998 ; Frusher and Hoenig, 2001; Hightower et al., 2001; Latour et al., 2003; Pollock et al., 2004). However, such methods are often impracticable and fishery scientists must approximate M by using estimates made for other stocks of the same or similar species or by predicting M from features of the species’ life history (Beverton and Holt, 1959; Beverton, 1963; Alverson and Carney, 1975; Pauly, 1980; Hoenig, 1983; Peterson and Wroblewski, 1984; Roff, 1984; Gunderson and Dygert, 1988; Chen and Watanabe, 1989; Charnov, 1993; Jensen, 1996; Lorenzen, 1996).

Strengthening impact evaluation in natural resource management

The workshop on Strengthening Evaluation in Natural Resource Management Research is part of an ACIAR-funded Small Research and Development Activity (SRA) on Assessing the Impacts of Natural Resource Management and Policy Research in Development Programs, with WorldFish and Commonwealth Scientific and Industrial Research Organization (CSIRO) as partners. The SRA objectives included a review of literature to identify challenges in assessing the impact of NRMR programs and to propose a framework that addresses them. An exploratory workshop was held in February 2012 to initiate collective action within the CGIAR Research Programs (CRPs) to identify and address their impact challenges and led to the creation of the NRMR impact community of practice (COP). This follow-up workshop brought together members of the COP and partners in the SRA to discuss and reach agreement on how to progress on our collective goals of building new and appropriate approaches for NRMR IE and how to put these approaches into action through our research programs. This report is a documentation of the workshop process and outputs.

Peces y aves del Paraguay natural ilustrado 1967. Manuscrito preparado bajo la dirección de Mariano N. Castex, 511 pp.

Este documento reproduce parte de la magnífica e importante obra del P. Francisco José Sánchez Labrador realizada durante su estadía en América desde su arribo en 1734 hasta la expulsión de la orden en 1767. Esta versión digital corresponde al libro editado por la Compañía General Fabril Editora S. A. en 1968 y cuyo manuscrito fuera preparado bajo la dirección del Dr. Mariano N. Castex (imagen).