ON THE INTERDEPENDENCE OF SEQUENTIALFISHERIES: THE BROWN SHRIMP, FARFANTEPENAEUSAZTECUS, FISHERIES IN THE NORTHWESTERNGULF OF MEXICO BY FRANCISCO ARREGUÍN-S` NCHEZ 1,3 ) and REFUGIO G. CASTRO-MELÉNDEZ 2,4 ) 1 ) Centro Interdisciplinariode Ciencias Marinas del IPN, CICIMAR, Apartado Postal 592, 23070 La Paz, Baja California Sur, Mexico 2 ) Centro Regional de Investigación Pesquera de Tampico, INP, Prol. Altamira s/n, Col. Isleta Pérez, 89000 Tampico, Tamaulipas, Mexico ABSTRACT This contribution deals with some aspects of sequential shrimp sheries, particularly the relation between survival after catch in inshore waters and recruitment to the offshore shery. This relation is described for the brown shrimp, Farfantepenaeus aztecus , in the northwestern Gulf of Mexico, using a modied catch equation, the solution of which is approached using catch data, with a delay between catch-at-migration time (inshore waters) and recruitment to the offshore shery. Recruitment decreases as a logarithmic function of catch, the form of which is dened by shing mortality and migration rate. For a period of 8 years of monthly data, the explained variance of recruitment at the offshore shery was more than 60%, but for the average pattern it increases to 80%. The main concept behind this model is to identify a desirable survival level in inshore waters after catch, that permits a number of recruits to the offshore shery to maintain stable yields. The model described above was unable to be directly used for management purposes, because of a large variance along the catch axis. The second derivative of the model was used to represent increments in survival rate (to offshore shery) as a function of inshore catch. Several tendencies were explored, but inshore catch that stabilizes survival is tentatively suggested as the more appropriate to be used as a criterion for management. In practice, the desired survival level can be approached by monitoring shing in inshore waters. RESUMEN Este trabajo trata algunos aspectos de las pesquerías secuenciales de camarón, particularmente la relación entre supervivencia después de la captura en aguas interiores y el reclutamiento a la pesquería de platafoma. Esta relación es descrita para el camarón café Farfantepenaeusaztecus en el noroeste del Golfo de México, utilizando una forma modicada de la curva de captura cuya solución es aproximada al utilizar datos de captura, con retraso entre la captura al momento de migración 3 ) e-mail: farregui@redipn.ipn.mx 4 ) e-mail: criptam@correo.tamnet.com.mx c ® Koninklijke Brill NV, Leiden, 2000 Crustaceana 73 (3): 333-343