STATUS OF PACIFIC MACKEREL AND TRENDS IN BIOMASS, 1978-1 993

Estimates from virtual population analysis indicate that Pacific mackerel (Scomber juponicus) biomass increased during 1978-82 to the highest level on record (829,000 short tons), and then declined to less than 100,000 tons by 1993 (estimates for recent years are imprecise). High biomass in early years was due to the strong 1978 and 1980-82 year classes. The declining biomass after 1982 was due to lower recruitment. Current conditions appear sdar to those in the mid 1940s, when Pacific mackerel declined after a period of hgh abundance. Abundance data and biomass indices during recent years were affected by ENSO conditions; more accurate estimates of biomass and assessmenc of ENSO effects will be possible after environmental conditions return to normal. Recent catch levels (46,000 and 23,000 tons year-' during 1992 and 1993) were large relative to biomass, and may have exceeded the target 30% total exploitation rate that is the basis for management in California. The economic condition of the fishery is poor, and resources available for management are at an all-time low because of changing priorities and financial constraints. Landings of Pacific mackerel increased in Mexico during recent years while California landings remained relatively constant, and biomass declined. Thus the future of the Pacific mackerel stock and fishery are uncertain. RESUMEN Estimaciones obtenidas por el anilisis virtual de poblaciones indican que la biomasa de la macarela (Scoulzbev juponiccrr) alcanzb durante 1978-82 10s miximos niveles que hayan sido registrados (829,000 toneladas cortas), y subsecuentemente declinb a menos de 100,000 tons. cortas en 1993 (las estimaciones en aiios recientes son imprecisas). Los altos niveles de biomasa referidos se debieron a la fuerza de las clases de edad de 1978 y 198G82, mientras que el decrement0 desput-s de 1982 se debib a 10s bajos niveles de reclutaniiento. Las condiciones actuales parecieran asemejarse a aquellas de mediados de 10s aiios 40, cuando la macarela declinb despuks de un period0 de alta abundancia. En aiios recientes, 10s datos