HR: 17:20h
AN: U34B-05    [Abstracts]
TI: Effects of Ocean Climate on Transboundary Movement of Coastal Pelagic Resources Between the EEZs of Mexico and the United States
AU: * Baumgartner, T R
EM: tbaumgar@cicese.mx
AF: División de Oceanología, CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BCN 22860, Mexico
AU: Garcia, J
EM: joaquin@cicese.mx
AF: División de Oceanología, CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BCN 22860, Mexico
AU: Sanchez, C
EM: crisan@cicese.mx
AF: División de Oceanología, CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BCN 22860, Mexico
AU: Lo, N C
EM: Nancy.Lo@noaa.gov
AF: Southwest Fisheries Science Center-NOAA/NMFS, 8604 La Jolla Shores Dr., La Jolla, CA 92037, United States
AU: Charter, R
EM: Richard.Charter@noaa.gov
AF: Southwest Fisheries Science Center-NOAA/NMFS, 8604 La Jolla Shores Dr., La Jolla, CA 92037, United States
AB: Interannual to multidecadal changes in ocean climate directly impact access to transboundary coastal pelagic resources between fisheries operating in U.S. and Mexican waters. This study provides a preliminary analysis of the scale of year-to-year shifts in the distribution of the Pacific sardine (Sardinops sagax caeruleus) with data from 2002 and 2003. One of the purposes of this initiative is to provide a template for collaborative research to guide regional policy development for responsible and sustainable utilization of the shared resource. This work is based on coordinated quarterly ocean surveys run by Mexican (the IMECOCAL program=Investigaciones Mexicanas de la Corriente de California) and U.S. scientists (the CalCOFI program=California Cooperative Oceanic Fisheries Investigations) allowing us to evaluate the annual state of the pelagic ecosystem from northern California to southern Baja California. The subject of this study is the "subarctic stock" of the Pacific sardine which is centered off California in the U.S. and extends southwards to the region off central Baja California. Estimates of sardine biomass in U.S. and Mexican waters, based on the rates of egg production measured during the IMECOCAL and CalCOFI surveys of April 2002 and April 2003, show order of magnitude differences in the relative proportions of biomass in the Mexican EEZ that is associated with the contrasts in ocean climate resulting from the regional effects of El Niño during April 2003. Results indicate a significant northward shift of the sardine stock off Mexico during 2003: we estimate that approximately 20 percent of the total biomass of the stock was located in the Mexican EEZ during spring of 2002 while the shift in ocean climate resulted in the presence of only 2 percent of the biomass of the stock in Mexican waters during April, 2003. A second, more southerly sardine stock extended from southern to central Baja California in April, 2003, but it was out of reach of the fleet operating from Ensenada in northern Baja California. These results are a warning of the vulnerability of the coastal pelagic fishery based in northern Baja California to long-term ocean warming coupled with effects of El Niño. Depending on the magnitude of the longer-term warming and the frequency of El Niños, there could be a persistent displacement of the Mexican portion of the subarctic sardine stock into the waters of the EEZ of the United States. However, this might be compensated somewhat by the simultaneous northward movement of the southerly stock, although this is difficult to predict now. Moreover, we do not know how the rate of production of the southerly stock and its resilience compares to that of the subarctic stock. It should also be noted that there is an increasing local demand for sardines in Baja California because of their use in mariculture operations as feed for fattening bluefin tuna in nearshore pens (for high-value export to Asia requiring that the tuna be feed on sardines to impart the desired flavor). If accessibility to the local sardine resource were to be limited by climate change, then the economy of the regional mariculture industry would surely suffer.
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
DE: 4830 Higher trophic levels
DE: 6334 Regional planning (1880)
DE: 6699 General or miscellaneous
SC: Union [U]
MN: 2007 Joint Assembly