TY - JOUR
T1 - Seasonal changes in larval fish assemblages in a semi-enclosed sea (Gulf of California)
AU - Sánchez-Velasco, L.
AU - Lavín, M. F.
AU - Peguero-Icaza, M.
AU - León-Chávez, C. A.
AU - Contreras-Catala, F.
AU - Marinone, S. G.
AU - Gutiérrez-Palacios, I. V.
AU - Godínez, V. M.
N1 - Funding Information:
This work was supported by SEP-CONACyT (Contracts 2004-C01-46349, D41881-F and 44055), CGPI-Instituto Politécnico Nacional (project codes 20080486 and 20090578), and Secretaría de Marina of Mexico (project Circulación del Golfo de California mitad norte ). We acknowledge the efforts of Tte. Corb. SMAM. L. Ocean. Francisco Padilla Ozuna (Secretaría de Marina) in organizing the June 2005 and February 2006 cruises. Thanks to Alberto Amador (CICESE) and Alma Rosa Padilla (Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autónoma de México) for physical data collection and processing, and to Carlos Cabrera (CICESE) for satellite data handling. Thanks to two anonymous referees, whose comments greatly improved this article.
PY - 2009/7/30
Y1 - 2009/7/30
N2 - The northern Gulf of California (NGC) is characterized by seasonal hydrography and circulation (cyclonic in summer and anticyclonic in winter), by intense tidal mixing in the midriff archipelago region (MAR), and by coastal upwelling on the eastern side from autumn to spring. We examined changes in larval fish assemblages (LFAs) in relation with hydrography and circulation during both phases of the seasonal circulation, as indicators of changes in the pelagic ecosystem. A canonical correspondence analysis defined LFAs (r>0.70), which were related with: (i) the coastal current on the mainland shelf, (ii) the central eddy and (iii) the MAR. In the early cyclonic phase, when the temperature and stratification were increasing and the coastal current was starting, demersal (Gobulus crescentalis, Lythrypnus dalli) and mesopelagic species (Benthosema panamense) dominated the NGC. The highest larval abundance was in the Current LFA area and the lowest in the MAR LFA area. In the mature cyclonic phase, the larval abundance increased in the NGC and species characteristic of eastern boundary current systems such as Opisthonema libertate and Engraulis mordax displaced the demersal species and became dominant, together with B. panamense in the Current LFA area; the latter species dominated in the Eddy LFA area. In the early anticyclonic phase, the direction of the coastal current reversed and the temperature and larval abundance decreased. E. mordax and B. panamense larvae continued dominating the NGC with higher abundance in the MAR than in the Current and Eddy LFA areas. In the mature anticyclonic phase, E. mordax larvae dominated in the Current and the Eddy LFA areas with the highest abundance in the former, while M. productus larvae (an eastern boundary current species) dominated in the Eddy LFA area. Results showed that in the NGC, the dramatically seasonal and predictable hydrographic and circulation features trigger the seasonal spawning of the dominant species. The biological richness of the coastal current area, in both circulation phases, suggested that this area has an important role in the pelagic ecosystem functionality of the NGC.
AB - The northern Gulf of California (NGC) is characterized by seasonal hydrography and circulation (cyclonic in summer and anticyclonic in winter), by intense tidal mixing in the midriff archipelago region (MAR), and by coastal upwelling on the eastern side from autumn to spring. We examined changes in larval fish assemblages (LFAs) in relation with hydrography and circulation during both phases of the seasonal circulation, as indicators of changes in the pelagic ecosystem. A canonical correspondence analysis defined LFAs (r>0.70), which were related with: (i) the coastal current on the mainland shelf, (ii) the central eddy and (iii) the MAR. In the early cyclonic phase, when the temperature and stratification were increasing and the coastal current was starting, demersal (Gobulus crescentalis, Lythrypnus dalli) and mesopelagic species (Benthosema panamense) dominated the NGC. The highest larval abundance was in the Current LFA area and the lowest in the MAR LFA area. In the mature cyclonic phase, the larval abundance increased in the NGC and species characteristic of eastern boundary current systems such as Opisthonema libertate and Engraulis mordax displaced the demersal species and became dominant, together with B. panamense in the Current LFA area; the latter species dominated in the Eddy LFA area. In the early anticyclonic phase, the direction of the coastal current reversed and the temperature and larval abundance decreased. E. mordax and B. panamense larvae continued dominating the NGC with higher abundance in the MAR than in the Current and Eddy LFA areas. In the mature anticyclonic phase, E. mordax larvae dominated in the Current and the Eddy LFA areas with the highest abundance in the former, while M. productus larvae (an eastern boundary current species) dominated in the Eddy LFA area. Results showed that in the NGC, the dramatically seasonal and predictable hydrographic and circulation features trigger the seasonal spawning of the dominant species. The biological richness of the coastal current area, in both circulation phases, suggested that this area has an important role in the pelagic ecosystem functionality of the NGC.
KW - Circulation
KW - Gulf of California
KW - Larval fish assemblages
KW - Mesoscale hydrographic structures
KW - Mexico
UR - http://www.scopus.com/inward/record.url?scp=67651171186&partnerID=8YFLogxK
U2 - 10.1016/j.csr.2009.06.001
DO - 10.1016/j.csr.2009.06.001
M3 - Artículo
SN - 0278-4343
VL - 29
SP - 1697
EP - 1710
JO - Continental Shelf Research
JF - Continental Shelf Research
IS - 14
ER -