RELATION BETWEEN CAPTURE OF SCOMBEROMORUS SIERRA (PERCOIDEI:SCOMBRIDAE) WITH SEA SURFACE TEMPERATURE AND CHLOROPHYLL A OFF THE COAST OF THE CENTRAL MEXICAN PACIFIC (2003–2013)

Castro–Garibay H.; Gallardo–Cabello M.; Espino–Barr; E.; Salmer�n Garc�a O.; Aguirre–G�mez R.

Volume : VI, Issue : XI, November - 2017

RELATION BETWEEN CAPTURE OF SCOMBEROMORUS SIERRA (PERCOIDEI:SCOMBRIDAE) WITH SEA SURFACE TEMPERATURE AND CHLOROPHYLL A OFF THE COAST OF THE CENTRAL MEXICAN PACIFIC (2003–2013)

Castro Garibay H. , Gallardo Cabello M. , Espino Barr, E. , Salmer N Garc A O. , Aguirre G Mez R.

Abstract :

Chlorophyll a concentrations (CHLOa) and nocturnal sea surface temperature (NSST) off the coast of Jalisco and Colima, M�xico (106�–101�O, 18�–23�N) from 2003 to 2013 were related to the capture of sierra Scomberomorus sierra (data obtained from Arrival Reports). Data of CHLOa showed an inverse proportional relation with NSST. From Feuary to April NSST had a lower average than 25�C and in this period CHLOa had the highest value. From July to October CHLOa reached its minimum value and NSST an average of 29�C. CHLOa concentrations reached its highest value at a distance of 0 to 6 nautical miles (nm) from the coast; from 18 to 24 nm values descended. During rainy season CHLOa maintained values higher than 2 mg∙m–3 in areas near the coast, due to river flow. With the NSST compound, the presence of a coastal current was detected from 0 to 6 nm from northwest to southeast direction, transporting water of lower temperature; signs of this current vanish in summer when the area reaches an isotherm. It was observed that most years show that the Oceanic Ni�o Index (ONI) and NSST have a significant correlation, being stronger in those years with a moderate phenomenon (Ni�o or Ni�a). Jalisco has higher catches of S. sierra than Colima, and variations from 18.5 t in March to 5.9 t in August. Most capture of S. sierra in Jalisco and Colima are from January to May and secondly in November and December. Significant correlations (p <0.05) were found between CHLOa and S. sierra catch, with changes from one year to the next. Significant inverse correlations (p<0.03) were found between NSST and S. sierra catch, higher than 70%, except 2003 and 2005. During 2003 three periods of distribution and reproduction of S. sierra were found: 1) January to May, high concentrations of CHLOa and a low NSST, coinciding with high values of the gonadosomatic (GSI), hepatosomatic (HIS) and gastric repletion (GRI) indexes. Also there are high registers of S. sierra capture. 2) From June to August high values of GSI and GRI were found, although there were low concentrations of CHLOa and a raise in the NSST, possibly the species secludes itself to zones with high concentrations of CHLOa thanks to the transportation of organic matter, therefore a drastic decrease of captures is observed. 3) From October to December the rainy season comes to its end, first in Jalisco and later in Colima, and from November on CHLOa starts to increase and NSST to decline; with this, a rise in captures is observed and also increments in the GSI, HIS and GRI, although values do not reach the first of the two periods.