Detection of the oxygen minimal zone — OMZ using fishing vessels in the Peruvian sea during 2007–2016

Using TASA fishing vessels on the Peruvian coast during the period 2007 to 2016, the Oxygen Minimum Zone (OMZ) was determined through echograms obtained using a digital echo sounders ES60 and ES70 SIMRAD. The purse-seine fleet operates during two seasons per year for anchovy fishing as well as in fishing activities for human consumption in the central-north and south area. Using Echoview software algorithms it is possible to determine the OMZ and to export the data in organized spreadsheet format for each season of the year and to calculate the area occupied using Surfer 8.0 program. Interannual variation were analyzed using the statistical program R. The results show that the OMZ can be obtained using the fishing fleets, but these results are based on the area covered by the fishing fleet. Due to the wide coverage of the fleet during the year, we can have a daily, monthly and seasonal monitoring during the year. The results show an average depth of 50 meters of the OZM.