EXPOSURE OF RAINBOW TROUT FARMING TERRITORY AND LIVELIHOODS TO POTENTIAL EFFECTS OF GLOBAL WARMING IN VERACRUZ, MEXICO

Abstract

Background. As this century passes, the effects of climate change are being felt in various productive activities, including aquaculture. In particular, trout farming in tropical countries may be at some level of vulnerability to the warming of the water in which it is farmed. Objective. To quantify the degree of exposure, as a component of vulnerability, of trout farming to the possible occurrence of the global warming forecasted effects. Methodology. A spatio-temporal model was constructed to assess one aspect of the vulnerability of finfish aquaculture, by measuring the exposure of the territory and livelihoods of rainbow trout farming to the potential global warming effects in the Neotropical, coastal state of Veracruz, Mexico. Air temperature data from a 100-plus year period, averaged and raster-mapped was used as the baseline, transformed to estimated water temperature, and spatially processed to find the geographic areas suited to grow rainbow trout, or Potential Trout Farming Territory (PTFT). Using the same procedure, optimal water temperature areas were outlined with raster maps from a climate change scenario for three forecasted horizons —short, medium, and long terms—. With these data, the potential loss of territory and livelihoods for trout producers in the area was quantified. Results. The PTFT would undergo a surface reduction of 21.06 km2year1, and at the same time will displace to higher altitudes, given the onset of the chosen climate change scenario RCP 8.5 Wm-2. By the end of the century, Veracruz would have lost 1,851 km2, about 37.6 % of the original PTFT. When this reduction was contrasted in the model with the real trout farming territory (TFT), defined by the actual location of trout farms, a number of farms were being left out of the PTFT on the sequential horizons, at a rate of 0.927 farms year-1. This would mean a 58% exposition of the livelihoods in the long term. Implications. The exposure caused by the reduction of territory and the loss of livelihoods would further affect certain groups of producers, who are exposed a priori. These producers are those who live in poverty below the national average, which significantly aggravates their condition. Conclusion. The results show that global warming potential effects may negatively affect the territory and livelihoods of tens of families, some of which were found to be already in a social and economic degree of vulnerability. This should bring up attention to the implementation of urgent vulnerability-reduction measures.

Keywords

• aquaculture
• fish farming
• poverty
• climate change
• vulnerability
• gis modeling.