Ground truthing the ground truth: reply to Garibaldi et al.'s comment on "Managing fisheries from space: Google Earth improves estimates of distant fish catches"
There has been a growing interest in the potential of Google Earth for scientific inquiries, and our previous paper (Al Abdulrazzak and Pauly, 2014. Managing fisheries from space: Google Earth improves estimates of distant fish catches. ICES Journal of Marine Science, 71: 450 454) on weirs and their catch in the Persian Gulf is a case in point. Garibaldi et al. (2014. Comment on: "Managing fisheries from space: Google Earth improves estimates of distant fish catchs" by Al Abdulrazzak and Pauly. ICES Journal of Marine Science) while agreeing in principle with using Google Earth for fisheries related purposes, criticized the assumptions, data, methodology, and results of this paper. Here, we refute their criticisms, notably by showing that the "derelict weirs" that they thought they had "ground truthed" are not weirs at all, but another type of fishing gear in one case, and debris from a boat anchoring system in the other. We develop the theme that ground truthing requires local knowledge, and provide recommendations for using Google Earth images in fisheries management.