Locating a moving target for an Underwater Wireless Sensor Network (UWSN) is a challenging task since traditional radio link based tracking methods can not be directly applied to the under water network. Underwater sensors use acoustic links for communication. Besides under the water, network architecture is also different from the traditional terrestrial WSN architecture. Replacement difficulty of underwater sensors in case of power failure adds more challenges. Therefore, a target localization protocol in UWSNs should have energy saving strategy. In our paper, we incorporate local search based energy saving tracking method for an UWSN. To handle the challenges, we present a meta-heuristic based algorithm by keeping the minimum number of sensors active which ultimately increases the network lifetime. We validate our method by experimental results and find that our algorithm can detect a moving target with less energy consumption. We measure the performance of our method by comparing the target trajectory with the true trajectory. We also compare the energy consumption with that of another frequently used method for this type of network. We find that our method works better.