The implementation of marine reserves and fishery closures affects where the purse seine fleet can operate. The closure of several EEZs along the east African coast in the mid-2010s modifies the characteristics of the fishery by excluding the purse seine fleet from parts of the productive spring and summer fishing grounds. In each instance of an EEZ being closed to the fishery, the immediate response of the fleet is to reallocate effort into adjacent areas. This initial reallocation of effort is exploratory, as fishers, forced to break from tradition, investigate alternative grounds (see [15]). After a few years, the allocation of effort settles into a new pattern as skippers become familiar with the modified grounds of the fishery. The EEZ closures mainly affect the activities of the fleet in the west and southwest regions of the fishery, although the most productive summer grounds in the northwest Indian Ocean remain accessible. However, this changes following the implementation of an IOTC high seas area closure in the mid-2020s, which denies the fleet access to a significant part of the Somali Basin fishing grounds. The response of the fleet is again to reallocate effort into adjacent areas. The size and positioning of the IOTC closure forces the majority of effort to be allocated into relatively less productive grounds in the central western Indian Ocean, many of which have already been fished intensively in previous months. Subsequently, facing a shortfall in catches and increased competition with other vessels, skippers attempt to maintain catch rates by intensifying the deployment of FADs (see [11] and [13]), and, in some cases where fishing opportunities are perceived to be very poor, fishing firms reallocate vessels into the Atlantic Ocean, where there are fewer spatial restrictions in place.