Developing a simple, rapid method for identifying and monitoring jellyfish aggregations from the air

• DOI: 10.3354/meps314159
• Publication Date: 2007-08-10T09:14:47Z
• Authors: JDR Houghton; TK Doyle; J Davenport; GC Hays
• Keywords: /dk/atira/pure/sustainabledevelopmentgoals/life_below_water; 0106 biological sciences; 570; name=Aquatic Science; name=Ecology; name=SDG 14 - Life Below Water; 14. Life underwater; /dk/atira/pure/subjectarea/asjc/1100/1104; /dk/atira/pure/subjectarea/asjc/2300/2303; 01 natural sciences

Within the marine environment, aerial surveys have historically centred on apex preda- tors, such as pinnipeds, cetaceans and sea birds. However, it is becoming increasingly apparent that the utility of this technique may also extend to subsurface species such as pre-spawning fish stocks and aggregations of jellyfish that occur close to the surface. In light of this, we tested the utility of aer- ial surveys to provide baseline data for 3 poorly understood scyphozoan jellyfish found throughout British and Irish waters: Rhizostoma octopus, Cyanea capillata and Chrysaora hysoscella. Our princi- pal objectives were to develop a simple sampling protocol to identify and quantify surface aggrega- tions, assess their consistency in space and time, and consider the overall applicability of this tech- nique to the study of gelatinous zooplankton. This approach provided a general understanding of range and relative abundance for each target species, with greatest suitability to the study of R. octo- pus. For this species it was possible to identify and monitor extensive, temporally consistent and pre- viously undocumented aggregations throughout the Irish Sea, an area spanning thousands of square kilometres. This finding has pronounced implications for ecologists and fisheries managers alike and, moreover, draws attention to the broad utility of aerial surveys for the study of gelatinous aggrega- tions beyond the range of conventional ship-based techniques.