Decapod crustaceans are ecologically and economically important invertebrates but are vulnerable to anthropogenic pressures and climate change. Understanding their spatial ecology is essential for their management and conservation, with telemetry emerging as a useful tool to quantify space-use and movements. Here, we synthesized the use of telemetry to study decapods among articles published from 1971 to 2019 (n = 102 studies), by taxonomic group of the study species, study location, objectives, number of animals tagged and their tag recovery rate, types (and trends) of telemetry used, and IUCN conservation status. These studies revealed insight into the behaviours and roles of decapods across habitats and geographic regions. The most common study species were crayfish and lobsters (41%, Astacidea), and these studies also had the highest number of individuals tagged per study (mean = 149 individuals). Most studies (86%) were conducted in the northern hemisphere. Acoustic tags were the most commonly used equipment (66% of studies) and were first employed in 1971, followed by radio-telemetry (mid-1990s), passive integrated transponders (mid-2000s), and data storage tags (late 2000s). Almost half (48%) of studies focused on species that had a conservation status of Least Concern, perhaps reflecting an applied science focus on animals of commercial interest rather than conservation importance. The positive allometric relationship between body length and movement rate (exponent = 0.86) demonstrates the type of broader ecological insight that combining these studies can provide. Tracking decapod movements will likely become increasingly important for managing fisheries, protecting sensitive species, and understanding invasion biology.

Bivalve aquaculture sites attract a variety of large benthic species. Previous studies have shown that American lobster Homarus americanus are more abundant in mussel Mytilus edulis farms than in areas outside of them, suggesting that farms provide lobsters with adequate food and shelter. This study used acoustic telemetry to evaluate the influence of longline mussel farms on lobster movement behavior. In 2014, 60 lobsters were acoustically tagged on a boat and released in a mussel farm and at 2 reference sites outside the farm. Most lobsters (92%) left the monitored area within 1 d post-tagging; those released in reference sites moved northeast, whereas those released in the farm moved in random directions. Of the 16 lobsters that stayed or returned to the study area over the course of the 2 mo experiment, 10 displayed nomadic movements, 3 displayed small, local movements—presumably associated with foraging behavior, and 3 displayed both movements. The time lobsters spent within a site, distance travelled, and walking speed did not differ between the farm and reference sites. A second experiment was done in 2017 over 2 mo to evaluate tagging method (‘on boat’ and in situ tagging) effects on lobster movement behavior. The experiment followed movements by 50 lobsters, half for each treatment, and showed that tagging method can affect walking speed during the first 24 h, but had no impact on the residence time and the distance travelled by the lobsters.

A worldwide increase in aquaculture has focussed attention on the interactions between aquaculture activities and the surrounding habitats and ecosystems. In Atlantic Canada, mussel aquaculture occurs alongside static-gear fisheries for American lobster Homarus americanus and rock crab Cancer irroratus. Current knowledge gaps surround how lobsters and crabs utilise aquaculture sites and the potential impacts of this use on wild fisheries. During 2015 and 2016, at 3 mussel farms within Malpeque Bay, Prince Edward Island, Canada, a combination of diver surveys and acoustic telemetry positional arrays were used to investigate differences in the abundance of lobsters between farms and adjacent reference sites, the number and duration of lobster visits to a mussel farm, and the fine-scale movements of lobsters and crabs inside and outside of mussel farms. Although lobster abundance at mussel farms varied from June-September, abundance only differed between the farms and their associated reference sites in June. Disturbance due to handling may have led some lobsters in the acoustic telemetry study to leave the mussel farm after tagging; however, those that remained crossed the farm boundary frequently, and there was little evidence that the farm was a refuge for lobsters. Both lobsters and crabs appeared to move at significantly slower speeds inside the mussel farm, suggesting that both species used the mussel farms for foraging and/or sheltering; this was particularly evident for the rock crab. The results of this multi-approach field study are informative for spatial planning and provide important insight into how commercially and ecologically important species use aquaculture facilities.