Participatory mapping of invasive species: A demonstration in a coastal lagoon

Abstract

Aquatic Invasive species (AIS) are a growing driver of change across marine and freshwater ecosystems but spatially-explicit information is seldom available for supporting management actions and decision making. Here we conceived and tested a new participatory method to map the distribution of three invasive species (Callinectes sapidus, Procambarus clarkii and Oreochromis niloticus) in the coastal lagoon of Lesina (Italy). Local fishers were asked to draw the distribution of each species on pre-printed maps, indicating districts of the lagoon characterized by different abundance levels. Then, maps were converted to a lattice grid and a Bayesian hierarchical Generalized Additive Modeling was adopted to model species distribution in the lagoon, calculating the coefficient of variation for model fitted values to map fishers agreement about the distribution of each species.The spatial gradient in the abundance of the three species in the lagoon aligned with their ecological requirements. C. sapidus was abundant throughout the whole lagoon, peaking in correspondence of saltmarsh vegetation, while P. clarkii and O. niloticus, were much less abundant and remained distributed near to freshwater inputs. Experts agreed about the spatial distribution of C. sapidus in the lagoon, with a median coefficient of variation in model fitted values of 3.9%. On the other hand, the coefficient of variation was higher for P. clarkii (19.9%) O. niloticus (18.4%), indicating a higher level of uncertainty about their estimated distribution.With this example, we provided new metrics to evaluate the quality of LEK-based participatory mapping in terms of agreement and consistency among experts. The resulting information provides new insights for spatially informed management across aquatic realms in relation to the increasing ecological and socio-economical pressures posed by biological invaders.

Euryhaline Aliens Invading Italian Inland Waters: The Case of the Atlantic Blue Crab Callinectes sapidus Rathbun, 1896

“…The new records of blue crab presented in this work can be discussed, considering the current distribution of the species along the Italian coasts. Records of C. sapidus in freshwaters of the Basilicata region herein collected occurred along the Ionian coast, in accordance with recent data on species distribution, showing that the blue crab in Italian coasts is more abundant in the Adriatic/Ionian area [15,25,26], with a "hotspot" of records from the Apulia region, especially around the Gargano Peninsula and in the Gulf of Taranto [25]. It is noteworthy that in the eastern Ionian Sea, the number of records increased significantly in recent years [10].…”

Mapping small‐scale fisheries through a coordinated participatory strategy

“…(Dunn, 2007)), can effectively inform policy and management bodies on a variety of environmental and socio-economic issues (e.g. (Azzurro & Cerri, 2021;Gill et al, 2019)).…”

“…(Dunn, 2007)), can effectively inform policy and management bodies on a variety of environmental and socio‐economic issues (e.g. (Azzurro & Cerri, 2021; Gill et al, 2019)). Participatory approaches—which promote public involvement, stimulate new partnerships and facilitate co‐management processes—have an intrinsic and widely recognized value (Kindon et al, 2007; Reid et al, 2020).…”

A New Signal of Tropicalization in the Northeast Atlantic: The Spread of the Spotfin Burrfish Chilomycterus reticulatus in Madeira Archipelago and Its Invasion Risk

“…Many of the featured recreational activities in oceanic islands, such as Madeira, focus on the sea, namely scuba diving, spearfishing, whale watching, and recreational fishing [73][74][75]. Involving stakeholders and their clients can complement and improve scientific data at various spatial and temporal scales [76,77]. Citizen science may contribute to ecological conservation by collecting environmental and biological data or by targeting particular species [77][78][79][80][81].…”