Economic mapping and assessment of Cymodocea nodosa meadows as nursery grounds for commercially important fish species. A case study in the Canary Islands

Abstract

Cymodocea nodosa seagrass meadows provide several socio-economically ecosystem services, including nurseries for numerous species of commercial interest. These seagrasses are experiencing a worldwide decline, with global loss rates approaching 5% per year, mainly related to coastal human activities. Cymodocea nodosa, the predominant seagrass in the Canary Archipelago (Spain), is also exposed to these threats, which could lead to habitat loss or even local disappearance. In this case study, we estimated the potential economic value of Cymodocea nodosa seagrass meadows for local fisheries at an archipelago scale. Habitat suitability maps were constructed using MAXENT 3.4.1, a software for modelling species distributions by applying a maximum entropy machine-learning method, from a set of environmental variables and presence and background records extracted from historical cartographies. This model allows characterising and assessing the C. nodosa habitat suitability, overcoming the implicit complexity derived from seasonal changes in this species highly dynamic meadows and using it as a first step for the mapping and assessment of ecosystem services. In a second step, value transfer methodologies were used, along with published economic valuations of commercially-interesting fish species related to C. nodosa meadows. We estimate that the potential monetary value of these species can add up to more than 3 million euros per year for the entire Archipelago. The simplicity of the proposed methodology facilitates its repeatability in other similar regions, using freely available data and hence, being suitable for data-scarce scenarios.

Coastal Biodiversity Assessment Aided by Citizen Science Volunteers: A Look at the Italian Central Adriatic

“…We also have detected the presence of Cymodocea nodosa (Ucria) Ascherson formations on the Central Adriatic coastal seabed. Cymodocea meadows may play a crucial role in supporting fish populations by offering refuge to schools, facilitating the establishment of trophic niches, and serving as nursery sites [95]. Additionally, these meadows have a significant function in safeguarding coastal areas from various environmental impacts [96].…”

Species Distribution Models at Regional Scale: Cymodocea nodosa Seagrasses

“…Although the distribution of C. nodosa has been already studied in the Archipelago [11][12][13][14][15][16] these one-time cartography attempts present limitations in terms of spatial coverage. Some areas were not covered due to technical infeasibility, and temporal discrepancies could be found in C. nodosa's historic distribution datasets, with a few years' time difference.…”