Citizen Science, a promising tool for detecting and monitoring outbreaks of the crown-of-thorns starfish Acanthaster spp.

Abstract

Monitoring potentially devastating coral-eating crown-of-thorns starfish (COTS) populations at scales relevant to management is a challenging task. Here, we investigated a citizen science approach to detect COTS outbreaks and prioritize management responses. Between 2014 and 2018, 38 000 COTS were recorded through 641 online observation reports submitted across New Caledonia, Vanuatu and Fiji by private stakeholders (51%), NGOs (22%), business operator (11%), research/government agencies (16%). COTS were observed in multiple areas, including in remote/inhabited reefs where they had never been reported. A three-level classification was developed to discriminate risk areas and propose operational guidelines to streamline management actions. About two-thirds of reports had low abundances (<10 starfish sighted) and could be addressed with low priority. Verification surveys at 65 reef sites confirmed outbreaks in half of the cases, along with high peak densities (7 000 ind.ha −1 ). Combining professional and non-professional observers increased the detection range (+27%) and the number of COTS detections (+129%). Citizen reports were eventually followed by removal campaigns organized within diverse institutional frameworks. While citizen monitoring has intrinsic limitations, we advocate that it constitutes a complementary and promising approach to support the ongoing management efforts in all countries affected by COTS.

Extremely high but localized pulses of coral recruitment in the southwestern lagoon of New Caledonia and implications for conservation

“…Instead, coral mortalities caused by disturbances have been acute in time and space, such as following cyclone Erica in 2003 (Wantiez et al 2006, Guillemot et al 2010, ephemeral increases in the abundance of the coral-killing seastar Acanthaster spp. in 2012− 2013 (Adjeroud et al 2018b, Dumas et al 2020, and the 2016 bleaching event (<10% coral mortality; Payri et al 2018, Bollati et al 2020.…”

Large-scale citizen science provides high-resolution nitrogen dioxide values and health impact while enhancing community knowledge and collective action

“…Some articles have already highlighted the need to statistically handle biases [36] of spatial data due to particular amateur preferences for species and habitats [89,90]. In some experiences, citizen science monitoring is then reduced to a complementary support to the ongoing conservation management efforts [91]. Unfortunately, there is still no systematic agreement about how to deal with these issues in air quality we developed the LUR model [17,86,87,94] with 371 sites out of the 671 samplers deployed by citizens.…”

Nation-wide hierarchical and spatially-explicit framework to characterize seagrass meadows in New-Caledonia, and its potential application to the Indo-Pacific

“…The equivalent of the L0R product would be the output of the seagrass modelling product. They also point to the role that citizen science can play in providing information, an approach not discussed here, but which could be implemented considering the successes of these participatory initiatives in New Caledonia (Derville et al 2018, Dumas et al 2020.…”