Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey Initiative
Estimating the detection probability of small cetaceans using either visual or acoustic surveys is difficult because they do not surface or vocalise continuously and can be imperceptible to an observer or hydrophone. Animals seen at the surface may have lower vocalisation rates, while submerged indi...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2023-10-01
|
| Series: | Frontiers in Marine Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2023.1244474/full |
| _version_ | 1827793296504651776 |
|---|---|
| author | Camille Ollier Camille Ollier Ilona Sinn Oliver Boisseau Vincent Ridoux Vincent Ridoux Auriane Virgili |
| author_facet | Camille Ollier Camille Ollier Ilona Sinn Oliver Boisseau Vincent Ridoux Vincent Ridoux Auriane Virgili |
| author_sort | Camille Ollier |
| collection | DOAJ |
| description | Estimating the detection probability of small cetaceans using either visual or acoustic surveys is difficult because they do not surface or vocalise continuously and can be imperceptible to an observer or hydrophone. Animals seen at the surface may have lower vocalisation rates, while submerged individuals may be more vocally active. This study aims to estimate visual, acoustic and combined detection probability by using Mark-Recapture Distance Sampling (MRDS) methodology. We used vessel-based visual sightings and acoustic data (based on click identification) collected simultaneously during the ACCOBAMS Survey Initiative in summer 2018 onboard the R/V Song of the Whale. This study focused on small cetaceans in the Mediterranean Sea, including the most commonly-encountered species, the striped dolphin (Stenella coeruleoalba). We identified duplicate events between visual and acoustic platforms using a decision tree based on time and distance thresholds to estimate g(0) (the detection probability on the trackline) for small cetaceans. A total of 30 duplicate events were identified from 107 and 109 events identified by the visual and acoustic platforms respectively. We tested the models with two key functions. With a hazard-rate key function, the g(0) was estimated at 0.52 (CV=21.0%) for both platforms combined, 0.29 (CV=25.6%) for the visual platform and 0.32 (CV=25.1%) for the acoustic platform. With a half-normal key function, g(0) was estimated at 0.51 (CV = 21.7%) for both platforms combined, 0.29 (CV = 25.6%) for the visual platform and 0.33 (CV = 23.2%) for the acoustic platform. Our results illustrate that passive acoustic monitoring can be used as an independent platform in MRDS to estimate the detection probability. Our estimate of g(0) was well below 1, far from the perfect detection commonly assumed for abundance estimation. Without correction for detection biases, total abundance would be underestimated by a factor of two when using both acoustic and visual data. This highlights the importance of using dual-platform surveys to estimate detection probability in order to improve abundance estimates and conservation efforts. |
| first_indexed | 2024-03-11T18:15:27Z |
| format | Article |
| id | doaj.art-b91b2b172ec54b80b533203c085253a6 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-03-11T18:15:27Z |
| publishDate | 2023-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-b91b2b172ec54b80b533203c085253a62023-10-16T08:53:43ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452023-10-011010.3389/fmars.2023.12444741244474Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey InitiativeCamille Ollier0Camille Ollier1Ilona Sinn2Oliver Boisseau3Vincent Ridoux4Vincent Ridoux5Auriane Virgili6Centre d’Etude Biologiques de Chizé, UMR 7372 CNRS, La Rochelle Université, Chizé, FranceObservatoire PELAGIS, UAR 3462 CNRS, La Rochelle Université, La Rochelle, FranceObservatoire PELAGIS, UAR 3462 CNRS, La Rochelle Université, La Rochelle, FranceMarine Conservation Research, Kelvedon, United KingdomCentre d’Etude Biologiques de Chizé, UMR 7372 CNRS, La Rochelle Université, Chizé, FranceObservatoire PELAGIS, UAR 3462 CNRS, La Rochelle Université, La Rochelle, FranceObservatoire PELAGIS, UAR 3462 CNRS, La Rochelle Université, La Rochelle, FranceEstimating the detection probability of small cetaceans using either visual or acoustic surveys is difficult because they do not surface or vocalise continuously and can be imperceptible to an observer or hydrophone. Animals seen at the surface may have lower vocalisation rates, while submerged individuals may be more vocally active. This study aims to estimate visual, acoustic and combined detection probability by using Mark-Recapture Distance Sampling (MRDS) methodology. We used vessel-based visual sightings and acoustic data (based on click identification) collected simultaneously during the ACCOBAMS Survey Initiative in summer 2018 onboard the R/V Song of the Whale. This study focused on small cetaceans in the Mediterranean Sea, including the most commonly-encountered species, the striped dolphin (Stenella coeruleoalba). We identified duplicate events between visual and acoustic platforms using a decision tree based on time and distance thresholds to estimate g(0) (the detection probability on the trackline) for small cetaceans. A total of 30 duplicate events were identified from 107 and 109 events identified by the visual and acoustic platforms respectively. We tested the models with two key functions. With a hazard-rate key function, the g(0) was estimated at 0.52 (CV=21.0%) for both platforms combined, 0.29 (CV=25.6%) for the visual platform and 0.32 (CV=25.1%) for the acoustic platform. With a half-normal key function, g(0) was estimated at 0.51 (CV = 21.7%) for both platforms combined, 0.29 (CV = 25.6%) for the visual platform and 0.33 (CV = 23.2%) for the acoustic platform. Our results illustrate that passive acoustic monitoring can be used as an independent platform in MRDS to estimate the detection probability. Our estimate of g(0) was well below 1, far from the perfect detection commonly assumed for abundance estimation. Without correction for detection biases, total abundance would be underestimated by a factor of two when using both acoustic and visual data. This highlights the importance of using dual-platform surveys to estimate detection probability in order to improve abundance estimates and conservation efforts.https://www.frontiersin.org/articles/10.3389/fmars.2023.1244474/fulldetection probabilityduplicate eventsmark-recapture distance samplingdual platformpassive acoustic monitoringline-transect surveys |
| spellingShingle | Camille Ollier Camille Ollier Ilona Sinn Oliver Boisseau Vincent Ridoux Vincent Ridoux Auriane Virgili Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey Initiative Frontiers in Marine Science detection probability duplicate events mark-recapture distance sampling dual platform passive acoustic monitoring line-transect surveys |
| title | Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey Initiative |
| title_full | Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey Initiative |
| title_fullStr | Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey Initiative |
| title_full_unstemmed | Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey Initiative |
| title_short | Matching visual and acoustic events to estimate detection probability for small cetaceans in the ACCOBAMS Survey Initiative |
| title_sort | matching visual and acoustic events to estimate detection probability for small cetaceans in the accobams survey initiative |
| topic | detection probability duplicate events mark-recapture distance sampling dual platform passive acoustic monitoring line-transect surveys |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2023.1244474/full |
| work_keys_str_mv | AT camilleollier matchingvisualandacousticeventstoestimatedetectionprobabilityforsmallcetaceansintheaccobamssurveyinitiative AT camilleollier matchingvisualandacousticeventstoestimatedetectionprobabilityforsmallcetaceansintheaccobamssurveyinitiative AT ilonasinn matchingvisualandacousticeventstoestimatedetectionprobabilityforsmallcetaceansintheaccobamssurveyinitiative AT oliverboisseau matchingvisualandacousticeventstoestimatedetectionprobabilityforsmallcetaceansintheaccobamssurveyinitiative AT vincentridoux matchingvisualandacousticeventstoestimatedetectionprobabilityforsmallcetaceansintheaccobamssurveyinitiative AT vincentridoux matchingvisualandacousticeventstoestimatedetectionprobabilityforsmallcetaceansintheaccobamssurveyinitiative AT aurianevirgili matchingvisualandacousticeventstoestimatedetectionprobabilityforsmallcetaceansintheaccobamssurveyinitiative |