Accuracy of ROV-based biodiversity surveys in remote, shallow, coral reef habitats

Efforts to measure tropical marine biodiversity often experience challenges due to the inaccessibility of marine habitats, limited funding available for monitoring programs, and unavailability of staff. Remotely operated underwater vehicles (ROVs) are becoming more popular as a tool for conservation studies by increasing monitoring capabilities when coupled with image-based surveys, and new, mini-ROVs have reduced the cost for managers. This study compared the use of inexpensive mini-ROVs to snorkel-based field surveys of coral reef benthic organisms and fish in Fiji, where remote accessibility, limited access to SCUBA, and calm, clear environments make ROVs a potentially useful tool. Species richness and community composition for benthic organisms like coral, sponges, and echinoderms and for fish species were compared between methods using generalized linear models, non-metric multidimensional scaling (nMDS) plots, and species accumulation curves. In situ measurements performed better than ROV-based image datasets, finding consistently higher levels of species richness for both benthic species and fish ( in situ richness counts were 159 and 137% higher, respectively), but ROV-based image analysis of benthic percent cover was a more accurate estimator of species richness according to species accumulation estimates. Further advances in mini-ROV affordability may make these methods better able to capture higher levels of species richness, but future studies should consider testing ROVs to monitor coral bleaching or habitat loss.ABSTRACT: E dau sotavi na dredre ena kena dau sasagataki me vakadikevi na bulabula kei na ituvaki ni veika bula ena noda wasawasa. E so na ka e dau vakataotaka na sasaga oqo sai koya na, matai, na kena sega ni rawa ni nunuvi na nodra itikotiko na veika bula, karua, na dredre ni kena soli na ilavo ena kena rawa ni caka kina eso na parokaramu ni nodra dikevi na veika bula, ka kena ka tolu, na kena sega ni rawa ni vakayagataki se vakarautaki na kena dau me laki lai vakadikeva. Na iyaya ni vakadidike ena loma ni noda wasawasa me vaka na remotely operated underwater vehicle se ROV e sa kilai levu tiko ena buturara ni vakadidike ena kena rawa ni vakayagataki me vakadikevi kina na noda veika bula ena loma ni wasawasa. Na iyaya oqo e rawa ni sovea taka na loma ni wai ka vakarautaka talega na kena iyaloyalo. Na yaya oqo e sa qai vakayagataki vou talega, ka lailai na kena tuvaki ka vakatokai tiko me mini-ROV, ka sega sara ni sau levu na kena isau. Na vakadidike oqo ena vakatautauvata taka tiko na kena rawa ni sovea taki e loma ni waitui na bulabula ni lase kei na veimataqali manumanu e Viti. E na vakatautauvata taki tiko na kena rawa ni qarava na itavi ni sovea na mini-ROV kei ns sovea vakanunu. Ena dau qarava sara vakavinaka na ROV na kena itavi kevaka e sega ni dau yavalati vakalevu na waitui, kevaka e drake vinaka ka maravu na wasawasa. Na bulabula ni nodra ituvaki na veimataqali manumanu kei na veimataqali ika e na vakatautauvata taki tiko na nodrau iwalewale e na kena vakayagataki tiko na generalized linear models, nMDS plots, kei na species accumulation curves. E levu na veimataqali manumanu (159%) kei na veimataqali ika (137%) e tauri mai vei na iwiliwili ni tukutuku mai na sovea vakanunu, ia na iwiliwili ni tukutuku e tauri mai vei na sovea ni ROV e rawa ni solia ga na esitimeti vaka pasede ni vanua e ra bula kina na veimataqali manumanu kei na lase. E gadrevi me vakatorocaketaki na kena rawa ni sovea taka vakavinaka na iwiliwili ni veimataqali veikabula na mini-ROV. Sa kerei na kena rawa ni vakayagataki na ROVs e na kena dikevi na mate ni lase se na kena vakacacani na nodra itikotiko na veimataqali veikabula.