Performance of a baited underwater video system vs. the underwater visual census technique in assessing the structure of fish assemblages in a Mediterranean marine protected area

Accurate, rapid and cost-effective fish assemblage monitoring is fundamental for marine protected area (MPA) management as a pivotal tool to verify whether what extent MPA conservation objectives have been achieved redefine these in the framework of an adaptive management. Recently, there has sharp increase number video-based methods study fauna, such baited remote underwater video (BRUV) systems, that, depending on monitoring, can provide complementary or additional data more commonly used visual census (UVC). Even though BRUV systems widely wide range geographic contexts habitats, their use Mediterranean basin still sporadic evaluation efficiency they be complement other techniques needs investigation. Thus, objective this was assess performance system evaluate its effectiveness assessing structure assemblages (abundance species richness) by comparing estimates with those obtained UVC technique. The fauna were monitored Capo Caccia – Isola Piana Marine Protected Area (Sardinia, Italy), July October-November 2020, at four sampling sites two areas, hundreds meters apart, each site. Overall, 46 taxa total 3620 individuals observed BRUV, while 36 2995 UVC. first front camera’s field view able reach maximum abundance planktivores (Chromis chromis Oblada melanura) followed several carnivorous belonging families Labridae, Serranidae Sparidae, lastly carnivores (Mullus surmuletus Mugilidae spp.) some high-level predators (Dentex dentex, Seriola dumerili, Sphyraena viridensis, Dicentrarchus labrax). richness reached between 39 50 min. cumulative increased until around 30 Species higher during compared monitoring. consistency findings better detecting (mainly predators), supports technique describing quantifying also Sea. Based results study, advantages/disadvantages, shortcomings, suggestions resources needed are outlined.