“How” and “what” matters: Sampling method affects biodiversity estimates of reef fishes

Abstract

Understanding changes in biodiversity requires the implementation of monitoring programs encompassing different dimensions of biodiversity through varying sampling techniques. In this work, fish assemblages associated with the “outer” and “inner” sides of four marinas, two at the Canary Islands and two at southern Portugal, were investigated using three complementary sampling techniques: underwater visual censuses (UVCs), baited cameras (BCs), and fish traps (FTs). We firstly investigated the complementarity of these sampling methods to describe species composition. Then, we investigated differences in taxonomic (TD), phylogenetic (PD) and functional diversity (FD) between sides of the marinas according to each sampling method. Finally, we explored the applicability/reproducibility of each sampling technique to characterize fish assemblages according to these metrics of diversity. UVCs and BCs provided complementary information, in terms of the number and abundances of species, while FTs sampled a particular assemblage. Patterns of TD, PD, and FD between sides of the marinas varied depending on the sampling method. UVC was the most cost‐efficient technique, in terms of personnel hours, and it is recommended for local studies. However, for large‐scale studies, BCs are recommended, as it covers greater spatio‐temporal scales by a lower cost. Our study highlights the need to implement complementary sampling techniques to monitor ecological change, at various dimensions of biodiversity. The results presented here will be useful for optimizing future monitoring programs.

Estimating the density of resident coastal fish using underwater cameras: accounting for individual detectability

“…The need of combining data gathered using different methods have been repeatedly claimed. Specifically, simultaneous use of RUV and UVC have been extensively advised (Willis et al 2000, Cappo et al 2003, Stobart et al 2007, Murphy & Jenkins 2010, Harvey et al 2013, Shortis et al 2013, Bacheler et al 2017, Bosch et al 2017. However, in most of those cases the results obtained using different methods are not combined but compared only (Cappo et al 2004, Assis et al 2013, Tessier et al 2013, Pita et al 2014, Mallet et al 2014, Bacheler et al 2017.…”

Mutualism promotes site selection in a large marine planktivore

“…There were regularly two dives in one day (one in the morning, one in the afternoon). The maximum number of cleaner fish counted per survey (MaxN) was used in subsequent analyses, as this alleviates concerns that an individual may be counted more than once if it leaves the observers field of view (Bosch et al., 2017). Locations were chosen based on previous observations of manta rays cleaning at the site.…”

How many fish? Comparison of two underwater visual sampling methods for monitoring fish communities

“…Other recent studies have examined and/or compared the performance of various UVS methods ( Bosch et al, 2017 ; Irigoyen et al, 2018 ). Bosch et al (2017) compared the output of three different methods for studying fish assemblages, UVC (strip transects of fixed length and width), Fish Traps, and Baited Cameras. The authors mainly focused on species diversity; they did not assess the performance of the methods to estimate species absolute or relative abundance.…”