Comparison of remote video and diver's direct observations to quantify reef fishes feeding on benthos in coral and rocky reefs

Abstract

This study compared remote underwater video and traditional direct diver observations to assess reef fish feeding impact on benthos across multiple functional groups within different trophic categories (e.g. herbivores, zoobenthivores and omnivores) and in two distinct reef systems: a subtropical rocky reef and a tropical coral reef. The two techniques were roughly equivalent, both detecting the species with higher feeding impact and recording similar bite rates, suggesting that reef fish feeding behaviour at the study areas are not strongly affected by the diver's presence.

Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil

“…Although this difference could contribute to the lack of relation between feeding pressure and density of cryptofauna, invertebrate feeders usually feed by the end of the day or during the night so their feeding pressure might be underestimated through the applied sampling method [43, 100]. The territorial herbivore Stegastes rocasensis performed a similar feeding pressure in both pool types of Rocas atoll and was abundant across the different habitats.…”

“…Reef fish feeding pressure on the benthos was evaluated through remote video recordings of 2 m 2 reef areas, demarcated with a 2 m transect tape, that was removed within the first minute of the video [43–44]. A total of 85 reef areas were sampled, 40 in open and 45 in closed pools (see S1 Table).…”

Temporal patterns of Pederson shrimp (Ancylomenes pedersoni Chace 1958) cleaning interactions on Caribbean coral reefs

“…While direct diver observations would provide a maximum observational period of 45-60 min, our cameras routinely recorded for 120-180 min per station. Second, while divers in the water may be able to shift their perspective in situations where the cleaner moves to the far side of the client fish and is obscured from view, additional movement on the part of the observer could magnify the already well-documented effect divers have on fish behavior and community composition (Chapman et al 1974;Kulbicki 1998;Lobel 2005;Fox and Bellwood 2008;Dearden et al 2010;Dickens et al 2011;Januchowski-Hartley et al 2011;Longo and Floeter 2012;Titus et al 2015). Finally, cameras circumvent the complicating factor of understanding the long-term historical use of each reef site by SCUBA divers.…”

An experimental evaluation of macroalgal consumption and selectivity by nominally herbivorous fishes on subtropical rocky reefs

“…The use of remote video has been widely used in reef ecology, since it offers some advantages for experiments that would otherwise require long periods of underwater observation, and allows feeding to be quantified in the absence of divers (Longo and Floeter, 2012). Afterwards, footage was analyzed and the number of bites of each fish towards each different macroalga was registered as well as the estimated size of each fish.…”