Baited remote underwater stereo-video (stereo-BRUV) stations and diver operated stereo-video (stereo-DOV) transects are increasingly used to sample both tropical and temperate fish assemblages. Compared to in situ visual census methods, the use of stereo-video reduces interobserver variability, improves definition of the sample unit area, increases accuracy of fish length estimates and provides a permanent record of the assemblage that can be validated where required or independently reanalysed. Previous studies have suggested that stereo-BRUV collects representative data on both carnivorous and herbivorous species and can be more cost-efficient than diverbased survey methods. This study compares estimates of common fish assemblage metrics obtained with stereo-BRUV stations and stereo-DOV transects across 3 biogeographic regions, and uses a costoptimization procedure to compare the efficiency of these 2 methods. Stereo-BRUV stations were found to sample greater species richness and obtain greater estimates of relative biomass of generalist carnivores, but no differences occurred in the biomass of herbivores sampled by the 2 techniques. Stereo-BRUV stations generally obtained estimates of assemblage metrics with less variance, resulting in greater power to detect spatial and temporal changes in the fish assemblage metrics. Cost -benefit analyses found that stereo-BRUV was generally more time efficient than stereo-DOV transects in terms of smaller standard error around the mean of the various metrics considered. However, across the 3 biogeographic regions sampled there was considerable variation in the magnitude of these differences. Results suggest that stereo-BRUV stations are, in general, a more cost-effective method for monitoring fish assemblages than stereo-DOV transects.KEY WORDS: Cost -benefit · Power to detect change · Biogeography · Baited remote underwater stereo-video · Diver operated stereo-videoResale or republication not permitted without written consent of the publisher Biol 9: 155-168, 2010 replicates and sites from pilot study data and, therefore, can also be used to evaluate the cost-effectiveness of different sampling methods.The complete sampling of reef fish communities in shallow waters is only possible using destructive methods. Indiscriminate methods such as dynamite have historically been used (Stephan 1904); however; the use of fish toxins such as rotenone (Krumholz 1948) have allowed more discrete and quantitative samples of the fish assemblage to be collected from complex habitats (Robertson & Smith-Vaniz 2008). Recent advances in diving technology have allowed these methods to be used to depths of 150 m, resulting in the description of large numbers of new cryptic species and observations of higher rates of endemism in deeper compared to shallow reefs (Pyle 2000). However, for most largescale studies, sampling the complete fish assemblage is likely unnecessary (Clarke & Warwick 1998) and destructive methods bias future samples obtained from the same locality and can compr...

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The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and fish habitat relationships across steep gradients in depth and in different benthic habitat types. The assemblage composition of demersal fish were assessed from baited remote underwater stereo-video samples (n = 304) collected from 16 depth and habitat combinations. Samples were collected across a depth range poorly represented in the literature from the fringing reef lagoon (1–10 m depth), down the fore reef slope to the reef base (10–30 m depth) then across the adjacent continental shelf (30–110 m depth). Multivariate analyses showed that there were distinctive fish assemblages and different sized fish were associated with each habitat/depth category. Species richness, MaxN and diversity declined with depth, while average length and trophic level increased. The assemblage structure, diversity, size and trophic structure of demersal fishes changes from shallow inshore habitats to deeper water habitats. More habitat specialists (unique species per habitat/depth category) were associated with the reef slope and reef base than other habitats, but offshore sponge-dominated habitats and inshore coral-dominated reef also supported unique species. This suggests that marine protected areas in shallow coral-dominated reef habitats may not adequately protect those species whose depth distribution extends beyond shallow habitats, or other significant elements of demersal fish biodiversity. The ontogenetic habitat partitioning which is characteristic of many species, suggests that to maintain entire species life histories it is necessary to protect corridors of connected habitats through which fish can migrate.

Fisheries are complex social-ecological systems, where managers struggle to balance the socioeconomic interests of fishing communities with the biology and ecology of fisheries species. Spatial closures are a popular measure to address conservation and fisheries management goals, including the protection of shark populations. However, very little research has been published on the effectiveness of shark-specific closures to protect sharks, or their impacts on fisher behavior. Situated within the global center of tropical marine biodiversity, Indonesia's shark fishery contributes more to the international shark fin trade than any other nation. Here we evaluate the effect of shark-specific closures on sharks and other species of interest, as well as shark fishers' responses to losing access to their former fishing grounds. We assessed shark diversity and abundance in an open access zone (OAZ) and two No-Take Zones (NTZs) of a Marine Protected Area within the recently established shark sanctuary in Raja Ampat, Indonesia, where sharks have high monetary value as a tourism attraction. Shark abundance was significantly higher in the privately managed NTZs than in the OAZ. Across all management zones, neither zone size, depth nor reef complexity explained variations in shark abundance, suggesting that governance is the main driver of successful shark conservation areas. These trends were also reflected in species targeted by small-scale reef fisheries, including snappers, emperor, groupers, tunas, mackerels, and large-bodied wrasse and parrotfish. Interviews with shark fishers who lost access to their primary fishing grounds when the shark sanctuary was established showed that while most fishers (88%) knew that sharks were protected in Raja Ampat, many were unsure about the purpose of the sanctuary. Few fishers felt that the agencies implementing fishing bans understood their livelihood needs. We found that shark fishers adapted to the loss of former fishing grounds by shifting fishing effort to other locations or diversifying their livelihoods, including illegal petrol transport. While conserving sharks for tourism can be effective, it may inadvertently result in displacing fishing effort to unprotected regions. Jaiteh et al. Shark Protection in Eastern Indonesia We propose that effective shark conservation in Indonesia will need to combine strategic spatial protection with efforts to support livelihood security and diversification.

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While there are numerous studies that have used no-take marine reserves (NTMRs) to understand the effects of commercial fishing, much less is known about the influence of NTMRs in regions subject to recreational fishing. We used meta-analysis to synthesise data from 4,444 samples from 30 years (1987-2017) of fish 7 surveys, inside and outside a large network of NTMRs in the Ningaloo Marine Park, Western Australia, 8 where the major fishing activities are recreational. The data were collected by different agencies, using 9 varied survey designs and sampling methods. We contrasted the relative abundance and biomass of target 10 and non-target fish groups between fished and NTMR locations. We considered the influence of, and 11 possible interactions between, seven additional variables: age and size of NTMR, one of two reserve network configurations, reef habitat type, the level of recreational fishing activity, shore-based fishing regulations and survey method. Taxa responded differently: commonly targeted lethrinids had clear higher average abundance and biomass inside NTMRs, while the abundance/biomass of other targeted (and nontargeted groups) were indistinguishable inside to outside. Reef habitat was an important factor governing lethrinid response to protection, and we showed this variable can interact with reserve size, with larger NTMRs only demonstrably more effective than smaller ones in the back reef/lagoon habitats. There was little evidence of changes in relative abundance/biomass with reserve age, or before and after rezoning and expansion of the NTMR network. Our study demonstrates the complexity of fish responses to protection and fishing, and also highlights some of the key factors and interactions that likely underlie the varied results found to date in NTMR assessments, and that should thus be considered in future reserve design and 22 assessment. 23 24 Keywords 25 Marine protected area; MPA; fisheries; coral reef; Ningaloo; adaptive management; recreational fishing; Lethrinus 1. Introduction Anthropogenic activities continue to expand worldwide, particularly in the tropics, threatening natural systems and the ecosystem services they provide (Barlow et al. 2018). As a result, 'protected areas' that seek 32 to balance extractive activities with other socio-ecological values are increasingly being used to manage 33 terrestrial and marine systems (Jenkins & Joppa 2009; Sala et al. 2018). Many studies have assessed the conservation effects of no-take marine reserves (NTMR) (reviewed by Mosquera et al. 2000; Russ 2002), including quantitative syntheses of regional and global studies, with most finding higher abundance and size of targeted species within reserve boundaries (Lester et al. 2009). The large majority of these findings are from regions with commercial fisheries operating, and less is documented about the impacts of recreational fisheries, despite several studies flagging the potentially high impacts of these fisheries (McPhee et al. 2002; Coleman et al. 2004; Cowx & Cooke 2004; Lewin et al. 2...

We studied the persistence of fishing impacts on coral reef fish assemblages by sampling 2 protected and 2 fished locations, using random replicate stereo baited remote underwater video. At each location we sampled a variety of coral reef habitats on 4 separate occasions between 2006 and 2007. We tested for consistency in differences in the biomass of target and nontarget species, trophic groups and overall assemblages. Generally, target species were more abundant and/or larger at protected locations. Many non-target species were either more abundant or depleted at protected sites, and some of these species were significantly larger or smaller. Trophic groups such as piscivores, piscivore invertivores, invertivores and planktivores were consistently more abundant within protected locations. Generally, greater numbers of species and individuals were found on protected reefs, though this was not consistent in all cases across all 4 sampling periods. These findings are consistent with the theory that protected areas can increase the abundance of not just target species but overall fish assemblages. These findings provide evidence for ecological mechanisms such as predator-prey interactions, competitive release, and benefits to invertivores, omnivores and other non-target groups from the presence of more abundant and larger target species within marine protected areas.