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Analysis of a Volunteer Method for Collecting Fish Presence and Abundance Data in the Florida Keys
Abstract
A roving diver fish survey method that requires relatively little time and equipment was developed for use by trained volunteer divers to regularly, rapidly, and inexpensively document patterns of reef fish distribution and abundance, In this method, a diver searches a dive site and records all observed fish species and their abundance in log10 categories, Results from 130 h of observation were analyzed from three regional surveys conducted in the Florida Keys at a total of 27 reefs by four observers during the summer of 1994. The Upper Keys had the most species (166) followed by the Lower Keys (151) and the Dry Tortugas (142). More uncommon species were found in the Dry Tortugas. Experienced volunteer divers were able to provide useful species listings, frequency of occurrence and abundance data. We recommend multiple surveys from one site and day and night surveys for providing most complete species listings. Cluster analysis of reefs using Jaccard similarity indicies showed that reefs within a region clustered together and that reefs in close geographical proximity generally had the highest similarity. Data showed spatial distributions and species abundance patterns consistent with previous studies.
... Vários projetos envolvendo voluntários já são praticados na Europa e nos Estados Unidos há muito tempo, a maioria em ambientes terrestres (Cohn, 2008). Mais recentemente, essa prática se estendeu também ao ambiente marinho, aproveitando o crescimento mundial do turismo de mergulho (Halusky et al., 1994;Schmitt e Sullivan, 1996). O mergulho autônomo recreativo foi a atividade de turismo marítimo que mais se desenvolveu nas últimas décadas. ...
... Em vários casos, a comparação dos dados obtidos por voluntários com os obtidos pelos cientistas não apresentou diferenças significativas, mas é necessário que seja provido um treinamento adequado aos participantes do programa (Evans e Birchenough, 2001;Foster-Smith e Evans, 2003). O papel do treinamento é fundamental para o sucesso da campanha, como demonstrado por Darwall e Dulvy (1996) e Schmitt e Sullivan (1996). Ele deve apresentar os aspectos básicos da pesquisa, como a identificação dos organismos que serão amostrados e a prática da metodologia a ser empregada. ...
... No estudo de comunidades de peixes, a identificação quanto à espécie é muito importante, e, por isso, o treinamento nesse sentido é fundamental (Schmitt e Sullivan, 1996;Pattengill-Semmens e Semmens, 1998). O tradicional método de censos visuais de transecto em linha vem sendo utilizado regularmente por mergulhadores voluntários (Darwall e Dulvy, 1996;Hodgson, 2001), mas exige que o mergulhador permaneça em uma mesma área desde o posicionamento do material para demarcação do transecto até sua retirada após a realização do censo, o que, de certa forma, consome um tempo considerável e faz com que o mergulhador recreativo mude muito o perfil de mergulho que está acostumado a fazer. ...
Esta coletânea apresenta uma síntese bibliográfica e relatos de pesquisas/
experiências emblemáticas de atividades consideradas de educação ambiental
desenvolvidas recentemente no litoral brasileiro. Tenciona difundir projetos,
programas, ações e atividades essencialmente de universidades públicas e do
Ministério do Meio Ambiente. A gestão costeira enfrenta uma série de desafios
para harmonizar desejos e interesses dos variados entes e setores que pleiteiam
direitos sobre o território litorâneo. Os conflitos gerados por pleitos totalmente díspares, cuja maioria impacta negativamente o ambiente, muitas vezes geram danos irreparáveis, como perda da vida e da dignidade de ambientalistas,
pescadores, funcionários públicos e cientistas. A educação ambiental, que é uma educação política com ideologia e paradigmas próprios, possui farto arsenal epistemológico, conceitual e metodológico para enfrentar, equacionar e resolver conflitos socioambientais e para atuar perante variados públicos usuários da região costeira. A presente coletânea apresenta alguns emblemáticos projetos, programas, ações e atividades desenvolvidos cotidianamente e outros que já se encerraram, mas são exemplos a serem recontextualizados e reaplicados. O livro foi dividido em duas seções. A primeira apresenta estudos básicos para a prática da educação ambiental, e a segunda, resultados aplicáveis da educação ambiental à gestão costeira.
... La méthode du plongeur itinérant (RDT) est une méthode d'enquête visuelle standardisée d'identification des poissons (Schmitt & Sullivan, 1996;Schmitt et al., 2002). Cette méthode a été développée pour fournir à moindres frais, des données fiables sur la présence (fréquence (Schmitt & Sullivan, 1996). ...
... La méthode du plongeur itinérant (RDT) est une méthode d'enquête visuelle standardisée d'identification des poissons (Schmitt & Sullivan, 1996;Schmitt et al., 2002). Cette méthode a été développée pour fournir à moindres frais, des données fiables sur la présence (fréquence (Schmitt & Sullivan, 1996). Elle a été utilisée à de multiples reprises pour évaluer l'abondance et la diversité de poissons (Schmitt & Sullivan, 1996;Kenyon et al., 2006;Rassweiler et al., 2020), les résultats obtenus sont d'ailleurs très proches de ce qui peut être obtenu à l'aide de méthodes dites plus rigoureuses, comme le transect ou le quadrat (Schmitt et al., 2002;Rassweiler et al., 2020). ...
... Cette méthode a été développée pour fournir à moindres frais, des données fiables sur la présence (fréquence (Schmitt & Sullivan, 1996). Elle a été utilisée à de multiples reprises pour évaluer l'abondance et la diversité de poissons (Schmitt & Sullivan, 1996;Kenyon et al., 2006;Rassweiler et al., 2020), les résultats obtenus sont d'ailleurs très proches de ce qui peut être obtenu à l'aide de méthodes dites plus rigoureuses, comme le transect ou le quadrat (Schmitt et al., 2002;Rassweiler et al., 2020). À ce jour, la RDT n'a pas été utilisée pour le suivi de maladies et/ou de parasites dans la littérature scientifique bien que cette technique ait le potentiel d'être une alternative plus simple et applicable que la méthode du transect, surtout lorsque la maladie ou le parasite recherché est peu prévalent dans la population. ...
Hard coral, as vital habitats for reefs organisms, are threatened by anthropogenic factors, making them more susceptible to diseases, including Stony Coral Tissue Loss Disease (SCTLD). First described in Florida in 2014, SCTLD has spread throughout the Caribbean Sea and has been observed in Grenada since 2018, threatening local reefs. The intricate relationship between local environmental factors and coral susceptibility remains poorly understood. Additionally, Grenada's reefs have witnessed skin hyperpigmentation in various fish species, whose etiology and connection to environmental factors remain unexplored. This study investigated potential correlations between SCTLD and hyperpigmentation in French grunt (Haemulon flavolineatum) and ocean surgeonfish (Acanthurus bahianus) across 12 popular dive sites. It also explored potential links between anthropic pressure scores and coral health. The findings revealed a 45% prevalence of SCTLD among hard coral colonies, lower than observed in Florida. Saint George's Bay, subjected to high anthropic pressure, experienced a significant 11% mean coral mortality rate, surpassing sites with minimal anthropic pressure (P=0.020). Furthermore, the prevalence of hyperpigmented fishes significantly correlated with SCTLD prevalence in coral (P=0.004), and anthropic pressure scores exhibited a positive relationship with dead coral percentages (P=0.001). This preliminary study provides crucial insights into SCTLD in Grenada, laying the groundwork for future longitudinal investigations.
... In the Northwestern GOM, artificial reefs are often comprised of decommissioned oil and gas platforms, and Texas currently manages 210 platform reefs through the Texas Parks and Wildlife Department's Artificial Reef Program (TPWD-ARP). Since 1993, the fish community on many of these platforms has been monitored with SCUBA-based roving diver surveys (RDS) (Schmitt and Sullivan, 1996;Schmitt et al., 2002) which evaluate species composition and categorical abundance on these deep (≥ 30 m) structures. The RDS was originally developed to allow volunteer divers to quickly evaluate and record species seen on recreational dives (Schmitt and Sullivan, 1996). ...
... Since 1993, the fish community on many of these platforms has been monitored with SCUBA-based roving diver surveys (RDS) (Schmitt and Sullivan, 1996;Schmitt et al., 2002) which evaluate species composition and categorical abundance on these deep (≥ 30 m) structures. The RDS was originally developed to allow volunteer divers to quickly evaluate and record species seen on recreational dives (Schmitt and Sullivan, 1996). When used by highly trained divers, comparisons between RDS and other UVC methods have demonstrated the ability of RDS to document a greater number of species, and it has been recommended as complimentary to more traditional methods that document fish size and density (Schmitt et al., 2002;Holt et al., 2013). ...
... Generally, for each site and date surveyed, 5-7 surveys were completed for a total of 65 individual surveys. In addition to retaining all individual survey data, an aggregate density score (DEN) (Schmitt and Sullivan, 1996) was calculated for each species for each sampling event (by site/date; n = 11). This pooled data were then used for comparisons with ROV generated datasets from each event. ...
Non-extractive visual survey methods are commonly used to assess a variety of marine habitats. The use of Underwater Visual Census (UVC) by SCUBA divers is predominant; however, remotely acquired video data (e.g., cameras systems, remotely operated vehicles (ROVs), submersibles) are becoming more frequently used to acquire community data. Both remote and diver-based surveys are currently used to survey artificial reef habitat in the Northwestern Gulf of Mexico (GOM) and have associated error due to inherent method bias. Because survey methods that most accurately document the occurrence and estimated abundance of several important fisheries species are greatly needed in the GOM, we compared data collected on the same days and sites from both Roving Diver Surveys (RDS) and micro-ROV surveys conducted on reefed oil and gas platforms. The combined datasets identified a total of 56 species from 22 families, and there was no significant difference in measured species richness between a comprehensive 30 min ROV survey and RDS. Five species of federally managed fish in the GOM were more frequently detected by ROV, as were the majority of species in the Lutjanid and Carangid families. However, abundance estimates from RDS surveys were up to an order of magnitude greater. Multivariate analyses indicated that method choice affected community composition, with Lutjanids and Carangids driving the differences. These two fish families in particular are subject to method bias, probably due to inflated abundance estimates with RDS, or alternatively, deflated estimates from ROV. Although our ROV surveys more frequently detected important fisheries species and produced conservative abundance estimates, a further examination of species distributions on these high-relief platform reefs is needed to fully determine the most accurate survey method. In addition, the attraction and/or gear avoidance of certain species to underwater vehicles deserves further investigation. Overall, our data indicate these methods are viable but the choice of survey method can have implications for the management of certain species, and that careful consideration of methodology is necessary to most accurately document species of interest.
... Thus, artificial reef managers look to fisheries science for cost effective, standardized reef data acquisition methods (Steimle and Meier 1997). Underwater visual survey methods have been used extensively for ecological and fisheries-based scientific field surveys of reef fishes (Colvocoresses andAcosta 2007, Schmitt andSullivan 1996). Among visual census methods applied to reef fish communities, quantitative transect (strip, belt, and line), quantitative point counts, and semiquantitative rapid visual techniques are most common (Holt et al. 2013, Thresher andGunn 1986). ...
... Transect methods however, are of limited use in quantifying fish populations across the wide range of materials and configurations of artificial reefs particularly as many of these reef structures are oriented vertically rather than horizontally. The roving diver technique (RDT) is a widely used rapid visual census method for surveying reef fish communities (Holt et al. 2013, Schmitt et al. 2002, Schmitt and Sullivan 1996. During RDT surveys, divers freely roam reef environments and record all fish species that can be positively identified in logarithmic abundance categories: i) Single (1 fish), ii) Few (2-10), iii) Many (11-100), or iv) Abundant (>100); hereafter referred to as SFMA data (www.REEF.org). ...
... Surveyor roles (exact count vs. SFMA) were alternated between two consecutive dives separated by a 2 hour surface interval during each site visit. Replicate visual surveys are preferred to more fully characterize fish biodiversity (Schmitt & Sullivan 1996). Abundances for both SFMA counts and exact counts were logged during each 30-40 min dive in contrast to the post-dive reporting often cited for RDT (Edgar et al. 2004). ...
Texas Parks and Wildlife Department’s (TPWD) Artificial Reef Program (ARP) has utilized the roving diver technique (RDT) recording abundances as order of magnitude counts [REEF-type: Single (1); Few (2-10), Many (11-100), and Abundant (> 100), SFMA hereafter] for many years. However, because SFMA counts do not provide numerical abundances in catch per unit effort (CPUE) or density, these data cannot be integrated with other state coastal survey data for stock assessment (e.g., trawl fisheries, gill net, vertical long line). Accordingly, a comparison of exact and order-of-magnitude counts (SFMA) from paired divers was conducted during five consecutive sampling quarters at the USTS Texas Clipper Reef located 17 nm offshore of South Padre Island, Texas, USA. SFMA data were converted to numerical abundances and compared to exact counts via rank correlations of their similarity matrices on the assertion that if both survey methods capture similar species richness and relative abundance, their correlation should be high. In this study, which eliminated roving bias, biodiversity was greatest for the order-of-magnitude count method compared to exact counting which tended to underrepresent small cryptic reef fish as well as pelagic schooling fish. Exact counts by divers were found to underestimate species richness by 15 - 30% compared to the SFMA method. In addition, we found that both enumeration methods produced similar results in capturing relative abundances of large, abundant, and conspicuous species. The results of our survey method comparison indicate that the log-category census method is an effective technique when diversity estimates are a major goal.
... Durante los meses de abril y mayo (época seca) de 2005, se muestrearon 20 estaciones ubicadas sobre formaciones coralinas del área de Santa Marta y el PNNT (Figura 1), cuya profundidad abarcó el ámbito de 6 a 12 m. Se empleó el método de censo visual de buceo errante -CBE-que proporciona listados de peces y estimaciones de la abundancia relativa de cada especie (Schmitt y Sullivan, 1996). El CBE consistió en nadar libremente durante 30 minutos dentro de los límites de profundidad establecidos y anotar todas las especies observadas, así como cada individuo por especie. ...
... El estado de las especies fue determinado a partir de dos variables: 1) la frecuencia de observación (FO) calculada como el porcentaje del número de censos en los cuales una especie es observada en el total de censos realizados por estación y 2) la abundancia relativa (AR) calculada como un puntaje ponderado (Schmitt y Sullivan, 1996) de la forma: AR= ((nax1)+(nbx2)+(ncx3)+(ndx4))…… (nix9)) / (Nº total de censos por estación) donde na, nb, nc y nd hasta ni representan el número de veces que cada categoría de abundancia le fue asignada a cada especie. Tabla 1. Listado de las estaciones de muestreo. ...
... bahianus, a. coeruleus, S aurofrenatum y S. viride) y carnívoros (Haemulon flavolineatum y Cephalopholis cruentata). Este resultado refleja la condición general de los arrecifes del Caribe, donde dichas especies están ampliamente distribuidas y se han reconocido entre las más comunes (Choat, 1991;Schmitt y Sullivan, 1996;Hoshino et al., 2003;Kramer et al., 2003;Nemeth et al., 2003;Pattengil-Semmens y Semmens, 2003). ...
Variables such as richness, diversity, evenness, relative abundance (RA), and sighting frequency (SF) were assessed in order to characterize reef fish assemblages in Santa Marta and Tayrona Natural National Park (TNNP). The effect of the TNNP protection on these attributes was evaluated. Data were registered in 20 sites by means of the roving diver in diversity and evenness between zones (p< 0.05) indicating a TNNP protection effect, but not differences in richness. Species composition was moderately similar between the two zones (Jaccard Index 0.69). Nevertheless, families such as Serranidae, Haemulidae, and Lutjanidae showed differences in species composition between evaluated zones. Large groupers and snappers exhibited RA and SF considerably low at both protected and not protected zones. Differences were only recorded between small body size and non-target species. These results suggest that the TNNP can be facilitating the preservation of high species diversity, but fishing control systems should be more efficient in order to promote protection and conservation of more vulnerable reef fish populations (snappers and groupers).
... Thus, artificial reef managers look to fisheries science for cost effective, standardized reef data acquisition methods (Steimle and Meier 1997). Underwater visual survey methods have been used extensively for ecological and fisheries-based scientific field surveys of reef fishes (Colvocoresses andAcosta 2007, Schmitt andSullivan 1996). Among visual census methods applied to reef fish communities, quantitative transect (strip, belt, and line), quantitative point counts, and semiquantitative rapid visual techniques are most common (Holt et al. 2013, Thresher andGunn 1986). ...
... Transect methods however, are of limited use in quantifying fish populations across the wide range of materials and configurations of artificial reefs particularly as many of these reef structures are oriented vertically rather than horizontally. The roving diver technique (RDT) is a widely used rapid visual census method for surveying reef fish communities (Holt et al. 2013, Schmitt et al. 2002, Schmitt and Sullivan 1996. During RDT surveys, divers freely roam reef environments and record all fish species that can be positively identified in logarithmic abundance categories: i) Single (1 fish), ii) Few (2-10), iii) Many (11-100), or iv) Abundant (>100); hereafter referred to as SFMA data (www.REEF.org). ...
... Surveyor roles (exact count vs. SFMA) were alternated between two consecutive dives separated by a 2 hour surface interval during each site visit. Replicate visual surveys are preferred to more fully characterize fish biodiversity (Schmitt & Sullivan 1996). Abundances for both SFMA counts and exact counts were logged during each 30-40 min dive in contrast to the post-dive reporting often cited for RDT (Edgar et al. 2004). ...
Texas Parks and Wildlife Department’s (TPWD) Artificial Reef Program (ARP) has utilized the roving diver technique (RDT) recording abundances as order of magnitude counts [REEF-type: Single (1); Few (2-10), Many (11-100), and Abundant (> 100), SFMA hereafter] for many years. However, because SFMA counts do not provide numerical abundances in catch per unit effort (CPUE) or density, these data cannot be integrated with other state coastal survey data for stock assessment (e.g., trawl fisheries, gill net, vertical long line). Accordingly, a comparison of exact and order-of-magnitude counts (SFMA) from paired divers was conducted during five consecutive sampling quarters at the USTS Texas Clipper Reef located 17 nm offshore of South Padre Island, Texas, USA. SFMA data were converted to numerical abundances and compared to exact counts via rank correlations of their similarity matrices on the assertion that if both survey methods capture similar species richness and relative abundance, their correlation should be high. In this study, which eliminated roving bias, biodiversity was greatest for the order-of-magnitude count method compared to exact counting which tended to underrepresent small cryptic reef fish as well as pelagic schooling fish. Exact counts by divers were found to underestimate species richness by 15 - 30% compared to the SFMA method. In addition, we found that both enumeration methods produced similar results in capturing relative abundances of large, abundant, and conspicuous species. The results of our survey method comparison indicate that the log-category census method is an effective technique when diversity estimates are a major goal.
... Thus, artificial reef managers look to fisheries science for cost effective, standardized reef data acquisition methods (Steimle and Meier 1997). Underwater visual survey methods have been used extensively for ecological and fisheries-based scientific field surveys of reef fishes (Colvocoresses andAcosta 2007, Schmitt andSullivan 1996). Among visual census methods applied to reef fish communities, quantitative transect (strip, belt, and line), quantitative point counts, and semiquantitative rapid visual techniques are most common (Holt et al. 2013, Thresher andGunn 1986). ...
... Transect methods however, are of limited use in quantifying fish populations across the wide range of materials and configurations of artificial reefs particularly as many of these reef structures are oriented vertically rather than horizontally. The roving diver technique (RDT) is a widely used rapid visual census method for surveying reef fish communities (Holt et al. 2013, Schmitt et al. 2002, Schmitt and Sullivan 1996. During RDT surveys, divers freely roam reef environments and record all fish species that can be positively identified in logarithmic abundance categories: i) Single (1 fish), ii) Few (2-10), iii) Many (11-100), or iv) Abundant (>100); hereafter referred to as SFMA data (www.REEF.org). ...
... Surveyor roles (exact count vs. SFMA) were alternated between two consecutive dives separated by a 2 hour surface interval during each site visit. Replicate visual surveys are preferred to more fully characterize fish biodiversity (Schmitt & Sullivan 1996). Abundances for both SFMA counts and exact counts were logged during each 30-40 min dive in contrast to the post-dive reporting often cited for RDT (Edgar et al. 2004). ...
Texas Parks and Wildlife Department's (TPWD) Artificial Reef Program (ARP) has utilized the roving diver technique (RDT) recording abundances as order of magnitude counts [REEF-type: Single (1); Few (2-10), Many (11-100), and Abundant (> 100), SFMA hereafter] for many years. However, because SFMA counts do not provide numerical abundances in catch per unit effort (CPUE) or density, these data cannot be integrated with other state coastal survey data for stock assessment (e.g., trawl fisheries, gill net, vertical long line). Accordingly, a comparison of exact and order-of-magnitude counts (SFMA) from paired divers was conducted during five consecutive sampling quarters at the USTS Texas Clipper Reef located 17 nm offshore of South Padre Island, Texas, USA. SFMA data were converted to numerical abundances and compared to exact counts via rank correlations of their similarity matrices on the assertion that if both survey methods capture similar species richness and relative abundance, their correlation should be high. In this study, which eliminated roving bias, biodiversity was greatest for the order-of-magnitude count method compared to exact counting which tended to underrepresent small cryptic reef fish as well as pelagic schooling fish. Exact counts by divers were found to underestimate species richness by 15-30% compared to the SFMA method. In addition, we found that both enumeration methods produced similar results in capturing relative abundances of large, abundant, and conspicuous species. The results of our survey method comparison indicate that the log-category census method is an effective technique when diversity estimates are a major goal.
... Programas de conservação e planos de manejo têm incluído voluntários dentro de seus grupos de pesquisa que participam e coletam dados junto aos pesquisadores. Estes são pescadores, mergulhadores, membros de comunidades tradicionais detentores de conhecimentos que estão além dos muros das universidades e que contribuem de forma significativa com a conservação dos ecossistemas (CHOU, 1994;SCHMITT;SULLIVAN, 1996;DARWALL;DULVY, 1996;HODGSON, 1999;PATTENGILL SEMMENS;SEMMENS, 2003;GOFFREDO et al., 2004;BELL et al., 2009;WILLIAMS et al., 2015). ...
... Programas de conservação e planos de manejo têm incluído voluntários dentro de seus grupos de pesquisa que participam e coletam dados junto aos pesquisadores. Estes são pescadores, mergulhadores, membros de comunidades tradicionais detentores de conhecimentos que estão além dos muros das universidades e que contribuem de forma significativa com a conservação dos ecossistemas (CHOU, 1994;SCHMITT;SULLIVAN, 1996;DARWALL;DULVY, 1996;HODGSON, 1999;PATTENGILL SEMMENS;SEMMENS, 2003;GOFFREDO et al., 2004;BELL et al., 2009;WILLIAMS et al., 2015). ...
Recreational diving is an important ecotourism activity that has contributed information about marine zoological groups. The objective of this study was to investigate the environmental perception of recreational divers on the coast of Ipojuca/PE regarding sea turtles and to report their perception of their practice within the marine ecosystem. Research was conducted with divers using semi-structured questionnaires applied through open interviews. Most divers are men, local residents and diving instructors. Thirty diving sites with recorded sea turtles were identified, with the most cited being the Tugboat Marte and Naufrágio Gonçalo Coelho (both 19%). In addition, four species of sea turtle were detected, with the most mentioned being Eretmochelys imbricata (50%). In general, sightings are occasional and peaceful, and tourism is not aimed at these animals, having a contemplative character. It was noted the evident need to train these professionals for a more conscious execution of their activity, mainly with regard to knowledge about the marine ecosystem. Keywords: Conservation, diving, testudines Sea turtles from the perspective of recreational divers on the coast of Ipojuca (Pernambuco, Northeast Brazil) A B S T R A C T Recreational diving is an important ecotourism activity that has been contributing with information about zoological groups in marine environments. The study aim was to investigate the environmental perception of divers about sea turtle's population Ipojuca/PE coast and report the perception of their practice inserted in the marine ecosystem. Research was carried out with divers using semi-structured questionnaires applied with free interviews. The most divers are men, local residents and dive instructors. A total of 30 dive sites were recorded with sea turtle records, with the most cited being the Mars Tugboat and Wreck Gonçalo Coelho (both 19%), In addition, four species of sea turtle were detected, the most mentioned being Eretmochelys imbricata (50%). In general, sightings are occasional, peaceful and tourism is not directed to these animals, having a contemplative character. It was noted and the evident need to train these professionals for a more conscious execution of their activity, mainly with regard to knowledge regarding the marine ecosystem.
... Additionally, three minnow traps per station were deployed, using fresh fish meat as bait, and left in place for 12 h [20]. In areas with Diversity 2024, 16, 517 3 of 11 hard bottoms, visual censuses were carried out using the Roving Diver Technique [21], which involves intensive random searches to record the maximum possible numbers of fish species along each station during the entire duration of a dive (typically 30-40 min each, n = 160). Data collected during these samplings were recorded using standardized tables and PVC plates; digital photographs were taken where possible. ...
... Additionally, three minnow traps per station were deployed, using fresh fish meat as bait, and left in place for 12 h [20]. In areas with hard bottoms, visual censuses were carried out using the Roving Diver Technique [21], which involves intensive random searches to record the maximum possible numbers of fish species along each station during the entire duration of a dive (typically 30-40 min each, n = 160). Data collected during these samplings were recorded using standardized tables and PVC plates; digital photographs were taken where possible. ...
Coastal environments, such as bays, are essential to the development of fishery resources due to their economic and ecological importance. This paper presents an updated checklist of coastal marine fishes as part of a long-term monitoring program in Aratu Bay (2014–2024), Bahia state, eastern Brazil. A total of 109 species belonging to 58 families and 24 orders were cataloged. Five endemic species and ten species listed as at risk according to the IUCN criteria (from Vulnerable onwards) were identified. The Carangidae was the most representative family in terms of species number, followed by Gobiidae and Sciaenidae. The ichthyofauna was dominated by mobile invertebrate feeders and macrocarnivores. Two non-native species were observed in the region: the Muzzled blenny, Omobranchus sewalli and the mud sleeper Butis koilomatodon. Aratu Bay supports a diverse ichthyofauna with diverse trophic guilds and habitats, rendering it an important area for the feeding and development of economically valuable species, including those facing threats.
... Underwater visual census (UVC) is a minimally invasive, fishery-independent method in which snorkel or SCUBA is used to assess biodiversity and/ or biomass in marine habitats (Pattengill-Semmens & Semmens, 2003). The roving diver technique (RDT; Schmitt & Sullivan, 1996) is a type of UVC especially suited for detecting shy, cryptic, or demersal fishes difficult to assess with other monitoring tools (Murphy & Jenkins, 2010). During RDT surveys, divers swim freely throughout a dive site while recording each observed fish species and a corresponding log-scale categorical abundance. ...
... This includes, but is not limited to, whether the species occurs at recreational diving depths, is cryptic or conspicuous, and if it can be discerned from closely related species without a specimen in hand (e.g., for meristic counts). Identifying the species that volunteers can potentially encounter and visually identify can improve the interpretation of data provided by this no-cost, high-value monitoring tool (Schmitt & Sullivan, 1996). ...
Long-term monitoring enables scientists and managers to track changes in the temporal and spatial distributions of fishes. Given the anthropogenic stressors affecting marine ecosystem health, there is a critical need for robust, comprehensive fish monitoring programs. Citizen science can serve as a meaningful, cost-effective strategy to survey fish communities. We compared data from 13,000 surveys collected over 21 years (1998–2019) by Reef Environmental Education Foundation (REEF) volunteer divers to a published compilation of Salish Sea ichthyofauna collected using an assortment of methods. Volunteer divers observed 138 of 261 recognized species in the Salish Sea, expanded the range of 18 species into additional Salish Sea sub-basins, and identified one species novel to the Salish Sea ( Gibbonsia metzi — Striped Kelpfish). To identify Salish Sea fish species that are most suitable to be monitored by underwater visual census and to evaluate confidence in in situ identification, we developed a categorization system based on the likelihood of recreational divers and snorkelers encountering a given species, and on whether identification required a specimen in hand or could be classified to species visually (with or without a high-quality photograph). REEF divers encountered 62% (138 of 223) of the visually detectable species occurring in the region and 85% (102 of 120) of species most likely to be observed by recreational divers. Our findings show that citizen scientists provide valuable monitoring data for over half of the 261 marine and anadromous fish species known to occupy the Salish Sea, many of which are not routinely monitored otherwise.
... Data were collected using BRUVs and roving diver technique (RDT) UVCs (Schmitt and Sullivan 1996) (Supplementary Table S2). Surveys were conducted both in summer and winter months, at deep and shallow sites, and typically between 08:00 and 12:00 owing to the logistics of boat launching. ...
... UVC duration ranged from 13 to 72 min, with an average time of 37.5 min. A modified version of the RDT UVC developed by Schmitt and Sullivan (1996) was used, in which divers 'rove' freely throughout the dive site while recording all observed fish species. RDT does not have the spatial and temporal boundaries of other UVC methods which have start locations and times within the dive, making this technique particularly advantageous for highly mobile species, species that occur at low abundances, and those that may be wary of divers (Stallings 2009;Ward-Paige and Lotze 2011). ...
Persistent threats from fishing pressure and increasing habitat degradation, as well as slow recovery rates resulting from K-selected life histories, are putting increasing numbers of elasmobranch species (sharks, rays and skates) at risk of extinction worldwide. Global declines in elasmobranch populations merit evidence-based conservation measures, but establishment of such measures has been hindered by a paucity of population-level data. Mozambique supports a high number of threatened (Vulnerable, Endangered or Critically Endangered) and Data Deficient elasmobranch species; however, most of these populations are poorly understood. We collected baseline data on the presence, species richness, diversity, and habitat use of elasmobranchs within Zavora Bay, Mozambique, using baited remote underwater video and underwater visual census surveys, at six sites, from January 2017 to March 2020. Our results show that Zavora Bay is used year-round by 20 elasmobranch species, all of which are listed on the IUCN Red List of Threatened Species as either Data Deficient, threatened, or Near Threatened with declining population trends. Many of these species are heavily targeted by fisheries or caught as bycatch throughout their range, and some do not encounter protected areas anywhere within their natural range, highlighting the urgency to establish adequate conservation strategies to prevent further population declines.
... Programas de conservação e planos de manejo têm incluído voluntários dentro de seus grupos de pesquisa que participam e coletam dados junto aos pesquisadores. Estes são pescadores, mergulhadores, membros de comunidades tradicionais detentores de conhecimentos que estão além dos muros das universidades e que contribuem de forma significativa com a conservação dos ecossistemas (CHOU, 1994;SCHMITT;SULLIVAN, 1996;DARWALL;DULVY, 1996;HODGSON, 1999;PATTENGILL SEMMENS;SEMMENS, 2003;GOFFREDO et al., 2004;BELL et al., 2009;WILLIAMS et al., 2015). ...
... Programas de conservação e planos de manejo têm incluído voluntários dentro de seus grupos de pesquisa que participam e coletam dados junto aos pesquisadores. Estes são pescadores, mergulhadores, membros de comunidades tradicionais detentores de conhecimentos que estão além dos muros das universidades e que contribuem de forma significativa com a conservação dos ecossistemas (CHOU, 1994;SCHMITT;SULLIVAN, 1996;DARWALL;DULVY, 1996;HODGSON, 1999;PATTENGILL SEMMENS;SEMMENS, 2003;GOFFREDO et al., 2004;BELL et al., 2009;WILLIAMS et al., 2015). ...
... Since these programs began, the use of volunteers to collect scientific data in the coastal zone has become commonplace in many countries, including Australia (Hassell et al. 2013), Belize (Mumby et al. 1995), Fiji (Leopold et al. 2009), Indonesia (Harding et al. 2000), New Zealand (Fletcher and Shortis 2001), the Philippines (Beger 2002), Tanzania (Darwall and Dulvy 1996), the USA (Schmitt and Sullivan 1996;Pattengill-Semmens and Semmens 2003;Shuman et al. 2011), and the Wider Caribbean Region (Ward-Paige et al. 2010). In the developed world, participants in marine citizen science programs generally participate as a hobby, focusing on areas of high-perceived value such as coral reefs and popular SCUBA dive sites. ...
... The importance of data collected by non-professionals is well documented, and, despite some criticism, the majority of studies comparing the validity of data collected by volunteers and experts using suitable methodologies have been favourable (Schmitt and Sullivan 1996;Hassell et al. 2013). Fewer studies have evaluated the ability of small-scale fishers from developing countries to collect accurate data, although Beger (2002) and Uychiaoco et al. (2005) found more variation in data collected by the fishers than what was collected by trainers. ...
Although, the involvement of artisanal fishing communities in conservation and management is now commonplace, their participation rarely goes beyond providing local and traditional knowledge to visiting scientists and managers. Communities are often excluded from ongoing monitoring, evaluation, and decision-making, even though these measures can have tremendous impacts on their livelihoods. For the past 17 years, we have designed, tested, and implemented a community-based monitoring model in three key marine ecosystems in Mexico: the kelp forests of Pacific Baja California, the rocky reefs of the Gulf of California, and the coral reefs of the Mesoamerican Reef System. This model is intended to engage local fishers in data collection by fulfilling two principal objectives: (1) to achieve science-based conservation and management decisions and (2) to improve livelihoods through access to knowledge and temporary employment. To achieve these goals, over 400 artisanal fishers and community members have participated in a nationwide marine reserve program. Of these, 222 fishers, including 30 women, have been trained to conduct an underwater visual census using SCUBA gear, and, to date, over 12,000 transects have been completed. Independent scientists periodically evaluate the training process and standards, and the data contribute to international monitoring efforts. This successful model is now being adopted by both civil society and government for use in different parts of Mexico and neighbouring countries. Empowering community members to collect scientific data creates responsibility, pride, and a deeper understanding of the ecosystem in which they live and work, providing both social and ecological benefits to the community and marine ecosystem.
... The reliability of data collected by non-specialist volunteers has been occasionally questioned (Greenwood, 1994). In response to such criticism, several papers focused on the preliminary steps of CS projects when protocols were tested and validated (Halusky et al., 1994;Mumby et al., 1995;Darwall and Dulvy, 1996;Schmitt and Sullivan, 1996;Forrester et al., 2015). Overall, a number of lessons can be learned from these and subsequent review/commentary works. ...
... Over the last two decades, volunteer divers have provided data about invasive species (Semmens et al., 2004) or species abundance and distribution on different temporal and spatial scales (Halusky et al., 1994;Mumby et al., 1995;Darwall and Dulvy, 1996;Schmitt and Sullivan, 1996;Pattengill-Semmens and Semmens, 2003;Bell, 2007;Huveneers et al., 2009;Forrester et al., 2015). However, few CS initiatives engaging Mediterranean divers are reported in the literature (Boero et al., 2009;Bramanti et al., 2011). ...
... The reliability of data collected by non-specialist volunteers has been occasionally questioned (Greenwood, 1994). In response to such criticism, several papers focused on the preliminary steps of CS projects when protocols were tested and validated (Halusky et al., 1994;Mumby et al., 1995;Darwall and Dulvy, 1996;Schmitt and Sullivan, 1996;Forrester et al., 2015). Overall, a number of lessons can be learned from these and subsequent review/commentary works. ...
... Over the last two decades, volunteer divers have provided data about invasive species (Semmens et al., 2004) or species abundance and distribution on different temporal and spatial scales (Halusky et al., 1994;Mumby et al., 1995;Darwall and Dulvy, 1996;Schmitt and Sullivan, 1996;Pattengill-Semmens and Semmens, 2003;Bell, 2007;Huveneers et al., 2009;Forrester et al., 2015). However, few CS initiatives engaging Mediterranean divers are reported in the literature (Boero et al., 2009;Bramanti et al., 2011). ...
Recreational diving engages 20 million people worldwide. Most of the literature refers to tropical destinations but at least 1 million dives per year take place in Mediterranean marine protected areas (MPAs).
Divers may negatively affect underwater habitats. However, if effectively engaged, they can contribute to science, territorial management and more sustainable local economies.
During 2006–2014, volunteers trained by the not‐for‐profit organization Reef Check Italia (RCI) completed 24 714 observations and 2417 dives in six Mediterranean countries, contributing to a dataset that supports scientific papers about climate change, rare and non‐indigenous species (NIS), and informs MPA management decision‐making.
The wide range of opportunities offered by this dataset is illustrated with two examples relevant to marine conservation in the context of MPA management. They concern: (i) the spread of the NIS Caulerpa cylindracea along the Ligurian coasts, with a focus on Portofino MPA, and (ii) the distribution and abundance of protected species in the Portofino MPA.
A diver‐focused survey showed that RCI volunteers are highly committed, and that participation in RCI activities has led to a better understanding of, and a sense of stewardship towards, favoured dive sites and the marine world. Knowing who volunteers are, and why they volunteer in their favourite sector, is crucial to designing citizen‐science based projects able to achieve their multiple goals.
Copyright © 2016 John Wiley & Sons, Ltd.
... We conducted UVC and eDNA seawater sample collection between June and October 2021. For UVC, four teams each consisting of two to three competent and trained fish identification researchers with SCUBA gear conducted Roving Diver Technique (RDT) surveys (Schmitt and Sullivan 1996), where divers survey the benthic water columns following a nonrepeating route and record every observed reef fish species. The UVC surveys were conducted in all 16 sites, with each dive on average lasting for 63 ± 12.1 (SD) min with an average depth of 6.3 ± 2.6 (SD) m. ...
Comprehensive assessments of coastal biodiversity in complex coral communities are crucial but challenging, particularly under unfavorable conditions such as poor underwater visibility in urbanized and eutrophic environments. Here we aim to examine the scope of underwater diversity detection and community shifts across habitat transitions spanning different geographic regions in Hong Kong SAR, a highly urbanized coastal city with limited underwater visibility of 3.93 ± 1.25 m during the sampling period. We employ and compare two methods: 12S rRNA eDNA metabarcoding coupled with custom built reference database and simultaneous extensive underwater visual census (UVC) surveys. eDNA detected a higher species richness per site. Yet, each survey method featured a distinct species profile with associated trophic guilds, where 98 (32.3%) species found exclusively by UVC and 120 (39.6%) species detected only by eDNA. eDNA featured species from diverse habitats and evolutionary distances, including cryptic and large mobile fishes, offering enhanced prediction on local ecosystem functions. eDNA also recorded 90 putative species that had never been recorded in additional seven yearlong UVC dataset, with seven prospective new occurrence records to the territorial waters. UVC on the other hand was more efficient in documenting reef‐associated species. Both methods captured similar patterns of community spatial structure along the habitat transitions while only eDNA detected more large fish species in offshore compared to sheltered inshore environments, This may suggest inshore overfishing and incapability of UVC in surveying large mobile species in turbid environments. Considering the discrepancies between two methods, we highlight the importance of complementing both UVC and eDNA metabarcoding survey for a complete overview of local biodiversity under unfavored underwater conditions in an urbanized seascape.
... Fish communities were monitored using visual diver surveys during 2008-2017. Visual surveys have been the preferred method to monitor fish assemblages on ARs (Bracho-Villavicencio, Matthews-Cascon, and Rossi 2023) and surveys on the Texas Clipper followed the roving diver (RD) method that has been widely used as a rapid visual method for surveying reef fish communities (Schmitt and Sullivan 1996;Schmitt, Sluka, and Sullivan-Sealey 2002;Holt et al. 2013). The RD survey method has several advantages over other visual methods (transect-based for example), because it is nondestructive, easily applied to variable forms of ARs, and requires relatively little sampling equipment (Hicks et al. 2016). ...
Fish communities on artificial reefs have rarely been monitored over long periods to evaluate success of reef deployment. Here, we used roving diver surveys to assess changes in fish assemblages on a large, reefed vessel during 2008-2017. Multivariate analyses revealed a dynamic community that stabilized after 5 years. Species richness increased and species dominance decreased during 2008-2017. The fish community shifted toward reef-associated species such as hogfish and pufferfish. Species composition shifted, but trophic structure was relatively stable, which suggested that functional groups may not reflect larger community shifts. Our results indicate that fish communities on artificial reefs are temporally dynamic and that long-term monitoring is needed to understand how fish assemblage structure changes through time.
... Figure 1). Data were collected by trained researchers on SCUBA, using a modified version of the 'Roving Diver' Underwater Visual Census (UVC) Technique (Schmitt and Sullivan 1996). Although a typical transect path was followed at each site, observers essentially 'roved' freely throughout the site to record marine megafauna species. ...
Mobulid rays are among the most vulnerable of chondrichthyans to overexploitation by fisheries due to their low population growth rates. In locations where catch data are lacking, long-term sightings data can provide valuable insight to infer population trends and status. We recorded underwater sighting data of reef manta rays (Mobula alfredi), oceanic manta rays (M. birostris), and shorthorned pygmy devil rays (M. kuhlii) between 2003 and 2023 in the waters off Praia do Tofo in the Inhambane Province, southern Mozambique, one of the major global hotspots for these rays. We modelled sightings data using a hierarchical generalised linear mixed model framework to account for a suite of environmental variables when examining temporal trends. Raw trend models including only ‘year’ as a predictor showed a 99% decline in sightings of reef manta rays, a 92.5% decline in oceanic manta ray sightings, and an 81.3% decline in devil ray sightings over the 20-year study period. The declining trends persisted for reef and oceanic manta rays once a suite of temporal and environmental variables were accounted for, indicating that the declines were driven by external factors not tested in the models. For shorthorned pygmy devil rays, models that incorporated environmental variables did not retain year as a significant predictor and showed a reduced overall decline in sightings of 36.5%. This indicates that the tested predictors were responsible for approximately half of the observed decline. Anthropogenic factors, particularly fisheries mortality, are likely to have played a significant role in the declining sightings of these three Threatened species. Improved conservation and management measures at a national and international level are critical to prevent further declines, which may otherwise lead to localised extinction.
... The diverse tropical and subtropical ichthyofauna on Florida's coral reef contains families that are typical on reefs throughout the western Atlantic. There are more than 160 noncryptic species that are regularly seen on visual surveys, with variability among ecoregions (Schmitt & Sullivan, 1996). In addition, there is a diverse cryptobenthic fish assemblage that is ecologically important but poorly studied, as is typical of this component of the assemblage globally (Brandl et al., 2019). ...
Parrotfishes are a functionally critical component of Caribbean reef fish assemblages, with large‐bodied parrotfish species exerting particularly important top‐down control on macroalgae. Despite their importance, low biomasses of large‐bodied parrotfishes on many reefs hamper our ability to study and understand their ecology. Florida reefs, where most parrotfish fishing has been illegal since 1992, present a unique opportunity to explore covariates of their distribution. Using boosted regression tree models and 23 covariates, this study identified the major predictors of four species of Atlantic large‐bodied parrotfishes. Maximum hard substrate relief, the area of the surrounding reef, and the availability of seagrass habitat were each positively related to parrotfish presence. Strong positive relationships between parrotfish presence and biomass and the biomass of other parrotfishes on a reef suggest that all four species responded to a similar subset of environmental conditions. However, relationships between parrotfish presence and biomass and depth, habitat type, coral cover, and the proximity of a reef to deepwater habitats differed among species, highlighting distinct habitat preferences. These results can improve managers’ ability to target important biophysical correlates of large‐bodied parrotfishes with appropriate management interventions and identify areas for protection.
... Anchovies, silversides, sardines, and menhaden could not be reliably distinguished from each other during surveys, so they were placed into a single group, henceforth referred to as "small, water-column fishes" (SWCF) following past precedent (Serafy et al. 2003, Humann andDeLoach 2014). While transects are effective at including common fish species, they can underestimate rare and cryptic species, as well as mobile predators (Schmitt and Sullivan 1996, Schmitt et al. 2002, Lennon 2023. Additionally, having an observer in the water impacts the behavior of the fish and may significantly lower the fish abundances recorded (Watson andHarvey 2007, Dickens et al. 2011). ...
Nearshore hardbottom communities are characterized by their invertebrate benthos, which provide food, habitat, and refuge for fish. Structural complexity supports greater species richness and abundance; thus, habitat degradation can reduce fish diversity and lead to a shift in community composition. Nearshore hardbottom communities in the Florida Keys, United States, have lost sessile benthic invertebrate diversity since the 1970s and the communities examined here have shifted from coral- and sponge-dominated to sponge- and algae-dominated. Two nearshore hardbottom communities (one oceanside site and one bayside) were surveyed from 1991 through 1996, and then were resurveyed in 2021 and 2022. Both communities experienced declines in fish richness, biodiversity, and trophic structure. Present-day fish species richness is approximately 30%–40% of what it was when surveying began in 1991. Sessile benthic invertebrate richness and density were correlated with fish richness and composition; the degradation of benthic communities appears to have negatively influenced fish assemblages. Diverse and abundant fish assemblages are key to healthy and productive coastal ecosystems; this loss of biodiversity will reduce the ecological functionality of nearshore hardbottom communities.
... com), and by the Malpelo Foundation at Malpelo. Visual surveys at each site were carried out using the Roving Diver Technique (RDT) (Schmitt and Sullivan 1996), which involves counting all individual sharks sighted by the diver during an immersion (30 min). The divers were either stationary or moving, depending on the location and current velocity. ...
The Eastern Tropical Pacific (ETP) is one of the last regions where large aggregations of the critically endangered scalloped hammerhead shark (Sphyrna lewini) can still be observed. In this regard, we comparatively assessed the seasonality in S. lewini’s relative abundance within three marine protected areas (MPAs) of the ETP and explored its relationship with environmental factors such as temperature. Abundance standardization via generalized linear mixed models revealed that Galapagos Islands (Ecuador) held an overall higher relative abundance of S. lewini when compared to Cocos Island (Costa Rica) and Malpelo (Colombia). The greatest relative abundance was observed from June to October for Cocos, followed by Galapagos (January, September, and November) and Malpelo (December, February, and March). Our results suggest that S. lewini observed relative abundances are significantly affected by water temperature and years (all three sites), and by the seasons, dive schedule, visibility and moon phase (to a lesser extend). This research contributes to the understanding of the temporal and spatial fluctuations of S. lewini at oceanic aggregation sites to improve the decision-making tools for the integral regional climate-smart management of the species. We recommended future studies to model the effect of climate change in the abundance at aggregation sites and potential distribution shifts across the ETP.
... More than 50 surveys were conducted, including more than10-night surveys and more than 20 dives deeper than 20 m, all longer than one hour. All surveys were carried out by examining the benthos using the "roving diver technique" (RDT) as described in Schmitt and Sullivan (1996) and Bourjon et al. (2018), searching under crevices and rocks, During this period (2019-2020), management surveys were implemented under the Vanuatu National Sea Cucumber Fishery Management Plan across six provinces of Vanuatu, recording specific abundances of commercial species. Target islands included Efate, Gaua, Santo, Maewo, Malekula, Maskelynes, Epi, Emau, Erromango and Tanna, along with associated islets (Fig. 2). ...
This contribution describes the results of a sea cucumber (Holothuroidea) survey that was conducted in Vanuatu (South Pacific) from 2019 to 2020. A field species inventory was undertaken around Efate Island during this period, of which outcomes are then compared with the results from the 2019-2020 sea cucumber monitoring surveys, implemented by the Vanu-atu Fisheries Department under the current Vanuatu National Sea Cucumber Fishery Management Plan. The main result of this survey is the correct health of sea cucumber populations, both abundant and diverse, including threatened species. These results bring the total number of sea cucumbers in Vanuatu to 36, including 20 species of commercial interest and 5 species of conservation interest observed throughout the course of the study.
... Another potentially valuable dataset is the citizen-science based database curated by the Reef Environmental Education Foundation (REEF). Their volunteer fish survey project, established in 1993 and operating ever since, was designed in partnership with fisheries scientists from NOAA Fisheries, the University of Miami, and the Nature Conservancy [19]; and validated as a useful dataset for determining species distribution and abundance patterns [21]. ...
... Roving fish surveys were standardized to 10 min and conducted at each horizontal level including the horizontal, vertical, and diagonal supports (Fig. 1). The standard Roving Diver Technique (RDT) (Schmitt and Sullivan 1996), whereby a diver swims freely throughout the dive area recording every fish observed and approximate abundance (single [1], few [2-10], many , and abundant [>100]), was modified to address the unique area of the platform. Fish surveys were restricted to the same horizontal level with the ceiling limit one meter below the next upper level. ...
High Island A-389-A (HI-A-389-A) is a gas platform situated in 125 m water within Flower Garden Banks National Marine Sanctuary in the northwestern Gulf of Mexico, and provides habitat to a diverse array of benthic organisms and fish species. Platform production ceased in 2012, beginning the decommissioning process for structural removal. Rather than complete removal of the structure, the lower portion was left intact as an artificial reef and the upper 21 m was removed. The biological communities (benthic and fish) were characterized during diver and remotely operated vehicle surveys, both before and after removal of the upper structure. The platform’s benthic community, primarily categorized as fouling organisms, was mainly composed of sponges, hydroids, macroalgae, bivalves, zoanthids, and stony corals. The dominant stony coral was orange cup coral (Tubastraea sp.), an exotic species, while native coral species were rare. Fish species were predominantly demersal planktivores. Analyses of the benthic and fish communities documented four distinct biological zones strongly associated with depth. Significant differences in the benthic community were observed after partial removal and varied with depth, including the loss of hydroids, increase in macroalgae cover, and sponge and coral community changes. Both demersal and pelagic fish communities exhibited significant differences by depth after removal but no significant changes were observed in federally managed species. Results reflect changes in benthic and fish communities after partial removal of the platform that is likely, in part, influenced by structure removal and temporal variations.
... REEF's Volunteer Fish Survey Project was started in the Tropical Western Atlantic in 1993 and has since expanded world-wide to almost all marine waters. Under REEF's protocol, surveyors Accepted Article Accepted Article employ a 'roving diver strategy' (Schmitt and Sullivan 1996); they have no set transects, depths, or methods for navigating the sites. They simply go out and dive, recording the species and abundances they encounter and are encouraged to look in cracks and crevices and observe species in the water column. ...
Long‐term data are key to understanding how species, communities, and habitats change over time. Citizen science programs can support data collection at greater spatial and temporal scales than other types of scientifically collected data which tend to be project‐specific and are often tied to short funding periods. This is particularly true for environments that are difficult to sample such as subtidal ecosystems. Reef Environmental Education Foundation (REEF) citizen science SCUBA surveyors have been collecting fish, invertebrate, and algae data in British Columbia since 1998. This study demonstrates how citizen science data from REEF can be used to answer scientific questions via case studies, the first on Lingcod (Ophiodon elongatus) population responses to management decisions and the second on detecting rockfish species (Sebastes spp.) young‐of‐year abundance pulses. The results of these case studies suggest that data from REEF, despite their limitations, can be used to improve our understanding of nearshore marine ecosystems.
... Timed, roving visual surveys were conducted by scuba divers to determine the abundance, total length (TL) and species identity of fishes following the protocols of Schmitt & Sullivan (1996) and modified by Looby & Ginsburg (2021). At most sites, divers performed a total of 6 visual surveys: 3 with Zostera (≥ 1 m) on either side of the diver and 3 along the edge of the Zostera bed adjacent to the unvegetated substrate. ...
Eelgrasses Zostera are foundation species that perform myriad ecosystem services, yet research into their habitat function is often focused on regions susceptible to intense anthropogenic disturbance. This trend has created a data gap on the role more remote eelgrass beds provide among the mosaic of other temperate marine habitats. In this study, we surveyed 15 Z. marina and Z. pacifica beds along Catalina Island and the Southern California Bight (SCB) mainland coast from 2018 to 2020 for areal coverage, structural components and fish assemblages, from which a relativized index of fish utilization was then created. We then evaluated the landscape and structural components that potentially drive fish utilization in Z. marina using the index as a response variable in a model selection procedure. Zostera beds ranged in size from 0.06 ha to >27.5 ha. Fish assemblages in Z. marina and Z. pacifica beds were significantly different, and in the case of fishes found in both, individuals were often below size at maturity in Z. marina and above size in Z. pacifica. Distance to the nearest reef and bed area, both positively related to the fish assemblage index, were the most important factors. The results suggest Z. marina beds function as a nursery habitat while Z. pacifica are used by mid-level predators for foraging. These data represent the first rigorous study of fish utilization of open-coast Z. marina and Z. pacifica beds, and are invaluable to marine spatial planning efforts that may incorporate a more holistic approach to habitat management in temperate regions.
... Citizen science is another source of useful data to be used in population studies (Forrester et al. 2015), as exemplified by the study made by Thorson et al. (2014). This study analysed citizen science data issued from the REEF database (Schmitt and Sullivan 1996) reported in the Florida Keys between 1993-2012 to model the populations of goliath grouper (E. itajara). ...
... Tan sólo el 20% restante de las especies presentó mayores abundancias relativas y altas frecuencias de observación (Stegastes partitus, Chromis multilineata, Thalassoma bifasciatum y Myripristis jacobus), incluyendo algunos herbívoros (Acanthurus bahianus, A. coeruleus, Sparisoma aurofrenatum y S. viride) y carnívoros (Haemulon flavolineatum y Cephalopholis cruentata). Este resultado refleja la condición general de los arrecifes del Caribe, donde dichas especies están ampliamente distribuidas y se han reconocido entre las más comunes (Schmitt y Sullivan, 1996;Hoshino et al., 2003;Kramer et al., 2003;Nemeth et al., 2003;Pattengil-Semmens y Semmens, 2003;Reyes-Nivia et al., 2004). ...
... Tan sólo el 20% restante de las especies presentó mayores abundancias relativas y altas frecuencias de observación (Stegastes partitus, Chromis multilineata, Thalassoma bifasciatum y Myripristis jacobus), incluyendo algunos herbívoros (Acanthurus bahianus, A. coeruleus, Sparisoma aurofrenatum y S. viride) y carnívoros (Haemulon flavolineatum y Cephalopholis cruentata). Este resultado refleja la condición general de los arrecifes del Caribe, donde dichas especies están ampliamente distribuidas y se han reconocido entre las más comunes (Schmitt y Sullivan, 1996;Hoshino et al., 2003;Kramer et al., 2003;Nemeth et al., 2003;Pattengil-Semmens y Semmens, 2003;Reyes-Nivia et al., 2004). ...
... The exploration allowed the recognition of the most common and conspicuous biota in the deep fore-reef terrace (30-50 m depth) and the upper reef slope (50-70 m depth) of Nirvana. The sampling involves digital imagery (Panasonic TM DMC-LX10, Nikon TM D7000), collection of typical sessile biota and visual census of fishes using roving diver technique (Schmitt and Sullivan, 1996). ...
Biodiversity and ecological units of MCE in San Andrés islands Colombia were studied. Two ecological units and 160 species of 3 kingdoms (Chromista, Plantae, and Animalia), 7 phyla, 11 classes, 29 orders, 66 families, and 103 genera between algae (14 spp.), sponges (34), cnidarians (36), crustaceans (1), ascidians (1), and fishes (74), were recognized. The link to the database is included.
... La densidad promedio más alta por sitio fue de 9,7 ± 2,1 ind/250 m 2 (388 ind/ha) y se registró en Bartolo (isla Fuerte) en octubre de 2015. La localidad con la densidad promedio más alta en los dos años fue isla Fuerte con 1,2 ± 2,8 ind/250 m 2 (48 ind/ha), seguido de Capurganá y Cartagena con 0,9 ± 1,3 ind/250 m 2 y 0,9 ± 1,2 ind/250 m 2 , of 88 %, which allows considering the species as frequent in the locations and years of sampling (> 70 %) according to the standards of Schmitt and Sullivan (1996). The sites where the species was not registered during the censuses were Pavitos in the Rosario archipelago, which was visited both years (n = 11); and Bajo Picuas (n = 4), Bajo del Medio (n = 4), Bajo Tiosolda (n = 4), Mangle island (n = 4) and Bajo Minalta 2 (n = 4), which are in the archipelago of San Bernardo and which were visited only in 2016 (Table 1). ...
The abundance of the invasive lionfish Pterois volitans was assessed through visual censuses conducted in 2015 and 2016 at 54 sites in six localities with coral reefs across the Colombian Caribbean coast. The invader was observed across locations and in most of the dives, with sighting frequency of 88 %, abundance values from 0 to 9.7 ± 2.1 ind/250 m2 (388 ind/ha), and 0.8 ± 1.3 ind/250 m2 (32 ind/ha) as total mean. The average density was similar to values reported in other works that counted lionfish in a broad spatial scale
on the invaded area and the highest value approximated the maximum density estimated in Colombia and other locations around the Caribbean.
... Data were collected using direct underwater observation approaches during two cruises conducted from 1-11 February 2014 (MV Sea Hunter) and 24 February -6 March 2015 (MV Argo). A modified roving diver transect (sensu Schmitt, Sullivan, 1996 ) was employed to survey behavioral interactions of piscivores and associated species at each station ( Fig. 1). SCUBA was employed during 111 person-dives at 39 dive stations between 10 and 35 m depth, for a total dive time of 188 h (inclusive of 2-4 divers on each dive). ...
Studies of mixed-species groups of animals can reveal emergent complexities of collective behaviors. In this study we collected data on mixed-species hunting groups composed primarily of piscivorous fishes (species composition, abundance, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results indicate that such collective behaviors exhibit consistent patterns of associations (33 species with 282 pair-wise links within the observed network) with 10 dominant species accounting for 60% of pair-wise interactions. Species richness within groups varied (mean = 2.4, range 2-6 species) as did group size (mean = 8.1 individuals, range 2-80). Mixed-species groups, in general, were composed of species representing morphologically diverse forms that appeared to enhance access to shelter sites and implement diverse strategies for prey capture. It is noteworthy that the composition of groups did not reflect the relative abundances of their component species within the overall community of fishes, suggesting that group membership was an elective choice. The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for studies to assess dynamics of mixed-species relationships, rates of predator success based on group membership, demographic consequences, and responses to variations in habitat attributes and associated prey resources. Such information could be used to interpret the nature of multispecies interactions within predator communities and potentially aid in conservation and management.
... For example, in Hawai'i, diver-based visual surveys have been a staple of the reef-monitoring programs at Hawai'i's Department of Land and Natural Resources (Tissot et al. 2004), the University of Hawai'i (Tissot and Hallacher 2003), The Nature Conservancy (2015), and NOAA's National Marine Fisheries Service ( Williams et al. 2011). Various citizen-science efforts, including Reef Check and Reef.org, have even organized networks of observers looking at fish abundance and coral cover at very little cost (Schmitt and Sullivan 1996, Hodgson et al. 1998, Holt et al. 2013), but the advantages of citizen-based in situ pelagic surveys have yet to be realized. To date, the majority of pelagic research diving has focused on the collection and behavioral notes of specific organisms (Brodeur 1998, Leis and Carson-Ewart 2000, Raskoff et al. 2003, Haddock 2004. ...
Plankton and micronekton occupy the base and intermediate levels of oceanic food webs and are generally regarded as difficult to quantify. Gelatinous plankton are the most abundant functional group of macroplankton, yet they remain largely unstudied. What little is known of plankton communities has been largely deduced from plankton samplers, optical counters, nets, and towed cameras. We introduce here a survey methodology that used recreational scuba divers to evaluate pelagic community structure observed on popular "blackwater" dives. The most abundant organisms encountered were salps, siphonophores, and ctenophores. Over a 19-month period, environmental data were compared against nightly observed diversity to build a generalized additive model that accounted for 43% of the total observed deviation in biodiversity. The three most important predictors of pelagic diversity were water temperature, bathymetry, and El Niño-Southern Oscillation (ENSO) index.
... The exploration method used by the snorkelers in this case study can be compared to the roving diver technique (RDT) highlighted by Schmitt & Sullivan (1996), which was evaluated by comparing its results with those obtained on two types of transects (Schmitt et al., 2002;Holt et al., 2013). Although more difficult to quantify (due to the variation in length of reef covered by any given observer and the variation in time), we estimate that the random-path snorkeling practice has the same advantages as the RDT for a rapid biodiversity assessment, which is the first step in detecting uncommon species. ...
Four amateur naturalists and underwater photographers established sixty first records and discovered three species probably new to science at Reunion Island (Indian Ocean) between January 2010 and January 2016, although the marine environment of this island has been studied for some forty years by professional scientists. These results were achieved after snorkeling in coastal areas at a maximum depth of 2 m. All records were validated by professional experts of the relevant groups, with appropriate reservations for photograph-based identifications. The analysis of the methodology used by this group of reef observers highlights three central elements: individual initiative, regular random-path snorkeling practice by local observers, and availability of correspondent observers with sufficient naturalist skills to select accurate data and manage an optimal link with professional scientists. Such achievement emphasizes the efficiency of a citizen-based approach aimed at creating or improving local fauna inventories and discovering new species. Considering that ecological data can be collected during observers' random-path snorkeling sessions, such a project is also of interest for local conservationists and marine ecosystems managers. We therefore recommend the inclusion of these practices in the process of designing standardised observation programs aimed at non-professionals everywhere snorkeling can be practiced, especially in under-studied regions. Résumé : Pour une participation des randonneurs subaquatiques à l'évolution ou à la création d'inventaires : une étude de cas dans l'Océan Indien. Quatre naturalistes amateurs et photographes sous-marins ont réalisé soixante premiers signalements et découvert trois espèces probablement nouvelles pour la science à La Réunion entre janvier 2010 et janvier 2016, bien que la faune marine de l'île soit étudiée depuis une quarantaine d'années par des scientifiques professionnels. Ces résultats ont été obtenus en randonnée subaquatique sur des fonds n'excédant pas 2 mètres. Ils ont été validés, avec les réserves d'usage pour les signalements d'après photos, par des taxonomistes spécialistes des groupes concernés. Ces succès démontrent l'efficacité d'une démarche participative orientée vers l'évolution ou la réalisation d'inventaires locaux et la découverte de nouvelles espèces. L'analyse du modus operandi de ce groupe d'observateurs dégage trois éléments centraux : la liberté d'initiative individuelle des participants, la pratique régulière du parcours aléatoire en randonnée subaquatique par des observateurs résidents et l'existence d'observateurs-relais possédant une culture naturaliste suffisante
... agrra.org) using belt transects (120 m 2 each, n = 30) at depths between 0.5 and 30 m; 2) an adaptation of the Roving Diver Technique (RDT) (Schmitt and Sullivan, 1996), which consists of intensive random searches recording the maximum possible numbers of ML-associated species (fishes and invertebrates) along a reef during the entire duration of a dive (usually 30-40 min each, n = 10). ...
... The total time spent searching (diver hours) and number of individual seahorses located were recorded, but using this search pattern it was not possible to record the area of benthos searched. Search effort was measured by time and the number of searching divers, so the relative abundance of seahorses (seahorse per diver hour) could be reported (Schmitt and Sullivan 1996). (b) Transect dives A random position within the general search area was assigned as the starting point. ...
Accurate taxonomy, population demography, and habitat descriptors inform species threat assessments and the design of effective conservation measures. Here we combine published studies with new genetic, morphological and habitat data that were collected from seahorse populations located along the European and North African coastlines to help inform management decisions for European seahorses. This study confirms the presence of only two native seahorse species (Hippocampus guttulatus and H. hippocampus) across Europe, with sporadic occurrence of non-native seahorse species in European waters. For the two native species, our findings demonstrate that highly variable morphological characteristics, such as size and presence or number of cirri, are unreliable for distinguishing species. Both species exhibit sex dimorphism with females being significantly larger. Across its range, H. guttulatus were larger and found at higher densities in cooler waters, and individuals in the Black Sea were significantly smaller than in other populations. H. hippocampus were significantly larger in Senegal. Hippocampus guttulatus tends to have higher density populations than H. hippocampus when they occur sympatrically. Although these species are often associated with seagrass beds, data show both species inhabit a wide variety of shallow habitats and use a mixture of holdfasts. We suggest an international mosaic of protected areas focused on multiple habitat types as the first step to successful assessment, monitoring and conservation management of these Data Deficient species.
Electronic supplementary material
The online version of this article (10.1007/s00227-017-3274-y) contains supplementary material, which is available to authorized users.
... r e e f . o rg) y el programa internacional A G R R A (Atlantic and Gulf Rapid Reef Assessment) (Schmitt y Sullivan, 1996). El censo consiste en nadar libremente durante 30 minutos dentro de los límites del nivel de profundidad y anotar todas las especies de peces observadas. ...
Five coral reef areas at the Colombian Caribbean were assessed between 1998 and 2003 through the “National Coral Reef Monitoring System of Colombia” (SIMAC), recording 198 species of fishes. T h e highest species number was observed in Chengue bay (149), including four new records for the Santa Marta area. At San Andrés Island, 138 species were identified, with nine new records for the Archipelago. At the Rosario Island, 128 species were recorded with eight new records, while 114 species and 12 new records were observed at San Bernardo Islands. Of the 119 fish species recorded at the Urabá area, 48 are reported for the first time.
... Citizen science, broadly defined as public participation in scientific research (EC, 2013), has become a convenient tool to assist researchers in data collection and analysis (e.g., Bhattacharjee, 2005;Bonney et al., 2009;Dickinson, Zuckerberg and Bonter, 2010). For some time now, scientists have used volunteers to help collect data for a variety of studies, from broad biodiversity assessments to abundance surveys of particular species (Darwall and Dulvy, 1996;Schmitt and Sullivan, 1996). Citizen science programs allow for large amounts of data to be collected over vast geographical areas and for long time periods in a cost-effective manner (Pereira et al., 2010;Sullivan et al., 2014). ...
We used a citizen science-based data collection protocol to investigate foraging and nesting marine turtle populations in the Republic of Maldives. With the aid of citizen scientists, we collected nine months of data covering 12.5 % of the country, increasing the available sightings and nesting data by ~2,000 %. Data indicated that the Maldives are an important foraging habitat for juvenile and adult green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles, though very few adult males of either species were reported. Hawksbill turtles were the more commonly sighted species in all but one surveyed atoll. The large number of juvenile hawksbills noted in Baa atoll, a UNESCO Biosphere Reserve, may signal faster recovery from decades of exploitation compared to other regions of the Maldives. Lhaviyani atoll appears to be an adult green turtle foraging hotspot that could warrant additional legal protection. Maldivian beaches appeared to host more green turtle nesting sites. This study provided the first estimate of green turtle nest development time and hatching success in the Maldives. Our method controlled for the data’s temporal structure and accounted for spatiotemporal differences in survey effort, allowing for the most accurate assessment of turtle distribution possible. Our results indicated that a citizen science approach can be a fast, effective way of expanding the spatiotemporal extent of a monitoring dataset and engaging the public in endangered species monitoring. Additionally, our data were used by the government to support a policy change regarding the protection of sea turtles in the Maldives.
... and as a cost effective monitoring strategy (Bhattacharjee 2005, Bonney et al., 2009Crall et al., 2011). In the marine realm, volunteer recreational divers have been involved in collection of data for biodiversity assessments and coral reef fish (Darwall and Dulvy 1996;Hodgson 1999;Pattengill-Semmens and Semmens 2003) and flora abundance surveys (Chou 1994;Schmitt and Sullivan 1996). In addition to these broadly scoped programmes, volunteer scuba divers are also involved in focal species programmes focused on sea horses (Goffredo et al., 2004), sea turtles (Bell et al., 2008b) and elasmobranchs (Hussey et al., 2011;Ward-Paige and Lotze 2011). ...
Five of the world’s seven species of sea turtles have been documented to use Mozambican habitats. While they are thought to be extensively distributed throughout Mozambican coastal waters, and the offshore waters of the Mozambican Channel, little is known about these populations. Specifically, information about the state and structure of sea turtle populations (population size estimates, species composition, age class distribution, movements of animals into and out of the study area, residency, habitat use and preferences) was scarce or non-existent for Mozambique. Therefore, my research adopted several complementary research techniques to increase knowledge on sea turtles in their foraging grounds and their exposure to human impacts.
The major research aim of my thesis is to understand factors related to the distribution, abundance and use of sea turtle populations within the Inhambane region, Mozambique, and use this knowledge to inform and improve conservation and management efforts.
In Chapters 2 and 3, I explore the use of citizen science and photo- identification (photo-ID) as tools to facilitate the collection of data on turtles encountered in-water. I found that citizen science is a useful tool for collecting basic biological information, particularly when coupled with photo-ID encounters. While the quality of dive log records was improved by having a few well-trained and consistent contributors, the photo-ID database benefitted from broadened public involvement. Results from the generalised linear modelling of the dive log data (Chapter 3) suggested that sightings and abundance of turtles were influenced by environmental conditions. It was also evident that factors such as visibility and diving depth lead to availability and perception bias in the citizen scientists’ records. It is important to be aware of such biases since they reflect physical environmental diving conditions rather than habitat or behavioural predictors that influence sea turtles. Overall, citizen science coupled with photo-ID datasets provided the first details of Mozambique’s foraging sea turtle populations. In Chapter 3, I described the use of coastal reefs by green and loggerhead sea turtles in Inhambane, Mozambique. Based on population models from the photo-ID dataset, both green and loggerhead populations were small but present year-round. Regardless of species, sea turtles favoured coastal nearshore waters and relatively shallow reef systems, which make them vulnerable to interaction with small scale fisheries (SSF). Impacts of SSF is unlikely to be consistent between species or age-classes. My findings suggest that the long-term residency of late-stage juvenile greens in these nearshore and shallow habitats make them most vulnerable to interactions with SSF.
In Chapter 4, I investigated the prevalence of illegal take of sea turtles in a coastal region of Mozambique – the Tofo area, Inhambane Province - and conducted a national-scale literature review. Transect- based sampling in the sand dunes demonstrated that the Tofo area and greater Inhambane peninsula are a hotspot for take of sea turtles. The literature review documented year-round take of sea turtles to occur through much of Mozambique. Use of sea turtles focused on their meat, and it was rare to detect more than an empty carapace or old bones. Small scale fisheries interact with turtles in their favoured habitats (close to reefs systems) in coastal waters, particularly in the south of the primary study area, between Praia do Tofinho and Praia de Rocha. Based on interviews with fishers, the opportunistic take of turtles is prevalent and widespread (Chapter 5) in Inhambane Province. A targeted marine megafauna multi-species fishery exists in the study area. Widespread use of gillnets and long-lines occurs and these fishing gears are favoured because of their non-selectivity and ability to capture turtles and other species. Sea turtle capture in these fisheries is neither bycatch nor accidental.
Interviews with fishers (Chapter 5) indicated that the motives and drivers influencing fishers to illegally take sea turtles were variable between communities and individuals. In the two fishing communities surveyed, opportunities for alternative livelihoods were lacking or insufficient to supplement or replace their reliance on fishing activities. Five of the six major drivers identified in Chapter 5 reflect Mozambique’s low socio- economic status. Similarities were evident between the drivers and motives of illegal take of turtles and the terrestrial mammal bushmeat hunting and trade. The majority of fishers had multiple motives for participating in illegal take of sea turtles. Awareness of turtle protection laws amongst fishers was high, although compliance was low. This suggests that simple campaigns to increase awareness of turtle legislation will have little impact in deterring illegal take. Future conservation efforts will need to address food security, livelihoods options and aim to minimise the number of motives an individual fisher or community may have to participate in illegal take.
I solicited opinions from local experts to quantitatively rank threats and investigate the context of conservation and management efforts underway in Mozambique (Chapter 6). Consensus of expert opinions revealed the most pressing threats to sea turtles were fisheries-related (bycatch from commercial trawling, SSF bycatch and hunting of nesting turtles). The top- ranking threat, bycatch within the commercial shallow-water prawn trawl industry, could be easily mitigated with effective implementation of pre- existing Turtle Exclusion Device legislation. This is not the case for the other two threats, which given their nature are likely to involve extensive changes/improvements to living standards and Mozambique’s overall socio-economic status. Compliance with sea turtle legislation was weak throughout the country and experts identified improving enforcement efforts as critical. Parallels are evident among the issues that hamper the conservation and management of terrestrial megafauna and marine megafauna. A holistic process will be required to solve large-scale issues (e.g. governance, corruption, compliance) and strengthen overall biodiversity conservation. Given the extremely limited funding allocated to the conservation of sea turtles, the marine environment and limited access to skilled people and resources, a prioritised list of management actions for sea turtle hotspot areas is necessary.
I conclude this study by discussing my key findings relating to the sea turtle populations using the Tofo area, the impacts they face and how and where conservation management efforts could be strengthened. I also suggest specific priorities for future research to enhance knowledge of sea turtle populations, socio-economic understanding of SSF and alternative livelihoods. A balance needs to be struck between the environment, economic development and social and cultural values of coastal people in order to achieve sustainable growth whilst preserving marine biodiversity and improving living standards.
... The standardized Morisita dispersion index (Ip) was used in order to evaluate the spatial distribution (KREBS, 1999). The relative abundance of octopus at depths greater than 5m was obtained through the Intensive Visual Search method (IVS), which consists of an adaptation of the sampling technique called Roving diver (SCHMITT; SULLIVAN, 1996). This method allows for coverage of a larger area in less time while diving, being more appropriate due to the limited scuba diving time (see adaptation in LEITE et al., 2009c). ...
Octopus insularis is the dominant octopus in the shallow tropical waters of the coast and oceanic islands in the North and Northeast of Brazil. Is the abundance, distribution, habitat and diet of this species on the continent the same as in oceanic islands? These factors were evaluated in seeking these answers at two areas of occurrence of Octopus insularis on the coast of Rio Grande do Norte, Brazil. Three main types of habitats were described where the species is concentrated, being: Deep Reefs (Reefs of Risca) (> 15 m), Flat Biogenic Plateaus (Restingas) (5-15 m) and Shallow Sedimentary Reefs (Pirangi reefs) (< 5 m). An aggregate spatial distribution was verified, along with bathymetric segregation in which small individuals occupied shallow areas. Regarding diet, O. insularis consumed mainly crustaceans (68%) in shallow reef areas, bivalves (86%) in biogenic plateau areas, and gastropods (33%) in deep reef areas. The characterization of new occurring habitats, such as the area of biogenic plateau, and changes in their diet due to habitat function have shown that O. insularis occupies a broader niche than has been described in literature to date, expanding our knowledge on the ecology and biology of this octopus species of economic interest.
... At all the study stations, fish abundance was observed visually using stationary point counts within differe nt areas of the jetties; under pilings and in the open water by snorkelling following rover diving technique (Schmitt and Sullivan 1996) that involves visually counting the fishes in a defined area for a definite period of time. Fishes were counted 5m either side of the diver. ...
Artificial Reefs (ARs) are those manmade structures (including marine jetties) which can support a
number of native populations both moving and sessile in marine ecosystem. The present study investigated the fish assemblage structure in the marine jetties at Marina Park (MP), Panighat (PG), Chatham (CT) and Dundus Point (DP) around Port Blair, South Andaman coast. The most number of pillars in the water was found in CT (26) and MP (22) while the longest marine jetties in length were MP and PG (60m). The average temperature ranged between 32 to 35 ˚C while average salinity varied from 30 to 33psu. The average pH was found to be alkaline (8.43 to 8.60), whereas the dissolved Oxygen (ml/l) varied from 4.42 - 5.78 and Biological Oxygen Demand (ml/l) was found to be highest in Dundus Point i.e. 1.07 and lowest was in Panighat (0.75). Sedentary organisms like oysters, barnacles, chiton, gastropods, algae etc. were recorded in all the stations, while soft corals were present only in Marina Park and Panighat. A total of 1971 individuals of fishes belonging to 38 species, 29 genera and 22 families were observed during the study. Lutjanids, Pomacentrids and Chaetodontids were the abundant in all the jetties. The diversity indices viz. Shannon Weaver’s species diversity index, Margalef’s species richness index, Simpson’s species evenness index and Pielou Species evenness index have shown that Marina Park Jetty is more diverse as well as abundant in fish species (1.82, 4.27, 0.72, and 0.54 respectively) even though the anthropogenic activities like tourism were observed very high compared to other jetties, while the lowest in diversity and abundance was Dundus Point Jetty (0.71, 0.74, 0.37, and 0.44 respectively). The percentage of plastic waste was maximum in all the study sites i.e. 61.1 (MP), 15.5 (PG), 71.4 (CT) and 54.5 (DP). While the minimum percentage was found to be of fishing nets i.e. 2.7 (MP), 3.8 (PG), 1.8 (DP) and Nil in Chatham. The other waste items included glass bottles, footwear, polythene covers and clothes. The results of the present study have shown that the abundance and species diversity of fishes is related mostly to the length of the jetty as well as number of pillars in the water which can act as an artificial habitat
... Understanding the structure and variability of such behavioral interactions within 64 populations and communities can provide important insights for their conservation and 65 sustainable use. Given the role that higher trophic level predators play in structuring marine 66 communities (O'Connor and Bruno 2007, Heithaus et al. 2008, Sandin et al. 2008 2011), studying the collective behavior of reef piscivores ultimately may provide increased 68 detail on the variability of interactions with this trophic guild beyond the scope provided by 69 census data of component species alone (Sih 1998, Lima 2002, Berger-Tal et al. 2011 Schmitt and Sullivan 1996) was employed to 97 survey behavioral interactions of piscivores and associated species at each station ( Fig. 1). ...
Discerning the role that facilitative behavioral interactions in mixed species groups of hunting piscivores play in growth and survivorship is important both in our fundamental understanding of fish community dynamics and for developing conservation strategies. In this study we collected data on mixed-species hunting groups (species composition, numbers, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results demonstrate that collective behaviors in mixed species hunting groups exhibit consistent patterns of associations within a set of dominant species (10 of 32 species within the network) and are a common attribute of this functional guild within the shallow fish community at Isla del Coco (to 80 m depth), Pacific Costa Rica. Indeed the removal of only a few dominant species from the behavior web model, to simulate overfishing, reduced the number of pair-wise linkages by 57% (32 species with 282 pair-wise links to 28 species with 122 links). The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for time-series monitoring to assess status and change in ecological interactions within the higher trophic level guild of fishes. That said, more work is needed to understand the temporal dynamics of network linkages and intensity of interactions as prey resources vary in distribution and abundance. Such information could be used to interpret the nature of multispecies interactions within predator communities and serve as an aid in conservation and management.
... Data collected by trained and tested recreational scuba divers between January 1, 2006 and December 31, 2015 and submitted to the Reef Environmental Education Foundation (REEF) Volunteer Fish Survey Project Database [21] were analyzed. Using the Roving Diver Technique [22] surveyors record sightings of positively identified species and at the end of the dive, assign them to one of four abundance index categories: 'Single' (1 individual), 'Few' (2-10 individuals), 'Many' (11-100 individuals), and ' Abundant' (>100 individuals) [23]. Data used were restricted to the 3 asteroids and two urchin species for which data were available: D. imbricata, P. brevispinus, P. helianthoides, green sea urchin (Strongylocentrotus droebachiensis) and red sea urchin (Mesocentrotus franciscanus). ...
Sea star wasting disease devastated intertidal sea star populations from Mexico to Alaska between 2013–15, but little detail is known about its impacts to subtidal species. We assessed the impacts of sea star wasting disease in the Salish Sea, a Canadian / United States transboundary marine ecosystem, and world-wide hotspot for temperate asteroid species diversity with a high degree of endemism. We analyzed roving diver survey data for the three most common subtidal sea star species collected by trained volunteer scuba divers between 2006–15 in 5 basins and on the outer coast of Washington, as well as scientific strip transect data for 11 common subtidal asteroid taxa collected by scientific divers in the San Juan Islands during the spring/summer of 2014 and 2015. Our findings highlight differential susceptibility and impact of sea star wasting disease among asteroid species populations and lack of differences between basins or on Washington’s outer coast. Specifically, severe depletion of sunflower sea stars (Pycnopodia helianthoides) in the Salish Sea support reports of major declines in this species from California to Alaska, raising concern for the conservation of this ecologically important subtidal predator.
... Thus the technique is particularly useful for the survey of rare or cryptic species (Kimmel 1985;Bortone et al. 1986Bortone et al. , 1989 and is particularly advantageous in situations where study sites are small enough to be holistically surveyed, e.g. small patch reefs such as artificial reefs (DeMartini and Roberts 1982;Schmitt and Sullivan 1996); in this situation it has been referred to as the patch count technique (Molles 1978). Pattengill-Semmens (2001) showed that the roving diver technique can be applied in volunteer-based studies. ...
This study conducted the first high-resolution investigation of the ichthyofaunal assemblages
on a high-latitude coral reef in the Western Indian Ocean (WIO). Two-Mile reef, in South
Africa, is a large, accessible patch-reef, and was selected as a candidate study area. Although
the effect of season in structuring coral reef fish communities is most-often overlooked, the
relationship between these fish communities and their habitat structure has been investigated.
In South Africa, however, neither of these potential community-level drivers has been
explored. As coral reefs worldwide are faced with high levels of usage pressure, nondestructive
underwater visual census (UVC) techniques were identified as the most
appropriate survey methods. This study had two primary aims that were; (1) to identify the
most suitable technique for the UVC of coral reef fishes, and to test variations of the selected
technique for appropriateness to implementation in long-term monitoring programs, and (2)
to determine if possible changes to ichthyofaunal community structure could be related to
trends in season and/or habitat characteristics.
A review of the literature indicated that the most appropriate UVC method for surveying
epibenthic coral reef fishes is underwater transecting. To compare the traditional slate-based
transects to variations that implement digital image technology, slate transects were
compared to a first-attempt digital photographic transect technique, and digital videographic
transects. Videographic transects produced the most favourable species richness, abundance,
and standard deviations of the three techniques. Diversity was not significantly different
between transect techniques. The minimum required sample size was lowest for videographic
transects (17 replicates), intermediate for photographic transects (27 replicates) and highest
for slate transects (37 replicates). Videographic and photographic transects required greater
analysis time to generate counts, but required lower observer training time. While
videographic transects produced the lowest proportion of species considered unidentifiable,
all three transect techniques showed similar functionality to surveying epibenthic coral reef
fishes. Videographic transects were therefore identified as the most appropriate UVC
technique for this study.
Videographic transects at shallow (6 – 14 m), intermediate (14 – 22 m) and deep (22 – 30 m)
depths in mid-winter and mid-summer, sampled a total of 41 families consisting of 209
species and 18172 individuals, dominated by pomacentrids in abundance and labrids in richness. The fish assemblages on Two-Mile Reef were found to be similar in composition to
lower-latitude WIO reefs. Overall ichthyofaunal abundance and richness was significantly
higher in summer than in winter, and was higher at shallow sites than at intermediate and
deep sites. A multivariate approach confirmed differences between seasons at shallow depths
but not between seasons at intermediate and deep depths. The fish assemblages on Two-Mile
Reef can therefore be described as being comprised of four relatively distinct communities: a
shallow, winter community; a shallow, summer community; a year-round intermediate
community; and a year-round deep community. The distributions of discriminating species
indicated that high abundances of the algal-feeding pomacentrids are observed only at
shallow and intermediate sites while high abundances of the zooplanktivorous serranid
subfamily, the Anthiinae, are observed predominantly at deep sites. Assessment of all
measured supplementary variables indicated that of all factor combinations, observed patterns
could be ascribed most strongly to depth. Quantification of reef characteristics indicated that
as depth increases, habitat complexity decreases, benthic communities shift from dense coral
domination to sparse sponge domination, and algal biomass and cover decreases.
The ability of the videographic transect technique to detect changes in community structure
with season and depth indicates that season and depth should be accounted for in future highlatitude
ichtyofaunal surveys, and that the videographic transect technique is suitable for
implementation in long-term monitoring programs on coral reefs. The similarity in fish
assemblages between Two-Mile Reef and lower latitude regions suggests that the protocol for
surveying epibenthic coral reef fishes, resulting from this study, is relevant throughout the
continental WIO.
... Understanding the structure and variability of such behavioral interactions within 64 populations and communities can provide important insights for their conservation and 65 sustainable use. Given the role that higher trophic level predators play in structuring marine 66 communities (O'Connor and Bruno 2007, Heithaus et al. 2008, Sandin et al. 2008 2011), studying the collective behavior of reef piscivores ultimately may provide increased 68 detail on the variability of interactions with this trophic guild beyond the scope provided by 69 census data of component species alone (Sih 1998, Lima 2002, Berger-Tal et al. 2011 Schmitt and Sullivan 1996) was employed to 97 survey behavioral interactions of piscivores and associated species at each station ( Fig. 1). ...
Discerning the role that facilitative behavioral interactions in mixed species groups of hunting piscivores play in growth and survivorship is important both in our fundamental understanding of fish community dynamics and for developing conservation strategies. In this study we collected data on mixed-species hunting groups (species composition, numbers, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results demonstrate that collective behaviors in mixed species hunting groups exhibit consistent patterns of associations within a set of dominant species (10 of 32 species within the network) and are a common attribute of this functional guild within the shallow fish community at Isla del Coco (to 80 m depth), Pacific Costa Rica. Indeed the removal of only a few dominant species from the behavior web model, to simulate overfishing, reduced the number of pair-wise linkages by 57% (32 species with 282 pair-wise links to 28 species with 122 links). The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for time-series monitoring to assess status and change in ecological interactions within the higher trophic level guild of fishes. That said, more work is needed to understand the temporal dynamics of network linkages and intensity of interactions as prey resources vary in distribution and abundance. Such information could be used to interpret the nature of multispecies interactions within predator communities and serve as an aid in conservation and management.
Anthropogenic and climate alterations of coastal environments impact enclosed tropical marine lagoons more directly than offshore marine systems. Long-term studies of lagoonal patch reefs in the central Bahamas were reviewed using a threat assessment matrix to understand spatial and temporal changes in patch reef diversity. A 13-year dataset that includes both epifaunal invertebrate and fish surveys was used to address two research questions: (1) Are there spatial patterns of diversity loss across the tropical lagoon linked to distance from potential land-based sources of pollution? (2) Are there temporal patterns of diversity loss in the tropical lagoon linked to specific storm events or anthropogenic changes over time? The answers to both questions were “yes”; there were spatial and temporal patterns in patch reef diversity, but these patterns were not as expected based on the threat assessment. Patch reefs across a spatial scale contribute individually to the biological diversity and function of the tropical lagoon. Temporal changes were more significant than spatial differences across the lagoon. Fish assemblages showed a significant loss of both species and trophic diversity over time. Changes in the benthic epifauna assemblages supported more weedy, short-lived species, contributing to reduced rugosity, which may have exacerbated declines in fish diversity. Results indicate a need for greater protective measures for the entire Elizabeth Harbour.
Developed a systematic survey methodology for artificial reef deployment like nature of sea bottom, bathymetry, tide, current pattern, ecology, physiochemical and biological characters were assessed for seabed suitability for Artificial reef deployment. SCUBA diving studies were utilized to select sea floor status studies. The bottom slope estimates to keep the AR in position and prevent them from sliding to deep waters due to sea swells. The sea bottom stability has also been recorded. To understand the sinking / sliding into the seafloor. Seafloor sediment type studies necessitate scouring protection and design. Developed scour protection for reef modules. Implemented IAS-free AR structure and novel deployment technique.
Hurricanes can pose a greater threat for small islands if larger and more frequent storms are the future reality due to climate change. Apart from property damage, hurricanes can damage natural coastal communities and wash solid waste into coastal waters and wetlands. Our goal was to develop a rapid, synoptic survey method to evaluate what happens to the coasts of small islands after hurricanes. This study reports on the development of a hurricane rapid ecological assessment method (H-REA) that was carried out on small islands in collaboration with local communities. The H-REA focused on property damage, vegetation damage, flooding, coastal erosion, and solid waste accumulation in the coastal environment. The H-REA method was developed to evaluate the hurricane damage from Hurricane Matthew in 2016 and then applied to assess Hurricane Irma’s damage to both the built and natural environments in 2017. The H-REA proved to be an important tool for the rapid assessment of 2017 hurricane impacts on the southern Bahamian islands; results are shown for Great Exuma. The H-REA results highlighted the variability of damage across the islands as well as the value of coastal set-backs and protected coastal wetlands in reducing both property damage and the amount of solid waste, including plastics, entering the coastal oceans. A spatial database was established to visualize the patterns of building damage, flooding, and vegetation loss; the spatial database allows for the assessment of damage from successive hurricanes.
Biological homogenization can alter the ecological function of systems as well as the economic value associated with those ecosystems through complex socio-ecological dynamics. The aim of this chapter is twofold: (1) to document evidence of biological homogenization across marine fish assemblages off the coast of Florida and (2) to discuss how social values may influence, and are influenced by, the biological homogenization of coastal fish assemblages. We measured biological homogenization by tracking taxonomic changes over a decade across 13 near-shore sites off the Atlantic coast of Florida. We created species-location matrices for each site, calculated recently and a decade prior, and quantitatively depicted assemblage similarity changes between sites using a hierarchical clustering algorithm. We found evidence of biological homogenization of some fish assemblages, but not all, and relatively little change in site species richness. Sites that were closer to populated coastlines, or have been subject to substantial disturbance events, are more likely to show homogenization. Protected reef sites show little evidence of homogenization. We postulate feedback mechanisms between societal values, diver practices, diver experience, and the severity of homogenization. We suggest that cultural values directly influence diver behavior, which in turn can affect assemblage homogenization. These socio-ecological feedbacks have received very little attention in the context of coastal fish conservation, but deserve attention given the perilous state of such ecosystems worldwide.
For an assemblage of fishes inhabiting a warm temperate, rock reef near San Diego, California (USA), a series of censuses were made based on frequency of occurrence and standard numerical counts. These data were then compared with a parallel study based on the rapid visual technique (RVT) of Jones and Thompson (1978). Because the RVT ranks abundances according to frequency of encounter and disregards variations in the spatial distributions of different species, the method overemphasizes the importance of widespread albeit rare fishes but under-emphasizes patchy although abundant species. The discussion considers the relative merits of the RVT method for characterizing assemblages of fishes on temperate rock reefs and on tropical coral reefs.
Monitoring has become fashionable. Business now talks about monitoring its activities, efficiency, costs and profits. The National Health Service is monitoring general practices and hospitals; it is keen to have more information about efficiency and the duration of stay of patients in different hospitals undergoing different types of treatment. These activities are usually carried out in relation to specific objectives with the aim of making activities more cost effective and competitive. Does the same apply in biology, ecology and nature conservation? Or, are we still enjoying conducting field surveys for the fun of it, at best with rather vague objectives and saying to our colleagues that we do our work because we need to know what is there? This book is an opportunity to consider some of the reasons why monitoring is important, how it differs from survey, how it may be able to answer specific questions and help with site management or problem solving. It will explore some of the taxa that are suitable for recording and how you may actually set about doing it. It is not intended as a catalogue of techniques but we will in each chapter give you sources of material so that with the minimum of effort you will be able to proceed with an efficient, relevant and not too time consuming monitoring programme. Some of the points that you need to consider before starting are also set down in the synthesis at the end of the book.
Species composition, species diversity, and relative abundance of four coral reef fish communities in John Pennekamp State Park, Key Largo, Florida, are compared with four communities at Fort Jefferson National Monument in the Dry Tortugas using the species-time, random count technique. The technique is similar to species-area methods hut time replaces area.Fish communities at Pennekamp Park showed the highest overall number of species, scores (reflecting species abundance), and species diversity. Two artificial reefs (ship-wrecks) are included in the study and both show closer relationships to adjacent reefs than to wreck-specific species.
Four methods of visually assessing reef fish assemblages were compared in “The Living Seas at Walt Disney World, EPCOT Center. An accurate “standard of reference (proportionate abundance of 44 species) was provided by approximately 43 man-hours of repetitive sampling of small groups (1-6) of species. Twenty 5-min censuses were obtained by (1) a remotely operated vehicle (ROV), (2) a SCUBA diver recording observations on a plastic slate (Slate), (3) a diver using an underwater tape recorder (Audiotape), and (4) a diver using a video camera (Cinetransect). The methods were evaluated and compared on the basis of their ability to accurately estimate the relative abundances and rank orders of pools of 44 and 31 species. The relative efficiencies of the four methods were also compared. Here, efficiency was defined as the amount of time necessary to achieve a stabilized picture of assemblage structure. Of the four methods tested, the Audiotape was the most accurate and efficient in estimates of proportionate abundance. Species rankings (based on abundance) produced by all methods were highly correlated. Unexpectedly, a variation of the basic method used to determine the reference standard was found to be far more accurate, for about the same amount of sampling effort, than any of the methods tested. This method, herein called Discrete Group Censusing, is based on sampling only a few community members at a time, and combining these data into an overall picture of assemblage structure.
Two visual census techniques frequently employed for quantifying coral reef fish assemblages, the rapid visual technique (RVT) and the strip transect technique (STT), were compared in terms of precision, observer bias, and species enumeration. Spearman rank correlation coefficients calculated between replicate RVT censuses were lower than for STT censuses, indicating that the RVT was less precise. The correlation coefficients for RVT censuses conducted by the same observer were greater than those for censuses conducted by different observers. Observer bias may be evident in the RVT because the order in which species are noticed is critical. Since there were no significant differences between the number of species recorded in each STT census and in the corresponding RVT census, the number of censuses required to assess species composition was equal for the two techniques. The correlation between averaged RVT and STT censuses was statistically significant. Both the RVT and the STT are valid visual census techniques. When quantitative estimates of abundance are desired, the STT must be used. When available field time is minimal and the main objective is to qualitatively characterize fish assemblages so that sites can be distinguished and compared on that basis, the RVT is more cost-effective.
Visual census techniques applicable to coral reef-associated fishes are reviewed and the results of field tests using six (three transect-based and three point-based) to estimate the density of carangids at Carter Reef, Great Barrier Reef, are presented. Data are analyzed with respect to the effects of observers on fishes seen, observer biasses, precision of the estimates and, as far as possible, accuracy of the estimates. Transects generate estimates of population density and structure different from those of point-based estimates. Various point-based census methods, however, generate density estimates consistent with one another and are generally more precise than transect-based methods. The results of the field study obviously cannot be generalized to other quite different types of reef fishes. The problems we encountered and a review of the techniques used to census reef fishes visually in the past, however, suggest that: (1) interval counts, such as Rapid Visual Census techniques, are likely to be inaccurate and difficult to compare; (2) for species with high probabilities of detection, instantaneous area counts appear to be the most effective way to estimate densities, whereas cryptic species are best censused using instantaneous variable distance point counts, and (3) strip transects may often be less efficient than line transects, due to inconstant levels of subject detectability.
Fish ecologists need to do pilot studies to develop accurate, precise and efficient sampling strategies. This paper presents a case study of the pilot investigations carried out to achieve this for three species of butterflyfish Chaetodon rainfordi, C. plebeius and Chelmon rostratus, at One Tree Reef. The effects of different transect sizes and methods on density estimates and their precision for each species were assessed. Varying transect dimensions (25, 50, 75 and 100 m lengthx1,2 and 3 m width) did not significantly affect the density estimates. However for C. rainfordi the precision of estimates was variable with the smallest transect length and width producing the least precise results. Higher density estimates were obtained for juvenile fish over a 1 m strip width than a 2 m width. A significant effect of disturbance on the densities of C. rainfordi and Chelmon rostratus was caused by the laying out of the transect tape. Consequently a technique of simultaneously censusing and delimiting transect boundaries was tested and found to give consistently higher density estimates. The potential effect of censusing at different times of the tide was examined and found to be insignificant for two species but quite complex for the other. Finally, a pilot sampling program was done at seven localities across One Tree Reef to determine the most efficient way of allocating sampling effort, for future census work.
Transect techniques for censusing reef fishes, and the sources of bias inherent in them are considered. A technique, derived from aeraly survey methods, is demonstrated to correct a bias in density estimates due to the width of the transect being censused. This bias is sufficient on a transect 1 m wide to underestimate density by 11.1–26.7% for five species or species groups examined. The bias is still greater on wider transects. Because this bias varies in degree among species, comparisons among species should not be made using uncorrected transect data. Comments are made on other probable sources of bias in transect data, and on ways of minimising bias when making visual transect censuses.
The community structure of Jamaican coral reefs has undergone drastic change since mass mortalities of the long-spined black sea urchin Diadema antillarum Philippi occurred in 1983. In the absence of Diadema, algal abundance has increased enormously, up to a mean of 95% cover or 4.6 kg wet weight · m −2. Coral cover, which was already low on some reefs following Hurricane Allen in 1980, has been further reduced by as much as 60% since 1983 by competition with algae. Densities of D. antillarum at 10 sites in 1986 ranged from 0 to 12% of pre-1983 levels. Other echinoids, which might potentially compensate for the lack of herbivory from D. antillarum, have not increased significantly in density. Numbers of herbivorous scarids and acanthurids also remain at relatively low levels, because of overfishing. In the absence of high densities of fish and sea urchins, it is likely that recent changes in community structure will continue, resulting in further replacement of corals by algae in shallow water. The impact of the urchin mass mortalities is qualitatively similar to previous experimental removals of this species. In both cases, removal of echinoids resulted in substantial increases in macroalgae. However, quantitatively, the responses of algal and coral communities to the natural die-off were significantly greater, probably due to wide differences in spatial and temporal scales of the respective perturbations.
"A Wiley Interscience publications" Incluye bibliografía e índice
It is shown that the computational behaviour of a hierarchical sorting-strategy depends on three properties, which are established
for five conventional strategies and four measures. The conventional strategies are shown to be simple variants of a single
linear system defined by four parameters. A new strategy is defined, enabling continuous variation of intensity of grouping
by variation in a single parameter. An Appendix provides specifications of computer programs embodying the new principles.
The Caribbean Sea a large ecosystem in crisis
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reef fish communities: time and area compensated. Northeast Gulf Science 10(2): 85-96.
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ADDRESS: The Department of Biology and The Nature Conservancy
- J H Zar
Zar, J. H. 1984. Biostatistical analysis. second edition. Pretice-Hall, Inc. Englewood Cliffs, New Jersey
07632. 718 p.
DATEACCEPTED: December 11, 1995.
ADDRESS: The Department of Biology and The Nature Conservancy, P.O. Box 249118, Coral Gables,
Florida 33124.