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opencc-zeroDec 2013View details →

Data from: Silent fish surveys: bubble-free diving highlights inaccuracies associated with SCUBA-based surveys in heavily fished areas

1. Underwater visual census (UVC) using SCUBA is a commonly used method for assessing reef fish communities. Evidence suggests, however, that fish avoid divers due to the sound of bubbles produced by open-circuit SCUBA, and avoidance behaviour is more pronounced as fishing pressure increases. Despite the potential for producing biased counts and conclusions, these behavioural effects have rarely been quantified, especially when assessing the effectiveness of marine protected areas (MPAs). 2. To test the magnitude of avoidance behaviour, we surveyed fish populations inside and outside two MPAs in Guam, using two diving systems: standard open-circuit (OC) SCUBA and a closed-circuit rebreather (CCR) that produces no bubbles. Data were collected using a diver-operated stereo-video system (stereo-DOV), which provided counts of relative abundance, measures of fish length and the minimum approach distance of the diver to a fish. 3. Inside MPAs, fish surveys conducted with CCR recorded similar community metrics to fish surveys conducted with conventional OC SCUBA. In contrast, outside the MPAs, the bubble-free diving system recorded 48% more species and up to 260% greater fish abundance. These differences reflected the ability of a diver wearing the silent CCR unit to sample the larger, most heavily targeted species that are shy of divers in fished areas. This difference was also large enough to change some results from 'reject' to 'accept' the null hypothesis of 'no significant differences exist between fished and protected areas'. 4. The use of CCR for fish surveys clearly minimizes behavioural biases associated with fish avoiding open-circuit SCUBA divers. We recommend the use of this bubble-free diving system for surveys assessing reef fish populations, especially in areas where fish are heavily targeted by spearfishing. If fish behaviour is not accounted for, surveys using SCUBA could result in erroneous conclusions when comparing fished and protected areas. While the behaviour of fish towards divers is rarely mentioned in conclusions from studies using UVC, it is an important source of bias that should be acknowledged and minimized where possible.

opencc-zeroDec 2011View details →

Data from: A survey of palaeontological sampling biases in fishes based on the phanerozoic record of Great Britain

Fishes represent more than half of all living vertebrate species, but patterns of fish diversity remain little explored in the fossil record. A compendium of fossil occurrences from Great Britain was assembled in order to address a series of questions concerning the palaeontological record of fishes. There are broad similarities between British richness trajectories and those compiled from global data, including an initial peak in the mid-Palaeozoic (Devonian or Carboniferous, depending on the compilation), with a late Palaeozoic trough followed by a sharp rise in diversity in the Late Cretaceous and Paleogene. The British dataset is too small to reveal any significant differences in richness between time bins using subsampling, but a modeling approach based on sampling and geological proxies consistently shows lower-than-predicted richness in the Silurian-Devonian and higher-than-predicted richness in the Late Cretaceous and Eocene. This positive excursion is robust to the exclusion of data from the early Eocene London Clay Lagerstätte. Chondrichthyans (sharks, rays, and ratfishes) and osteichthyans (ray-finned and lobe-finned fishes) show contrasting relationships with geological and sampling proxies, possibly reflecting different taphonomic profiles or idiosyncratic variation in the relative proportion of freshwater and marine deposits over the British Phanerozoic.

opencc-zeroDec 2016View details →

Data from: Assessing the utility of eDNA as a tool to survey reef-fish communities in the Red Sea

Relatively small volumes of water may contain sufficient environmental DNA (eDNA) to detect target aquatic organisms via genetic sequencing. We therefore assessed the utility of eDNA to document the diversity of coral reef fishes in the central Red Sea. DNA from seawater samples was extracted, amplified using fish-specific 16S mitochondrial DNA primers, and sequenced using a metabarcoding workflow. DNA sequences were assigned to taxa using available genetic repositories or custom genetic databases generated from reference fishes. Our approach revealed a diversity of conspicuous, cryptobenthic, and commercially relevant reef fish at the genus level, with select genera in the family Labridae over-represented. Our approach, however, failed to capture a significant fraction of the fish fauna known to inhabit the Red Sea, which we attribute to limited spatial sampling, amplification stochasticity, and an apparent lack of sequencing depth. Given an increase in fish species descriptions, completeness of taxonomic checklists, and improvement in species-level assignment with custom genetic databases as shown here, we suggest that the Red Sea region may be ideal for further testing of the eDNA approach.

FIGURE 7. Jaydia novaeguineae. A. SMF 35008, 8.8 in Survey of demersal fishes from southern Saudi Arabia, with five new records for the Red Sea

FIGURE 7. Jaydia novaeguineae. A. SMF 35008, 8.8 cm SL, Jizan, Saudi Arabia. B. KAUMM 58, 7.2 cm SL, Jizan, Saudi Arabia.

FIGURE 5. Dactyloptena gilberti, SMF 35003, 6.6 in Survey of demersal fishes from southern Saudi Arabia, with five new records for the Red Sea

FIGURE 5. Dactyloptena gilberti, SMF 35003, 6.6 cm SL, Jizan, Saudi Arabia. A. Lateral view. B. Dorsal view.

FIGURE 2 in Survey of demersal fishes from southern Saudi Arabia, with five new records for the Red Sea

FIGURE 2. Species accumulation curve for the survey of trawled fishes in the Jizan area, southern Red Sea, Saudi Arabia. Numbers for trawls 1 to 11 correspond to actual numbers of cumulative species collected in St1 to St11 by bottom trawl with all species including pelagic species (grey solid line) and demersal species only (black solid line). Dashed line from trawls 12 to 50 corresponds to estimated cumulative species numbers for demersal species from extrapolation for additional samplings by bottom trawling with upper and lower 95% confidence intervals (dotted lines). The number of trawls at which 90% and 95% of total expected demersal species are collected (i.e. 23 and 30 trawls, respectively) is indicated by vertical lines that meet the respective horizontal lines at the extrapolated species accumulation curve.

FIGURE 1 in Survey of demersal fishes from southern Saudi Arabia, with five new records for the Red Sea

FIGURE 1. Map of the Red Sea with details of the shelf area between the city of Jizan and Farasan Island in southern Saudi Arabia (water depth of 0–200 m in light grey,>200–1,000 m in mid grey and>1,000 m in dark grey). Positions of trawling stations St1 to St11 (S1 to S11 in the map) are shown as lines between starting point and end point of the trawl.

opencc-zeroFeb 2022View details →

Historical fish survey datasets from productive aquatic ecosystems in Lithuania

Here we present a newly digitized fish monitoring dataset for two major Lithuanian inland ecosystems – Curonian Lagoon and Kaunas Water reservoir. The data comprises fish surveys conducted during <a>1950s to 1980s</a>, using a range of fishing gears and sampling methods. Three different definitions or methods describe the level of detail for each fish community study: Method 1 surveys include individual fish sizes and weights, Method 2 surveys record frequencies of fish in length or weight groups, whereas Method 3 only records the total catch biomass of a given species.

opencc-by-4.0May 2024View details →

On the study of fauna (macroinvertebrates, fish, amphibians, reptiles, birds and mammals) of the lower course of Shokhdara river valley in Pamir, Mountain Bodakhshan, Tajikistan.Appendices. Lists of terrestrial vertebrates recorded in the field survey at the Shokhdara and Panj Rivers

Appendix 1. A list of records of batracho- and herpetofauna in the field survey. Appendix 2. List of avifauna of the surveyed region. Appendix 3 A list of mammals recorded in the field survey.

opennotspecifiedJun 2022View details →

Fig. 3. Flood debris from which the sample for Appendix 1 in Coleoptera in Floods: Biotic Surveys, Fish Food, Adaptation, Reconstruction of Paleoenvironments, and Preconstruction of Neoenvironments

Fig. 3. Flood debris from which the sample for Appendix 1 was taken: Rock Creek Trail, Kensington, Maryland, USA, 21 April 2017.

opennotspecifiedJun 2022View details →

Fig. 2 in Coleoptera in Floods: Biotic Surveys, Fish Food, Adaptation, Reconstruction of Paleoenvironments, and Preconstruction of Neoenvironments

Fig. 2. Jong-Seok Park and Sarah Samson collecting beetles in a temporary pond created by a flash flood in Hidalgo Co., New Mexico, USA during 2 August 2014. Insert: Beetles waiting out the flood.

opencc-zeroDec 2022View details →

Mediterranean underwater fish visual census surveys data

The positive effect of fully protected Marine Protected Areas (MPAs) on marine biodiversity, specifically on fishes, has been widely documented. In contrast, the potential of MPAs to mitigate the impact of adverse climatic conditions has seldom been investigated. Here, we assessed the effectiveness of MPAs, quantified as increasing fish biomass, across wide geographic and environmental gradients across the Mediterranean Sea. We performed underwater visual surveys within and outside MPAs to characterize fish assemblages in 52 rocky reef sites across an extent of over 3,300 km. We used the steep spatial temperature gradient across the Mediterranean as a 'space-for-time' substitution to infer climate-driven temporal changes. We found that, as expected, Mediterranean MPAs increased fish biomass. At the same time, higher seawater temperatures are associated with decreased fish biomass, changes in species composition, and shifts towards more thermophilic species. Importantly, we found that the rate of decrease in fish biomass with temperature was similar between protected and fished sites. Taken together, these results suggest that the capacity of MPAs to harbor higher fish biomass, compared to surrounding areas, is maintained across a broad temperature range. At the same time, MPAs will not be able to offset larger-scale biotic alterations associated with climate change. Policy implications: Our results suggest that sustained warming will likely reduce fish biomass in the Mediterranean Sea and shift community structure, requiring more conservative targets for fishery regulations. At the same time, protection from fishing will remain an important management tool even with future high-water temperatures, and MPAs are expected to continue to provide local-scale benefits to conservation and fisheries.