Costs and benefits of towed videos and remotely operated vehicles for sampling shallow reef habitats and fish

Where several different tools are available for research, the costs and benefits associated with each option become an important part of the selection process. Towed video (ToV) and remotely operated vehicles (ROVs) are both widely used to assess shallow reef benthic habitats and fish assemblages, but quantitative data on their comparative performance is limited. The relative abilities of commercially available ToV and ROV were assessed using two low-cost (less than A$10000), manually deployable systems. These systems were deployed to collect photographs of marine habitats and videos of fish assemblages along six 200-m transects at three separate sites. The time required to operate each system and the specific limitations and advantages of each system were compared. Both systems performed equally in terms of the resolution of data collected on benthic habitats and fish assemblages on shallow reefs. However, ToV required significantly less time (~60% less) to collect data than ROV, and should allow cost savings with no loss in data quality. We recommend ToV as a cost-effective and easily deployable system for assessing rocky reef habitats and fish assemblages.

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Monitoring rocky reef biodiversity by underwater geo-referenced photoquadrats

Underwater Technology The International Journal of the Society for Underwater ◽

10.3723/ut.38.017 ◽

2021 ◽

Vol 38 (1) ◽

pp. 17-24

Author(s):

Gonzalo Bravo ◽

Juan Pablo Livore ◽

Gregorio Bigatti

Keyword(s):

Low Cost ◽

Rocky Reef ◽

Intelligence Analysis ◽

High Definition ◽

Sampling Protocol ◽

Sampling Methodology ◽

Rocky Reefs ◽

Marine Habitats ◽

Non Destructive ◽

Excellent Tool

Digital images are an excellent tool for divers to sample hard-bottom subtidal habitats as bottom time is limited and high-definition images can be collected quickly and accurately. The present paper describes a sampling protocol for benthic rocky reef communities using geo-referenced photoquadrats and tests the method over several rocky reefs of Atlantic Patagonia. This method was tested in two localities, separated by 100 km in a semi-enclosed gulf, covering a total of 5800 m of 11 rocky reefs using track roaming transects. The protocol is non-destructive, relatively low-cost and can adequately assess changes in marine habitats as rocky reefs. The implementation of artificial intelligence analysis using human expert training may reduce analysis time and increase the amount of data collected. The present study recommends this sampling methodology for programs aimed at monitoring changes in biodiversity.

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Towards spatial management of fisheries in the Gulf: benthic diversity, habitat and fish distributions from Qatari waters

ICES Journal of Marine Science ◽

10.1093/icesjms/fsx116 ◽

2017 ◽

Vol 75 (1) ◽

pp. 178-189 ◽

Cited By ~ 1

Author(s):

Mark E M Walton ◽

Jamie Hayes ◽

Mohsin Al-Ansi ◽

Mohamed Abdallah ◽

Ibrahim Al Maslamani ◽

...

Keyword(s):

Coral Reef ◽

Fish Assemblages ◽

Habitat Type ◽

Fish Communities ◽

Video Data ◽

Benthic Habitat ◽

Soft Sediment ◽

Benthic Habitats ◽

Marine Habitats ◽

Spatial Management

Abstract As with many other regions in the world, more complete information on the distribution of marine habitats in the Gulf is required to inform environmental policy, and spatial management of fisheries resources will require better understanding of the relationships between habitat and fish communities. Towed cameras and sediment grabs were used to investigate benthic habitats and associated epifauna, infauna and fish communities in the central Gulf, offshore from the east coast of Qatar, in water depths of between 12 and 52 m. Six different habitats were identified: (i) soft sediment habitats of mud and (ii) sand, and structured habitats of (iii) macro-algal reef, (iv) coral reef, (v) mixed reef, and (vi) oyster bed. The epibenthic community assemblage of the mud habitat was significantly different to that of sand, which in turn differed from the structured habitats of coral reef, mixed reef and oyster bed, with the macroalgal assemblage having similarities to both sand and the other structured habitats. Fish assemblages derived from video data did not differ between habitats, although certain species were only associated with particular habitats. Epibenthic diversity indices were significantly lower in mud, sand and macro-algal habitats, with no differences recorded for fish diversity. Soft sediment grab samples indicated that mud habitats had the highest benthic diversity, with Shannon-Weiner values of >4, and were more diverse than sand with values of 3.3. The study demonstrates high biodiversity in benthic habitats in the central and southwestern Gulf, which may in part be due to the absence of trawling activity in Qatari waters. There is a strong influence of depth on benthic habitat type, so that depth can be used to predict habitat distribution with a high level of accuracy. The presence of outcrops of hard substrata creates a mosaic of patchy shallow structured benthic habitat across extensive areas of the offshore seabed. Such heterogeneity, and the association of commercially exploited fish species with specific habitats, indicates that this region is well suited to a spatial approach to fisheries management.

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The Costs and Benefits of Shareholder Democracy: Gadflies and Low-Cost Activism

Review of Financial Studies ◽

10.1093/rfs/hhaa128 ◽

2020 ◽

Cited By ~ 1

Author(s):

Nickolay Gantchev ◽

Mariassunta Giannetti

Keyword(s):

Low Cost ◽

Shareholder Value ◽

Career Concerns ◽

Costs And Benefits ◽

Cross Sectional ◽

Shareholder Proposals ◽

Active Individual ◽

Shareholder Democracy ◽

To Receive

Abstract We show that there is cross-sectional variation in the quality of shareholder proposals. On average, proposals submitted by the most active individual sponsors are less likely to receive majority support, but they occasionally pass if shareholders mistakenly support them and may even be implemented due to directors’ career concerns. While gadfly proposals destroy shareholder value if they pass, shareholder proposals on average are value enhancing in firms with more informed shareholders. We conclude that more informed voting could increase the benefits associated with shareholder proposals.

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Rapid Antibody Selection Using Surface Plasmon Resonance for High-Speed and Sensitive Hazelnut Lateral Flow Prototypes

Biosensors ◽

10.3390/bios8040130 ◽

2018 ◽

Vol 8 (4) ◽

pp. 130 ◽

Cited By ~ 6

Author(s):

Georgina Ross ◽

Maria Bremer ◽

Jan Wichers ◽

Aart van Amerongen ◽

Michel Nielen

Keyword(s):

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

High Speed ◽

Selection Process ◽

Low Cost ◽

Real Life ◽

Cross Reactivity ◽

Lateral Flow ◽

Label Free

Lateral Flow Immunoassays (LFIAs) allow for rapid, low-cost, screening of many biomolecules such as food allergens. Despite being classified as rapid tests, many LFIAs take 10–20 min to complete. For a really high-speed LFIA, it is necessary to assess antibody association kinetics. By using a label-free optical technique such as Surface Plasmon Resonance (SPR), it is possible to screen crude monoclonal antibody (mAb) preparations for their association rates against a target. Herein, we describe an SPR-based method for screening and selecting crude anti-hazelnut antibodies based on their relative association rates, cross reactivity and sandwich pairing capabilities, for subsequent application in a rapid ligand binding assay. Thanks to the SPR selection process, only the fast mAb (F-50-6B12) and the slow (S-50-5H9) mAb needed purification for labelling with carbon nanoparticles to exploit high-speed LFIA prototypes. The kinetics observed in SPR were reflected in LFIA, with the test line appearing within 30 s, almost two times faster when F-50-6B12 was used, compared with S-50-5H9. Additionally, the LFIAs have demonstrated their future applicability to real life samples by detecting hazelnut in the sub-ppm range in a cookie matrix. Finally, these LFIAs not only provide a qualitative result when read visually, but also generate semi-quantitative data when exploiting freely downloadable smartphone apps.

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A Weighted Routing Scheme for Industrial Wireless Sensor Networks

International Journal of Wireless Networks and Broadband Technologies ◽

10.4018/ijwnbt.2015040101 ◽

2015 ◽

Vol 4 (2) ◽

pp. 1-14

Author(s):

Manish Kumar ◽

Rajeev Tripathi ◽

Sudarshan Tiwari

Keyword(s):

Routing Protocol ◽

Selection Process ◽

Low Cost ◽

High Energy ◽

Delivery Ratio ◽

Monitoring And Control ◽

Industrial Wireless Sensor Networks ◽

Control Center ◽

Packet Delivery ◽

Path Discovery

The WSNs replace the medium of communication from wired to wireless in industrial environment. This offer several advantages that includes easy and fast installation, low-cost maintenance and energy saving. In industrial monitoring and control application, the sensory measures should be delivered to control center in predefined deadline time, so the necessary actions may timely initiated. The geographical routing as reactive routing protocol plays a massive role for real-time packet delivery. The proposed routing protocol follows path discovery on demand basis to reduce the path discovery overhead. Moreover, the routing protocol follows weighted forwarding node selection process. This selects the shorter path over speedy reliable links for smaller deadline time and distributes the traffic over energy efficient node for larger deadline time. Through simulation, the authors demonstrate, compared to existing routing protocol the proposed routing protocol improves the packet delivery ratio along with enhanced network life while maintaining the high energy efficiency and low delivery latency.

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Spatial, temporal and ontogenetic variation in the association of fishes (family Labridae) with rocky-reef habitats

Marine and Freshwater Research ◽

10.1071/mf10315 ◽

2011 ◽

Vol 62 (7) ◽

pp. 870 ◽

Cited By ~ 13

Author(s):

Jason K. Morton ◽

William Gladstone

Keyword(s):

Fish Assemblages ◽

Spatial Scales ◽

Abundant Species ◽

Habitat Associations ◽

Rocky Reef ◽

Habitat Variability ◽

Life History Stages ◽

Multiple Spatial Scales ◽

Habitat Specialisation ◽

Rocky Reefs

Habitat variability is an important factor structuring fish assemblages of rocky reefs in temperate Australia. Accepting the generality of this model requires that habitat-related variation is consistent through time, across multiple spatial scales, and applies to all life-history stages. We used repeated underwater visual surveys at multiple spatial scales over a 22-month period to test whether three distinct rocky-reef habitats had different wrasse assemblages and whether these assemblages were subject to spatial, temporal and ontogenetic variability. Overall, the strongest and most consistent habitat association was with sponge gardens, which had the most distinct assemblage, and the greatest species richness and density of individuals. Habitat associations in fringe and barrens were less consistent. A substantial increase in the abundance of small individuals, coinciding with warmer sea temperatures, contributed to temporal fluctuations in the density of wrasses. Overall, habitats were not strongly partitioned among larger individuals of the most abundant species, suggesting that adults are largely habitat generalists whereas small, recruiting individuals showed greater habitat specialisation. The present study emphasises the importance of incorporating spatial, temporal and ontogenetic variability into surveys of fish assemblages to understand more fully the dynamics of temperate rocky-reef systems.

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Subtidal assemblages associated with a geotextile reef in south-east Queensland, Australia

Marine and Freshwater Research ◽

10.1071/mf04202 ◽

2005 ◽

Vol 56 (2) ◽

pp. 133 ◽

Cited By ~ 17

Author(s):

Rhys A. Edwards ◽

Stephen D. A. Smith

Keyword(s):

Fish Assemblages ◽

Benthic Communities ◽

Artificial Reef ◽

Demersal Fish ◽

Diverse Range ◽

Marine Habitats ◽

Sessile Invertebrates ◽

Hard Structures ◽

Asymmetrical Design ◽

Natural Reefs

In marine habitats, the use of geotextile materials as a ‘soft-engineering’ solution is increasingly being considered as an alternative to hard structures. However, very little is known about biological assemblages that develop on geotextile structures. This study provides the first ecological comparison of subtidal assemblages between Narrowneck Artificial Reef (NAR), a geotextile reef in south-east Queensland, Australia, and three nearby natural reefs. Benthic community structure, fish assemblages and habitat complexity were compared between reef types using an asymmetrical design. Although natural reefs supported distinct biotic assemblages, as a class, these reefs differed significantly from NAR. The artificial reef was dominated by macroalgae and supported fewer benthic categories, whereas the natural reefs were characterised by a diverse range of sessile invertebrates. Benthic and demersal fish assemblages were less diverse on NAR, but pelagic fish assemblages were similar on both reef types. The substratum of NAR was less complex than that of the natural reefs; this physical variable was correlated with some of the differences in benthic communities and benthic and demersal fish assemblages. It is likely that the key determinants of the biotic patterns observed in this study are interactions between the age of NAR and the physical properties of geotextile substratum.

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A Low-Cost Named Entity Recognition Research Based on Active Learning

Scientific Programming ◽

10.1155/2018/1890683 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Han Huang ◽

Hongyu Wang ◽

Dawei Jin

Keyword(s):

Active Learning ◽

Language Processing ◽

Selection Process ◽

Conditional Random Field ◽

Low Cost ◽

Named Entity Recognition ◽

Entity Recognition ◽

Training Set ◽

Processing Technologies ◽

Named Entity

Named entity recognition (NER) is an indispensable and very important part of many natural language processing technologies, such as information extraction, information retrieval, and intelligent Q & A. This paper describes the development of the AL-CRF model, which is a NER approach based on active learning (AL). The algorithmic sequence of the processes performed by the AL-CRF model is the following: first, the samples are clustered using the k-means approach. Then, stratified sampling is performed on the produced clusters in order to obtain initial samples, which are used to train the basic conditional random field (CRF) classifier. The next step includes the initiation of the selection process which uses the criterion of entropy. More specifically, samples having the highest entropy values are added to the training set. Afterwards, the learning process is repeated, and the CRF classifier is retrained based on the obtained training set. The learning and the selection process of the AL is running iteratively until the harmonic mean F stabilizes and the final NER model is obtained. Several NER experiments are performed on legislative and medical cases in order to validate the AL-CRF performance. The testing data include Chinese judicial documents and Chinese electronic medical records (EMRs). Testing indicates that our proposed algorithm has better recognition accuracy and recall rate compared to the conventional CRF model. Moreover, the main advantage of our approach is that it requires fewer manually labelled training samples, and at the same time, it is more effective. This can result in a more cost effective and more reliable process.

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