Historically, forested riparian buffers have been created to provide protection for aquatic organisms and aquatic ecosystem functions. Increasingly, new and existing riparian buffers are being used also to meet terrestrial conservation requirements. To test the effectiveness of riparian buffers for conserving terrestrial fauna, we conducted a meta-analysis using published data from 397 comparisons of species abundance in riparian buffers and unharvested (reference) riparian sites. The response of terrestrial species to riparian buffers was not consistent between taxonomic groups; bird and arthropod abundances were significantly greater in buffers relative to unharvested areas, whereas amphibian abundance decreased. Edge-preferring species were more abundant in buffer sites than reference sites, whereas species associated with interior habitat were not significantly different in abundance. The degree of buffer effect on animal abundance was unrelated to buffer width; wider buffers did not result in greater similarity between reference and buffer sites. However, responses to buffer treatment were more variable in buffers <50 m wide, a commonly prescribed width in many management plans. Our results indicate that current buffer prescriptions do not maintain most terrestrial organisms in buffer strips at levels comparable to undisturbed sites.

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Okinawa, Japan is known for its high marine biodiversity, yet little work has been performed on examining impacts of numerous large-scale coastal development projects on its marine ecosystems. Here, we examine apparent impacts of the construction of the Kaichu-Doro causeway, which was built over 40 years ago. The causeway is a 4.75 km long embankment that divides a large tidal flat and has only two points of water exchange along its entire length. We employed quadrats, transects, sampling, visual surveys, and microbial community analyses combined with environmental, water quality data, and 1m cores, at five stations of two paired sites each (one on each side of Kaichu-Doro) to investigate how the environment and biota have changed since the Kaichu-Doro was built. Results indicate reduction in water flow, and site S1 was particularly heavily impacted by poor water quality, with low diversity and disturbed biotic communities.

In this paper, we propose a navigation method of multiple AUVs and give a performance analysis on position estimation for a wide area survey. The key idea of the proposed method is alternating roles of the AUVs between Moving and Measuring Role (MMR) and Landmark Role (LR). AUVs in the MMR move based on the AUVs in the LR. On the other hand, AUVs in the LR keep their positions on the seabed to act as landmarks for the moving AUVs. By alternating their roles, the two groups of AUVs can observe in a wide area while maintaining a good position estimate.AUV position is estimated by mutual acoustic measurements of relative distance among AUVs and direction among them. These position measurements are fused with other on-board sensors such as Doppler velocity logger (DVL), fiber optic gyro (FOG) and depth sensor by particle filter for a robust position estimate against sensor noises and lack of measurements.We verified the performance of the method through navigation simulation based on the performance of sensors obtained during various experiments performed in a pool environment and at sea. In the simulation, the proposed method achieved a positioning error considerably smaller than dead reckoning and conventional navigation methods of a single AUV. In the proposed method, each AUV also achieved state estimation, suppressing deviation from its true position and heading due to alternating roles and evaluating outliers of positioning measurements by particle filter. Therefore, the proposed method is suitable for a wide area survey without sensor drifts and deviation from true state compared with conventional navigation methods.

We propose a docking method for a hovering type AUVs at a seafloor station. Although hovering type AUVs are suitable for detailed surveys of local area, docking methods are currently less studied compared with ones for cruising type AUVs. This paper proposes a docking method for hovering type AUVs based on both the acoustic and visual positioning. The proposed method was implemented in the AUV Tri-TON and a trial station in order to verify its performance through tank experiments. The vehicle succeeded in docking at the station 13 times, which accounts for half of the total number of trials. The possible causes of the failures and improvement methods are also discussed.

No abstract

Community-based diversity analyses, such as metabarcoding, are increasingly popular in the field of metazoan zooplankton community ecology. However, some of the methodological uncertainties remain, such as the potential inflation of diversity estimates resulting from contamination by pseudogene sequences. Furthermore, primer affinity to specific taxonomic groups might skew community composition and structure during PCR. In this study, we estimated OTU (operational taxonomic unit) richness, Shannon’s H’, and the phylum-level community composition of samples from a coastal zooplankton community using four approaches: complement DNA (cDNA) and genomic DNA (gDNA) mitochondrial COI (Cytochrome oxidase subunit I) gene amplicon, metatranscriptome sequencing, and morphological identification. Results of mismatch distribution demonstrated that 90% is good threshold percentage to differentiate intra- and inter-species. Moderate level of correlations appeared upon comparing the species/OTU richness estimated from the different methods. Results strongly indicated that diversity inflation occurred in the samples amplified from gDNA because of mitochondrial pseudogene contamination (overall, gDNA produced two times more richness compared with cDNA amplicons). The unique community compositions observed in the PCR-based methods indicated that taxonomic amplification bias had occurred during the PCR. Therefore, it is recommended that PCR-free approaches be used whenever resolving community structure represents an essential aspect of the analysis.

Abmmf-Autonomous Underwater Vehicles (AWs) are suitable for condition SUNV of artillcial sbocinres such as pillars and caissons in harbors. This paper describes a method to trace the structure's surface using a iight-section p m w g system. This proliling system determines the continuous shape of the target objects over a wide area by the light sectioning method The vehicle navigates referencing the principal shape of the stlpcture, tracing its surface while taking video images. This method dso enables threedimenslond mapping oftraced structures and the seabed The method is implemented using testbed A W "Tri-Dog 1" and vedied by tank tests. The AUV navigate robustly against Mvid objects such as small obstades and Uoating particles. Precise depth mapping of the tank botlom Is carried out. I. JNTRODIJCITONAutonomous Underwater Vehicles (AWs) are suitable for ocean observation since they can swim k l y without the restriction imposed by an umbilical cable. It can be said &at A W s are increasingly finding practical applications worldwide [1][2][3][4][5]. Commercial obsemtion of the seabed, for investigation of underwater oilfields and resources, has already been executed by A W s using side scan sonar, mdtibeam sonar, sub-bottom profiler etc [6].There is a great demand for A W s not only for wide area survey but also for condition survey of artificial underwater structures such as pillars and caissons in harbors, dams, bodies of ships, and installations of deepsea oilfields. Such structures require periodic inspection. These task are typically carried out by human divers and Remotely Operated Vehicles (ROVs). However the use of buman divers carries an inherent risk and is not applicable at great depth. ROVs require an umbilical cable that restricts their movement. The demand for development of highly intelligent A W s that can undertake such missions is expected to increase greatly over the next few years.Intelligent behavioral control, sensing, navigation and motion control are essential to accomplish autonomous observation of underwater structures using A W s . In an underwater environment, it is especially difficult to detect obstacles (sensing) and to obtain precise position data (navigation). The authors have proposed the autonomous observation method using A W s that can overcome these challenges [7][8]. The method has been implemented by detecting the target objects, localizing them, and then approaching them by taking video images while closely tracing their shape. A laser ranging system consisting of laser pointing devices and a CCD camera was introduced for sensing. The system was shown to provide precise distance to the target object so that the vehicle could trace its shape vhile maintaining a constant distance and attitude to it. This method is hown as relative navigation. The method wa8 implemented using the testbed A W 'Tri-Dog 1" 191 and has been proved experimentally by tank tests. Sea trials were also carried out at Kamaishi port in Japan [IO]. The A W performed observation of breakwater caissons.D...