Explore the vast range of titles available.

The seafloor covers some 70% of the Earth’s surface and has been recognised as a major sink for marine litter. Still, litter on the seafloor is the least investigated fraction of marine litter, which is not surprising as most of it lies in the deep sea, i.e. the least explored ecosystem. Although marine litter is considered a major threat for the oceans, monitoring frameworks are still being set up. This paper reviews current knowledge and methods, identifies existing needs, and points to future developments that are required to address the estimation of seafloor macrolitter. It provides background knowledge and conveys the views and thoughts of scientific experts on seafloor marine litter offering a review of monitoring and ocean modelling techniques. Knowledge gaps that need to be tackled, data needs for modelling, and data comparability and harmonisation are also discussed. In addition, it shows how research on seafloor macrolitter can inform international protection and conservation frameworks to prioritise efforts and measures against marine litter and its deleterious impacts.

In Iraq, there are some asphalt concrete mixtures suffer from appearing of cracking and deformation immediately after finishing the construction of a base course. In the flexible pavement, the pavement is considered to be degraded after opening to traffic by repeated traffic loading, climatic conditions, aging of asphalt mixture, etc. Crack plays a critical mode in pavement degradation. Several experimental studies have been carried out to gain a deeper understanding of the environment and weak construction monitor the action of pavement fractures. However, one downside of these previous studies was that the majority of them were carried out in a laboratory environment. A trial road section was studied after finishing base course construction by monitoring the early cracking. The major causes of appearing the early cracking have been investigated and debated. In this survey, three trial road sections with defined asphalt layers were considered. These trial sections were constructed with local materials brought from Nasrya refinery and Najaf quarry. On the basis of the findings obtained, two sections have deteriorated, while the third one was made as control for comparison purposes The observed early cracking could be attributed to the asphalt cement type and poor construction procedure occurring in an asphalt base layer as a result of low underlying sub-base course type and specifications.

The Indian Ocean humpback dolphin (Sousa plumbea) and the Indo-Pacific finless porpoise (Neophocaena phocaenoides) are resident to the inshore waters of India. Despite urgent conservation concerns facing both species, population assessments and long-term monitoring efforts face several challenges, particularly due to limitations in conducting conventional visual surveys. Our study explores the use of combined acoustic and visual surveys along a 376 km[Formula: see text] area off the Sindhudurg coast, India, to address these limitations. We begin by examining the two platforms for efficiency in species detection by comparing encounter rates across acoustic and visual methods. Acoustic (0.04 groups/km) and visual (0.03 groups/km) encounter rates for humpback dolphins do not show a stark difference. However, acoustic (0.12 groups/km) and visual (0.03 groups/km) encounter rates for finless porpoises vary greatly. Visual and acoustic group size estimates also vary for both species. We then use generalized additive mixed models (GAMM) to determine factors responsible for variation in detectability between the two platforms. Distance from shore and vessel traffic are variables affecting mixed detections of humpback dolphins. Acoustic detections for finless porpoises are most influenced by distance from shore and depth. Our findings highlight the importance of considering species-specific variations in acoustic and visual detectability when designing integrated surveys for multiple species.

Aim Rapid shifts in marine species distributions driven by ocean warming require more effective monitoring across entire ranges to detect emerging ecological change. Traditionally, visual surveys have been used to track these distributional shifts, but they often overlook small‐bodied, rare or cryptic species, potentially underestimating range changes. Environmental DNA (eDNA) bypasses these limitations, yet its effectiveness in detecting species near their range limits remains understudied. Location Eastern Australia. Methods We combined eDNA metabarcoding and visual surveys to assess reef fish communities across nine sites spanning a 2000‐km latitudinal gradient within a global warming hotspot encapsulating tropical, subtropical and temperate reefs. Variation in detectability across methods and biogeographic ranges was also assessed at the level of functional traits (trophic guild, thermal guild and water column position). Results eDNA and visual surveys revealed different fish species compositions, potentially underestimating the extent of fish biogeographic ranges. eDNA detected 44 more unique tropical species than visual surveys across their range, and was more effective at detecting tropical carnivores, omnivores, invertivores, planktivores, detritivores and all water column positions. In contrast, visual surveys were more effective at detecting temperate carnivores, invertivores and benthic species. For tropical fishes at their cold range edge in temperate ecosystems, eDNA identified 12 unique species, including herbivores and cryptic species not previously recorded by long‐term visual surveys. Contrastingly, eDNA detected 20 fewer temperate species than visual surveys across their biogeographic range and was less effective (five unique species) than visual surveys (nine unique species) at detecting temperate species at their warm trailing range in subtropical ecosystems. Conclusions Combining eDNA and visual surveys improves the detection of reef fishes near the limits of their known distributions. This approach helps reveal overlooked species, particularly those that are cryptic, rare or low in abundance, and supports more accurate assessments of species distributions across biogeographic gradients.

Appropriate sampling methods are essential for monitoring and managing all wildlife. There is limited information on how to monitor ground-dwelling invertebrates in the alpine zone compared to more commonly studied lower-elevation habitats. We aim to understand the strengths, weaknesses, and cost-effectiveness of invertebrate survey methods when deployed in the alpine zone. We tested four methods on the South Island of New Zealand (Aotearoa): pitfall traps, tracking tunnels, visual surveys, and trail cameras. We focused on methods for ground-dwelling large-bodied invertebrates, a group most likely to be impacted by introduced mammalian predators. Pitfall traps and trail cameras were practical methods for surveying alpine invertebrates. Tracking tunnels only reliably detected large wētā (Orthoptera: Anostostomatidae), as other invertebrates were too light to leave distinguishable tracks. Visual surveys did not generate enough observations to be considered a successful method. We found no difference in the total abundance or easily recognised taxonomic groups detected by pitfall traps and trail cameras. Trail cameras detected fewer wētā compared to tracking tunnels and pitfall traps. Of the successful methods, pitfall traps were the most cost-effective, followed by tracking tunnels and trail cameras. Tracking tunnels were the fastest to install and required the least processing time, followed by pitfall traps and trail cameras. We recommend using pitfall traps to survey large-bodied alpine ground-dwelling invertebrates to better understand population trends or community composition. This method was consistent across all alpine habitat types and has the potential to be an effective method to inform conservation monitoring and management programmes.Implications for insect conservationMonitoring is vital to understand how invertebrates respond to change and evaluate conservation management program outcomes. This study provides practical information on potential monitoring tools for invertebrates in the alpine zone and recommends pitfall traps to survey large-bodied alpine invertebrates.

1. Aerial seabird surveys are often conducted so that changes in abundance may be monitored. For example, large-scale offshore wind farms are proposed for UK waters, and surveys are currently being conducted to quantify numbers and distribution ahead of construction. 2. Technological advances mean that strip transect surveys may now be conducted, using digital methods. We address survey design and data analysis issues for such digital surveys, contrasting them with visual aerial line transect surveys. 3. We also explore the relative performances of the methods for estimating the size of a large aggregation of common scoters in Carmarthen Bay, Wales. We found that abundance estimates from two digital methods were closely comparable, while estimates from visual aerial surveys were appreciably lower. 4. Synthesis and applications. Efficient survey methods to quantify abundance and distribution of seabirds are needed, to assess change arising from climate change, or developments such as the construction of large-scale offshore wind farms. The traditional survey methods are visual surveys conducted along transects from ships or aircraft. Digital video and stills surveys can be conducted from aircraft flying sufficiently high to avoid disturbance, while still being able to detect and identify seabirds. Given the rapid technological developments, we expect digital surveys largely to replace visual surveys for seabirds in offshore regions.

Ecological monitoring programs typically aim to detect changes in the abundance of species of conservation concern or which reflect system status. Coral reef fish assemblages are functionally important for reef health and these are most commonly monitored using underwater visual surveys (UVS) by divers. In addition to estimating numbers, most programs also collect estimates of fish lengths to allow calculation of biomass, an important determinant of a fish’s functional impact. However, diver surveys may be biased because fishes may either avoid or are attracted to divers and the process of estimating fish length could result in fish counts that differ from those made without length estimations. Here we investigated whether (1) general diver disturbance and (2) the additional task of estimating fish lengths affected estimates of reef fish abundance and species richness during UVS, and for how long. Initial estimates of abundance and species richness were significantly higher than those made on the same section of reef after diver disturbance. However, there was no evidence that estimating fish lengths at the same time as abundance resulted in counts different from those made when estimating abundance alone. Similarly, there was little consistent bias among observers. Estimates of the time for fish taxa that avoided divers after initial contact to return to initial levels of abundance varied from three to 17 h, with one group of exploited fishes showing initial attraction to divers that declined over the study period. Our finding that many reef fishes may disperse for such long periods after initial contact with divers suggests that monitoring programs should take great care to minimise diver disturbance prior to surveys.

This paper provides results of marine litter surveys carried out on 14 small uninhabited islands located in the coastal waters of Estonia, northeastern Baltic Sea. The islands were visited four times in total during 2019–2020. On each island, a litter survey was conducted on the beach and in terrestrial vegetation with a focus on macrolitter. Calculated over all surveys, the median value of macrolitter items per 100 m long beach section was 10.65, and the median density was 0.006 items m–2. At the sub-basin level, the three islands located in the Gulf of Finland had the highest number of beach litter items per 100 m and the highest density (items m–2), 38.05 and 0.017, respectively. The main litter material, representing 57.3% of all findings, was plastic; however, there were some variances across islands due to local conditions. The environmental variables most strongly correlated with differences in the composition of macrolitter were related to water movement and depth. Microlitter was found in low amounts (up to 60 items kg–1) in the sediment of all studied islands. Litter items used as nest material were noted on all the islands with seabird colonies.

Land managers generally assume that postfire surveys conducted by fire personnel are effective at quantifying mortality or injury of box turtles (Terrapene spp.) because individuals should be readily observable in burned areas. Box turtle surveys conducted by humans in unburned habitats can be ineffective, yet little information exists on the efficacy of postfire surveys. We quantified detection probability of eastern box turtles (Terrapene carolina carolina) shortly after a prescribed fire in southwestern Michigan, USA, during May 2015. Immediately prior to a May (growing season) fire, we confirmed that 7 adult box turtles fitted with radio transmitters occupied the proposed burn area. Two days after the burn we reconfirmed turtle locations and subsequently conducted 6 independent visual-encounter surveys through 2 burned areas (0.75 and 1.0 ha) that contained telemetered turtles. For these 12 surveys, we found that average detection probability per survey was low (0.11, SE = 0.09) and highly variable among observers (range = 0.00–0.50). We found that individual turtles directly exposed to fire remained buried for up to 12 hr after the fire was extinguished and were thus unavailable for detection immediately after the burn. Further confounding postfire survey results, buried turtles rapidly moved to unburned areas after emerging from their subterranean refugia. Our results suggested that typical visual-encounter surveys conducted for eastern box turtles after prescribed burning do not accurately reflect occupancy status or fire-caused mortality.