Transect Surveys Research Articles

Monitoring within-patch, flying season population dynamics of an endangered mire-dwelling dragonfly, Petalura gigantea (Odonata: Petaluridae)

ABSTRACT Understanding within-patch seasonal demographics of patchily distributed odonates is fundamental to understanding aspects of their behaviour, ecology, and landscape-scale population dynamics. Such knowledge underpins effective conservation management and is dependent upon appropriate survey methods. The objective of this study was to understand the within-patch, flying season, population dynamics of imagos of the endangered mire-dwelling dragonfly, Petalura gigantea, using a modified Pollard Walk, a line transect survey technique. Relative abundance of imagos was monitored at nominally weekly intervals, by sex, across the duration of the flying season in six mire patches in the Blue Mountains, New South Wales. There was a preponderance of adult males and a relatively consistent trend in changing relative abundance of adult males compared to females within mire habitat across all surveys, with a marked seasonal peak in male abundance, confirming that surviving adult females generally occupy non-mire habitat other than for reproduction. This study confirmed the utility of this technique to monitor changing relative abundance of adult males within mire patches across a flying season, and potentially, for comparison among years for a separate, longitudinal, landscape-scale study. Successful use of the technique is contingent upon a sound understanding of the species’ habitat preferences and behaviour, with caveats for survey timing and weather protocols, to satisfy minimum requirements for detectability, repeatability, and replicability. The technique could be used, with species- and habitat-specific modifications, for monitoring other patchily distributed odonates, including petalurids, and contribute to their improved conservation management.

Seas the DNA? Limited detection of cetaceans by low‐volume environmental DNA transect surveys

AbstractEnvironmental DNA (eDNA) has begun to show promise as a robust and reproducible tool for monitoring cetaceans in coastal and offshore waters. Some limiting factors preventing the wider application of eDNA for cetacean monitoring includes lack of species‐specific qPCR assays and limited in situ validation. In this study, we determined 15 monitoring stations within cetacean hotspots in Chatham Sound (British Columbia, Canada), from which we collected a combination of visual and acoustic data, and low‐volume eDNA samples (equivalent to ~250 mL seawater). We designed novel eDNA assays for gray whale and Dall's porpoise and validated existing assays for harbor porpoise, killer whale, and humpback whale. Overall, we collected a total of 120 paired eDNA samples across four sampling intervals, 60 preserved with absolute ethanol and 60 preserved with propylene glycol antifreeze. Positive rates for visual (18%) and acoustic (4%) detections were higher than the eDNA detection rate (<3%), with only one sample (antifreeze‐preserved) producing a positive detection for humpback whales at one of the stations. We discuss factors which could have influenced the lack of detections and highlight the need for higher sample volumes and species‐specific sample approaches to improve detection success and confidence in eDNA applicability for cetacean monitoring.

Host-specificity of biocontrol agents in the field – The significance of sampling sympatric relatives of target weeds (Acacia holosericea versus A. auriculiformis)

Acacia auriculiformis is an invasive weed that causes significant environmental damage across Florida, USA. Previous native range surveys in Australia identified a number of herbivores that are commonly associated with this plant, including several species of leaf-tying moths (Macrobathra spp.) and a chrysomelid beetle (Calomela intemerata). These herbivores are considered strong candidates as biological control agents, but the range of host species they use has not been determined. We therefore conducted a transect survey of herbivorous insects on A. holosericea, a closely-related sympatric relative of A. auriculiformis. These species share areas of sympatry and the latter was sampled simultaneously (in sympatry and allopatry). DNA barcoding approach identified an array of herbivorous insects feeding on A. holosericea, but few were found on both the Acacia species sampled. A literature survey suggested this pattern of host specificity may be consistent across Australian acacias, to the extent that each Acacia species may largely host its own suite of herbivores. These results do not negate the need for host testing procedures in biological control, but they do increase our confidence substantially that several promising potential biological control agents of A. auriculiformis (Macrobathra moths and Calomela beetles) have a restricted host species range. Our study illustrates how exploring the herbivore diversity of plant species closely related to the target weed can provide crucial information for biological control researchers.

Available Forage and the Conditions for Avoiding Predation of the Siberian Roe Deer (Capreolus pygargus) in the Lesser Xing’an Mountains

Our study focused on quantifying available forage and the conditions for avoiding predation provided within the home ranges of Siberian roe deer (Capreolus pygargus). We conducted transect surveys in both winter and summer–autumn home ranges of the Siberian roe deer in the Tieli Forestry Bureau of the Lesser Xing’an Mountains. Our results revealed significant differences: (1) In terms of the quantity and quality of available forage, the summer–autumn home range had substantially more available forage than the winter home range, with meadows and cornfields showing the highest edible biomass in each, respectively. In terms of forage quality, there were differences in hemicellulose, cellulose, and lignin content between the two ranges. (2) In terms of the conditions for avoiding predation, the winter home range had lower vegetation coverage and greater visibility, making escape strategies more viable. In contrast, the summer–autumn home range had denser vegetation and limited visibility, making hiding strategies more viable. Our study offers comprehensive insights into the available forage and the conditions for avoiding predation, which is crucial for wildlife conservation strategies and habitat management in the region, as it directly informs strategies that address the seasonal forage requirements and predation avoidance of these deer, ultimately enhancing their prospects for survival in the area.

A pathogen's spatial range is not constrained by geographical features in the flax rust pathosystem.

Climate change and shifting environmental conditions can allow pathogens to spread into previously unburdened areas. For plant pathogens, this dynamic has the potential to disrupt natural ecosystem equilibria and human agriculture, making predicting plant pathogen range shifts increasingly important. Although such predictions will hinge on an accurate understanding of the determinants of pathogen range-namely the environmental, geographical, and host range characteristics that modulate local pathogen habitation-few studies to date have probed these in natural plant populations. Here, we characterize range determinants for the model system of Lewis flax (Linum lewisii) and its pathogen, flax rust (Melampsora lini), in the Rocky Mountains. Transect surveys were performed to assess three relationships: (i) the effect of geographical features-elevation, slope aspect, slope grade, and land cover-on flax presence and density, (ii) the effect of geographical features on flax rust presence and prevalence, and (iii) the effects of flax's local population density and metapopulation structure on flax rust presence and prevalence. We found that flax population density, but not host metapopulation structure, influences the distribution of flax rust. Additionally, we showed that, while the distribution of flax was broadly constrained to a relatively narrow range of geographical and resulting environmental features, flax rust was evenly distributed across the full range of settings measured. These results indicate that a warming environment, which is expected to modulate such features, may restrict the optimal range of the plant more than that of its pathogen. Importantly, our results also suggest that even if flax shifts its spatial range to escape increasing climatic pressures, flax rust will not face any significant barriers to track this movement.

Combining passive acoustic data from a towed hydrophone array with visual line transect data to estimate abundance and availability bias of sperm whales (Physeter macrocephalus).

Visual line transect (VLT) surveys are central to the monitoring and study of marine mammals. However, for cryptic species such as deep diving cetaceans VLT surveys alone suffer from problems of low sample sizes and availability bias where animals below the surface are not available to be detected. The advent of passive acoustic monitoring (PAM) technology offers important opportunities to observe deep diving cetaceans but statistical challenges remain particularly when trying to integrate VLT and PAM data. Herein, we present a general framework to combine these data streams to estimate abundance when both surveys are conducted simultaneously. Secondarily, our approach can also be used to derive an estimate of availability bias. We outline three methods that vary in complexity and data requirements which are (1) a simple distance sampling (DS) method that treats the two datasets independently (DS-DS Method), (2) a fully integrated approach that applies a capture-mark recapture (CMR) analysis to the PAM data (CMR-DS Method) and (3) a hybrid approach that requires only a subset of the PAM CMR data (Hybrid Method). To evaluate their performance, we use simulations based on known diving and vocalizing behavior of sperm whales (Physeter macrocephalus). As a case study, we applied the Hybrid Method to data from a shipboard survey of sperm whales and compared estimates to a VLT only analysis. Simulation results demonstrated that the CMR-DS Method and Hybrid Method reduced bias by >90% for both abundance and availability bias in comparison to the simpler DS -DS Method. Overall, the CMR-DS Method was the least biased and most precise. For the case study, our application of the Hybrid Method to the sperm whale dataset produced estimates of abundance and availability bias that were comparable to estimates from the VLT only analysis but with considerably higher precision. Integrating multiple sources of data is an important goal with clear benefits. As a step towards that goal we have developed a novel framework. Results from this study are promising although challenges still remain. Future work may focus on applying this method to other deep-diving species and comparing the proposed method to other statistical approaches that aim to combine information from multiple data sources.

Fine-scale habitat characteristics influence the winter habitat use of swamp deer (Rucervus duvaucelii) in Shuklaphanta National Park, Nepal

Endemic to India and Nepal, the swamp deer (Rucervus duvaucelii) is crucial for restoring and sustaining populations of top predators like tigers. Despite recent signs of species recovery in protected areas, the species remains vulnerable to extinction due to increasing anthropogenic activities. Information on factors influencing the occurrence of swamp deer is essential to formulate suitable management plans that can help to maintain their viable population and protect their habitats. We recorded swamp deer presence via direct sightings and indirect signs (pellets and footprints) through line transect surveys. Two ecological drivers i.e., habitat variables and disturbance variables that included eleven predictor variables were measured in the field where swamp deer was present (“used plots”) and absent (“habitat availability plot”). Binary logistic regression was used to analyze the factors associated with the probability of detecting the swamp deer. The model's outcomes showed that an increase in road/path/fireline distance and settlement distance, mixed forest habitat, and depth of leaf litter were positively correlated with the probability of locating swamp deer, while the other significant predictor variables (canopy cover, distance from water source, and presence of predator) had inverse relationships. In summary, our study has provided crucial insights into the factors influencing the presence of swamp deer in their habitat. These findings are useful for local governments and protected area authorities by providing fine-scale field-based scientific information, that can benefit swamp deer and its habitat. We also recommend similar studies in species range locations considering other influencing factors such as season, climate, interaction with other herbivore species, and predators that might affect the habitat use of swamp deer.

First estimate of distribution, abundance, and risk of encounter with aquaculture vessels for the rare Chilean dolphin in the entire Northern Chilean Patagonia

Abstract Assessing distribution and abundance patterns for rare species is challenging yet imperative, considering the extant, potentially hazardous, anthropogenic activities. In particular, the poorly studied Chilean dolphin (Cephalorhynchus eutropia) exhibits an extremely patchy distribution and low densities, co‐occurring with the intensive aquaculture industry in Southern Chile, among other anthropogenic activities. The distribution and abundance patterns of Chilean dolphins were assessed in the entire Northern Chilean Patagonia. A hierarchical species distribution model was fitted to data from line transect surveys using distance sampling techniques and environmental variables derived from topographic features and oceanographic models. A second version of this model used a joint‐likelihood approach to incorporate presence–pseudoabsence data for improving parameter estimation. Spatial predictions arising from these models were used to evaluate the relative probability of a dolphin encountering vessels from the local, predominantly aquaculture fleet. The results show that using a joint‐likelihood approach drastically reduced uncertainty in the parameters controlling the effect of covariates and in the total abundance estimates. This model estimated an overall low abundance (median 2,225.8; 95% CI 1,340–3,867) for this species in the region, and indicates their preference for shallow, sheltered bays and inner channels, near river mouths, where low salinity is expected. The highest probabilities of dolphin–vessel interactions were found on the eastern coast of Chiloe Big Island, coinciding with the largest number of aquaculture concessions in the area. Considering that the overall population of the Chilean dolphin is expected to be in the low thousands, that suitable habitat for the species is highly restricted, and that the species is facing increasing anthropogenic impacts, with some areas undergoing or planning major expansions in development, the results provided here should be considered in management plans for extant marine protected areas, and in the evaluation of current International Union for Conservation of Nature (IUCN) and national conservation categories for the species.

Effects of Climate Change and Fencing on Forage Nutrition Quality of Alpine Grasslands in the Northern Tibet.

How climate change and fencing will affect forage nutrition quality of alpine grasslands is still unknown in the Northern Tibet. Here, we reported the effects of climate change and fencing on forage nutrition quality (i.e., CP: crude protein, ADF: acid detergent fiber, NDF: neutral detergent fiber, Ash: crude ash, EE: ether extract and DTS: dissolvable total sugar) in alpine grasslands across the Northern Tibet based on a transect survey dataset from 2018. Over the whole survey transect, fencing reduced the NDF content by 5.15% and the EE content by 15.79%, but did not affect forage nutrition quality (R2 = 0.04, p = 0.389). Air temperature and precipitation explained 24% and 8% of variation in the CP content under the fencing conditions, respectively. Precipitation explained 22% of variation in the NDF content under the fencing conditions. The CP content decreased and increased exponentially with increasing air temperature under the fencing and grazing conditions, respectively. The NDF content showed logarithmic and negative relationships with precipitation under the fencing and grazing conditions (-8.45 vs. -6.68lnNDF). The response of the CP content to fencing showed negative relationships with temperature and the response of AGB to fencing, but showed a positive relationship with precipitation. The CP and DTS contents showed negative relationships with AGB under the fencing and grazing conditions. In contrast, the ADF content showed a positive relationship with AGB. The response of AGB, SR and community composition to fencing explained 11%, 56% and 35% of variation in the response of forage nutrition quality to fencing, respectively. Therefore, climate change may not always have adverse effects on forage nutrition quality, whereas fencing may not always have favorable effects on forage nutrition quality. Fencing and climate change can have an interactive effect on forage nutrition quality. Fencing can alter the temperature and precipitation sensitivities of forage nutrition quality. In colder and wetter regions, the forage nutrition quality may be more responsive to fencing. There may be a trade-off between forage nutrition quality and quantity. Compared to the change in AGB caused by fencing, the changes in species α-diversity and community composition caused by fencing can have greater effects on the response of forage nutrition quality to fencing. Local climate conditions and the trade-offs between forage nutrition quality and biomass should be considered when evaluating the effects of fencing on the restoration of degraded grassland plants.

Do you see what I see? Variation in detection, identification and enumeration of mammals during transect surveys

AbstractEffective monitoring, management and conservation of wildlife axiomatically depend on accurate data but causes of variation, including inter‐observer variation, are rarely explicitly quantified. Here, under controlled conditions, we demonstrate considerable variation in detection, identification and enumeration of (theoretically) readily identifiable African mammals at a reserve with a known species assemblage. Detection: 97.8% of sightings were missed by ≥1 observer; frequency of detection was affected by observer ID, detection distance, visibility and animal group size. Identification: just 3/14 species were identified consistently at all sightings. Enumeration: lack of consensus for 60.5% of sightings; consensus likelihood was affected by visibility and group size.

The fine‐scale movement pattern of Amur tiger (Panthera tigris altaica) responds to winter habitat permeability

AbstractThe number of Amur tigers living in protected regions is increasing, and China has achieved significant progress in this regard, especially at the Sino‐Russia border region around Hunchun where most of the Amur tigers are found in China. However, there is a need to increase the dispersal of Amur tigers further from the border as the region is not large enough to support the sustainable survival of the population. In the winter of 2012–2015 and January 2022, we tracked 38 Amur tiger snow traces and performed line transect and camera trap surveys in Hunchun to assess Amur tiger movements in response to the landscape and its permeability at fine scales. Our results showed that towns, shrubs, and forest roads are the main factors influencing Amur tiger movements. Furthermore, tiger paths were characterized by lower tortuosity in preferred habitats. This provides information for small‐scale habitat modification to increase landscape permeability and facilitate dispersal.

Soil erodibility for water and wind erosion and its relationship to vegetation and soil properties in China's drylands

Drylands with fragile socio-ecological systems are vulnerable to soil erosion. China's drylands face the dual threat of water (WAE) and wind erosion (WIE). To mitigate soil erosion in drylands, China has implemented numerous ecological restoration measures. However, whether vegetation and soil have different effects on soil erodibility for water erosion (soil erodibility, K) and wind erosion (soil erodible fraction, EF) in drylands is unclear, hindering decision makers to develop suitable ecological restoration strategies. Here, we conducted a large-scale belt transect survey to explore the spatial variation of K and EF in China's drylands, and examined the linear and nolinear effects of aridity (aridity index), vegetation (fractional vegetation cover and below-ground biomass), and soil properties (bulk density, total nitrogen, and total phosphorus) on K and EF. The results showed in China's drylands that the K ranges from 0.02 to 0.07, with high values recorded in the northern Loess Plateau and the eastern Inner Mongolia Plateau. The EF ranges from 0.26 to 0.98, and shows longitudinal zonation with higher values in the east and lower values in the west. Aridity has a negative linear effect on K and an inverse U-shaped nonlinear effect on EF. Aridity can affect K and EF by suppressing vegetation growth and disrupting soil properties. However, K and EF had different responses to some vegetation and soil variables. K and EF had opposite relationships with soil bulk density, and EF was significantly affected by fractional vegetation cover, while K was not. Overall, the effects of aridity and soil properties on soil erodibility were more pronounced than those from vegetation, whose effect on soil erodibility was limited. This study provides relevant information to support reducing soil water and wind erosion by highlighting the hotspot areas of soil erodibility, relevant for implementing vegetation restoration and soil conservation measures in drylands.

Mapping small mammal optimal habitats using satellite-derived proxy variables and species distribution models.

Small mammal species play an important role influencing vegetation primary productivity and plant species composition, seed dispersal, soil structure, and as predator and/or prey species. Species which experience population dynamics cycles can, at high population phases, heavily impact agricultural sectors and promote rodent-borne disease transmission. To better understand the drivers behind small mammal distributions and abundances, and how these differ for individual species, it is necessary to characterise landscape variables important for the life cycles of the species in question. In this study, a suite of Earth observation derived metrics quantifying landscape characteristics and dynamics, and in-situ small mammal trapline and transect survey data, are used to generate random forest species distribution models for nine small mammal species for study sites in Narati, China and Sary Mogul, Kyrgyzstan. These species distribution models identify the important landscape proxy variables driving species abundance and distributions, in turn identifying the optimal conditions for each species. The observed relationships differed between species, with the number of landscape proxy variables identified as important for each species ranging from 3 for Microtus gregalis at Sary Mogul, to 26 for Ellobius tancrei at Narati. Results indicate that grasslands were predicted to hold higher abundances of Microtus obscurus, E. tancrei and Marmota baibacina, forest areas hold higher abundances of Myodes centralis and Sorex asper, with mixed forest-grassland boundary areas and areas close to watercourses predicted to hold higher abundances of Apodemus uralensis and Sicista tianshanica. Localised variability in vegetation and wetness conditions, as well as presence of certain habitat types, are also shown to influence these small mammal species abundances. Predictive application of the Random Forest (RF) models identified spatial hot-spots of high abundance, with model validation producing R2 values between 0.670 for M. gregalis transect data at Sary Mogul to 0.939 for E. tancrei transect data at Narati. This enhances previous work whereby optimal habitat was defined simply as presence of a given land cover type, and instead defines optimal habitat via a combination of important landscape dynamic variables, moving from a human-defined to species-defined perspective of optimal habitat. The species distribution models demonstrate differing distributions and abundances of host species across the study areas, utilising the strengths of Earth observation data to improve our understanding of landscape and ecological linkages to small mammal distributions and abundances.

Partitioning spatial dynamics in abundance of marine fisheries stocks between fine- and broad-scale variation: A Bayesian approach

Fisheries stocks are often characterized by pronounced spatial patterning. This occurs at different scales, which may be driven by separate mechanisms. Regression kriging is often used to generate population estimates which may parse variation among these scales. A previous application of this and other frequentist methods to estimate the abundance of Atlantic sea scallops (Placopecten magellanicus) found that semi-parametric regression kriging performs best among model-based methods. We expanded upon these results by adapting the model structure for a Bayesian framework. This approach demonstrated the trade-off between abundance as a function of depth and broad spatial habitat features, and of fine-scale spatial aggregation. We applied our model to the 2015 belt transect survey of Atlantic sea scallops in Georges Bank and the Mid-Atlantic Bight off the eastern coast of the United States. The overall Bayesian predictions generally agreed with those of the frequentist method. However, the former favored broad spatial trends coupled with very fine-scale aggregation, while the latter favored finer trends and broad aggregation as the dominant driver of scallop abundance. Therefore, one can draw similar conclusions about abundance, yet disparate conclusions about the drivers. Careful consideration of the benefits and limitations of each approach is warranted.

Distribution and Abundance of the East Asian Finless Porpoise in the Coastal Waters of Shandong Peninsula, Yellow Sea, China

The baseline data pertaining to the population of the East Asian finless porpoise (Neophocaena asiaeorientalis sunameri) in Chinese waters are significantly deficient. Boat-based visual line transect surveys were conducted from 2018 to 2020 to evaluate the distribution and abundance of the East Asian finless porpoise in the coastal waters (depth < 30 m) of the Yellow Sea, with a specific focus on the Shandong Peninsula. A total of 50 transects covering 2705 km were conducted, encompassing an area of 23,604 km2 between 119°30′ E–123°15′ E and 35°25′ N–38° N. Throughout the surveys, a total of 117 East Asian finless porpoise groups were detected, with over 90% of these groups occurring within 15 km of the coast or adjacent islands. The estimated abundance of the East Asian finless porpoise in the study area was determined to be 3978 individuals (CV = 22.39%, 95%CI = 2561–6177), reflecting a low density of 0.169 individuals/km2 (CV = 22.39%, 95%CI = 0.109–0.262) within the coastal waters of the Yellow Sea in the Shandong Peninsula. The findings highlight the need for conservation measures to address the threats faced by this species, including bycatch, habitat degradation, and pollution. The establishment of marine protected areas and the implementation of bycatch mitigation measures are crucial for the long-term survival of the East Asian finless porpoise population in the study area. By providing valuable data on the distribution and abundance of the East Asian finless porpoise, this study contributes to our understanding of the population dynamics and conservation status of this threatened species in the Yellow Sea of the Shandong Peninsula.

Assessing protected area effectiveness in western Tanzania: Insights from repeated line transect surveys

AbstractIn many parts of East Africa, wildlife populations have declined over the past decades. Given these trends, site‐based studies are needed to assess how protected areas with differing management strategies enable the effective conservation of wildlife populations. In Tanzania, game reserves are managed for tourist hunting, while national parks are managed for non‐consumptive wildlife‐based tourism. To assess the relative performance of these management strategies, we here focus on two areas: Rukwa Game Reserve (RGR) and Katavi National Park (KNP). Based on systematically designed line distance surveys in 2004 and 2021, we compared densities and group sizes of large mammal populations (African elephant, giraffe, buffalo, zebra, topi, and hartebeest) over time. Contrary to published ecosystem‐wide declines observed in numerous species which considered earlier baselines, we did not detect significant population declines between 2004 and 2021. While these new results showing apparent stable populations do not invalidate earlier studies on wildlife declines, they could indicate a stabilisation phase after declines. This highlights the importance of considering appropriate temporal baselines and historical contexts when assessing conservation effectiveness.

Monitoring of coral-killing sponge (Terpios hoshinota) caused rapid coral tissue loss assessment through environmental parameters in the Palk Bay

Coral-killing cyanobacteria sponge T. hoshinota has been affecting the Palk Bay coral reef since 2009, causing rapid destruction to coral tissues. Monitoring studies provide essential information on the prevalence of T. hoshinota and an understanding of the environmental parameters contributing to coral tissue loss, further helping conservation policies to be made. The study conducted a benthic transect survey using the standard method in 2017 and 2020 in the Palk Bay region. Results revealed that T. hoshinota prevalence has increased by 46.68% from the 2017 survey; it was (Mean ±SE) 11.25 ± 1.01% in 2017 and 21.09 ± 1.53% in 2020. Coral mortality due to T. hoshinota impact was observed in the 2017 survey at 0.84 ± 0.06% and significantly increased (75.29%) in the 2020 survey, recorded at 3.42 ± 0.11%. The Pearson correlation plot showed that SST and PAR were strongly correlated during the survey periods, while turbidity has not been correlated with any other environmental parameter. The R-based hierarchical regression analysis revealed that environmental parameters NO3 (β=0.58; p = 0.004) and PAR (β=0.35; p = 0.02) were associated with T. hoshinota causing rapid tissue loss in the Palk Bay coral reef. The coral-killing sponge T. hoshinota and associated environmental parameters rapidly progressed over the study period in the Palk Bay coral reef, resulting in rapid tissue loss and coral mortality. Consequentially, the live coral cover in Palk Bay would decline. Hence, T. hoshinota based conservation management activities have to be made in Palk Bay.

Mesoscale habitat use by St. Lawrence estuary beluga over the annual cycle from an acoustic recording network.

The spatial-temporal distribution pattern of St. Lawrence Estuary (SLE) beluga is examined with a passive acoustic monitoring network of 13 stations from June 2018 to October 2021. A beluga calling index, correlated with beluga density, is used as a proxy for habitat use by the population at weekly, monthly, and yearly scales. The seasonal pattern along SLE upstream-downstream axis was repeated annually. In summer, beluga habitat was confined to a 150 km segment of the SLE, with higher occurrences in its ∼20 km central portion, including the head of the Laurentian Channel and Saguenay Fjord mouth. During fall, the distribution gradually shifted to the downstream portion of the SLE and into the Northwestern Gulf, leaving low to no occurrences upstream in winter, until the spring return, characterized by the highest upstream occurrences. Occurrences off Ste. Marguerite Bay, 25 km upstream in Saguenay Fjord, were essentially from June to October. This multi-year continuous habitat use pattern provides a baseline for year-round SLE beluga distribution dynamics for assessing and mitigating anthropogenic threats to this endangered population, such as shipping noise. It also provides insights for optimizing the assessments of population size from aerial line transect surveys.

Using Social Media Text Data to Analyze the Characteristics and Influencing Factors of Daily Urban Green Space Usage—A Case Study of Xiamen, China

While urban green spaces (UGSs) are important places for residents’ leisure activities, studies describing the long-term daily UGS usage of residents (including the total number of activities, the types of activities, and the touring experience) have not been conducted due to difficulties in data collection. Based on social media text data (SMTD), in this study, the total number of daily activities, the intensities of optional and social activities, and the daily touring experience in 100 UGSs in Xiamen, China, were inferred based on the ERNIE 3.0 text pre-training semantic classification model. Based on this, linear regression modeling was applied to analyze the internal environmental factors of the effects of places and external urban form factors regarding daily UGS usage. The research results revealed the following. (1) A descriptive study was conducted on the total numbers, types, and touring experience of activities using SMTD, and the results were verified by line transect surveys, management statistics, and a publicly available dataset. (2) The number of human activities in UGSs was found to be significantly influenced by historical and cultural facilities, nighttime lighting, population density, and the proportion of the floating population. (3) During the daytime, optional activities were found to be significantly influenced by the park type and historical and cultural facilities, and social activities were found to be significantly influenced by historical and cultural facilities and population density. In the evening, optional activities were found to be significantly influenced by the park type, historical and cultural facilities, nighttime lighting, and the proportion of the floating population, and social activities were found to be influenced by the proportion of the floating population. (4) Regarding the touring experience, in the daytime, the park type, green space ratio, and proportion of the floating population had significant effects on the touring experience. In the evening, the park type, historical and cultural facilities, and security factors were found to have significant effects on the touring experience. The methodology and findings of this study aid in the understanding of the differences in daytime and nighttime activities, and in the discovery of planning tools to promote human leisure activities in UGSs.

Study of Beach Litter on Remote Island, Case Study: Ainoshima Island, Japan

Ainoshima Island is a Remote Island located north of Kyushu Island which is also known as a popular tourist attraction named Cat Island. The island is inhabited by a small population but is frequented by tourists to enjoy nature and fishing. The coastline is in the form of cliffs and sandy beaches, but there is a lot of marine debris on the sandy beaches. In addition, its location allows waste from the surrounding area to be carried by currents to this island. This research examines the diversity of categories and types of macroplastic litter trapped on the sandy beach of Ainoshima Island. Survey transects were conducted in the spring of 2023 via visual observation based on a survey method developed by NOAA, in 2012. The survey results were then categorized based on a photo guide database from the OSPAR Maritime Area for Active Monitoring of Marine Debris on the Beach. Data on the types of waste found are divided into artificial polymer materials (plastic), rubber, cloth, paper/cardboard, processed/finished wood, metal, glass, and ceramics. As a result, the plastic category is the dominant category of the total type of waste trapped in sandy beach areas.