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Exposure of wildlife to anticoagulant rodenticides from sewer baiting and bait application is poorly understood. We analyzed residues of eight anticoagulant rodenticides in liver samples of 96 great cormorants, 29 common mergansers, various fish species, and coypu, in different German regions. Results show that hepatic residues of anticoagulant rodenticides were found in almost half of the investigated cormorants and mergansers due to the uptake of contaminated fish from effluent-receiving surface waters. By contrast, exposure of coypu to rodenticides via aquatic emissions was not observed. The maximum total hepatic anticoagulant rodenticide concentration measured in waterfowl specimens was 35 ng per g based on liver wet weight. Second-generation anticoagulant rodenticide active ingredients brodifacoum, difenacoum, and bromadiolone were detected almost exclusively, reflecting their estimated market share in Germany and their continuing release into the aquatic compartment. Overall, our findings reveal that second-generation anticoagulant rodenticides accumulating in wild fish are transferred to piscivorous predators via the aquatic food chain. [ABSTRACT FROM AUTHOR]

Pulsed resources resulting from animal migrations represent important, transient influxes of high resource availability into recipient communities. The ability of predators to respond and exploit these large increases in background resource availability, however, may be constrained when the timing and magnitude of the resource pulse vary across years. In coastal Newfoundland, Canada, we studied aggregative responses of multiple seabird predators to the annual inshore pulse of a key forage fish species, capelin (Mallotus villosus). Seabird aggregative responses to fish biomass were quantified from weekly hydroacoustic and seabird surveys during July–August within an annually persistent foraging area (10 km2) associated with a cluster of capelin spawning sites across 10 years (2009–2010, 2012, 2014–2020). Seabird predators included breeding members of the families Alcidae (Common Murres Uria aalge, Razorbills Alca torda, Atlantic Puffins Fratercula arctica) and Laridae (Great Black‐backed Gulls Larus marinus, American Herring Gulls L. argentatus smithsonianus) and Northern Gannets Morus bassanus, along with non‐breeding, moulting members of the Family Procellariidae (Sooty Shearwaters Ardenna griseus, Great Shearwaters A. gravis). The inshore migration of spawning capelin resulted in 5–619 times (mean ± SE, 146 ± 59 times) increase in coastal fish biomass along with a shift towards more, larger and denser fish shoals. Within years, seabird abundance did not increase with inshore fish biomass but rather peaked near the first day of spawning, suggesting that seabirds primarily respond to the seasonal resource influx rather than short‐term variation in fish biomass. Across years, the magnitude of the seabird aggregative response was lower during low‐magnitude resource pulse years, suggesting that predators are unable to perceive low‐magnitude pulses, avoid foraging under high competitor densities, and/or shift dietary reliance away from capelin under these conditions. The seabird response magnitude, however, was higher when the resource pulse was delayed relative to the long‐term average, suggesting that predators increase exploitation during years of minimal overlap between the resource pulse and energetically demanding periods (e.g. breeding, moulting). This long‐term study quantifying responses of multiple predators to a pulsed resource illustrates the ability of natural systems to tolerate natural and human‐induced disturbance events. [ABSTRACT FROM AUTHOR]

The highly efficient linear and elliptical antenna array design presented in this article is intended to synthesize far-field radiation patterns for 5G communication. The objective is to achieve the best possible radiation pattern, which includes a lower side lobe level (SLL) and a narrower half-power beam width (HPBW). A low SLL is crucial to minimize intervention in the entire side lobe region, whereas long-distance communication requires a low HPBW. The marine predator's algorithm (MPA) is used here to determine the optimal feeding currents to each array element to reduce the SLL and HPBW values. Two linear antenna array (LAA) design examples and the three elliptical antenna array (EAA) design examples are discussed in this article which are achieved using the optimal current excitations to each array element. Two well-established evolutionary optimization techniques, namely the genetic algorithm (GA) and the differential evolution (DE) technique, are also employed for comparison to demonstrate the superiority of the MPA optimization-based technique. The results achieved utilizing the MPA show the improvement of SLL contraction compared to the uniform antenna array and the methods affirmed in the recently published article. [ABSTRACT FROM AUTHOR]

Onboard generation of reentry trajectory optimization for a reusable launch vehicle (RLV) is challenging as it must meet strict requirements for real-time performance. Machine learning has brought this field fresh insights due to its great extraction of data performance and predictive accuracy. In this work, the extreme learning machine (ELM), which is often favored in real-time applications, is employed to make onboard trajectory predictions by exploiting the underlying functional relationship obtained from offline data of state-control variable pairs. To boost the generalization performance of the ELM, a regularization term is added, and the marine predator whale optimization algorithm (MPWOA) is utilized to optimize the input weights as well as hidden layer biases of the networks. Afterward, four-hidden layer feedforward neural networks (FLFNNs), a single-hidden layer hybrid MPWOA-BPNN (backpropagation neural networks), an ELM model, and three ELM-based particle swarm optimization, whale optimization algorithm and marine predators algorithm models, were developed for comparison. The results revealed that the MPWOA-ELM model outperformed the other models in the testing phase performance indices of the mean absolute error, mean absolute percentage error, root mean squared error, and determination coefficient. Meanwhile, Monte Carlo simulations showed that the model performed remarkably well in real-time, with a trajectory being generated in about 3.405 s. Specifying the current flight state of the RLV, the proposed model can directly generate guidance instructions and then achieve an onboard generation of reentry trajectory with high computational efficiency and reliability. [ABSTRACT FROM AUTHOR]

Leopard seals have traditionally been considered Antarctic predators with a Southern Ocean distribution. Historically, sightings north of the Antarctic Polar Front were considered extralimital. However, recent studies suggest a significant presence of leopard seals in subantarctic regions. Here, we assess the spatial occurrence, residency status, and temporal trends of leopard seals in Chile using historical records, stranding reports, standardized monitoring data, photo-identification (photo ID) catalogs, and sightings from four research expeditions. We also characterize glaciers where sightings are concentrated, identifying glaciological and geomorphic attributes that prolong iceberg residency time, which is linked to high leopard seal concentrations. Based on these attributes, we evaluated other potential suitable glacial habitats in Patagonia. We obtained 438 sighting records of leopard seals from 1927 to 2023. Over the last 15 years, we documented a 4-18% annual increase in stranding events reported to national authorities. Most sightings (75%) were concentrated in two hotspots: National Park San Rafael Lagoon, located in Northern Patagonia, and Parry Fjord in Tierra del Fuego. Using photo ID catalogs, we identified 19 resident leopard seals, including 16 multi-year residents observed between 2010-2023 (10 in San Rafael, 6 in Tierra del Fuego) and 3 potential residents (observed multiple months in the same year in Tierra del Fuego). San Rafael monitoring data showed no inter-annual trend, but seasonal trends were observed. We also provide evidence of breeding in Chile, with records of at least 14 pups born and at least two females giving birth in multiple years. Our habitat characterization suggests that calving flux, fjord sinuosity, and fjord width variation are crucial for prolonging iceberg residency in hotspot areas. Based on these attributes, we identified 13 additional fjords in Patagonia as "very likely" suitable for leopard seals. Our study confirms that Patagonia is part of the species' breeding distribution, shifting the paradigm that leopard seals are merely visitors north of the Antarctic Polar Front. Given the limited number of suitable glaciers in Chile and the potential impacts of climate change, our assessment highlights glacial retreat as a major threat for the ecosystem of this pagophilic marine apex predator in South America. [ABSTRACT FROM AUTHOR]

Determining the factors influencing habitat selection and hunting success in top predators is crucial for understanding how these species may respond to environmental changes. For marine top predators, such factors have been documented in pelagic foragers, with habitat use and hunting success being linked to chlorophyll-a concentrations, sea surface temperature and light conditions. In contrast, little is known about the determinants of benthic marine predators. The Australian fur seal (Arctocephalus pusillus doriferus) is a benthic-diving forager that has a breeding and foraging distribution largely restricted to Bass Strait, the shallow (max. depth 80 m) continental shelf region between the Australian mainland and Tasmania. The species forages mostly on benthic prey and represents the greatest resident marine predator biomass in south-eastern Australia. The region is also one of the world's fastest-warming marine areas and oceanographic changes are influencing shifts in prey distribution and abundance. In the present study, GPS-derived locations of benthic dives (n = 288,449) and dive behaviour metrics were used to determine seafloor habitat selection and factors influencing hunting success in 113 lactating adult females from Kanowna Island during the winters of 2006–2021. Individuals non-randomly selected foraging habitats comprised of deeper, steeper sloped, muddy-sandy areas with less gravel and highly disturbed regions (P < 0.01). Hunting success was greatest in shallower rocky reefs (< 30 m) and deep areas (> 40 m) characterised by moderate presence of gravel (25–50%) and substantial rock composition (50–75%) on the seabed. These findings suggest that habitat use and hunting success in adult female Australian fur seals could be impacted by predicted oceanographic changes, such as rising temperature, altered currents and waves which may modify seafloor characteristics and benthic communities. [ABSTRACT FROM AUTHOR]

Global marine biodiversity declines require bold and ambitious plans to safeguard ecosystem services. Overfishing, habitat loss and projected climate impacts have yielded deleterious effects on marine predators, in particular, driving increasing threat of extinction for many shark species with implications for ecosystem health. Identifying and protecting critical habitat areas for sharks is fundamental to their protection, and may allow for species recovery. Here we use baited remote underwater video stations to investigate spatial and temporal patterns of habitat use by sharks in a Special Area of Conservation (SAC) that is centrally important to the regional blue economy in the UK, the Cardigan Bay SAC. Our results show heterogeneous spatial habitat use and temporal trends in habitat sharing between smallspotted catsharks Scyliorhinus canicula and nursehounds S. stellaris. Nearshore reef habitats are substantially more important than non-reef habitats for both species. The relative abundance of each species, however, is roughly inversely seasonally proportional, with S. canicula and S. stellaris relative abundance highest in March and September, respectively. Temporal niche partitioning may be an important mechanism in marine systems, but has not been widely investigated in sympatric shark communities. These findings are directly relevant for ongoing development of the Welsh Marine Evidence Strategy (2019-2025) and the Welsh National Marine Plan, particularly to inform spatial planning to strengthen the role of SAC management design in protecting important shark areas. [ABSTRACT FROM AUTHOR]

White sharks (Carcharodon carcharias) are among the most widespread, charismatic, and studied predators in the ocean. However, their conservation status is concerning in many ocean sectors, most notably the Mediterranean Sea, which hosts one of the least known and most endangered populations globally. Though they were historically abundant and widely distributed in the region, Mediterranean white sharks have declined to dangerously low abundance levels, impacted by centuries of coastal and, more recently, industrial fishing. The IUCN lists this species as Critically Endangered in the region, but information about its current abundance and ecology is scarce, hindering effective management and conservation. Here, we describe our initial effort to find and track the remaining Mediterranean white sharks and report what we have learned from these activities. In 2021-2023, we conducted three pilot expeditions in the Sicilian Channel, covering four major sites, collecting 159 eDNA samples, and carrying out 359 hrs of pelagic mid-water baited video surveys, 43 hours of deep-water benthic baited video surveys, and 111 hrs of fishing. Baited video surveys detected 42 species of bony fishes, elasmobranchs, marine mammals, and turtles. We detected white sharks at four sites from eDNA samples. Though we did not observe white sharks directly, these activities supported the identification of one of the last strongholds of this population in the region and started a multi-institutional white shark conservation program in the Mediterranean Sea, aiming to track the last white sharks in the region, estimate their abundance and extinction risk, characterize the species' ecology and inform management and conservation. [ABSTRACT FROM AUTHOR]

Animal movement and population connectivity are key areas of uncertainty in efforts to understand and predict the spread of infectious disease. The emergence of highly pathogenic avian influenza (HPAI) in South America poses a significant threat to globally significant populations of colonial breeding marine predators in the South Atlantic. Yet, there is a poor understanding of which species or migratory pathways may facilitate disease spread. Compiling one of the largest available animal tracking datasets in the South Atlantic, we examine connectivity and inter‐population mixing for colonial breeding marine predators tagged at the Falkland Islands. We reveal extensive connectivity for three regionally dominant and gregarious species over the Patagonian Shelf. Black‐browed albatrosses (BBA), South American fur seals (SAFS) and Magellanic penguins (MAG) used coastal waters along the Atlantic coast of South America (Argentina and Uruguay). These behaviours were recorded at or in close proximity to breeding colonies and haul‐out areas with dense aggregations of marine predators. Transit times to and from the Falkland Islands to the continental coast ranged from 0.2–70 days, with 84% of animals making this transit within 4 days ‐ a conservative estimate for HPAI infectious period. Our findings demonstrate BBA, SAFS and MAG connectivity between the Falkland Islands and mainland South America over an expansive spatial network and numerous pathways, which has implications for infectious disease persistence, transmission and spread. This information is vital in supporting HPAI disease surveillance, risk assessment and marine management efforts across the region. [ABSTRACT FROM AUTHOR]

Variations in the size and shape of the eye have been observed in many species of fish. As eye size is positively related to visual acuity, larger eyes should favour foraging and detection of predators.However, few studies have examined the variation in eye morphology in relation to the complexity of lake conditions, including environmental perturbation and spatial variation in predation and competition. Such tests are especially important as the degrading of the visual climate is expected due to climate change, where browning, turbidity and variations in structural complexity should set different demands for visual acuity of foraging fish under predation risk.In this study, we tested the variation of the eye size among 667 individuals of an aquatic predator perch, Perca fluviatilis, from littoral and pelagic habitats of 14 lakes. We used Secchi depth to assess the effects of the visual climate of our lake systems, as fish foraging is highly related to visual conditions, and studied eye size variation in relation to the contribution of the pelagic resources to an individual's diet and the risk of predation.Secchi depth, the pelagic contribution to the diet and the percentage of piscivores had significant effects on eye size.These variable outcomes suggest that the lake environment in terms of visual climate, predation landscape and diet are major factors of eye size variation in this generalist predator. As many fish species trade off foraging against predation risk, future studies will show whether the complexity of intra‐ and interspecific interactions contribute to the variation in eye size in freshwater fish. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Identifying the species of shark responsible for a bite on humans is both complex and important for understanding and managing the shark risk. Depending on the species, tiny teeth may or may not be present in the symphyseal space at the junction of the upper and lower half‐jaws. In the case of bites, these tiny teeth (if present) often leave specific marks that may enable species to be quickly and reliably distinguished. We first present the anatomo‐morphological characteristics of the jaws of the three most traumatogenic species for humans which are the white, tiger, and bull sharks. The white shark has no symphyseal teeth, while the tiger and bull sharks do. On the basis of three confirmed real case studies involving those species, we then show that for the white shark, the wide symphyseal space between the first two teeth of each jaw usually leads to wounds including the presence of (quite) large flesh flaps, without any tooth imprint. Conversely, wounds following bites made by the tiger and bull sharks will generally leave characteristic small imprints of symphyseal teeth, especially in the case of incomplete or superficial bites. Although not systematic, this diagnostic approach provides fast, reliable, and clean results. The discrimination between two species with symphyseal teeth can then be made on the basis of complementary anatomic information such as jaw curvature and details linked to the anatomy of the teeth themselves, as well as the ecological context. [ABSTRACT FROM AUTHOR]

By changing the spatiotemporal availability of resources, tourism-related feeding can have potentially detrimental impacts on the movement ecology of animals, thus possibly undermining its own conservation benefits. A lack of baseline data on natural behaviour and the noninclusion of observation data that adequately incorporates the previous experience of animals with tourism-related feeding have generated contradictory results, causing the true impacts of feeding to remain obscure. Further, the relationship between the energy consumption of fed animals and their space use remains unexplored. Here, we coupled passive acoustic telemetry with previously published observation data at a tourism-related feeding site to investigate how direct feeding affects space use and residency patterns of great hammerhead sharks, Sphyrna mokarran , in Bimini, The Bahamas, at various timescales (ranging from days to 8 years). We first constructed movement models for 28 known fed and naïve sharks (i.e. those that were present at the study site but never attended feeding events) to quantify differences in space use and spatial overlap between those groups. We then compared bait uptake of fed sharks with their space use. Fed sharks showed a marked reduction in space use in response to feeding events and an amplification of these impacts over 5 consecutive years. In contrast, naïve shark space use remained unchanged over the same period. The seasonal residency of fed and naïve great hammerheads remained stable across 8 years, with the sharks leaving the study site during the summer of each year. Our study underscores how the intensification of tourism-related direct feeding progressively alters the space use of apex predators across short and long timescales, with enduring effects on fed animals. Our study further highlights the utility of a naïve animal group for assessing feeding impacts in the absence of baseline data. • Tourism-related feeding reduced short-term local space use of fed sharks. • Long-term amplification of these impacts occurred across 5 years in fed sharks. • Reduction in local space use of fed sharks was independent of bait consumption. • Local space use of naïve sharks was not impacted by tourism-related feeding. • Feeding site residency indices of fed and naïve sharks were stable across 8 years. [ABSTRACT FROM AUTHOR]

Orcas (Orcinus orca) are the top marine predators of the ocean, targeting multiple taxa including teleost fishes, elasmobranchs, seabirds, sea turtles, pinnipeds, odontocetes and other large cetaceans. According to their foraging strategies, genetics, acoustics, and morphology, orcas differentiate into ecotypes. Despite their cosmopolitan distribution, orcas are poorly studied in areas such as the Humboldt Current System of the Southeast Pacific coast. Since 2018 in northern Chile, presumed Type A orcas have been observed foraging on South American sea lions (Otaria byronia), benefiting from the presence of fishing vessels facilitating their hunt. These orcas were observed also pursuing large mixed groups of dusky (Lagenorhynchus obscurus) and long-beaked common dolphins (Delphinus capensis); however, predation on dusky dolphins was not documented. Here, we provide 28 additional sightings of orcas in two upwelling hotspots along northern Chile (15 around the Chañaral, Choros, and Damas Islandsin the Humboldt Penguin National Reserve from 2010-2023 and 13 in the Mejillones Peninsula from 2022-2023) and the first records of orcas effective hunting on dusky dolphins in this area. We present three new observations of orca tooth rake marks on fin whales (Balaenoptera physalus) dorsal fins in northern Chile. Furthermore, we observed the same orcas on two occasions foraging on dusky dolphins and sharing dolphin meat among group members. Overall, these observations suggest that orcas in northern Chile forage on marine mammals, especially on dusky dolphins, and the number of such predation events seems to be increasing near the coast. [ABSTRACT FROM AUTHOR]

Aim: Competition is often proposed to drive niche segregation along multiple axes in speciose communities. Understanding spatial partitioning of foraging areas is particularly important in species that are constrained to a central place. We present a natural experiment examining variation in habitat preferences of congeneric Southern Ocean predators in sympatry and allopatry. Our aim was to ascertain consistency of habitat preferences within species, and to test whether preferences changed in the presence of the congener. Location: Southern Hemisphere. Taxon: Multiple colonies of both species within the genus Phoebetria (sooty albatrosses). Methods: The two Phoebetria albatrosses breed on islands located from ~37–55°S – sooty albatrosses (P. fusca) in the north and light‐mantled albatrosses (P. palpebrata) in the south – with sympatric overlap at locations ~46–49°S. We analysed GPS and PTT tracks from 87 individuals and multiple remotely sensed environmental variables using GAMs, to determine and compare the key factors influencing habitat preference for each species at each breeding colony. Results: While foraging habitat preferences are consistent in light‐mantled albatrosses, there is divergence of preferences in sooty albatrosses depending on whether they are in sympatry with their congener or in allopatry. Main Conclusions: This study represents the most comprehensive work on this genus to date and highlights how habitat preferences and behavioural plasticity may influence species distributions under different competitive conditions. [ABSTRACT FROM AUTHOR]

Southeast Greenland (SEG) is characterized by complex morphology and environmental processes that create dynamic habitats for top marine predators. Active glaciers producing solid-ice discharge, freshwater flux, offshore sea ice transport, and seasonal landfast-ice formation all contribute to a variable, transient environment within SEG fjord systems. Here, we investigate a selection of physical processes in SEG to provide a regional characterization that reveals physical system processes and supports biological research. SEG fjords exhibit high fjord-to-fjord variability regarding bathymetry, size, shape, and glacial setting, influencing some processes more than others. For example, during fall, the timing of offshore sea ice formation near SEG fjords progresses temporally when moving southward across latitudes, while the timing of offshore sea ice disappearance is less dependent on latitude. The rates of annual freshwater flux into fjords, however, are highly variable across SEG, with annual average input values ranging from ∼ 1 × 108 to ∼ 1.25 × 1010 m3 (∼ 0.1–12.5 Gt) for individual fjords. Similarly, the rates of solid-ice discharge in SEG fjords vary widely – partly due to the irregular distribution of active glaciers across the study area (60–70° N). Landfast sea ice, assessed for eight focus fjords, is seasonal and has a spatial distribution highly dependent on individual fjord topography. Conversely, glacial ice is deposited into fjord systems year-round, with the spatial distribution of glacier-derived ice depending on the location of glacier termini. As climate change continues to affect SEG, the evolution of these metrics will vary individually in their response, and next steps should include moving from characterization to system projection. Due to the projected regional ice sheet persistence that will continue to feed glacial ice into fjords, it is possible that SEG could remain a long-term refugium for polar bears and other ice-dependent species on a centennial to millennial scale, demonstrating a need for continued research into the SEG physical environment. [ABSTRACT FROM AUTHOR]

We are already experiencing the rapid pace of environmental perturbation in the Anthropocene, necessitating the development of new tools and techniques for measuring changes in ecosystem dynamics. Sentinel species, from birds to invertebrates, have been used to provide insights into ecosystem function, as leading indicators of risk to human health and as harbingers of future change, with implications for ecosystem structure and function. Here, we offer an update to previous research identifying marine top predators as indicators of ecosystem shifts and examine terrestrial sentinels and the latest research on sentinels of pollution and human health. Using ecosystem sentinels enables rapid response and adaptation to ecosystem variability and environmental change in part because they may be easier to observe and in part because they may serve as leading indicators of ecosystem disruption. While there may not be a given taxon that is best suited as sentinels, we highlight how to select the most effective sentinels, including examples of when sentinel species have been incorporated into management. Choosing a suite of appropriate sentinels both will give insight into ecosystem processes and can help manage changing ecosystems into the future. [ABSTRACT FROM AUTHOR]

This article provides a study on the foraging behavior and habitat selection of harbor seals in the archipelago of Saint-Pierre-and-Miquelon in the Northwest Atlantic. The study used telemetry data from ten harbor seals to analyze their diving behavior, spatio-temporal trends at sea, and habitat selection. The results indicate that harbor seals primarily feed on benthic prey but can occasionally forage on pelagic prey. They exhibit nocturnal foraging behavior, with most foraging dives occurring at night. The study also found that harbor seals spend a significant amount of time at sea and tend to select habitats within 100 km of their haul-out sites, with a preference for shallow waters. This information is valuable for wildlife managers in understanding the foraging areas and rhythms of harbor seals in this region. [Extracted from the article]

The capacity for natural coral reef recovery and the effectiveness of active restoration efforts are often contingent upon uncertain and understudied background variables, such as chronic predation for example. In the Maldives, small coral colonies (< 10 cm), primarily from the genera Pocillopora and Acropora (often found recolonising degraded reefs) are frequently predated on by the spiny cushion sea-star (Culcita schmideliana). Incidentally, these same corals (especially Acroporids) are often prioritised in active reef restoration practices. However, the level of risk these corallivores pose on restoration success has not yet been assessed. Here, we aimed to initially document the population densities of C. schmideliana on a degraded reef system in the Maldives (Kunfunadhoo, Baa Atoll). We then assessed their associated predatory effects on coral recruits and transplants, and explored the benefits of C. schmideliana removal on the survival of these corals. Population densities ranged between 1.2 and 3.3 individuals per 100 m2, which resulted in high predation rates on coral recruits (4 – 20%) and transplants (11 – 43%). Culcita schmideliana predation accounted for the majority of the documented mortality (85%). Where C. schmideliana were removed, a significant increase in survival for recruits (9% higher) and transplants (24% higher) was shown. Further observations linked a cessation of C. schmideliana removal to a significant rise in predation instances for previously protected corals (up to 52%). Our study therefore highlights the severe impacts of C. schmideliana predation and shows Culcita spp. population management as a viable passive solution for effective reef restoration. [ABSTRACT FROM AUTHOR]

Harmful Algal Blooms (HABs) can produce phycotoxins that accumulate in shellfish and subsequently poison aquatic predators and human consumers, potentially causing significant economic impacts to the shellfish aquaculture industry. HAB events are challenging to foresee as they are driven by complex inter‐annual and seasonal changes in physical, chemical and biological factors. Accounting for these environmental drivers and their interactions in statistical models allows for the development of HAB early warning systems. Typically, these have a forecasting horizon of 1–2 weeks, allowing shellfish businesses and regulators to increase monitoring intensity and take evasive action, including harvesting suspensions to protect consumer health. However, there is critical need for longer‐term predictions of risk, to enable more proactive mitigation, business planning, harvest scheduling and supply chain management. We present a statistical framework for providing seasonal‐scale early warnings of the occurrence and impacts of Dinophysis spp. HABs on shellfish aquaculture in Scotland, UK. We use penalized smooth functions of winter‐spring daily sea surface temperature to predict the severity and impact of ensuing summer blooms, including the percentage of toxicity measurements exceeding the harvesting closure threshold, as well as the anticipated start, end, and overall duration of closures. We illustrate the application of this framework to two Scottish aquaculture regions: One with a high spatial concentration of harvesting sites (Shetland) and one with more dispersed sites (West Scotland and the Hebrides). Through a comprehensive yearly prediction experiment, we demonstrate considerable skill in predicting the impact of unseen HAB seasons at a regional level. Key Points: We present a new statistical approach for seasonal predictions of toxic Dinophysis species blooms in two regions of ScotlandResults indicate a link between low winter‐spring sea surface temperatures and high summer toxin concentrations in shellfish samplesWe demonstrate improved early warnings of harmful summer blooms using the first 120 days of sea surface temperature measurements each year [ABSTRACT FROM AUTHOR]

Nowadays, liver cancers are well-known cancers attacking the human body. The larger segment of liver carcinomas is highly affected by alcohol-associated hepatitis as well as cirrhosis circumstances. In order to increase the survival rate of humans, premature and early diagnosis of liver cancer is very vital. Currently, discriminating the tumor and liver segments from medical imaging with the help of entirely automated computer-aided software is a highly difficult task, because the liver tumor may differ from one human being to another human being. Thus, this paper endeavors to present a new liver tumor segmentation and classification approach by incorporating an optimization-enabled deep learning model. Here, the adopted model comprises four stages, pre-processing, liver segmentation, liver tumor detection, and classification. To begin with, the collected images are given to the pre-processing stage using the African vulture's optimization-based adaptive histogram equalization (AVOAHE). The integration of the African vulture's optimization (AVO) concept in adaptive histogram equalization is named AVOAHE. After the image pre-processing phase, the liver region is segmented by utilizing kernel-based fuzzy C-means clustering. Then, the detection of liver tumor is performed using the Swin-Unet. Finally, tumor detection is done by utilizing the deep convolutional neural network (Deep CNN). Moreover, a hybrid optimization approach, called double exponential smoothing (DES)-marine predator algorithm (MPA), is developed by combining DES and MPA, which is used to train Deep CNN and serves as an enhancement. Finally, the experimental analysis has shown that the adopted technique has achieved better results in terms of accuracy, specificity, sensitivity, and precision with values of 0.957, 0.969, 0.941 and 0.915, respectively. [ABSTRACT FROM AUTHOR]

Background: In ecosystems influenced by strong seasonal variation in insolation, the fitness of diverse taxa depends on seasonal movements to track resources along latitudinal or elevational gradients. Deep pelagic ecosystems, where sunlight is extremely limited, represent Earth's largest habitable space and yet ecosystem phenology and effective animal movement strategies in these systems are little understood. Sperm whales (Physeter macrocephalus) provide a valuable acoustic window into this world: the echolocation clicks they produce while foraging in the deep sea are the loudest known biological sounds on Earth and convey detailed information about their behavior. Methods: We analyze seven years of continuous passive acoustic observations from the Central California Current System, using automated methods to identify both presence and demographic information from sperm whale echolocation clicks. By integrating empirical results with individual-level movement simulations, we test hypotheses about the movement strategies underlying sperm whales' long-distance movements in the Northeast Pacific. Results: We detect foraging sperm whales of all demographic groups year-round in the Central California Current System, but also identify significant seasonality in frequency of presence. Among several previously hypothesized movement strategies for this population, empirical acoustic observations most closely match simulated results from a population undertaking a "seasonal resource-tracking migration", in which individuals move to track moderate seasonal-latitudinal variation in resource availability. Discussion: Our findings provide evidence for seasonal movements in this cryptic top predator of the deep sea. We posit that these seasonal movements are likely driven by tracking of deep-sea resources, based on several lines of evidence: (1) seasonal-latitudinal patterns in foraging sperm whale detection across the Northeast Pacific; (2) lack of demographic variation in seasonality of presence; and (3) the match between simulations of seasonal resource-tracking migration and empirical results. We show that sperm whales likely track oceanographic seasonality in a manner similar to many surface ocean predators, but with dampened seasonal-latitudinal movement patterns. These findings shed light on the drivers of sperm whales' long-distance movements and the shrouded phenology of the deep-sea ecosystems in which they forage. [ABSTRACT FROM AUTHOR]

The ethical considerations and scepticism over the ecological benefits have fuelled debate about the rehabilitation of wildlife. Although there is evidence that many rehabilitated species are able to survive after rehabilitation, there is a paucity of research on the behaviour of rehabilitated pinnipeds, including grey seals (Halichoerus grypus). In this study, 14 rehabilitated grey seal juveniles were equipped with biotelemetry devices in order to conduct remote post-release monitoring and to investigate ontogeny of their movements in the Baltic Sea. The study revealed that their movements were similar to wild, non-rehabilitated grey seal pups when leaving their natal site: at first, they exhibited highly exploratory behaviour with largely transient movements, then switched into a resident movement pattern, while maximising foraging and minimising travelling time. Neither sex nor year of release, which varied in terms of rehabilitation time and body mass, had a significant effect on the ontogeny of these movements. Movements were significantly influenced by the time after release, suggesting that rehabilitated juveniles have gained experience and developed their movements over time in order to survive in the wild. [ABSTRACT FROM AUTHOR]

The Mesozoic Marine Revolution restructured the world's ocean biodiversity into the complex marine ecosystems of today. This revolution began during the Triassic but the origin of this complexity is poorly understood due to a lack of detailed ecosystem reconstructions throughout time. We present the first site-specific ecological network for a marine Mesozoic fauna based on the Early Cretaceous Paja Formation biota of Colombia that preserves numerous, large-bodied, predatory marine reptiles. The trophic food-web was quantitatively reconstructed based on inferred trophic interactions of marine producers, consumers, and large apex predators. Compared to well-studied Caribbean reef ecosystem networks, the Paja biota network is missing a great proportion of benthic invertebrates and fishes, despite its rich higher trophic levels. We hypothesize that the ammonites from the Paja biota either mirrored the diversity represented by some fishes today or established a novel trophic unit with no living analogue. Recalibrating the Paja biota network to trophic analogues in the Caribbean, such as sea turtles, estimates that the largest Paja marine reptile hyper-apex predators occupied trophic levels a full tier higher than any extant marine apex predator. The Paja biota network is a starting point to tracing the evolution of marine ecosystems across the Mesozoic Marine Revolution. [ABSTRACT FROM AUTHOR]

Simple Summary: Organic insecticides against Aedes aegypti L. mosquitoes are regarded as one of the most important tools for containing arboviruses transmitted by this species, such as dengue, Zika, and chikungunya in tropical countries including Thailand, considering the development of mosquito resistance to synthetic chemical larvicides. The most critical way to contain outbreaks is to control the vector that transmits pathogens. Monoterpenes are new, effective, and eco-friendly alternatives. This study investigated the larvicidal and pupicidal activities of two monoterpenes—geranial and trans-cinnamaldehyde—and their combinations. The efficacies of each formulation were compared against each other and temephos. Binary mixtures were significantly more effective than single formulations or temephos. They are safe for the non-target aquatic predator, guppies (Poecilia reticulata). These combinations make excellent insecticides for both larvae and pupae mosquito vector control, and the results open up the opportunity for both compounds to be developed into eco-friendly products. Monoterpenes are effective and eco-friendly alternatives to conventional chemical larvicides. We tested single and binary mixtures of monoterpenes—geranial and trans-cinnamaldehyde—for their larvicidal and pupicidal activities against Aedes aegypti L. and for non-target toxicity on guppies (Poecilia reticulata Peters), using 1% (w/w) temephos as a reference. Geranial and trans-cinnamaldehyde at 250 ppm showed stronger larvicidal and pupicidal activities with a 100% mortality rate and an LT50 ranging from 0.3 to 0.6 h. All combinations were strongly synergistic against larvae and pupae compared to single formulations, with an increased mortality value (IMV) of 6% to 93%. The combination of geranial + trans-cinnamaldehyde (1:1) at 200 ppm showed the highest impact, with an IMV of 93%. The strongest larvicidal and pupicidal activities, a 100% mortality rate, and an LT50 of 0.2 h were achieved by geranial + trans-cinnamaldehyde (1:1) 500 ppm. They were thirty times more effective than a 1% temephos solution (LT50 ranging from 6.7 to 96 h) and caused obviously shriveled cuticles and a swollen respiratory system. All single and binary mixtures were not toxic to the guppies. Thus, the combination of geranial + trans-cinnamaldehyde has great potential as a safe insecticide for controlling mosquito larvae and pupae. [ABSTRACT FROM AUTHOR]

Populations of marine top predators have been sharply declining during the past decades, and one‐third of chondrichthyans are currently threatened with extinction. Sustainable management measures and conservation plans of large pelagic sharks require knowledge on population genetic differentiation and demographic connectivity. Here, we present the case of the Mediterranean blue shark (Prionace glauca, L. 1758), commonly found as bycatch in longline fisheries and classified by the IUCN as critically endangered. The management of this species suffers from a scarcity of data about population structure and connectivity within the Mediterranean Sea and between this basin and the adjacent Northeast Atlantic. Here, we assessed the genetic diversity and spatial structure of blue shark from different areas of the Mediterranean Sea and the Northeast Atlantic through genome scan analyses. Pairwise genetic differentiation estimates (FST) on 203 specimens genotyped at 14,713 ddRAD‐derived SNPs revealed subtle, yet significant, genetic differences within the Mediterranean sampling locations, and between the Mediterranean Sea and the Northeast Atlantic Ocean. Genetic differentiation suggests some degree of demographic independence between the Western and Eastern Mediterranean blue shark populations. Furthermore, results show limited genetic connectivity between the Mediterranean and the Atlantic basins, supporting the hypothesis of two distinct populations of blue shark separated by the Strait of Gibraltar. Although reproductive interactions may be limited, the faint genetic signal of differentiation suggests a recent common history between these units. Therefore, Mediterranean blue sharks may function akin to a metapopulation relying upon local demographic processes and connectivity dynamics, whereby the limited contemporary gene flow replenishment from the Atlantic may interplay with currently poorly regulated commercial catches and large‐scale ecosystem changes. Altogether, these results emphasise the need for revising management delineations applied to these critically endangered sharks. [ABSTRACT FROM AUTHOR]

This study investigates the mosquitocidal potential of crude petroleum ether extract fractions derived from Gloriosa superba against the dengue mosquito vector Aedes aegypti. Chemical profiling through gas chromatography identified four major metabolites, with nonadecane showing the highest peak area percentage (70.34%). A lethal dosage of fraction IV of G. superba (Gs‐F4), at a maximum concentration of 5.0 ppm, exhibited high mortality rates in second (78%), third (71%) and fourth (51%) instars of Ae. aegypti. A sublethal dosage of Gs‐F4 (3.0 ppm) significantly altered the larval midgut enzymes of cytochrome P450, esterases and glutathione S‐transferases. The repellent activity of Gs‐F4 was dosage dependent, with repellency percentages decreasing from 96% to 50% as the exposure time increased from 15 to 210 mins. The impact of Gs‐F4 on aquatic mosquito predators was marginally toxic (<50%) compared with the commercial compound temephos (1.0 ppm), which exhibited a higher toxicity (>50%). In silico toxicity screening using the BeeToxAI server indicated that three of the four compounds in Gs‐F4 were safe or non‐toxic to honeybees, except for α‐gurjunene (6.29 μg/bee). Although G. superba demonstrates effective larvicidal and repellent activity against Ae. aegypti, the non‐target toxicity against mosquito predators necessitates further toxicological screening on beneficial species under field conditions. [ABSTRACT FROM AUTHOR]

This article discusses the first recorded case of a stranded Southern Right Whale calf on Ecuador's north coast. The cause of the stranding is unknown, but it is speculated that the calf may have become separated from its mother. The text explores various factors that can contribute to whale strandings, including illness, predation, exposure to toxins, tidal changes, human activities, and climate change. Efforts are being made to rescue stranded whales and protect their populations through monitoring, regulations, and raising awareness. The document is a compilation of scientific articles and reports on southern right whales and other marine mammals, covering topics such as habitat suitability, migration patterns, genetic diversity, and anthropogenic threats. It provides valuable information for library patrons conducting research on southern right whales in the Eastern South Pacific. Additionally, a document published by the International Whaling Commission Scientific Committee provides an update on the movements and behavior of southern right whales in the southwest Atlantic, contributing to their understanding and conservation. [Extracted from the article]

In the deployment of Wireless Sensor Networks (WSNs), fault tolerance and energy consumption are the two crucial challenges. For this, clustering is the most effective energy-saving techniques for extending throughput and enhancing fault tolerance. The most energy saving method for extending network lifespan is clustering method. Therefore, Cluster based Hybrid Flamingo Hazelnut Tree with Improved Marine Predators for Energy Efficient Fault Tolerant Routing in WSN (CHFHIM-EEFR) is proposed for Main Cluster Head (MainCH)election and optimum routing in the network. Initially Hybrid Flamingo Hazelnut tree search algorithm is utilized to elect the MainCH on the basis offitness function. Based on the selected MainCH, Back Up Node (BCH) is selected for improving the fault tolerant. A harmful node enters after the BCH-based MainCH selection; therefore, an Improved Marine Predators Algorithm (Im-MPA) is utilized for choosing the most efficient route out of the multiple paths. Finally, the secure data communication is done in the optimum trust path. The developed approach is executed in Network Simulator and validated with the existing protocols. The simulations outcomes show that the CHFHIM-EEFRmethod attains 2.2mslowerdelay, 99.95% higher PDR99% high throughput, 20.3 ms low time complexity and 99.98 Mbps high network life time. [ABSTRACT FROM AUTHOR]

At first, the Kannada character images are collected via benchmark datasets. After image collection, it is undergone the feature extraction process. Here, the extraction techniques are employed to acquire geometric features, texture features, and morphological features. Further, it is fused together with an optimal selection of features with optimal weights, thus it is provided as weighted fused attributes. Here, the optimisation of weight is done by the developed Fish-based Position of Marine Predators and Forest Optimisation (FP-MPFO). At last, the features which are weighted are given to a Hybrid Deep Learning Network (HDLNet), where the two models like Dense Long-Short Memory (DLSTM) and Attention-Based Deep Temporal Convolution Network (ADTCN) are incorporated with each other. To acquire the optimal value, several parameters are optimally tuned by developed FP-MPFO. Hence, the key outcomes illustrate that it has the potential to recognise the Kannada characters effectively. [ABSTRACT FROM AUTHOR]

Biodiversity is critical for maintaining ecosystem function but is threatened by increasing anthropogenic pressures. In the Southern Ocean, a highly biologically productive region containing many endemic species, proactive management is urgently needed to mitigate increasing pressures from fishing, climate change, and tourism. Site‐based conservation is one important tool for managing the negative impacts of human activities on ecosystems. The Key Biodiversity Area (KBA) Standard is a standardized framework used to define sites vital for the persistence of global biodiversity based on criteria and quantitative thresholds. We used tracking data from 14 species of Antarctic and subantarctic seabirds and pinnipeds from the publicly available Retrospective Analysis of Antarctic Tracking Data (RAATD) data set to define KBAs for a diverse suite of marine predators. We used track2kba, an R package that supports identification of KBAs from telemetry data through identification of highly used habitat areas and estimates of local abundance within sites. We compared abundance estimates at each site with thresholds for KBA criteria A1, B1, and D1 (related to globally threatened species, individual geographically restricted species, and demographic aggregations, respectively). We identified 30 potential KBAs for 13 species distributed throughout the Southern Ocean that were vital for each individual species, population, and life‐history stage for which they were determined. These areas were identified as highly used by these populations based on observational data and complement the ongoing habitat modeling and bioregionalization work that has been used to prioritize conservation areas in this region. Although further work is needed to identify potential KBAs based on additional current and future data sets, we highlight the benefits of utilizing KBAs as part of a holistic approach to marine conservation, given their significant value as a global conservation tool. [ABSTRACT FROM AUTHOR]

To increase the accuracy of indoor visible light positioning, a novel indoor visible light localization technique based on the marine predator algorithm-optimized least squares support vector machine (MPA-LSSVM) is suggested. The light signals of each reference point are recorded in the first place and a fingerprint database is created. Introduced thereafter is the marine predator algorithm, which, through iterative optimization of the hyperparameters of the least squares support vector machine, aims to establish an optimal localization model using finely-tuned hyperparameters. This culminated in the development of a positioning model, successfully attaining the objective of enhancing accuracy in positioning while minimizing time expenditure. In an indoor-positioning scene (size: 1 m × 1 m × 1 m), the average positioning error of the proposed positioning method is 0.041 m, and the proportion of test points with positioning errors less than 0.1 m is 96.7%. [ABSTRACT FROM AUTHOR]

Marine monitoring efforts are increasingly supported by opportunistic shipboard surveys. However, opportunistic survey methods often require adaptation to suit the vessel and the operations being conducted onboard. Whilst best-practice techniques for surveying marine wildlife on vessels of opportunity are yet to be established, testing and development of alternative methods can provide means for capturing ecological information in otherwise under-surveyed areas. Explicitly, survey methods can be improved while baseline ecological data for new regions are gathered simultaneously. Herein, we tested different survey approaches on a vessel of opportunity in a remote offshore area where little is known about the community composition of top-order marine vertebrate predators: western and south-western Tasmania, Australia. We found that continuous surveys provide greater species counts than structured "snapshot" surveys over the course of a voyage, but that structured surveys can be more practical when managing factors such as observer fatigue. Moreover, we provide a baseline dataset on the marine vertebrate community encountered in western and south-western Tasmania. This information will be critically important for industry and conservation management objectives, and is key to our understanding of the offshore ecosystem around Tasmania. [ABSTRACT FROM AUTHOR]

Humans and large aquatic predators compete for fish and negative interactions are widely reported as 'human–wildlife conflicts'. When aquatic predators are perceived to damage fisheries or fishing equipment, lethal control can occur. The perceptions and reality of damage are infrequently compared, but this relationship is key to determining how negative outcomes can be mitigated. We examine coexistence between people and six large aquatic piscivores (two caiman, two dolphins, two otters) in Amazonian Peru. We determine the extent of damage to fishing equipment caused by each species and compare this to the amount of damage perceived by fishers. Giant otter populations have recently recovered in some areas, so we expected different perceptions relating to experiences with otters. We trained fishers to complete fishing registers (n = 278, 1173 h of fishing) to record damage to nets by wildlife. We interviewed 302 people from three sites to determine perceptions of damage by predators, and attitudes towards giant otters. Rates of damage to nets reflected the presence and populations of different aquatic predators at each site, but when present, dolphins and caimans damaged nets more than otters, which rarely damaged nets. People living where giant otters had recently recovered perceived higher relative levels of damage to nets by them and had more negative attitudes about them, compared to people from areas where giant otters had been present for longer, aquatic predators were more abundant, and community resource management was longer‐established. Better knowledge and more experience with a species may lead to more accurate perceptions of damage and increased tolerance. Where humans and animals compete for natural resources, conflict mitigation rarely includes better resource management. If tolerance of predators is greater where predators are common, and resources have not been overexploited, resource management may yield greater gains for stakeholders than other commonly prescribed forms of mitigation. [ABSTRACT FROM AUTHOR]

The importance of scale when investigating ecological patterns and processes is recognised across many species. In marine ecosystems, the processes that drive species distribution have a hierarchical structure over multiple nested spatial and temporal scales. Hence, multi‐scale approaches should be considered when developing accurate distribution models to identify key habitats, particularly for populations of conservation concern. Here, we propose a modelling procedure to identify the best spatial and temporal scale for each modelled and remotely sensed oceanographic variable to model harbour porpoise (Phocoena phocoena) distribution within the Irish Exclusive Economic Zone. Harbour porpoise sightings were recorded during dedicated line‐transect aerial surveys conducted in the summers of 2016, 2021 and 2022. Binary generalised additive models were used to assess the relationships between porpoise presence and oceanographic variables at different spatial (5–40 km) and temporal (daily, monthly and across survey period) scales. Selected variables included sea surface temperature, thermal fronts, chlorophyll‐a, sea surface height, mixed layer depth and salinity. A total of 30,514 km was covered on‐effort with 216 harbour porpoise sightings recorded. Overall, the best spatial scale corresponded to the coarsest resolution considered in this study (40 km), while porpoise presence showed stronger association with oceanographic variables summarised at a longer temporal scale. Habitat models including covariates at coarse spatial and temporal scales may better reflect the processes driving availability and abundance of resources at these large scales. These findings support the hypothesis that a multi‐scale approach should be applied when investigating species distribution. Identifying suitable spatial and temporal scale would improve the functional interpretation of the underlying relationships, particularly when studying how a small marine predator interacts with its environment and responds to climate and ecosystem changes. [ABSTRACT FROM AUTHOR]

The effects of the COVID-19 lockdown on wildlife aggression toward humans have received little attention. Records from French Polynesia show that the annual average of about five shark bites on humans from 2009 to 2019 increased significantly to 15 in 2020, despite the virtual absence of humans from the marine environment during a six-week curfew in April–May 2020. Bites then returned to baseline levels in 2021 (N = 4), 2022 (N = 5), and 2023 (N = 2). Most bites in 2020 occurred just after the lockdown and were attributed to gray reef sharks, Carcharhinus amblyrhynchos , displaying territoriality rather than self-defense or predatory behaviours. This temporary increase in shark bites suggests that natural territorial behavior, typically suppressed by continued human presence, reemerged during the Anthropause, providing new insights into shark risks for ocean users and the management of human–predator interactions. [ABSTRACT FROM AUTHOR]

Terrestrially breeding marine predators have experienced shifts in species distribution, prey availability, breeding phenology, and population dynamics due to climate change worldwide. These central‐place foragers are restricted within proximity of their breeding colonies during the breeding season, making them highly susceptible to any changes in both marine and terrestrial environments. While ecologists have developed risk assessments to evaluate climate risk in various contexts, these often overlook critical breeding biology data. To address this knowledge gap, we developed a trait‐based risk assessment framework, focusing on the breeding season and applying it to marine predators breeding in parts of Australian territory and Antarctica. Our objectives were to quantify climate change risk, identify specific threats, and establish an adaptable assessment framework. The assessment considered 25 criteria related to three risk components: vulnerability, exposure, and hazard, while accounting for uncertainty. We employed a scoring system that integrated a systematic literature review and expert elicitation for the hazard criteria. Monte Carlo sensitivity analysis was conducted to identify key factors contributing to overall risk. We identified shy albatross (Thalassarche cauta), southern rockhopper penguins (Eudyptes chrysocome), Australian fur seals (Arctocephalus pusillus doriferus), and Australian sea lions (Neophoca cinerea) with high climate urgency. Species breeding in lower latitudes, as well as certain eared seal, albatross, and penguin species, were particularly at risk. Hazard and exposure explained the most variation in relative risk, outweighing vulnerability. Key climate hazards affecting most species include extreme weather events, changes in habitat suitability, and prey availability. We emphasise the need for further research, focusing on at‐risk species, and filling knowledge gaps (less‐studied hazards, and/or species) to provide a more accurate and robust climate change risk assessment. Our findings offer valuable insights for conservation efforts, given that monitoring and implementing climate adaptation strategies for land‐dependent marine predators is more feasible during their breeding season. [ABSTRACT FROM AUTHOR]

This article discusses the observation of the critically endangered soupfin shark in the Changing Salish Sea. The study confirms the presence of soupfin sharks in Hammersley Inlet through fishing efforts and sampling. The findings suggest that the presence of soupfin sharks may have implications for trophic dynamics and fisheries management in the region. The article also provides a list of references for further research on marine ecosystems in the Salish Sea and surrounding areas. [Extracted from the article]

This study presents a hybrid method, namely the marine predator algorithm (MPA) and Aquila optimizer (AO). The proposed algorithm is named MAO. AO duplicated the existence of the Aquila bird in nature while hunting for prey while MPA was inspired by predators in marine animal life. Although AO is widely accepted, it has several disadvantages. This causes various weaknesses such as a weak exploitation phase and slow growth of the convergence curve. Thus, certain exploitation and exploration in conventional AO can be studied to achieve the best balance. The MPA demonstrates the capacity to deliver optimal design and statistically efficient outcomes. The proposed method used AO as the main algorithm. To measure the performance of the proposed method, this study depicted a comparison using the AO, MPA, and whale optimization algorithm (WOA) methods. This paper was evaluated the performance of MAO on twenty-one CEC2017 benchmark functions test and droop control performance on direct current (DC) microgrid. From the simulation, MAO shows superior convergence ability. The proposed method and its application to droop control was successfully implemented and implied a promising performance. [ABSTRACT FROM AUTHOR]

Global climate‐driven ocean warming has decreased dissolved oxygen (DO) levels (ocean deoxygenation) leading to expansions of hypoxic zones, which will affect the movements, behaviour, physiology and distributions of marine animals. However, the precise responses of animals to low DO remains poorly understood because movements and activity levels are seldom recorded alongside instantaneous DO in situ.We describe a new animal‐attached (dissolved oxygen measuring, DOME) archival tag with an optical oxygen sensor for recording DO, in addition to sensors for temperature and depth, a triaxial accelerometer for fine‐scale movements and activity, and a GPS for tag recovery. All sensors were integrated on a single electronic board.Calibration tests demonstrated small mean difference between DOME tag and factory‐calibrated DO sensors (mean relative error of 5%). No temporal drift occurred over a test period three times longer than the maximum deployment time. Deployments on four blue sharks (Prionace glauca) in the central North Atlantic Ocean showed regular vertical oscillations from the surface to a maximum of 404 m. Profiles from diving sharks recorded DO concentrations ranging from 217 to 272 μmol L−1, temperatures between 13°C and 23°C, and identified an oxygen maximum at ~45 m depth, all of which were consistent with ship‐based measurements. Interestingly, the percentage of time sharks spent burst swimming was greater in the top 85 m compared to deeper depths, potentially because of higher prey availability in the surface layer.The DOME tag described blue shark fine‐scale movements and activity levels in relation to accurately measured in situ DO and temperature, with the potential to offer new insights of animal performance in low oxygen environments. Development of a tag with physico‐chemical and movement sensors on a single electronic board is a first step towards satellite relay of these data over broader spatiotemporal scales (months over thousands of kilometres) to determine direct and indirect responses of marine animals to heatwave and deoxygenation events. [ABSTRACT FROM AUTHOR]

Worldwide, lobsters are considered key predators that control urchin populations. It has been widely reported that lobster size plays a significant role in the size of urchins they feed on, as does the size of the urchin. Generally, it is thought that small palinurid "spiny" lobsters measuring less than 120 mm carapace length (CL) are morphologically incapable of eating urchins, while large lobsters are voracious predators. Urchin size is expected to affect predation with larger urchins of greater than 90 mm test diameter (TD) presenting the most difficult prey. These generalities, however, have not been quantitatively tested for the eastern spiny lobster Sagmariasus verreauxi and recently the accepted size paradigm for lobsters eating urchins has come into question. The aim of this study was to assess whether lobster predation on urchins would differ with urchin size or species, or the size of lobster. Our results indicate that S. verreauxi does not fit the common lobster patterns regarding urchin predation. There were generally low rates of predation and a significant negative relationship between feeding and both lobster size and urchin size. We found that small lobsters were capable urchin predators with a higher likelihood of eating urchins than larger lobsters, which were more reluctant predators. While we did find the expected effect of smaller urchins being significantly more vulnerable prey, there was none of the expected size limitations for small lobsters eating large urchins and predation did not differ between urchin species, indicating that this was a general pattern. Overall, we observed low rates of predation, suggesting that either S. verreauxi may not be a key urchin predator like other lobster species elsewhere, or that small lobsters are underestimated as urchin predators in temperate marine ecosystems. [ABSTRACT FROM AUTHOR]

White sharks (Carcharodon carcharias) play a crucial ecological role, shaping ecosystems through direct predation and risk effects. On the east coast of Australia, immature white sharks are broadly distributed, inhabiting a wide range of habitats and ecosystems from temperate Tasmania to tropical North Queensland. Using stable isotopes and fatty acids of muscle and plasma, we examined the diet and habitat use of 136 immature white sharks (152-388 cm total length) captured on SMART drumlines on the East Australian coast. This facilitated the temporal assessment of white shark trophic ecology from a few weeks to approximately a year. Biochemistry of muscle samples showed that white sharks predominantly feed on low trophic level prey from coastal environments. A seasonal shift in diet was evident, with the increasing proportions of essential fatty acids in muscle tissues during spring and summer suggesting a greater consumption of high-nutrition preys during those months compared to autumn and winter. By combining stable isotope and fatty acid analysis, we gain a comprehensive understanding of immature white shark diet in eastern Australia. Our results confirm that white sharks are generalist predators that exhibit seasonal shifts in their diet. Their high use of coastal habitats reinforces the importance of these areas for foraging, which is crucial for growth and development during this critical life stage. [ABSTRACT FROM AUTHOR]

Simple Summary: Sharks belong to the class Chondrichthyes in the phylum Chordata. They are widely distributed in tropical, temperate, and polar oceans worldwide. As the top predator in the marine food chain, sharks have late sexual maturity and a long reproductive cycle. In recent years, due to the threat of illegal fishing and overfishing, their numbers have fallen sharply, and 23 species of sharks have been listed in protected lists, which poses a direct threat to the balance of marine ecosystems. In order to explore ways to increase the number of sharks by improving their reproductive performance under artificial breeding conditions, we used the striped bamboo shark (Chilosophy plagiosum) as an experimental animal, which has been listed as a near-threatened species in the Red List of Endangered Species of the World Conservation Union and legally bred in Chimelong Ocean Kingdom of Zhuhai, China. The results of the breeding experiment showed that feeding sharks a nutritional fortifier in the breeding season can improve the spawning quantity and egg quality of the striped bamboo shark, which provides new ideas and strategies for improving the protection and utilization level of shark resources, and has important economic, ecological, and social benefits. To explore a method of improving the reproductive performance of the striped bamboo shark, three groups (D0, D1, and D2) of mature individuals were fed squid with (D1 and D2) or without (D0) a nutritional fortifier during the breeding seasons of 2022 and 2023. Compared with the D0 group, the D1 and D2 groups had an increase of 20.90% and 31.34% in total eggs, increases of 32.73% and 41.82% in the proportion of lecithal eggs, and a total 119.07% increase in hatching rate, respectively, in 2022. In 2023, the corresponding increase was 17.12% and 9.91% in total eggs, 19.63% and 12.15% in the proportion of lecithal eggs, 43.37% and 43.94% in fertilization rate, 23.94% and 22.22% in hatchability rate, and 66.70% and 8.70% in the survival rate of fry. Moreover, the levels of serum estradiol, testosterone, progesterone, albumin, and total antioxidant capacity and the levels of ARA, EPA, DHA, n-3 PUFA, and n-6 PUFA in both serum and lecithal eggs significantly increased, while the levels of serum triglyceride and total cholesterol were the opposite (p < 0.05). The results demonstrate that feeding the sharks with a nutritional fortifier can increase spawn production and the quality of eggs, regulate the production of sex steroids, and improve the nutrition of eggs and the health of broodstocks. [ABSTRACT FROM AUTHOR]

Simple Summary: Dolphins, top predators able to accumulate high levels of environmental contaminants, are used as sentinel species of marine pollution. In this study, the content of metals and metalloids (Hg, Pb, Cd, As, Se and Zn) has been evaluated through ICP-MS analysis in several organs/tissues (liver, muscle, lung, kidney and skin) of striped dolphins (Stenella coeruleoalba) and common dolphins (Delphinus delphis) stranded along the Sicilian coastlines of the Mediterranean Sea. The results confirm the exposure of both dolphin species to metals and metalloids, with the highest Hg content correlated to the pollution of the environment where they lived. Significant differences were observed in metals distribution in different organs/tissues analyzed and confirmed by the comparative analysis of metals according to sex and state of development of both dolphin species. These data underline the important role of Stenella coeruleoalba and Delphinus delphis as sentinels of the aquatic environment for assessment of the trend of metals pollution in coastal ecosystems and, indirectly, the health of aquatic species of the Mediterranean Sea. Dolphins, top predators of the aquatic food chain, are used as sentinel species of marine pollution as they are sensitive to environmental changes and able to accumulate a large content of contaminants. Several EU directives promote study of marine mammalians as bio-indicators to evaluate the presence of contaminants in the aquatic environment, such as the Mediterranean Sea, which is rich in environmental pollutants due to its geographic and geo-morphological characteristics. The aim of this study was to evaluate the content of toxic and essential metals and metalloids (Hg, Pb, Cd, As, Se and Zn), through ICP-MS analysis, in organs/tissues (liver, muscle, lung, kidney and skin) of striped dolphins (Stenella coeruleoalba) and common dolphins (Delphinus delphis) stranded along the Sicilian coastlines of the Mediterranean Sea. The results confirm the exposure of dolphins to toxic metals and metalloids, with the highest Hg levels observed in skin and liver, although a low Metal Pollution Index (MPI) was found in all samples of both dolphin species. From a comparative analysis of trace metals and metalloids according to sex and state of development, the highest levels of Cd and As were found in females vs. males and adults vs. juveniles, except for Pb in both species, and significant differences were observed between the two species, size of specimens, and organs/tissues analyzed. The highest Hg levels were correlated to those of essential metals Se and Zn, expressed as molar ratios, to evaluate the potential synergic effect of these detoxifying elements against Hg toxicity. This study confirms the rule of Stenella coeruleoalba and Delphinus delphis as valid sentinel species of the Mediterranean Sea, to verify the trend of metals pollution in this aquatic environment and, consequently, the health of these marine species. [ABSTRACT FROM AUTHOR]

Social identity influences policy preferences and actions regarding wildlife. Using data from a survey of residents, commercial fishers, and tourists on Cape Cod, Massachusetts, this study examined the relationships between self-selected social identities (i.e., animal protection, environmental, hunter, and angler) within these stakeholder groups and ocean management priorities, support for the Marine Mammal Protection Act (MMPA), and acceptance of lethal management of seals and white sharks. Results revealed three social identity clusters: (1) identification with environmental and animal protection groups (non-consumptive), (2) identification with both non-consumptive (environmental, animal protection) and consumptive (angler, hunter) groups, and (3) identification with none of the groups. Residents were a mix of identities; tourists primarily identified with the non-consumptive and, to a lesser extent, no identification clusters; and commercial fishers identified with the mixed nonconsumptive/consumptive and no identification clusters. The overlap between consumptive and non-consumptive identifications illustrates the heterogeneity of social identity. Participants in the non-consumptive cluster favored policies prioritizing wildlife, the environment, and marine mammal protections more strongly than those in other clusters. Findings contribute to research examining social identity theory to improve understanding of public wildlife management preferences, within the novel context of rebounding populations of marine predators such as pinnipeds and white sharks. [ABSTRACT FROM AUTHOR]

Estimating the densities of marine prey observed in animal-borne video loggers when encountered by foraging predators represents an important challenge for understanding predator-prey interactions in the marine environment. We used video images collected during the foraging trip of one chinstrap penguin (Pygoscelis antarcticus) from Cape Shirreff, Livingston Island, Antarctica to develop a novel approach for estimating the density of Antarctic krill (Euphausia superba) encountered during foraging activities. Using the open-source Video and Image Analytics for a Marine Environment (VIAME), we trained a neural network model to identify video frames containing krill. Our image classifier has an overall accuracy of 73%, with a positive predictive value of 83% for prediction of frames containing krill. We then developed a method to estimate the volume of water imaged, thus the density (N·m-3) of krill, in the 2-dimensional images. The method is based on the maximum range from the camera where krill remain visibly resolvable and assumes that mean krill length is known, and that the distribution of orientation angles of krill is uniform. From 1,932 images identified as containing krill, we manually identified a subset of 124 images from across the video record that contained resolvable and unresolvable krill necessary to estimate the resolvable range and imaged volume for the video sensor. Krill swarm density encountered by the penguins ranged from 2 to 307 krill·m-3 and mean density of krill was 48 krill·m-3 (sd = 61 krill·m-3). Mean krill biomass density was 25 g·m-3. Our frame-level image classifier model and krill density estimation method provide a new approach to efficiently process video-logger data and estimate krill density from 2D imagery, providing key information on prey aggregations that may affect predator foraging performance. The approach should be directly applicable to other marine predators feeding on aggregations of prey. [ABSTRACT FROM AUTHOR]

The article discusses a rare behavior observed in whale sharks at Ningaloo Reef, Western Australia, where a juvenile male was seen gulping close to the seabed in an inverse head-down posture. This behavior, involving vertical feeding, suggests a potential link to foraging on benthic prey items. The observation highlights the plasticity of whale shark foraging behavior and the need for further research to understand their feeding habits. The study acknowledges the Traditional Owners of the Ningaloo World Heritage Area and the tour operator who recorded the observation. [Extracted from the article]

The blue shark Prionace glauca plays a critical role as a predator in marine ecosystems but is threatened by by‐catch. To obtain more precise biological data, a Bayesian approach was used, and 536 vertebrae samples collected during 1 year at the landing stage called "Playita Mía" Manta, Ecuador, were analysed. The objective was to estimate the age and growth parameters of the species. The size of the specimens varied between 116 and 310 cm in total length (TL). Using a Bayesian approach based on the Markov Chain Monte Carlo (MCMC) method, growth parameters were evaluated. The von Bertalanffy model was the one that best fitted the data and provided more adequate estimates (females: L∞ = 325.50 cm, L0 = 53.23 cm, and k = 0.12 years; males: L∞ = 331.47 cm, L0 = 51.59 cm, k = 0.12 years −1; combined sexes: L∞ = 329.65 cm, L0 = 53.64 cm, k = 0.11 year−1). The results indicated that females and males have a similar growth, and that the species has a slow growth. Further studies using multi‐model Bayesian approaches and covering a broader range of sizes in the Pacific Ocean are suggested. These studies will provide crucial information for the management and conservation of this species. [ABSTRACT FROM AUTHOR]

Knowledge of the diet of marine predators such as seabirds is fundamental to understanding the ecological cascades they may influence and the impact that environmental changes may have on them. Diet analysis of seabirds frequently relies on the identification of fish otoliths in pellets. However, it is recognised that the true dietary importance of fish with small and fragile otoliths is likely underestimated, requiring an additional method. In this study, we compared the identification of otoliths with that of vertebrae in pellets to gain a more complete picture of seabird diet. We identified fish otoliths and vertebrae from 2584 great skua Stercorarius skua pellets collected between 2014 and 2017 from five colonies in Scotland. Diet varied markedly between colonies, comprising mostly fish in Shetland and mostly birds in St Kilda. 10% of pellets contained otoliths compared to 70% with fish vertebrae. Atlantic herring Clupea harengus and Atlantic mackerel Scomber scombrus were the most common fish species at all colonies when using vertebrae in contrast to being virtually absent when using otoliths. Conversely, the occurrence of Norway pout Trisopterus esmarkii and pollock Pollachius pollachius otoliths was six and eight times, respectively, higher than for vertebrae. Therefore, combining data from both otoliths and vertebrae provides a more complete profile of the fish component of seabird diet. This is fundamental to improving our understanding of the impacts of marine management policies on seabirds, as well as how changes in the population size of such seabird species might affect their prey species. [ABSTRACT FROM AUTHOR]

Simple Summary: Houseflies (Musca domestica: Diptera) are serious medical and veterinary vectors of several human and animal pathogens. Ovicides reduce breeding housefly populations and the risk of housefly vector diseases. The natural ovicides of plant essential oils (EOs) and their main ingredients were suitable and sustainable options at this time against houseflies. This study evaluated the housefly ovicidal activities of four single-component formulations and two combination formulations of essential oils and their main constituents. The efficacy of each treatment was compared to that of α-cypermethrin (a synthetic insecticide). Two combinations: lemongrass (Cymbopogon citratus) EO + trans-anethole and star anise (Illicium verum) EO + geranial, were at least 1.1 times as effective in ovicidal activity as all single-component treatments and α-cypermethrin. They induced embryonic damage and mortality inside the activities of the eggs, disrupting the eggshell, hatching line, aeropyles, plastron, and micropyle. More significantly, the two combinations and all single-component formulations were safe for two non-target aquatic species: guppy (Poecilia reticulate: Poeciliidae) and molly (Poecilia latipinna: Poeciliidae), while α-cypermethrin was not safe for them. The two combinations could be developed into an effective and safe natural ovicide for reducing housefly populations and managing housefly vector diseases. This study attempted to evaluate the ovicidal activity of single-component formulations and combination formulations of lemongrass and star anise essential oils (EOs) and their main constituents against housefly eggs. The efficacies of the combinations were compared with those of single-component formulations and α-cypermethrin. Safety bioassays of all treatments and α-cypermethrin on non-target predators—guppy and molly—were conducted. Two combinations: 1% lemongrass EO + 1% trans-anethole and 1% star anise EO + 1% geranial, exhibited a strong ovicidal activity with an inhibition rate of 94.4 to 96.2%. They were 1.1 times as effective as α-cypermethrin. The two combinations also showed high synergistic activity compared to single-component formulations, with a high synergistic index and a high increased inhibition value of 37.4 to 57.7%. All EO treatments were benign for all non-target aquatic species with a high 50% lethal time (LT50) and safety index. In contrast, α-cypermethrin was highly toxic to them with a low LT50. The morphological abnormalities observed in housefly eggs at death were those such as the shrivelling of the eggs, aberrations and damage to the eggshells, hatching lines, aeropyles, plastron, and micropyle. The potential of these two combinations as a cypermethrin replacement is compelling. [ABSTRACT FROM AUTHOR]

Interspecific interactions, including predator–prey, intraguild predation (IGP) and competition, may drive distribution and habitat use of predator communities. However, elucidating the relative importance of these interactions in shaping predator distributions is challenging, especially in marine communities comprising highly mobile species.We used individual‐based models (IBMs) to predict the habitat distributions of apex predators, intraguild (IG) prey and prey. We then used passive acoustic telemetry to test these predictions in a subtropical marine predator community consisting of eight elasmobranch (i.e. shark and ray) species in Bimini, The Bahamas.IBMs predicted that prey and IG prey will preferentially select habitats based on safety over resources (food), with stronger selection for safe habitat by smaller prey. Elasmobranch space‐use patterns matched these predictions. Species with predator–prey and asymmetrical IGP (between apex and small mesopredators) interactions showed the clearest spatial separation, followed by asymmetrical IGP among apex and large mesopredators. Competitors showed greater spatial overlap although with finer‐scale differences in microhabitat use.Our study suggests space‐use patterns in elasmobranchs are at least partially driven by interspecific interactions, with stronger spatial separation occurring where interactions include predator–prey relationships or IGP. [ABSTRACT FROM AUTHOR]