Sexual segregation in feeding strategies has been widely reported in seabirds. Most seabirds occupy wide breeding distributional ranges, and dissimilar ecological settings may result in distinct environmental pressures on males and females leading to geographical differences in sexual segregation. Using GPS loggers and stable isotope analysis of whole blood (δ15N, δ13C), we assessed the occurrence

Population outbreaks of the coral-eating crown-of-thorns starfish (CoTS) have resulted in extensive coral mortality on reefs in the Indo-Pacific region and is considered one of the major contributors of significant declines in coral cover in Australia’s Great Barrier Reef (GBR). Effective management of CoTS outbreaks rely on improved understanding of the drivers of individual and population-level differences

Stable isotope analysis is increasingly used to investigate diet and foraging behaviour in marine wildlife. For marine mammals, samples from offspring are being used as proxies for their mothers foraging isotope niche as the transfer of nutrients between mother and neonates is solely through milk. Most of these proxy studies have, however, used only easily collected tissues, such as fur or whiskers

How animals partition activity throughout the day is influenced by processes that affect supply and obtainability of resources. However, as resource supply and usability are often entrained by the same diurnal pattern, it has been difficult to disentangle their relative importance. Given the strong influence that tide has on the distribution and accessibility of resources, intertidal systems present

Adult sea turtles migrate between foraging areas and nesting sites that may be 100 s–1000 s of km away. Little is known of the connectivity between these sites in the Arabian region for green sea turtles. We document linkages between two foraging areas in the United Arab Emirates (UAE) with key nesting sites and provide insights on effectiveness of marine protected areas for green sea turtles. Tracking

During tidal cycles, fiddler crabs undergo alternating periods of submersion and desiccation. We compare physiological and biochemical adjustments to submersion and desiccation challenge in two gelasminids from the Galapagos archipelago: the indigenous Leptuca helleri, and Minuca galapagensis. We examine population distributions and habitat characteristics; survival and hemolymph osmolality after 6 h

Determination of sexual size dimorphism (SSD) in marine turtles is challenging because females are observed on nesting beaches, while males remain at sea and are rarely encountered. Data obtained from a sea turtle bycatch survey and a nesting monitoring program conducted in the same area in the Republic of the Congo give access to the body size of both male and female olive ridleys (Lepidochelys olivacea)

The marine topshell Phorcus sauciatus is currently found along the temperate–subtropical shores of the Northeast Atlantic Ocean. Although present in the Iberian Peninsula, Madeira, and Canaries for centuries, P. sauciatus has only recently reached another oceanic volcanic archipelago in the region. In 2013, a small population was recorded for the first time in Santa Maria Island (Azores), widening

The Osumi Strait and its neighboring waters are major spawning grounds for commercially important small pelagic and coastal fish in the Pacific coastal area of Japan. Mesopelagic fish larvae are also abundant here, co-occurring with the larvae of commercial species. However, it is unknown whether these fish groups compete for prey. We examined the diet of four commercial fish groups (Engraulis japonicus

Macroalgal removal is a critical ecosystem function yet few studies have considered its temporal variability, especially on impacted reefs with limited herbivorous fish biodiversity. To address this, we quantified macroalgal removal and mass-standardised bite rates of herbivorous fishes monthly from July 2016 to June 2017 using a series of transplanted Sargassum ilicifolium assays and underwater video

The Persian Gulf hosts marine mega-herbivores that forage in its coastal habitats. Some areas, mainly along its southern coast, contain abundant benthic plants; however, marine plant resources are limited throughout most of this warm sea, which presents nutritional challenges for large herbivores. We measured curved carapace length (CCL) for 102 green turtles (Chelonia mydas) from foraging grounds

Difficulties quantifying in situ prey patch quality have limited our understanding of how marine predators respond to variation within and between patches, and throughout their foraging range. In the present study, animal-borne video, GPS, accelerometer and dive behaviour data loggers were used to investigate the fine-scale foraging behaviour of Macaroni penguins (Eudyptes chrysolophus) in response

Growth rate affects body size, and larger body sizes are often associated with the capacity to produce more surviving offspring. However, the assumption that growth rate should positively relate to fitness is rarely tested, especially in colonial marine invertebrates where size and age can be decoupled. We measured growth, survival, and reproduction through repeated census of 97 colonies from two populations

Our understanding of the ecology of the hadal zone (> 6000 m depth) is based solely on subduction trenches, leaving other geomorphological features, such as fracture zones, troughs, and basins, understudied. To address this knowledge gap, the Wallaby-Zenith Fracture Zone, Indian Ocean (WZFZ; ~ 22°S, 102°E; maximum depth 6625 m measured during Expedition SO258) was studied using free-fall baited landers

While most studies assessing the ecological impacts of climate change have examined impacts from warming temperatures, less attention has been given to other parameters such as increased rainfall events. At a nesting rookery in the northern Great Barrier Reef, Australia, we used data loggers to examine the impact of heavy rainfall and shade on the nest temperatures for green (Chelonia mydas) and hawksbill

Stress-induced reductions in the world’s coral populations are, in many locations, giving way to an increase in macroalgae, for example the common brown macroalgal genus Lobophora. While many ecological studies report a single species (Lobophora variegata), DNA-based identification methods have recently shown that Lobophora is a highly diverse genus with over 100 reported species. Here, we aim to identify

Coastal marine fishes that form spawning aggregations most commonly exhibit a two-point movement pattern, with locations separated by migration: home range to spawning aggregation site and return to home range. However, the bonefish, Albula vulpes, partakes in a unique three-point spawning migration. Bonefish migrate up to 80 km from shallow water home flats to form nearshore pre-spawning aggregations

Seabirds are one of the most threatened of all bird groups, with a marked community-wide decline across the last decades. Yet, some seabird species are more resilient than others, and it is essential to study under which conditions even these highly resilient organisms are affected by global changes. Here, we report such a case in northern gannets (Morus bassanus). Using global location sensors (GLS)

Large diversity and abundance of cetacean species occur along the Brazilian outer continental shelf and slope waters. In the present study, we analyzed carbon (δ13C) and nitrogen (δ15N) stable isotopes in skin biopsies of ten odontocete species (Delphinidae and Physeteridae) to assess the intra- and inter-specific patterns in the use of resources along the region. Our isotopic analysis allowed us to

Connectivity between shallow coral reefs and adjacent deeper habitats may be crucial to reef ecosystem stability. However, deeper habitats such as mesophotic coral ecosystems (MCEs) remain understudied. We investigated the depth structuring of shore-fish assemblages in the central Philippines across shallow (10–30 m) and mesophotic (upper: 30–60 m, lower: 60–90 m) depth zones. Baited video surveys

Mesopelagic fishes are important consumers of zooplankton and are the prey of oceanic predators. Some mesopelagic fishes (e.g., Myctophidae) undertake a diel vertical migration where they ascend to the near-surface waters during the night to feed and descend into the depths during the day to avoid predators. Other mesopelagic fishes (e.g., Sternoptyx) remain at depth throughout the day. Although fishes

To better understand dietary requirements, trophic shifts, and trophic interactions of the threatened green turtle (Chelonia mydas), we conducted a comprehensive global review and literature tabulation (177 studies) reporting diets of individuals > 25 cm carapace length. We analysed those studies involving natural sites and healthy animals that reported relative proportions of all diet components (67

Genetic studies of introduced non-native species are a valuable tool to investigate invasion history and pathways, source populations and multiple introductions of alien species, as well as evolutionary genetic changes following establishment in a new environment. We used a set of nine polymorphic microsatellites to analyse the population genetic structure of the introduced Asian shore crab Hemigrapsus

To maximise reproductive fitness, species make trade-offs among reproductive traits, e.g., offspring quantity vs. offspring size, within energetic, anatomical, and physiological constraints. Sea turtles are a model taxon to study reproductive trade-offs, because they lack parental care and because there are strong selective pressures on hatchlings due to high predation rates. Natural selection therefore

Intertidal macrobenthic assemblages associated with monospecific stands of Zostera muelleri, Cymodocea serratula, Halodule uninervis and Halophila ovalis seagrasses are known to display uniform spatial patchiness on the Moreton Bay coast of North Stradbroke Island, Queensland, as do those in Z. capensis in the Knysna estuarine bay, South Africa. Thirty-seven historical datasets of these macrobenthic

Nutrient enrichment is a major threat to subtidal macroalgal forests. Several studies have shown that nutrient inputs can enhance the ability of opportunistic algal species to acquire space freed by disturbance, at the expense of architecturally complex species that form forests. However, competition between canopy- and turf-forming macroalgae is not limited to the aftermath of disturbance. Canopy-forming

Marine coasts are dynamic environments where spatial-physical gradients interact with seasonality. In the Patagonia in particular, high temperatures and strong winds lead to stressing physical conditions that shape intertidal communities. In a previous study, we found that the interaction between the sponge Hymeniacidon perlevis and the macroalga Ulva lactuca was context-dependent, switching from positive

A primary goal in the study of producer–herbivore interactions is to characterize the tradeoffs between primary producer growth and defense. Across the Aleutian Island Archipelago, the widespread decline in sea otters has resulted in reduced predation on sea urchins, which has led to increases in urchin populations, the formation of urchin barrens, and ultimately to overgrazing of much of the region’s

Copepods are an important link in marine food webs, transferring crucial nutrients such as essential fatty acids (EFA) from primary producers to higher consumers. Yet data on lipid dynamics in marine ecosystems associated with small lipid-poor copepods are scarce. In this study, we used the coastal calanoid copepod Eurytemora herdmani, which is an opportunistic generalist feeder, to assess EFA-specific

The abundant pelagic tunicate Salpa thompsoni is a major grazer in the Southern Ocean (SO) with high ingestion rates, fast-sinking faecal pellets, and the potential to rapidly grow and form dense blooms. We investigated the length-frequency distribution, maturity stage composition, growth, development speed, and size-specific diel vertical abundance patterns at one of the northernmost habitats of S

Oceans are undergoing successive heatwaves. Several invertebrate taxa associate with dinoflagellates and are susceptible to bleaching caused by heat stress. Although the impacts of a single bleaching event have been well documented, the consequences of successive events are less understood. We investigated the effects of multiple thermal stress events on juvenile Cassiopea andromeda, while also addressing

The landward wall of the New Britain Trench (NBT) is an active continental margin. Unlike passive margins, it lacks a continental rise and the abyssal plain, and has a steep continental slope ending in an oceanic trench. Although the trench systems are receiving more and more attentions, our understanding of the microbiology of the NBT and its trench walls is limited. In this study, we collected a

The growing intensity of anthropogenic activities has led to an increase in the number of studies assessing the effects of stressors on marine ecosystems. Yet, the cumulative effects of multiple stressors are rarely studied although they seldom operate in isolation of each other. Our study aimed to investigate the effects of multiple stressors on fish assemblages in a series of semi-enclosed bays.

Diet selection by a species is determined by comparing the consumption (i.e., use) and abundance (i.e., availability) of prey within their area of occupancy. Because individuals commonly use only a portion of habitat available to them (e.g., a 10-ha home range within a 1000-ha foraging habitat), it is important to quantify forage availability within individuals’ home ranges and core areas, and include

Cardiac morphology and mass have been associated with activity levels for bony fishes and elasmobranchs; however, there is little information on cardiac morphology of deep-sea sharks (living primarily below 200 m) and how that morphology compares to cardiac morphology of shallow coastal species. We examined relative heart mass and relative ventricle dry mass in 10 species of sharks from coastal to

Leptocephali are the unique larvae of eels and their relatives of the teleost superorder Elopomorpha that have remained poorly understood despite their ubiquitous presence at tropical to temperate latitudes. This review examines recent advancements in understanding the behavioral ecology and distribution of leptocephali. Their regional distributions and abundance are determined by when and where the

Habitat area and fragmentation are recognised as important factors that influence population size, community structure and extinction risk. Abundance and species richness universally increase with habitat area. However, the effects of different aspects of habitat fragmentation, including variation in patch size, number and isolation are often not distinguished from each other or the overall effects

This study analysed the anthropogenic microparticles in the stomach content of the European anchovy (Engraulis encrasicolus) in the Ligurian Sea (NW Mediterranean). The results showed that 30–40% of the anchovies had ingested anthropogenic microparticles (on average, 0.34 ± 0.29 fibres ind−1 and 0.12 ± 0.12 fragments ind−1). The fibres were probably ingested via filtration, and were significantly correlated

Loggerhead sea turtles (Caretta caretta) occupy an array of marine habitats throughout their lives and understanding how this threatened species utilizes these habitats can help guide conservation efforts. This study used a combination of isotopic analysis (δ13C; δ15N) of turtle epidermis and epibiotic community composition to examine habitat-use patterns of nesting loggerheads from the South West

Most of the reef-building Acropora corals around Okinawa Island spawn in May and/or June. We found that two morphotypes of Acropora divaricata spawned in August and/or September. The “robust” and “slender” morphotypes differed in branch width and in the diameter of axial corallites. Histological analyses showed that the onset of gamete production/maturation occurred from June onwards. Most of the other

Pocillopora acuta, formerly synonymized with P. damicornis, is an ecologically important reef-building coral that exhibits mixed reproductive modes, geographic variation in clonality, and conflicting reports of population genetic structure. Using 16 polymorphic microsatellite loci, this study examined clonality, genetic differentiation, and connectivity of genetically identified P. acuta (n = 428)

Ocean acidification is a consequence of chemical changes driven mainly by a continuous uptake of carbon dioxide, resulting in pH decrease. This phenomenon represents an additional threat to marine life, with expected effects ranging from changes in behavioral responses and calcification rates to the potential promotion of oxidative stress. To unravel the impacts of ocean acidification on the antioxidant

The giant squid, Architeuthis dux, has been reported for centuries, but its distribution and ecology have remained famously mysterious. We investigated the A. dux distribution in the Sea of Japan using the environmental DNA (eDNA) method, which has recently been considered as a useful technique for evaluating the distributions of rare species. To develop the eDNA method to detect A. dux, we first created

Habitat availability underpins the diversity and distribution of benthic marine communities. Sponges are significant structural components of seabeds; therefore, understanding sponge-community associations are important for the effective management of marine biodiversity. Invertebrate communities were quantified from 11 sponge species having distinct morphologies from Ningaloo Reef (tropical) and Rottnest

Given the recent trend towards establishing very large marine protected areas (MPAs) and the high potential of these to contribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos Archipelago, interspersed with and

Resting cysts represent the dormant life stage produced by sexual reproduction of dinoflagellates; it generally maintain a limited level of metabolic activities. In the present study, changes in the photosynthetic apparatus of Akashiwo sanguinea during the encystment process in different nitrogen (N) conditions were characterized, and the transcriptional responses of nine photosynthesis genes were

For species that do not provide parental care after birth, excess maternal provisioning during development, beyond what is required for embryogenesis, provides offspring with resources to increase their chances of survival. Maternally derived resources are expected to be important for buffering offspring against limited food resources at birth or time needed to learn how to properly feed. Young-of-the-year

Heterotrophic dinoflagellates are major grazers of microalgae in marine food webs. The feeding of the newly described heterotrophic dinoflagellate Gyrodinium jinhaense was explored by providing 19 common microalgal prey species and the ciliate Mesodinium rubrum as prey. Furthermore, the specific growth and ingestion rates of G. jinhaense feeding on the chlorophyte Dunaliella salina were determined

In the original article, the light cycle was indicated as 12:12 h light:dark.

In this study, we investigated the composition of the gill tissue relative to the reproductive status of the lucinid clam Loripes orbiculatus (sensus Poli, 1791) according to seasonal as well as biological parameters to provide insights into the physiological variability of this symbiotic bivalve. Temporal variation in population density was also studied. The species was investigated in Zostera noltii

Gastropods from the family Eulimidae are known as parasites of all living classes of echinoderms. Here we determine the trophic relationships between ectoparasitic eulimids Echineulima mittrei and their hosts, sea urchins Diadema setosum in Vietnam. Stable isotope analysis showed the differences in δ13C and δ15N saturation in echinoderms tissues. The eulimids’ muscle and gonad tissues have the same

Natural selection should favour strategies that maximise reproductive success. Females may use different resources during progressive stages of reproduction according to energetic demands, behavioural constraints and prey availability. We used South American fur seal, Arctocephalus australis australis, pup whisker isotope values as proxies for maternal diet and habitat use to determine how resource

Elasmobranch fishes (sharks, skates, and rays) are hypothesized to use environmental cues, such as the geomagnetic field (GMF), to navigate across the ocean. However, testing the sensory and navigation abilities of large highly migratory fishes in the field is challenging. This laboratory study tested whether the yellow stingray, Urobatis jamaicensis, could detect and distinguish between the GMF cues

Methane enrichments are frequently observed in the oxic upper water column of the central Baltic Sea during summer months. However, methane sources as well as the fate of methane produced in surface near waters still remain unclear. In the present study, we conducted ship-based grazing experiments to examine the presence of methanogenic archaea in copepod faecal pellets. We quantified bacterial and

Indoles, including 5-methoxy-2-methyl-indole (5MeO2MeIn), are a potent trigger of strobilation in jellyfish polyps. Indoles may be an alternative method to cooling to induce strobilation, but the ephyrae produced should have similar or better rates of survival, deformities, growth, and behaviour to those produced by cooling, and polyps should remain viable after strobilating. We used two experiments

Compound specific nitrogen isotope analysis of amino acids (AA CSIA) has been used to study the trophic ecology of many marine organisms because of its ability to characterize the δ15N value at the base of a food web while simultaneously providing trophic position information from a single tissue sample of a consumer. Although application of this method is becoming more widely used in trophic studies

Fitness is a product of survival and fecundity, which arise from a host of individual traits that vary among individuals. Estimating fitness is central to many research programs in ecology and evolution. Yet, because researchers are rarely able to track individuals through a complete lifetime, they typically rely on proxies of reproductive success. Because it can be readily measured, the number of

Many environmental processes influence animal somatic growth rates. However, elucidating specific drivers of somatic growth variation has been challenging for marine megafauna. Using a 20+ year dataset of somatic growth generated through skeletochronology, we evaluated the relationship between multiple region-wide environmental factors—the Deepwater Horizon (DWH) oil spill, increasing population density

Anthropogenic activities have accelerated the movement of non-indigenous species throughout the world. One approach to predict the spread of non-indigenous species is to employ bioclimatic envelope models which often assume niche conservation among sympatric, closely related species. Here, we test this assumption by comparing early developmental progress of two non-indigenous calcareous biofouling