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'Natural' disasters (also known as geophysical disasters) involve physical processes that have a direct or indirect impact on humans. These events occur rapidly and may have severe consequences for resident flora and fauna as their habitat undergoes dramatic and sudden change. Although most studies have focused on the impact of natural disasters on humans and terrestrial systems, geophysical disasters can also impact aquatic ecosystems. Here, we provide a synthesis on the effects of the most common and destructive geophysical disasters on aquatic systems (life and habitat). Our approach spanned realms (i.e., freshwater, estuarine, and marine) and taxa (i.e., plants, vertebrates, invertebrates, and microbes) and included floods, droughts, wildfires, hurricanes/cyclones/typhoons, tornadoes, dust storms, ice storms, avalanches (snow), landslides, volcanic eruptions, earthquakes (including limnic eruptions), tsunamis, and cosmic events. Many geophysical disasters have dramatic effects on aquatic systems. The evidence base is somewhat limited for some natural disasters because transient events (e.g., tornadoes and floods) are difficult to study. Most natural disaster studies focus on geology/geomorphology and hazard assessment for humans and infrastructure. However, the destruction of aquatic systems can impact humans indirectly through loss of food security, cultural services, or livelihoods. Many geophysical disasters interact in complex ways (e.g., wildfires often lead to landslides and flooding) and can be magnified or otherwise mediated by human activities. Our synthesis reveals that geophysical events influence aquatic ecosystems, often in negative ways, yet systems can be resilient provided that effects are not compounded by anthropogenic stressors. It is difficult to predict or prevent geophysical disasters but understanding how aquatic ecosystems are influenced by geophysical events is important given the inherent connection between peoples and aquatic ecosystems. Key words: Geophysical disasters, natural disasters, natural hazards, aquatic ecosystems, ecosystem services, threats, Introduction 'Natural' disasters can be defined as 'some rapid, instantaneous or profound impact of the natural environment upon the socioeconomic system' (Alexander 2018) usually with a restricted temporal and spatial [...]

The ocean plays a crucial role in the functioning of the Earth System and in the provision of vital goods and services. The United Nations (UN) declared 2021–2030 as the UN Decade of Ocean Science for Sustainable Development. The Roadmap for the Ocean Decade aims to achieve six critical societal outcomes (SOs) by 2030, through the pursuit of four objectives (Os). It specifically recognizes the scarcity of biological data for deep-sea biomes, and challenges the global scientific community to conduct research to advance understanding of deep-sea ecosystems to inform sustainable management. In this paper, we map four key scientific questions identified by the academic community to the Ocean Decade SOs: (i) What is the diversity of life in the deep ocean? (ii) How are populations and habitats connected? (iii) What is the role of living organisms in ecosystem function and service provision? and (iv) How do species, communities, and ecosystems respond to disturbance? We then consider the design of a global-scale program to address these questions by reviewing key drivers of ecological pattern and process. We recommend using the following criteria to stratify a global survey design: biogeographic region, depth, horizontal distance, substrate type, high and low climate hazard, fished/unfished, near/far from sources of pollution, licensed/protected from industry activities. We consider both spatial and temporal surveys, and emphasize new biological data collection that prioritizes southern and polar latitudes, deeper (> 2000 m) depths, and midwater environments. We provide guidance on observational, experimental, and monitoring needs for different benthic and pelagic ecosystems. We then review recent efforts to standardize biological data and specimen collection and archiving, making “sampling design to knowledge application” recommendations in the context of a new global program. We also review and comment on needs, and recommend actions, to develop capacity in deep-sea research; and the role of inclusivity - from accessing indigenous and local knowledge to the sharing of technologies - as part of such a global program. We discuss the concept of a new global deep-sea biological research program ‘Challenger 150,’ highlighting what it could deliver for the Ocean Decade and UN Sustainable Development Goal 14.

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]

As humans continue to alter the species composition and size structure of marine food webs, it is critical to understand size-dependent effects of predators on prey. Yet, how shifts in predator body size mediate the effect of predators is understudied in tropical marine ecosystems, where anthropogenic harvest has indirectly increased the density and size of small-bodied predators. Here, we combine field surveys and a laboratory feeding experiment in coral reef fish communities to show that small and large predators of the same species can have similar effects. Specifically, surveys show that the presence of a small predator (Paracirrhites arcatus) was correlated with lower chances of prey fish presence, but these correlations were independent of predator size. Experimental trials corroborated the size-independent effect of the predator; attack rates were indistinguishable between small and large predators, suggesting relatively even effects of hawkfish in various size classes on the same type of prey. Our results indicate that the effects of small predators on coral reefs can be size-independent, suggesting that variation in predator size-structure alone may not always affect the functional role of these predators.

Benefits to wildlife communities stemming from the protection of a single species have been documented in terrestrial and marine systems but remain understudied within the context of freshwater‐protected areas (FPAs). We used five long‐standing (>80 years) FPAs in three lakes in eastern Ontario, Canada, which were initially established to protect native black bass (Micropterus spp.) from angling exploitation, to assess whether this protection affected wildlife communities found in the riparian areas of these FPAs. From May to July 2021, we used baited remote camera traps and visual surveys to assess species diversity within and outside of FPAs. We recorded 61 species spanning mammalian, avian and herpetofauna taxa, with the two assessment methods identifying unique sets of species (23% overlap). Camera traps showed that animals were more active in riparian areas during the day (62% of detections) than at night. FPAs had a variable but overall positive influence on riparian wildlife biodiversity, hosting more bird, mammal, amphibian and reptile species than non‐protected areas and having higher species richness. FPAs differed from other sites in the lakes by having higher habitat complexity, less human infrastructure and less human use, which potentially contributed to these differences. This study raises awareness that even small FPAs can have legacy, umbrella‐type benefits that extend beyond fishes to the wildlife that use the adjacent riparian areas. [ABSTRACT FROM AUTHOR]

Orcas (Orcinus orca) have a worldwide distribution and as apex predators feed on a wide variety of prey, including marine mammals, seabirds, sea turtles, cephalopods, teleost fish and elasmobranchs. Historically, there have been few observations of orca predation on large elasmobranch species nor are they commonly identified in the stomach contents of deceased orcas. In recent years there has been an increase in observational records of orca predation, such as on white sharks (Carcharodon carcharias) in South Africa, which could indicate that elasmobranchs serve a greater importance in their diet than previously considered. These events are often documented by members of the public due to the development and affordability of innovative cameras, including the use of the drones (unoccupied aerial vehicles). Here we describe new predator-prey interactions between orcas and large shark species in Cabo Pulmo National Park (CPNP), a small no-take marine protected area located in the Gulf of California. In this paper, we were able to successfully identify individuals from the described orca pods in the region; specifically, the same individuals hunting sharks over a period of nearly two years. We discuss the potential implications of these new ecological interactions, given the importance of tourism to sustain the management of CPNP, as cascading impacts have been documented elsewhere in light of orca predations on sharks. [ABSTRACT FROM AUTHOR]

This article explores the reproductive behavior of bluntnose sixgill sharks in the deep sea. The researchers used remote deep-sea camera systems to observe the sharks and found evidence of mating scars on one female shark. However, they acknowledge that there could be other explanations for the scarring. The study emphasizes the need for further research on the reproductive habitats of deep-sea sharks and the importance of conservation efforts in these areas. Additionally, the article discusses the capture of a pregnant bluntnose sixgill shark in the Gulf of Tunis and highlights the importance of deep diving by large marine predators. It also emphasizes the need for diverse perspectives in deep-sea ocean field programs. [Extracted from the article]

Misty Groupers (Hyporthodus mystacinus) are one of the largest and most geographically widespread grouper species and one of the few grouper species known to occur at depths greater than 200 m. However, aspects of their basic biology, behavior, and ecology remain poorly understood, leaving significant gaps in our ability to evaluate their functional role throughout the vertical water column, as well as our understanding of their conservation needs in a changing ocean. Through in-situ video observation obtained using deep-sea landers in both The Bahamas and Cayman Islands over multiple years, we documented Misty Grouper occurrence up to 470 m depth in the mesopelagic zone. These observations provide a new depth range extension for the species and illuminate the potential importance of deep-water habitats for large grouper species in the wider Caribbean. [ABSTRACT FROM AUTHOR]

Studying the behavior of pelagic sharks can be challenging due to the logistical difficulties of locating migratory individuals in the open ocean. This is further compounded by their rarity in certain ocean regions due to overfishing. The accessibility of deep-water basins in The Bahamas provides a unique model system for describing how pelagic sharks connect surface and deep ocean habitats through vertical behavior. Using custom deep-sea landers in The Bahamas, we provide novel depth data for two species of pelagic sharks: a depth range extension for the dusky shark at 767 m and novel occurrence at twilight zone depth for the silky shark at 470 m. These observations expand the vertical niche for these two species, suggesting that deep diving behavior is likely more common than previously thought and likely important for ecosystem connectivity. [ABSTRACT FROM AUTHOR]

Effective management and conservation of threatened species biodiversity requires knowledge of reproductive biology, such as cyclicity, mode, and age at maturity. We combined reproductive endocrinology and in-situ ultrasonography to examine reproductive characteristics of female Caribbean reef sharks Carcharhinus perezi, a widely distributed, threatened marine predator which remains largely understudied throughout its range. Unique to this study was the opportunity to conduct longitudinal assessments of two individuals, recaptured across multiple seasons during sampling in The Bahamas. Within- individual, paired hormone analyses and in-situ ultrasounds of female sharks that were confirmed as either pregnant, non-pregnant, or reproductively active, suggest a biennial reproductive cycle for Carcharhinus perezi. This unique opportunity to assess the reproductive biology of the same individuals over time underscore the importance of repeated sampling for elucidating population reproductive cyclicity of highly mobile sharks in the wild. [ABSTRACT FROM AUTHOR]

This document provides a compilation of scientific articles that explore various aspects of killer whale behavior, ecology, and interactions with other marine species. The articles discuss the use of drones to study killer whales, their feeding habits and prey selection, their distribution and abundance, and their role in marine ecosystems. The document emphasizes the importance of using drone footage and citizen science to gain insights into killer whale behavior and conservation efforts. The articles cover a range of regions around the world, providing valuable information on killer whales in different contexts. [Extracted from the article]

A prerequisite to studying the physiological status of wild animals is the ability to obtain blood samples that reflect the condition prior to capture or handling. Based on research in avian taxa, it is recommended that such samples be obtained within 3 min of capture; however, this guideline has not been validated in wild teleosts. The present study addresses the time course of physiological changes in a number of blood metrics across six species of freshwater fish. Fishes were caught using a standardized angling protocol and held in a water-filled trough prior to the collection of a blood sample, via caudal phlebotomy, between 0.5 and 11 min after capture. Changes in whole-blood glucose and lactate concentrations, hematocrit, and plasma cortisol concentrations were assessed. Change-point analyses indicated that blood lactate concentrations and hematocrit did not deviate from baseline values until ~2-5 min of handling for all species, whereas blood glucose concentrations generally did not deviate significantly from baseline over the 11 min test period. In all species, plasma cortisol concentrations began to increase above baseline between ~4 and 8 min after capture. Thus, to ensure that blood samples are representative of baseline conditions across multiple metrics, we recommend that sampling be limited to less than 2 min in teleost fishes. Key words: stress, cortisol, field endocrinology, glucose, lactate, blood sampling, hematocrit, 3 min rule, wild animals, teleost, largemouth bass, Micropterus salmoides, smallmouth bass, Micropterus dolomieu, rock bass, Ambloplites rupestris, pumpkinseed, Lepomis gibbosus, bluegill, Lepomis macrochirus, northern pike, Esox lucius. Une condition préalable à l'étude de l'état physiologique d'animaux sauvages est la capacité d'obtenir des échantillons de sang qui reflètent l'état avant la capture ou la manipulation. À la lumière de travaux de recherche sur des taxons d'oiseaux, il est recommandé que de tels échantillons soient obtenus dans les 3 min suivant la capture. Cette directive n'a toutefois pas été validée pour les téléostéens vivant à l'état sauvage. L'étude s'est penchée sur la chronologie de changements physiologiques pour différents paramètres sanguins pour six espèces de poissons d'eau douce. Les poissons ont été capturés en suivant un protocole normalisé de pêche à la ligne et maintenus dans une cuve remplie d'eau avant le prélèvement d'un échantillon de sang par ponction caudale, de 0,5 à 11 min après la capture. Les variations des concentrations de glucose et de lactate du sang entier, de l'hématocrite et des concentrations de cortisol plasmatique ont été évaluées. Les analyses des points de changement indiquent que les concentrations de lactate du sang et l'hématocrite ne divergent pas des valeurs de référence avant ~2-5 min de manipulation pour toutes les espèces, alors que les concentrations de glucose du sang ne divergent pas significativement, en général, des valeurs de référence pendant toute la période de manipulation de 11 min. Chez toutes les espèces, la concentration de cortisol plasmatique commence à augmenter au-delà de la valeur de référence entre ~4 et 8 min après la capture. Ainsi, pour s'assurer que les échantillons de sang soient représentatifs des conditions de référence pour différents paramètres, nous recommandons que leur prélèvement soit fait dans les 2 min suivant la capture chez les poissons téléostéens. [Traduit par la Rédaction] Mots-clés : stress, cortisol, endocrinologie de terrain, glucose, lactate, prélèvement sanguin, hématocrite, règle de 3 minutes, animaux sauvages, téléostéen, achigan à grande bouche, Micropterus salmoides, achigan à petite bouche, Micropterus dolomieu, crapet de roche, Ambloplites rupestris, crapet-soleil, Lepomis gibbosus, crapet arlequin, Lepomis macrochirus, grand brochet, Esox lucius., Introduction In many vertebrate species, the physiological dynamics of blood have served as an important tool in assessing whole-organism responses to environmental change and stressors. For example, acute increases in [...]

Many predator species make regular excursions from near-surface waters to the twilight (200 to 1,000 m) and midnight (1,000 to 3,000m) zones of the deep pelagic ocean. While the occurrence of significant vertical movements into the deep ocean has evolved independently across taxonomic groups, the functional role(s) and ecological significance of these movements remain poorly understood. Here, we integrate results from satellite tagging efforts with model predictions of deep prey layers in the North Atlantic Ocean to determine whether prey distributions are correlated with vertical habitat use across 12 species of predators. Using 3D movement data for 344 individuals who traversed nearly 1.5 million km of pelagic ocean in >42,000 d, we found that nearly every tagged predator frequented the twilight zone and many made regular trips to the midnight zone. Using a predictive model, we found clear alignment of predator depth use with the expected location of deep pelagic prey for at least half of the predator species. We compared high-resolution predator data with shipboard acoustics and selected representative matches that highlight the opportunities and challenges in the analysis and synthesis of these data. While not all observed behavior was consistent with estimated prey availability at depth, our results suggest that deep pelagic biomass likely has high ecological value for a suite of commercially important predators in the open ocean. Careful consideration of the disruption to ecosystem services provided by pelagic food webs is needed before the potential costs and benefits of proceeding with extractive activities in the deep ocean can be evaluated. [ABSTRACT FROM AUTHOR]

The response to capture is important in fisheries because it can reveal potential threats to species beyond fishing mortalities resulting from direct harvest. To date, the vast majority of studies assessing shark stress responses have used physiology or biotelemetry to look at sensitivity after capture, leaving a gap in our understanding of the behaviours of sharks during capture. We examined the behavioural responses of sharks to capture by attaching accelerometers to fishing gear and measuring the immediate and prolonged forces they exerted while on the line. We recorded acceleration vectors and derived the rate of intense fighting behaviours of 23 individual sharks comprising three species. Results suggest that blacktip sharks (Carcharhinus limbatus) exhibited intense bouts of fighting behaviour at the onset of hooking, while nurse (Ginglymostoma cirratum) and tiger sharks (Galeocerdo cuvier) displayed more subdued acceleration values during capture. We also obtained plasma lactate from a subset of individuals and detected a strong correlation with maximum acceleration. These results align with previously published values and suggest that shark movement during fisheries capture is an important factor during bycatch and catchand-release interactions. La reaction a la capture est importante pour les peches puisqu'elle peut reveler des menaces potentielles pour les especes autres que la mortalite par la peche decoulant directement de la prise. A ce jour, la grande majorite des etudes visant a evaluer les reactions au stress des requins a fait appel a la physiologie ou la biotelemetrie pour examiner la sensibilite apres la capture, les comportements des requins durant la capture demeurant donc mal compris. Nous avons examine les reactions comportementales de requins a la capture en fixant des accelerometres aux engins de peche et en mesurant les forces immediates et soutenues que les requins exercent quand ils sont hameconnes a la ligne. Nous avons enregistre les vecteurs d'acceleration et calcule la frequence de comportements de lutte intense de 23 individus de trois especes de requins differentes. Les resultats portent a croire que les requins bordes (Carcharhinus limbatus) manifestaient des pointes intenses de comportement de lutte au debut de l'hameconnage, alors que les requins-nourrices (Ginglymostoma cirratum) et les requins-tigres (Galeocerdo cuvier) presentaient des valeurs d'acceleration plus faibles durant la capture. Nous avons egalement obtenu des concentrations de lactate plasmatique d'un sous-ensemble d'individus et decele une forte correlation de ces teneurs avec l'acceleration maximum. Ces resultats concordent avec des valeurs deja publiees et donnent a penser que le mouvement des requins durant la capture pendant la peche est un important facteur des interactions associees a la prise accessoire et la remise a l'eau. [Traduit par la Redaction], Introduction For various reasons (e.g., to comply with harvest regulations, lack of market for a given fish, conservation ethic), some fish captured by fishers are released. Interestingly, fishes exhibit among [...]