Boat noise reduces vocalization rate and alters vocal characteristics in wild plainfin midshipman fish.

Anthropogenic noise pollution has been accelerating at an alarming rate, greatly altering aquatic soundscapes. Animals use various mechanisms to avoid acoustic masking in noisy environments, including altering calling rates or the frequency (pitch) of their vocalizations or increasing the amplitude (loudness) of their vocalizations (i.e.

Actively soniferous tropical reef fishes are diverse, vulnerable, and valuable.

Active (i.e., intentional) fish sound production provides informative cues for numerous ecological functions, including larval recruitment or reproduction, and can facilitate monitoring and restoration.

Deep-sea cabled video-observatory provides insights into the behavior at depth of sub-adult male northern elephant seals, Mirounga angustirostris.

The Ocean Networks Canada (ONC) cabled video-observatory at the Barkley Canyon Node (British Columbia, Canada) was recently the site of a Fish Acoustics and Attraction Experiment (FAAE), from May 21, 2022 to July 16, 2023, combining observations from High-Definition (HD) video, acoustic imaging sonar, and underwater sounds at a depth of 645 m, to examine the effects of light and bait on deep-sea fish and invertebrate behaviors. The unexpected presence of at least eight (six recurrent and two temporary) sub-adult male northern elephant seals (Mirounga angustirostris) was reported in 113 and 210 recordings out of 9737 HD and 2805 sonar videos at the site, respectively. Elephant seals were found at the site during seven distinct periods between June 22, 2022 and May 19, 2023.

Centering relationships to place for more meaningful research and engagement.

Research has the potential to simultaneously generate new knowledge and contribute meaningful social-ecological benefits; however, research processes and outcomes can also perpetuate extractive patterns that have manifested the climate, biodiversity, and social justice crises. One approach to enhance the societal value of research processes is to strengthen relationships with places of study and the peoples of those places. Deepening relational engagement with the social-ecological context and history of a place can lead to more accurate results and improved public trust in the scientific process and is particularly important for natural scientists who work at the interface of nature and society.

Boat noise impedes vocalizations of wild plainfin midshipman fish.

Marine noise is recognised as a growing threat that can induce maladaptive behavioural changes in many aquatic animals, including fishes. The plainfin midshipman is a soniferous fish with a prolonged breeding period, during which males produce tonal hums that attract females, and grunts and growls during agonistic interactions. In this study, we used acoustic recordings to assess the effects of boat noise on the presence, peak frequencies, and durations of plainfin midshipman calls in the wild.

Global inventory of species categorized by known underwater sonifery.

A working group from the Global Library of Underwater Biological Sounds effort collaborated with the World Register of Marine Species (WoRMS) to create an inventory of species confirmed or expected to produce sound underwater. We used several existing inventories and additional literature searches to compile a dataset categorizing scientific knowledge of sonifery for 33,462 species and subspecies across marine mammals, other tetrapods, fishes, and invertebrates. We found 729 species documented as producing active and/or passive sounds under natural conditions, with another 21,911 species deemed likely to produce sounds based on evaluated taxonomic relationships.

The importance of context in the acoustic behaviors of marine, subtropical fish speciesa).

Despite the importance of acoustic signaling in fishes, the prevalence of the behavioral contexts associated with their active (i.e., intentional) sound production remains unclear.

Preliminary examination of sounds produced by Pacific salmon (Oncorhynchus spp.) during their fall spawning migrationa).

A preliminary description of sounds produced by three species of Pacific salmon was conducted to address the lack of quantified call characteristics in previous studies. Wild Chinook salmon (Oncorhynchus tshawytscha), pink salmon (O. gorbuscha), and coho salmon (O.

Integrating technologies provides insight into the subsurface foraging behaviour of a humpback whale (Megaptera novaeangliae) feeding on walleye pollock (Gadus chalcogrammus) in Juan de Fuca Strait, Canada.

Subsurface foraging is an important proportion of the activity budget of rorqual whales, yet information on their behaviour underwater remains challenging to obtain. Rorquals are assumed to feed throughout the water column and to select prey as a function of depth, availability and density, but there remain limitations in the precise identification of targeted prey. Current data on rorqual foraging in western Canadian waters have thus been limited to observations of prey species amenable to surface feeding, such as euphausiids and Pacific herring (Clupea pallasii), with no information on deeper alternative prey sources.

Otolith mineralogy affects otolith shape asymmetry: a comparison of hatchery and natural origin Coho salmon (Oncorhynchus kisutch).

Many aspects of natural and hatchery origin salmonid genetics, physiology, behaviour, anatomy and life histories have been compared due to the concerns about what effects domestication and hatchery rearing conditions have on fitness. Genetic and environmental stressors associated with hatchery rearing could cause greater developmental instability (DI), and therefore a higher degree of fluctuating asymmetry (FA) in various bilaterally paired characters, such as otoliths. Nonetheless, to appropriately infer the effects of DI on otolith asymmetry, otolith mineralogy must be accounted for.

Fine-scale diversity of prey detected in humpback whale feces.

Predator diets are largely influenced by prey availability and abundance. Yet, in heterogenous marine environments, identifying the prey species consumed by diving mammals remains a fundamental challenge. For rorqual whales, the energetic constraints of prey engulfment require that the whales seek areas of high prey abundance and execute discrete lunge feeding events on patches of high-density prey.

Grazing preference and isotopic contributions of kelp to mesograzers.

In seagrass food webs, small invertebrate mesograzers often exert top-down control on algal epiphytes growing on seagrass blades, which in turn releases the seagrass from competition for light and nutrients. Yet, nearshore habitat boundaries are permeable, and allochthonous subsidies can provide alternative food sources to production in seagrass meadows, which may in turn alter mesograzer-epiphyte interactions. We examined the contribution of allochthonous kelp (), autochthonous epiphytic macroalgal (), , and seagrass production to mesograzer diets in a subtidal (eelgrass) meadow.

Required sampling intensity for community analyses of intertidal infauna to detect a mechanical disturbance.

In coastal ecosystems, infaunal (animals living within the sediment) invertebrates are used to study and monitor disturbances. However, it is an open question as to the minimal required sampling intensity to detect that a disturbance has influenced such communities. As such, we implemented a manipulative experiment using an infaunal community with a known response (community composition and population abundances) to a mechanical disturbance (sediment scour), to determine the minimum sampling intensity required to detect differences in the infaunal community.

Anchored bulk carriers have substantial impacts on the underwater soundscape in Cowichan Bay, British Columbia.

In recent decades shipping traffic has increased, leading to elevated underwater ambient noise levels. Research has been conducted on the noise generated by ships underway, however little is known about potential noise from ships at anchor. In coastal regions, commercial vessels can seek anchorages prior to entering port, leading to concern regarding the impacts on the soundscape and marine ecosystems.

Large size (>100-μm) microplastics are not biomagnifying in coastal marine food webs of British Columbia, Canada.

Microplastics (MPs) contamination in marine environments is of increasing concern, as plastic particles are globally ubiquitous across ecosystems. A large variety of aquatic taxa ingest MPs, but the extent to which animals accumulate and transfer MPs through food webs is largely unknown. In this study, we quantified MP uptake in bivalves, crabs, echinoderms, and fish feeding at different trophic levels at three sites on southern Vancouver Island.

Host-pathogen-environment interactions predict survival outcomes of adult sockeye salmon (Oncorhynchus nerka) released from fisheries.

Incorporating host-pathogen(s)-environment axes into management and conservation planning is critical to preserving species in a warming climate. However, the role pathogens play in host stress resilience remains largely unexplored in wild animal populations. We experimentally characterized how independent and cumulative stressors (fisheries handling, high water temperature) and natural infections affected the health and longevity of released wild adult sockeye salmon (Oncorhynchus nerka) in British Columbia, Canada.

A Gulf in lockdown: How an enforced ban on recreational vessels increased dolphin and fish communication ranges.

From midnight of 26 March 2020, New Zealand became one of the first countries to enter a strict lockdown to combat the spread of COVID-19. The lockdown banned all non-essential services and travel both on land and sea. Overnight, the country's busiest coastal waterway, the Hauraki Gulf Marine Park, became devoid of almost all recreational and non-essential commercial vessels.

Global COVID-19 lockdown highlights humans as both threats and custodians of the environment.

The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence.

Underwater sound levels in the Canadian Arctic, 2014-2019.

The Arctic has been a refuge from anthropogenic underwater noise; however, climate change has caused summer sea ice to diminish, allowing for unprecedented access and the potential for increased underwater noise. Baseline underwater sound levels must be quantified to monitor future changes and manage underwater noise in the Arctic. We analyzed 39 passive acoustic datasets collected throughout the Canadian Arctic from 2014 to 2019 using statistical models to examine spatial and temporal trends in daily mean sound pressure levels (SPL) and quantify environmental and anthropogenic drivers of SPL.

A Bayesian analysis of the factors determining microplastics ingestion in fishes.

Microplastic particles (MPs) occur widely in aquatic ecosystems and are ingested by a wide range of organisms. While trophic transfer of MPs is known to occur, researchers do not yet fully understand the fate of MPs in food webs. We explored the factors influencing reported ingestion of MPs in marine and freshwater fishes by conducting a literature review of 123 studies published between January 2011 and June 2020.

Reproductive biology and ecology of Pacific hagfish (Eptatretus stoutii) and black hagfish (Eptatretus deani).

The reproductive biology of Pacific hagfish Eptatretus stoutii (Lockington, 1878) and black hagfish Eptatretus deani (Evermann & Goldsborough, 1907) was assessed using current and historical data. Our results found that the reproductive characteristics of both hagfish species reflect those of K-selected species, which tend to live long and exhibit slow growth rates, low fecundity (approximately 20 eggs per female) and late maturity. Additionally, females of both species commence maturation prior to males.

The soundscape of the Anthropocene ocean.

Oceans have become substantially noisier since the Industrial Revolution. Shipping, resource exploration, and infrastructure development have increased the anthrophony (sounds generated by human activities), whereas the biophony (sounds of biological origin) has been reduced by hunting, fishing, and habitat degradation. Climate change is affecting geophony (abiotic, natural sounds).

The sources and prevalence of anthropogenic noise in Rockfish Conservation Areas with implications for marine reserve planning.

Underwater noise pollution is a recognized threat to marine life. In British Columbia, Canada, Pacific rockfish (Sebastes spp.) were historically overfished, prompting the establishment of Rockfish Conservation Areas (RCAs).