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Infauna have an intimate relationship with the sediments they inhabit, and any study conducted upon infauna must, at the very least, describe sediment conditions. Common sediment assessments in intertidal systems include particle size distribution, as well as water and organic matter contents. These measures require extracting and processing a sediment core, and this disturbance may result in data that do not necessarily reflectin situconditions. Sediment penetrability measuredin situusing a penetrometer can circumvent this limitation. However, relationships between sediment penetrability and other sediment variables are poorly understood, especially in coastal systems. We evaluated the relationship between sediment penetrability and depth to the apparent redox potential discontinuity, mean particle size, organic matter content, and water content on tidal flats along the Pacific and Atlantic coasts of Canada. We also assessed whether adding penetrability into environmental models of the infaunal community improved model performance. We observed that while penetrability is statistically related to other sediment variables, relationships to covariates were weak. Further, inclusion of penetrability with other sediment variables improved the performance of models predicting infaunal community composition. Therefore, penetrability can be considered a separate variable, and contributes to an integrated assessment of environmental conditions experienced by biota. Finally, since we evaluated this method in different soft-sediment intertidal ecosystems (mudflats to sandflats), this method is applicable to a range of systems in other geographical areas.

The sounds of Arctic marine fishes recorded in situ have been largely ignored in the literature, despite the successful application of passive acoustic monitoring (PAM) for mapping the presence of fishes at lower latitudes. Polar cod, Boreogadus saida, is a known soniferous species that holds keystone status in the Arctic and for which PAM could be a useful tool for understanding their distributions-particularly during their spawning seasons during the Arctic winter. PAM recordings from Sachs Harbour and Ulukhaktok (covering 1.5 years between them) were analysed for fish sounds. A total of 44 grunts and 3 knocks were recorded, the majority of which were recorded at Ulukhaktok during January. A difference in the number of fish calls was also seen between months with the highest number occurring during January. No diurnal patterns in the number of fish calls were observed. K-means cluster analyses based on the 90% bandwidth, duration, peak and centre frequencies showed three clusters. Type 1 occurred during October through April, Type 2 from October through February and Type 3 during October. Type 2 calls were only noted near Ulukhaktok and Type 1 calls resembled those from polar cod. These results either suggest different species or the vocal repertoire of a single species. Based on the spectral and temporal characteristics, all fish sounds resembled those from gadids. The detection of fish calls and the apparent spatio-temporal variation following the expected spawning season of polar cod illustrate the potential usefulness of PAM for Arctic fishes—particularly at a time when climate change is forcing Arctic nations to better prepare for ecological shifts and changing predator/prey relationships.

Intra- and interspecifically, larger-bodied predators generally occupy higher trophic positions (TPs). With widespread declines in large predators, there is a need to understand their size-based trophic roles to predict ecosystem-level responses. In British Columbia, Canada, we examined size-based trophic interactions between predatory fishes—3 rockfish species (genus Sebastes) and lingcod Ophiodon elongatus—and their prey, converting predator δ15N signatures to TP and analyzing stomach contents. Intraspecifically, TP scaled positively with predator length and gape width, but the rates of change varied by species. Interspecifically, TP did not scale positively with the observed mean sizes or known maximum sizes of species. Lingcod TP was lower than that of yelloweye and quillback rockfishes, which were 51 and 37%, respectively, smaller than lingcod. Yellowtail rockfish had the smallest average size, yet their mean TP did not differ significantly from that of lingcod. Neither species differences in some morphometric traits known to influence body size-TP relationships nor phylogenetic history explained these results. Most prey consumed were

Campbell, Lily, Dudas, Sarah E., Juanes, Francis, Allen Gerwing, Alyssa M., Gerwing, Travis G. (2020): Invertebrate communities, sediment parameters and food availability of intertidal soft-sediment ecosystems on the north coast of British Columbia, Canada. Journal of Natural History 54 (15-16): 919-945, DOI: 10.1080/00222933.2020.1770886, URL: http://dx.doi.org/10.1080/00222933.2020.1770886

Sablefish sounds, named rasps, were recorded at two captive facilities in British Columbia and Washington State. Rasps consisted of highly variable broadband trains of 2 to 336 ticks that lasted between 74 and 10 500 ms. The 260 rasps that were measured contained frequencies between 344 and 34 000 Hz with an average peak frequency of 3409 Hz. The frequency structure of ticks within rasps was highly variable and included both positive and negative trends. This finding makes sablefish one of the few deep-sea fish for which sounds have been validated and described. The documentation of sablefish sounds will enable the use of passive acoustic monitoring methods in fisheries and ecological studies of this commercially important deep-sea fish.

Stable nitrogen (δ15 N) and carbon (δ13 C) isotope ratios from muscle, liver and yolk were analysed from the mother and embryos of an ovoviviparous shark, Hexanchus griseus. Embryonic liver and muscle had similar δ15 N and δ13 C ratios or were depleted in heavy isotopes, compared to the same maternal somatic and reproductive yolk tissues, but no relationship existed between δ15 N or δ13 C and embryo length, as expected, because a switch to placental nourishment is lacking in this species. This study expands the understanding of maternal nourishment and embryonic stable isotope differences in ovoviviparous sharks.

Spatial subsidies are associated with pronounced ecosystem responses, as nutrients cross ecological boundaries and cascade through food webs. While the importance of subsidies is known, the role of shellfish, specifically molluscs, as a marine subsidy has not been formally described. Focusing primarily on the Pacific coast of North America, we identify vectors that transport shellfish‐derived nutrients into coastal terrestrial environments, including birds, mammals, and over 13 000 yr of marine resource use by people. Evidence from recipient ecosystems suggests shellfish drastically influence soil chemistry, forest productivity and the diversity of primary producers at the regional and landscape level. Responses in higher trophic levels have not yet been investigated, but given documented responses in lower trophic levels, this may be due to a lack of examination. To determine if the processes we describe within the northeast Pacific are pertinent to coastal environments worldwide, we also explore shellfish subsidies globally, with a specific focus on temperate and tropical islands. As shellfish are not as spatially or temporally constrained as other subsidies, our examination suggests our findings are applicable to many other geographical regions along the marine–terrestrial interface.

16 pages, 4 figures, 2 tables, Increasing interest in the acquisition of biotic and abiotic resources from within the deep sea (e.g., fisheries, oil–gas extraction, and mining) urgently imposes the development of novel monitoring technologies, beyond the traditional vessel-assisted, time-consuming, high-cost sampling surveys. The implementation of permanent networks of seabed and water-column-cabled (fixed) and docked mobile platforms is presently enforced, to cooperatively measure biological features and environmental (physicochemical) parameters. Video and acoustic (i.e., optoacoustic) imaging are becoming central approaches for studying benthic fauna (e.g., quantifying species presence, behavior, and trophic interactions) in a remote, continuous, and prolonged fashion. Imaging is also being complemented by in situ environmental-DNA sequencing technologies, allowing the traceability of a wide range of organisms (including prokaryotes) beyond the reach of optoacoustic tools. Here, we describe the different fixed and mobile platforms of those benthic and pelagic monitoring networks, proposing at the same time an innovative roadmap for the automated computing of hierarchical ecological information on deep-sea ecosystems (i.e., from single species’ abundance and life traits to community composition, and overall biodiversity), This work was developed within the framework of the Tecnoterra (ICM-CSIC/UPC) and the following project activities: ARIM (Autonomous Robotic sea-floor Infrastructure for benthopelagic Monitoring; MartTERA ERA-Net Cofound), ARCHES (Autonomous Robotic Networks to Help Modern Societies; German Helmholtz Association), RESBIO (Grant TEC2017-87861-R; Ministerio de Ciencia, Innovación y Universidades), RESNEP (Grant CTM2017-82991-C2-1-R; Ministerio de Ciencia, Innovacion y Universidades), MERCES (Marine Ecosystem Restoration in Changing European Seas - GA No. 689518), and IDEM (Implementing the MSFD to the Deep Mediterranean Sea, GA No. 11.0661/2017/750680/SUB/ENV.C2)

Determining how energy flows through ecosystems reveals underlying ecological patterns that drive processes such as growth and food web dynamics. Models that assess the transfer of energy from producers to consumers require information on the energy content or energy density (ED) of prey species. ED is most accurately measured through bomb calorimetry, but this method suffers from limitations of cost, time, and sample requirements that often make it unrealistic for many studies. Percent dry weight (DW) is typically used as a proxy for ED, but this measure includes an indigestible portion (e.g., bones, shell, salt) that can vary widely among organisms. Further, several distinct models exist for various taxonomic groups, yet none can accurately estimate invertebrate, vertebrate and plant ED with a single equation. Here, we present a novel method to estimate the ED of organisms using percent ash‐free dry weight (AFDW). Using data obtained from 11 studies diverse in geographic, temporal and taxonomic scope, AFDW, DW as well as percent protein and percent lipid were compared as predictors of ED. Linear models were produced on a logarithmic scale, including dummy variables for broad taxonomic groups. AFDW was the superior predictor of ED compared to DW, percent protein content and percent lipid content. Model selection revealed that using correction factors (dummy variables) for aquatic animals (AA) and terrestrial invertebrates (TI) produced the best‐supported model—log10(ED) = 1.07*log10(AFDW) − 0.80 (R 2 = 0.978, p 0.97), suggesting that AFDW can be used with high degrees of certainty to predict the ED of taxonomically diverse organisms. Our AFDW model will allow ED to be determined with minimal cost and time requirements and excludes ash‐weight from estimates of digestible mass. Its ease of use will allow for ED to be more readily and accurately determined for diverse taxa across different ecosystems., Determining how energy flows through ecosystems reveals underlying ecological patterns that drive processes such as growth and food web dynamics. Models that assess the transfer of energy from producers to consumers require information on the energy density (ED) of prey species, however, measuring this value carries limitations of cost, time, and sample requirements. Here, we present a novel method to accurately estimate the ED of invertebrates, vertebrates, and plants using a single equation, with minimal cost and time requirements using percent ash‐free dry weight.

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. An almost instant change in the marine soundscape ensued, with ambient sound levels in busy channels dropping nearly threefold the first 12 h. This sudden drop led fish and dolphins to experience an immediate increase in their communication ranges by up to an estimated 65%. Very low vessel activity during the lockdown (indicated by the presence of vessel noise over the day) revealed new insights into cumulative noise effects from vessels on auditory masking. For example, at sites nearer Auckland City, communication ranges increased approximately 18 m (22%) or 50 m (11%) for every 10% decrease in vessel activity for fish and dolphins, respectively. However, further from the city and in deeper water, these communication ranges were increased by approximately 13 m (31%) or 510 m (20%). These new data demonstrate how noise from small vessels can impact underwater soundscapes and how marine animals will have to adapt to ever-growing noise pollution.

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. Returning adults were collected before and after entering the Fraser River, yielding marine- and river-collected groups, respectively. Fish were exposed to a mild (seine) or severe (gill net) fishery treatment at collection, and then held in circulating freshwater tanks for up to four weeks at historical (14°C) or projected migration temperatures (18°C). Using weekly nonlethal gill biopsies and high-throughput qPCR, we quantified loads of up to 46 pathogens with host stress and immune gene expression. Marine-captured fish had less severe infections than river-captured fish, a short migration distance (100 km, 5-7 d) that produced profound infection differences. At 14°C, river-collected fish survived 1-2 weeks less than marine-collected fish. All fish held at 18°C died within 4 weeks unless they experienced minimal handling. Gene expression correlated with infections in river-collected fish, while marine-collected fish were more stressor-responsive. Cumulative stressors were detrimental regardless of infections or collection location, likely due to extreme physiological disturbance. Because river-derived infections correlated with single stressor responses, river entry likely decreases stressor resilience of adult salmon by altering both physiological status and pathogen burdens, which redirect host responses toward disease resistance.

Monitoring coral reefs is vital to the conservation of these at-risk ecosystems. While most current monitoring methods are costly and time-intensive, passive acoustic monitoring (PAM) could provide a cost-effective, large scale reef monitoring tool. However, for PAM to be reliable, the results must be field tested to ensure that the acoustic methods used accurately represent the certain ecological components of the reef being studied. For example, recent acoustic studies have attempted to describe the diversity of coral reef fish using the Acoustic Complexity Index (ACI) but despite inconsistent results on coral reefs, ACI is still being applied to these ecosystems. Here, we investigated the potential for ACI and sound pressure level (SPL – another common metric used), to accurately respond to biological sounds on coral reefs when calculated using three different frequency resolutions (31.2 Hz, 15.6 Hz, and 4 Hz). Acoustic recordings were made over two to three-week periods in 2017 and 2018 at sites around Kiritimati (Christmas Island), in the central equatorial Pacific. We hypothesized that SPL would be positively correlated with the number of nearby fish sounds in the low frequency band and with snapping shrimp snaps in the high frequency band, but that ACI would rely on its settings, specifically its frequency resolution, to describe sounds in both frequency bands. We found that nearby fish sounds were partially responsible for changes in low frequency SPL in the morning, during crepuscular chorusing activity, but not at other times of day. Snapping shrimp snaps, however, were responsible for large changes in high frequency SPL. ACI results were reliant on the frequency band chosen, with the 31.2 Hz frequency resolution models being chosen as the best models. In the low frequency band, the effect of fish knocks was positive and significant only in the 31.2 Hz and 15.6 Hz models while in the high frequency band snapping shrimp snaps were negatively associated with ACI in all frequency resolutions. These results contribute to a growing body of evidence against the continued use of ACI without standardization on highly energetic underwater ecosystems like coral reefs and highlight the importance of extensive field testing of new acoustic metrics prior to their adoption and proliferation.

Multiple stressors are commonly encountered by wild animals, but their cumulative effects are poorly understood, especially regarding infection development. We conducted a holding study with repeated gill and blood sampling to characterize the effects of cumulative stressors on infection development in adult coho salmon. Treatments included chronic thermal stress (15°C vs. 10°C) and acute gill net entanglement with an air exposure (simulating fisheries bycatch release). The potential loadings of 35 infectious agents and the expression of 17 host immune genes were quantified using high-throughput quantitative polymerase chain reaction, while host physiology was characterized with chemical analysis of blood. Temporal increases in infectious agent richness and loads were concurrent with decreased expression of immune genes in fish sampled in the river. In the laboratory, mortality was minimal in cool water regardless of fishery treatment ( 1 wk) and enhanced mortality associated with handling and biopsy (∼40% both sexes). Experimental gillnetting at high temperature further enhanced female mortality (73%). Fish held at high temperature demonstrated heavier infectious agent loads, osmoregulatory impairment, suppressed female maturation, and upregulation of inflammatory and extracellular immune genes. At high temperature, heavy Parvicapsula minibicornis loads were associated with premature mortality. Females exhibited physiological impairment from both stressors after 1 wk, and infection burdens correlated poorly with immune gene regulation compared with males. Cumulative effects of multiple stressors on female mortality are likely a function of physiological impairment and enhanced infections at high temperature.

Aquatic ecosystems have been managed for millennia. Indigenous communities in North America pioneered numerous marine resource management strategies to ensure food security and support thriving economies, which have been active throughout the Northwest Coast of North America for over 14 000 years. Developed to increase shellfish productivity, clam gardens have been active for millennia. The diverse infaunal communities within these ecosystems can act as indicators of habitat alterations and provide an opportunity to study ecological community responses to seascapes shaped by millennia-old resource management structures. To determine how community structure differs between clam gardens and unmodified areas, we assessed infaunal diversity and density between intertidal mudflats, sandflats, and clam gardens. Differences in community composition were found among site types, with certain taxa, including culturally important species increasing within clam gardens. Per cent similarity analyses indicated that infaunal communities were more dissimilar among, than within site types. Furthermore, regression trees indicated that increases in diversity and density were closely correlated with the amount of shell and gravel within each habitat, which are associated with clam garden function and management practices. Species-specific and environmental responses to clam gardens indicate that human modifications in nearshore habitats created novel and distinct types of soft sediment communities.

Gelatinous zooplankton (GZ) can impact productivity of marine ecosystems through competition with small pelagic fish and predation on early life history stages of species from multiple trophic levels. Nevertheless, GZ do not always represent ‘trophic dead ends.’ Some predators directly consume GZ, and many species host parasitoids which in turn are prey for other organisms. We characterized trophic relationships between the fried-egg jellyfish Phacellophora camtschatica, its hyperiid amphipod parasite (Hyperia medusarum), and juvenile Chinook Salmon Oncorhynchus tshawytscha in the Salish Sea. Hyperia medusarum occurred in 29–47% of Chinook Salmon stomachs over 3 years and were observed in high abundance on P. camtschatica medusae (mean = 428 individuals per medusa). Light and transmission electron microscopy confirmed the presence of morphologically similar nematocysts in the foreguts of H. medusarum from both medusae and Chinook Salmon stomachs. Occurrence of H. medusarum in Chinook Salmon diets was also positively related to an index of P. camtschatica abundance. Chinook Salmon stomachs contained almost exclusively mature female H. medusarum while males and juveniles were common on medusae. Size and sex ratio differences between hyperiids in Chinook Salmon diets and on medusae could reflect predator selectivity or sex and/or life-stage specific differences in H. medusarum behavior. Our results support previous speculation that GZ abundance may facilitate predation on hyperiids by Pacific Salmon. Hyperiid-mediated energy flow from GZ to fish is not limited to medusa-associated fish species and should be considered in studies of marine food webs.

Rockfish, particularly yelloweye (Sebastes ruberrimus) and quillback (Sebastes maliger), are vulnerable to overfishing because they mature late and have affinity for shallow water (50–200 m) habitats. Because studies relating habitat characteristics with the distribution and presence of rockfishes at large scales (100s of kilometres) remain scarce, we sought to investigate the relationships between benthic characteristics with the presence–absence and abundance of rockfishes caught in longline surveys in nearshore waters of southern British Columbia. Habitat parameters were calculated from a 20 m resolution bathymetry layer. Yelloweye and quillback were examined separately and combined with 19 other rockfish species in a species aggregate (total rockfish); occurrence data were fitted with generalized linear mixed effects models, and abundance data were fitted with zero-inflated mixed effects models. The relationship between rockfish abundance with presence–absence and slope, distance to rocky habitat, and fine bathymetric position index suggests that these species prefer rocky, steep habitat. While underwater visual observation data offer measures of visual fish habitat and abundance, longline surveys may be a more cost-effective method for large-scale studies.

Formosa landlocked salmon (FLS), Oncorhynchus formosanus, is a Critically Endangered species (IUCN Red List, Kottelat 1996) native to Taiwan and only remaining in a small mountain stream, Chichiawan Stream in Shei-Pa National Park (Yan 2000). The species is at a critical crossroads; it is facing a variety of threats including small population numbers, fragmented habitat due to damming, invasive species, and climate change. It is thought that FLS originally migrated south from the Sea of Japan when ocean waters were cooler than they are today (Numachi et al. 1990; Gwo et al. 2008; Gwo 2019a). They inhabited one river system, the Tachia River, and became landlocked when sea level rose. It is now relegated to small populations between flood and erosion control dams. Conservation strategies will depend on how the authorities answer the question posed in the title of this paper; do they want to conserve FLS as a distinct taxonomic entity with the likelihood that it will go extinct given its limited genetic variability, or should they perform genetic rescue, thereby bringing in new genetic material from a different species/subspecies to increase genetic variability but risking the unique status of FLS?

Many small pelagic fish species exhibit dramatic fluctuations in abundance accompanied by range expansions during periods of favorable environmental conditions. The location and extent of suitable habitats also shift in response to both short term variability and long term trends in climate. Near the margins of a contemporary range, trends in abundance may reflect a continuation of historical variability but may also foreshadow future changes in distribution. The Salish Sea (all inland marine waters of Washington State and southern British Columbia; made up of the Strait of Georgia, Strait of Juan de Fuca, and Puget Sound) is a highly productive estuarine system at the northern end of the distribution of Northern Anchovy (Engraulis mordax). An apparent recent (2014–2016) increase in Northern Anchovy abundance has generated interest in the dynamics of this species in the Salish Sea. We compiled recent and historical data to understand spatiotemporal patterns of distribution and fluctuations in abundance over the last century. Spatially-consistent occurrence of eggs, larvae, and juveniles, and year-round presence of multiple age classes, confirm that successful spawning and recruitment of Northern Anchovy occurs within the Salish Sea. Most periods of elevated Northern Anchovy abundance in the last century have corresponded to, or lagged, periods of elevated ocean temperatures. While a 2005 peak in abundance within the Salish Sea also corresponded to higher abundance of Northern Anchovy in adjacent regions of the coastal Pacific Ocean, it seems unlikely that Salish Sea abundance is controlled primarily by advection or migration from external populations. Persistence of elevated ocean temperatures like those observed from 2014 to 2016 could lead to consistently high abundance of Northern Anchovy within the Salish Sea, with implications for trophic relationships and ecosystem function.

Efficiently evaluating industrial activities plays an essential role in determining the extent to which human–ecosystem interactions may lead to species loss, disrupted community dynamics, ...

Infectious disease dynamics of wild Pacific salmon are poorly understood and may play a prominent role in recent declines of Chinook salmon (Oncorhynchus tshawytscha) populations. Multiple stressors influence migration success of adult salmon, such as rising river temperatures and capture and release by fisheries, and likely modulate infection development. To understand how these factors impact survival and migration behaviour of adult salmon in fresh water, we conducted simultaneous holding and telemetry studies with gillnet treatments and nonlethal biopsy. Laboratory fish were held and treated in either cool (9 °C) or warm (14 °C) water. High temperature reduced survival but did not amplify simulated gillnetting effects. Gillnetting reduced migration rate and distance traveled upriver and increased infection burdens, but had no effect on longevity. Heavy infections were associated with reduced longevity and faster migrations. Blood properties and immunity were associated with stressors, survival, and infections. These results improve our predictive capability regarding how stressors can reduce migration success and longevity of Pacific salmon, demonstrating multiple impacts of infections and adding to growing knowledge of disease dynamics in wild fish populations.

Large scale dams have numerous significant impacts on river and nearshore components of watersheds. Large scale dam removal is therefore an increasingly useful restoration tool that reestablishes physical processes and habitats that form nearshore ecosystems. Removing large scale dams will likely affect the functional ecology of nearshore ecosystems, but this concept has yet to be explored. Here we use data from a decade long study to define how the functional ecology of fish responded to large scale dam removal. Dam removal resulted in shifts in the nearshore through the reconnection of riverine and marine hydrodynamic system, large-scale and rapid creation of nearshore habitats, and a shift in nearshore habitats from tidally influenced to non-tidally influenced habitats. The functional diversity of the fish community within the system restored by dam removal was volatile during and after dam removal. Dam removal released sediment that formed new lower river and estuary. These new nearshore habitats supported a fish community of significantly greater functional dispersion and entropy relative to previously present beaches within and outside the new delta. That is, species unique in their diet, habitat use, morphology, and size were abundant relative to less functionally unique fish in newly formed beaches. These trends were temporary as there were no significant differences in functional diversity or entropy of fishes among sites after the restoration. Newly formed habitats proved to be more diverse but had lower resiliency after dam removal. Newly establishing nearshore sites appear more vulnerable to non-native and nuisance species that could disrupt the establishment of the watershed and shoreline. While functional richness at the original estuary sites dropped dramatically after dam removal, resiliency was higher after dam removal corresponding to a shift from estuary to lower river side channel habitat, indicating a more stable nearshore zone than new sites. We anticipate that functional diversity at the newly formed nearshore areas will stabilize as the habitats are vegetated and mature.

[Abstract] 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). Existing evidence shows that anthrophony affects marine animals at multiple levels, including their behavior, physiology, and, in extreme cases, survival. This should prompt management actions to deploy existing solutions to reduce noise levels in the ocean, thereby allowing marine animals to reestablish their use of ocean sound as a central ecological trait in a healthy ocean., [Background] Sound is the sensory cue that travels farthest through the ocean and is used by marine animals, ranging from invertebrates to great whales, to interpret and explore the marine environment and to interact within and among species. Ocean soundscapes are rapidly changing because of massive declines in the abundance of sound-producing animals, increases in anthropogenic noise, and altered contributions of geophysical sources, such as sea ice and storms, owing to climate change. As a result, the soundscape of the Anthropocene ocean is fundamentally different from that of preindustrial times, with anthropogenic noise negatively impacting marine life., [Advances] We find evidence that anthropogenic noise negatively affects marine animals. Strong evidence for such impacts is available for marine mammals, and some studies also find impacts for fishes and invertebrates, marine birds, and reptiles. Noise from vessels, active sonar, synthetic sounds (artificial tones and white noise), and acoustic deterrent devices are all found to affect marine animals, as are noise from energy and construction infrastructure and seismic surveys. Although there is clear evidence that noise compromises hearing ability and induces physiological and behavioral changes in marine animals, there is lower confidence that anthropogenic noise increases the mortality of marine animals and the settlement of their larvae., [Outlook] Anthropogenic noise is a stressor for marine animals. Thus, we call for it to be included in assessments of cumulative pressures on marine ecosystems. Compared with other stressors that are persistent in the environment, such as carbon dioxide emitted to the atmosphere or persistent organic pollutants delivered to marine ecosystems, anthropogenic noise is typically a point-source pollutant, the effects of which decline swiftly once sources are removed. The evidence summarized here encourages national and international policies to become more ambitious in regulating and deploying existing technological solutions to mitigate marine noise and improve the human stewardship of ocean soundscapes to maintain a healthy ocean. We provide a range of solutions that may help, supported by appropriate managerial and policy frameworks that may help to mitigate impacts on marine animals derived from anthropogenic noise and perturbations of soundscapes., This research was funded by KAUST through the Tarek Ahmed Juffali Research Chair in Red Sea Ecology and baseline funding to C.M.D.

18 pages, 5 figures, supplementary data https://doi.org/10.1016/j.biocon.2021.109175.-- The data supporting the findings of this study are available in the Supplementary Materials (Appendix 3–5, Table A3-A5). Raw datasets (where available) and results summary tables for each analysis of human mobility and empirical datasets are deposited in a github repository: https://github.com/rjcommand/PAN-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. However, negative effects of lockdown on conservation also emerged, as confinement resulted in some park officials being unable to perform conservation, restoration and enforcement tasks, resulting in local increases in illegal activities such as hunting. Overall, there is a complex mixture of positive and negative effects of the pandemic lockdown on nature, all of which have the potential to lead to cascading responses which in turn impact wildlife and nature conservation. While the net effect of the lockdown will need to be assessed over years as data becomes available and persistent effects emerge, immediate responses were detected across the world. Thus initial qualitative and quantitative data arising from this serendipitous global quasi-experimental perturbation highlights the dual role that humans play in threatening and protecting species and ecosystems. Pathways to favorably tilt this delicate balance include reducing impacts and increasing conservation effectiveness, The Canada Research Chairs program provided funding for the core writing team. Field research funding was provided by A.G. Leventis Foundation; Agence Nationale de la Recherche, [grant number ANR-18-32–0010CE-01 (JCJC PEPPER)]; Agencia Estatal de Investigaci; Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI), [grant number M1420-09-5369-FSE-000002]; Alan Peterson; ArcticNet; Arkadaşlar; Army Corp of Engineers; Artificial Reef Program; Australia's Integrated Marine Observing System (IMOS), National Collaborative; Research Infrastructure Strategy (NCRIS), University of Tasmania; Australian Institute of Marine Science; Australian Research Council, [grant number LP140100222]; Bai Xian Asia Institute; Batubay Özkan; BC Hydro Fish and Wildlife Compensation Program; Ben-Gurion University of the Negev; Bertarelli Foundation; Bertarelli Programme in Marine Science; Bilge Bahar; Bill and Melinda Gates Foundation; Biology Society of South Australia; Boston University; Burak Över; California State Assembly member Patrick O'Donnell; California State University Council on Ocean Affairs, Science & Technology; California State University Long Beach; Canada Foundation for Innovation (Major Science Initiative Fund and funding to Oceans Network Canada), [grant number MSI 30199 for ONC]; Cape Eleuthera Foundation; Centre National d'Etudes Spatiales; Centre National de la Recherche Scientifique; Charles Darwin Foundation, [grant number 2398]; Colombian Institute for the Development of Science and Technology (COLCIENCIAS), [grant number 811–2018]; Colombian Ministry of Environment and Sustainable Development, [grant number 0041–2020]; Columbia Basin Trust; Commission for Environmental Cooperation; Cornell Lab of Ornithology; Cultural practices and environmental certification of beaches, Universidad de la Costa, Colombia, [grant number INV.1106–01–002-15, 2020–21]; Department of Conservation New Zealand; Direction de l'Environnement de Polynésie Française; Disney Conservation Fund; DSI-NRF Centre of; Excellence at the FitzPatrick Institute of African Ornithology; Ecology Project International; Emin Özgür; Environment and Climate Change Canada; European Community: RTD programme - Species Support to Policies; European Community's Seventh Framework Programme; European Union; European Union's Horizon 2020 research and innovation programme, Marie Skłodowska-Curie, [grant number 798091, 794938]; Faruk Eczacıbaşı; Faruk Yalçın Zoo; Field research funding was provided by King Abdullah University of Science and Technology; Fish and Wildlife Compensation Program; Fisheries and Oceans Canada; Florida Fish and Wildlife Conservation Commission, [grant numbers FWC-12164, FWC-14026, FWC-19050]; Fondo Europeo de Desarrollo Regional; Fonds québécois de la recherche nature et technologies; Foundation Segré; Fundação para a Ciência e a Tecnologia (FCT Portugal); Galapagos National Park Directorate research, [grant number PC-41-20]; Gordon and Betty Moore Foundation, [grant number GBMF9881 and GBMF 8072]; Government of Tristan da Cunha; Habitat; Conservation Trust Foundation; Holsworth Wildlife Research Endowment; Institute of Biology of the Southern Seas, Sevastopol, Russia; Instituto de Investigación de Recursos Biológicos Alexander von Humboldt; Instituto Nacional de Pesquisas Espaciais (INPE), Brazil; Israeli Academy of Science's Adams Fellowship; King Family Trust; Labex, CORAIL, France; Liber Ero Fellowship; LIFE (European Union), [grant number LIFE16 NAT/BG/000874]; María de Maeztu Program for Units of Excellence in R&D; Ministry of Science and Innovation, FEDER, SPASIMM,; Spain, [grant number FIS2016–80067-P (AEI/FEDER, UE)]; MOE-Korea, [grant number 2020002990006]; Mohamed bin Zayed Species Conservation Fund; Montreal Space for Life; National Aeronautics and Space Administration (NASA) Earth and Space Science Fellowship Program; National Geographic Society, [grant numbers NGS-82515R-20]; National Natural Science Fund of China; National Oceanic and Atmospheric Administration; National Parks Board, Singapore; National Science and Technology Major Project of China; National Science Foundation, [grant number DEB-1832016]; Natural Environment Research Council of the UK; Natural Sciences and Engineering Research Council of Canada (NSERC), Alliance COVID-19 grant program, [grant numbers ALLRP 550721–20, RGPIN-2014-06229 (year: 2014), RGPIN-2016-05772 (year: 2016)]; Neiser Foundation; Nekton Foundation; Network of Centre of Excellence of Canada: ArcticNet; North Family Foundation; Ocean Tracking Network; Ömer Külahçıoğlu; Oregon State University; Parks Canada Agency (Lake Louise, Yoho, and Kootenay Field Unit); Pew Charitable Trusts; Porsim Kanaf partnership; President's International Fellowship Initiative for postdoctoral researchers Chinese Academy of Sciences, [grant number 2019 PB0143]; Red Sea Research Center; Regional Government of the Azores, [grant number M3.1a/F/025/2015]; Regione Toscana; Rotary Club of Rhinebeck; Save our Seas Foundation; Science & Technology (CSU COAST); Science City Davos, Naturforschende Gesellschaft Davos; Seha İşmen; Sentinelle Nord program from the Canada First Research Excellence Fund; Servizio Foreste e Fauna (Provincia Autonoma di Trento); Sigrid Rausing Trust; Simon Fraser University; Sitka Foundation; Sivil Toplum Geliştirme Merkezi Derneği; South African National Parks (SANParks); South Australian Department for Environment and Water; Southern California Tuna Club (SCTC); Spanish Ministry for the Ecological Transition and the Demographic Challenge; Spanish Ministry of Economy and Competitiveness; Spanish Ministry of Science and Innovation; State of California; Sternlicht Family Foundation; Suna Reyent; Sunshine Coast Regional Council; Tarea Vida, CEMZOC, Universidad de Oriente, Cuba, [grant number 10523, 2020]; Teck Coal; The Hamilton Waterfront Trust; The Ian Potter Foundation, Coastwest, Western Australian State NRM; The Red Sea Development Company; The Wanderlust Fund; The Whitley Fund; Trans-Anatolian Natural Gas Pipeline; Tula Foundation (Hakai Institute); University of Arizona; University of Pisa; US Fish and Wildlife Service; US Geological Survey; Valencian Regional Government; Vermont Center for Ecostudies; Victorian Fisheries Authority; VMRC Fishing License Fund; and Wildlife Warriors Worldwide, With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S

27 pages, Four operational factors, together with high development cost, currently limit the use of ocean observatories in ecological and fisheries applications: 1) limited spatial coverage, 2) limited integration of multiple types of technologies, 3) limitations in the experimental design for in situ studies, and 4) potential unpredicted bias in monitoring outcomes due to the infrastructure's presence and functioning footprint. To address these limitations, we propose a novel concept of a standardised ‘ecosystem observatory module’ structure composed of a central node and three tethered satellite pods together with permanent mobile platforms. The module would be designed with a rigid spatial configuration to optimise overlap among multiple observation technologies, each providing 360° coverage of a cylindrical or hemi-spherical volume around the module, including permanent stereo video cameras, acoustic imaging sonar cameras, horizontal multibeam echosounders, and a passive acoustic array. The incorporation of multiple integrated observation technologies would enable unprecedented quantification of macrofaunal composition, abundance, and density surrounding the module, as well as the ability to track the movements of individual fishes and macroinvertebrates. Such a standardised modular design would allow for the hierarchical spatial connection of observatory modules into local module clusters and larger geographic module networks providing synoptic data within and across linked ecosystems suitable for fisheries and ecosystem-level monitoring on multiple scales

We describe three portable volumetric audio/video arrays capable of identifying species-specific fish sounds in the wild. Each array can record fish sounds, acoustically localize the fish in three-dimensions (using linearized or fully non-linear inversion), and record video to identify the species and observe their behavior. The design of each array accommodates specific logistical and financial constraints, covering a range of nearshore habitats and applications. The first platform is composed of six hydrophones, an acoustic recorder, and two video cameras secured to a 2 × 2 × 3 m PVC frame. Hydrophone placement is defined using simulated annealing to maximize localization accuracy. The second platform uses a single video camera, four hydrophones, and an acoustic recorder on a one cubic meter PVC frame. It can be deployed on heterogeneous substrates but has lower localization capabilities. The third platform consists of four hydrophones connected to an acoustic recorder mounted on a tethered underwater drone with built-in video. It allows remote control and real-time positioning in response to observed fish presence but with reduced localization capabilities. The three platforms were deployed off British Columbia, Canada, and used to identify and characterize new sounds from quillback rockfish, copper rockfish, and lingcod.

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. SPL (50–1000 Hz) ranged from 70 to 127 dB re 1 μPa (median = 91 dB). SPL increased as wind speed increased, but decreased as both ice concentration and air temperature increased, and SPL increased as the number of ships per day increased. This study provides a baseline for underwater sound levels in the Canadian Arctic and fills many geographic gaps on published underwater sound levels.

Masking is often assessed by quantifying changes, due to increasing noise, to an animal's communication or listening range. While the methods used to measure communication or listening ranges are functionally similar if used for vocalizations, they differ in their approaches: communication range is focused on the sender's call, while the listening range is centered on the listener's ability to perceive any signal. How these two methods differ in their use and output is important for management recommendations. Therefore it was investigated how these two methods may alter the conclusions of masking assessments based on Atlantic cod calls in the presence of a commercial air gun array. The two methods diverged with increasing distance from the masking noise source with maximum effects lasting longer between air gun pulses in terms of communication range than listening range. Reductions in the cod's communication ranges were sensitive to fluctuations in the call's source level. That instability was not observed for the listening range. Overall, changes to the cod's communication range were more conservative but very sensitive to the call source level. A high level of confidence in the call is therefore required, while confidence in the receiver's audiogram and soundscape is required for the listening range method.

The soundscape composition of temperate freshwater habitats is poorly understood. Our goal was to document the occurrence of biological and anthropogenic sounds in freshwater habitats over a large (46,000 km2) area along the geographic corridors of five major river systems in North America (Connecticut, Kennebec, Merrimack, Presumpscot, and Saco). The underwater soundscape was sampled in 19 lakes, 17 ponds, 20 rivers and 20 streams, brooks and creeks that were grouped into broad categories (brook/creek, pond/lake, and river). Over 7,000 sounds were measured from 2,750 minutes of recording in 173 locations over a five-week period in the spring of 2008. Sounds were classified into major anthropophony (airplane, boat, traffic, train and other noise) and biophony (fish air movement, also known as air passage, other fish, insect-like, bird, and other biological) categories. The three most significant findings in this study are: 1) freshwater habitats in the New England region of North America contain a diverse array of unidentified biological sounds; 2) fish air movement sounds constitute a previously unrecognized important component of the freshwater soundscape, occurring at more locations (39%) and in equal abundance than other fish sounds; and 3) anthropogenic noises dominate the soundscape accounting for 92% of the soundscape by relative percent time. The high potential for negative impacts of the anthropophony on freshwater soundscapes is suggested by the spectral and temporal overlap of the anthropophony with the biophony, the higher received sound levels of the anthropophony relative to the biophony, and observations of a significant decline in the occurrence, number, percent time, and diversity of the biophony among locations with higher ambient received levels. Our poor understanding of the biophony of freshwater ecosystems, together with an apparent high temporal exposure to anthropogenic noise across all habitats, suggest a critical need for studies aimed at identification of biophonic sound sources and assessment of potential threats from anthropogenic noises.

We describe the “FishCam”, a low-cost ( 500 USD) autonomous camera package to record videos and images underwater. The system is composed of easily accessible components and can be programmed to turn ON and OFF on customizable schedules. Its 8-megapixel camera module is capable of taking 3280 × 2464-pixel images and videos. An optional buzzer circuit inside the pressure housing allows synchronization of the video data from the FishCam with passive acoustic recorders. Ten FishCam deployments were performed along the east coast of Vancouver Island, British Columbia, Canada, from January to December 2019. Field tests demonstrate that the proposed system can record up to 212 h of video data over a period of at least 14 days. The FishCam data collected allowed us to identify fish species and observe species interactions and behaviors. The FishCam is an operational, easily-reproduced and inexpensive camera system that can help expand both the temporal and spatial coverage of underwater observations in ecological research. With its low cost and simple design, it has the potential to be integrated into educational and citizen science projects, and to facilitate learning the basics of electronics and programming.

Parents providing care must sometimes choose between rearing locations that are most favourable for offspring versus those that are most favourable for themselves. Here, we measured how both parental and offspring performance varied in nest sites distributed along an environmental gradient. The plainfin midshipman fish Porichthys notatus nests along a tidal gradient. When ascending from the subtidal to the high intertidal at low tide, both nest temperature and frequency of air exposure increase. We used one lab and two field experiments to investigate how parental nest site choices across tidal elevations are linked to the physiological costs incurred by parents and the developmental benefits accrued by offspring. Under warmer incubation conditions, simulating high intertidal nests, offspring developed faster but had higher mortality rates compared to those incubated in cooler conditions that mimicked subtidal nests. In the field, males in higher intertidal nests were more active caregivers, but their young still died at the fastest rates. Larger males claimed and retained low intertidal nests, where offspring survival and development rates were also highest. Our results suggest that males compete more intensively for nest sites in the low intertidal, where they can raise their young quickly and with lower per-offspring investments. Smaller, less-competitive males forced into higher intertidal sites nest earlier in the season and provide more active parental care, possibly to bolster brood survival under harsh environmental conditions.

Parents are expected to reduce offspring investment when confronted with reliable cues of compromised parentage, yet establishing which cues are reliable is an empirical challenge. Presenting a potential cuckolder to a breeding male is often used in experiments as an indirect cue of paternity loss. However, determining the reliability and hence the utility of this cue is an important but often-overlooked research step. Furthermore, cues of compromised parentage are typically manipulated only during the narrow time window(s) when copulations take place, and so we currently have a poor understanding of whether these cues also convey useful information at other critical timepoints in the reproductive cycle, such as during nest site selection. Here, we present a series of field and laboratory studies using a paternal care giving toadfish, the plainfin midshipman fish (Porichthys notatus) to address these questions. We tested whether the presence of a potential cuckolder near a potential nesting site reduces the odds that males will choose to nest at that site, or reduces the amount of care they provide for offspring. Overall, we found no clear effect of cuckolder presence on the likelihood that a male would occupy nor abandon a nesting site, nor on the amount of paternal care provided. The presentation of a single sneaker male may have been too weak a signal of cuckoldry to elicit a response from guarder males. Alternatively, a single sneaker male may not represent a severe enough threat to paternity to warrant a response. We highlight the importance of considering the diverse range of natural history and ecological factors that underlie paternity cue utility across different model organisms. Breeding decisions, such as which nesting sites to occupy or how much to invest into offspring, may be affected by external cues of parentage loss (e.g. cuckoldry) or risk thereof. Here, we tested whether the presence of a cuckolder male in the breeding environment affects male nest site selection and paternal care. Despite being a commonly used putative indirect cue of sperm competition and paternity loss, we found no clear evidence that the presence of a single sneaker male affected these breeding decisions. Our results underscore the importance of first establishing the utility of various cues, which involves considering the ecological context from which the cues arise, before using them to assess the mechanisms underlying animal decision-making.

Trout and char (hereafter, trout) represent some of the more cul-turally, economically and ecologically important taxa of freshwater fishes worldwide (Kershner, Williams, Gresswell, & Lobón-Cerviá, 2019a). Native to all continents in the Northern Hemisphere (as well as western Mediterranean Africa), trout belong to seven genera (Oncorhynchus, Salvelinus, Salmo, Hucho, Parahucho, Brachymystax and Salvethymus), which are distributed across more than 60 countries (Muhlfeld et al., 2019). Despite their broad im-portance as indicators of biodiversity in cold-water ecosystems (Haak & Williams, 2013), as well as cultural icons for food and rec-reation, nearly half of the world's recognised trout species (IUCN, 2018) are imperilled or at risk of global extinction (Muhlfeld et al., 2018, 2019). The root causes of their vulnerability include broad-scale alteration of landscapes and watersheds, dams, overhar-vest, pollution, interactions with hatchery-bred conspecifics and non-native species. However, emerging threats such as climate change and related problems such as the spread of diseases and parasites pose significant challenges and uncertainties to native trout and their habitats (Kovach et al., 2016; Muhlfeld et al., 2018). Ultimately, conservation of native trout depends on understand-ing their diversity, a willingness to address threats at their root causes and implementing progressive conservation solutions that promote persistence of these iconic species in the face of growing human pressures.

Accumulations of beach-cast seaweeds and other debris, collectively known as wrack, are a common and ecologically important occurrence along coastal regions worldwide. As the rate of seaweed introductions continues to increase, so too does their beach-cast collection for aesthetic or commercial purposes. The ecological effects of these harvests are poorly characterized in the literature, especially for nutrient-rich regions such as the Northeast Pacific. Within the southern extremity of Baynes Sound, British Columbia, beach wrack contains an introduced species of red alga called Mazzaella japonica, which became the target of a commercial beach-cast harvest in 2007. The objectives of this research were threefold: 1) to quantify the contribution of M. japonica to wrack inputs within the harvest region; 2) to explore how wrack characteristics influence macrofauna communities; and 3) to determine if the commercial removal of beach-cast seaweeds has a detectable effect on wrack characteristics and macrofauna communities. To answer these questions we monitored a series of permanent transects at six sites across the harvest region from November 2014 until March 2015. We recorded as much as 853 kg (±173 SD) of wrack per meter of shoreline, approximately 90% of which was M. japonica. Despite the removal of 675 tonnes of beach-cast seaweeds, we found that the trends in wrack biomass were similar between both harvested and unharvested locations. Macrofauna communities differed between study sites, as well as with the age class, and depth of the wrack from which they were sampled. These findings contribute to the limited literature on beach-cast seaweed harvesting and provide an important record of M. japonica wrack inputs for future research or monitoring of this non-indigenous seaweed.

Marine protected areas (MPAs) can be useful for conservation efforts, yet the effectiveness of MPAs relies on their size and location, as well as the spatial ecology of the focal species. We investigated the effectiveness of a small MPA adjacent to Cape Cod, MA (USA) for protecting American horseshoe crabs (Limulus polyphemus). We used a fixed acoustic telemetry array to study the spatial ecology of 24 adult horseshoe crabs off the coast of Chatham, Massachusetts, from June 2010 to November 2011. Two groups of horseshoe crabs were tagged in spawning habitats (separated by ∼2.0 km) with differing commercial harvesting pressure: one group inside Stage Harbor where harvesting is permitted, and the other within Monomoy National Wildlife Refuge and the Cape Cod National Seashore (the MPA) where harvesting is prohibited. In the first year of study, crabs tagged in the MPA did not go to Stage Harbor, but instead remained in the MPA and adjacent high-energy beach, whereas crabs tagged in Stage Harbor moved throughout the entire study area. In the second year of study, crabs from both tagging locations used all areas. All crabs generally moved greater distances in the MPA than in other areas, and the majority of movement we recorded was in late spring and summer. All crabs that we tagged used similar areas around Cape Cod. The MPA only provides protection when crabs are in that area, which may only be for a few months of the year. Given that all crabs used Stage Harbor, they were all exposed to potential harvest, but the MPA did provide some protection for all crabs.

Passive acoustic monitoring (PAM) can be an effective tool in the identification of fishes and mapping of their temporal and spatial distribution patterns and thereby aids in ecosystem management in remote locations. However, to date measurements of the acoustic properties of piranha have been primarily made in aquaria on captive specimens obtained through the aquarium trade. Data on the sound production of wild piranha taken under natural field conditions would enhance PAM applications. Piranha captured as part of routine annual monitoring by Operation Wallacea within the Pacaya–Samiria National Reserve in Peru were auditioned for sound production prior to release. Auditioning was done by gently holding a fish underwater in the river near a suspended hydrophone, thus recordings included the piranha sound as well as natural ambient sound. Seventy‐nine per cent of the 129 auditioned piranha, including Pygocentrus nattereri, Serrasalmus maculatus, Serrasalmus cf. sanchezi and an unidentified Serrasalmus spp. complex, produced sounds consisting of 2 to 23 barks in a sequential series. Sound production by S. maculatus and S. cf. sanchezi are reported for the first time. Bark characteristics exhibited high variation within bark series of individual fish. Piranha could not be distinguished by single variables but did exhibit significant multivariate differences. The relationship of several variables to fish size also differed significantly among species. Measurements of within‐fish variation and bark series pattern attributes were found to be useful for discrimination of sounds among piranha species. We demonstrate that closely related species of piranha can be distinguished by their sounds under natural acoustic conditions based on multivariate analyses, suggesting that passive acoustic monitoring (PAM) can be an effective tool for ecosystem management in the Amazon. More broadly, our study also suggests (a) the need to report more detailed statistical descriptions of fish sounds, including measures of within‐fish variation, (b) the importance of describing characteristics of sound series produced by fishes in addition to those of individual sound types and (c) the need to deposit museum voucher specimens to anchor specific sounds to specific individuals.

Although the importance of diversity to maintaining metapopulation stability is widely recognized, the ecological characteristics that lead to synchronous dynamics within population aggregates are often unclear. We used a constrained dynamic factor analysis to explore patterns of covariance in productivity among 16 Fraser River sockeye salmon (Oncorhynchus nerka) conservation units (CUs). Specifically, we tested whether coherent trends in productivity covaried with five distinct ecological attributes: physical characteristics of nursery lakes, large-scale management interventions, genetic similarity, adult migration phenology, or juvenile migratory traits. The top-ranked model had two trends based on nursery lake characteristics and juvenile migratory traits. One trend represented the dynamics of CUs that rear in nursery lakes prior to ocean entry and undergo relatively rapid marine migrations. The second included a sea-type CU, Harrison River, which enters the marine environment without rearing in a nursery lake and migrates more slowly. The uniform response of lake-type CUs, as well as Harrison River CU’s unique life history, suggests that coherent trends are structured by traits that covary with broad life history type, rather than fine-scale characteristics. Furthermore, we document substantial temporal variability in the strength of synchronous dynamics among Fraser River CUs. Greater synchrony in recent years suggests that the importance of shared regional drivers, relative to local processes, may have increased.

A rapidly expanding human footprint - comprised of anthropogenic land-use change and infrastructure - is profoundly affecting wildlife distributions worldwide. Cumulative effects management (CEM) is a regional approach that seeks to manage combined effects of the human footprint on biodiversity across large spatial scales. Challenges to implementing this approach include a lack of ecological data at large spatial scales, the high cost of monitoring multiple indicators, and the need to manage multiple footprints across industries. To inform development of effective CEM, we used large mammals as indicators to address the following questions: a) do species respond more strongly to individual footprint features or to cumulative effects (combined area of all footprint types, measured as total footprint), b) which features elicit the strongest responses across species, and c) are the direction of responses to footprint consistent? We used data from 12 years of snowtrack surveys (2001-2013) in the boreal forest of Alberta, coupled with regional footprint and landcover data, to develop generalized linear mixed-effects models relating the relative abundance of five boreal mammals [gray wolf (Canis lupus), Canada lynx (Lynx canadensis), coyote (Canis latrans), white-tailed deer (Odocoileus virginianus) and moose (Alces alces)] to individual and cumulative effects of the human footprint. We found that across species the strongest responses were to agriculture, roads, and young cutblocks (

The usefulness of the apparent redox potential discontinuity (aRPD) in assessments of marine benthic habitat quality was explored at two intertidal mudflats along the north Pacific coast of Canada. Two transects were established at each intertidal site, with three sediment biogeochemistry cores collected from each transect four times over the summer of 2016. Measurements of the sediment pore water dissolved oxygen (DO) content and redox (Eh) conditions were taken at the surface of the core (measured vertically), as well as at increasing depths (1 cm between readings) into the sediment (measured horizontally through predrilled holes in the biogeochemistry corer). While oxic, anoxic, oxidized, and reduced sediment pore water was observed above and below the aRPD, in general, sediment above the aRPD had higher DO content, and higher Eh values than sediment below the aRPD. Therefore, the aRPD depth can be used as a relative indicator of sediment pore water DO and Eh conditions: sediment with a deeper aRPD depth has more available DO, and the pore water has higher Eh values (more oxidized or less reduced) than sediment with a shallower aRPD depth. As such, the aRPD depth is a useful parameter to include in models that assess the quality of marine benthic habitats.

Although many fish are soniferous, few of their sounds have been identified, making passive acoustic monitoring (PAM) ineffective. To start addressing this issue, a portable 6-hydrophone array combined with a video camera was assembled to catalog fish sounds in the wild. Sounds are detected automatically in the acoustic recordings and localized in three dimensions using time-difference of arrivals and linearized inversion. Localizations are then combined with the video to identify the species producing the sounds. Uncertainty analyses show that fish are localized near the array with uncertainties

Sounds produced by Arctic cod were recorded for the first time and suggest passive acoustic monitoring (PAM) can be an effective additional tool for the study and management of the species. Each of the 38 calls detected in three different aquatic facilities consisted of a single grunt with 6 to 12 pulses and a mean duration of 289 ms. Call frequency ranged between 59 and 234 Hz, with a mean peak frequency of 107 Hz. These preliminary data suggest Arctic cod can be distinguished from other gadids, but additional studies of sympatric species are needed before PAM can be confidently adopted.

This is Publication Number 16 from the Salish Sea Marine Survival Project (marinesurvivalproject.com). We thank the Pacific Salmon Foundation for funding this project, and also would like to acknowledge the Canadian Foundation for Innovation, the British Columbia Knowledge Development Fund, and Natural Sciences and Engineering Research Council Discovery Grants for equipment and lab technician support. We thank the numerous people who assisted with collection and processing samples for this project, as well as Project Watershed and the Sea- Change Society for support. Dr. Moira Galbraith assisted with zooplankton and stomach contents identification for this project. We thank Dr. Julia Baum and Dr. Natalie Ban for helpful suggestions on an earlier draft, as well as the reviewers whose insight greatly improved this publication. We would also like to thank Geoffrey Osgood for statistical guidance. There is no conflict of interest declared in this article.

Development of tools for early detection of invasive species is critically important as the threat of global invasions increase. Early detection as applied to invasive species is a system of active and passive surveillance to find and verify the identity of new invaders as quickly and efficiently as possible. The earlier such species can be detected the more feasible their control and potential eradication will be. A sensor is a device that detects or measures a physical or biological property (here an invasive species), and records, indicates or responds to it. Here, I summarize what features of visual and acoustic sensors make effective tools for early detection of invasives, and suggest future potential for their use. Visual sensors are by far the dominant mode of detection, particularly in terrestrial habitats. At small scales they include photography and video technology along with the advent of advanced image acquisition and automatic identification. At larger scales remote sensing by use of drones, satellites and video technology are being developed to map invasive species habitats in both terrestrial and aquatic environments. Future use will depend in part on further development of automatic detection methodology. There is also large potential in the use of acoustic methods for early detection of invasives, especially cryptic ones, but such technology is still in its infancy due to technological and analytic limitations. In conclusion, the use of visual and acoustic sensors holds much promise for detecting and monitoring invasive species, particularly in remote settings.