Marine Wildlife Research Articles

Polymer composition analysis of plastic debris ingested by loggerhead turtles (Caretta caretta) in Southern Tyrrhenian Sea through ATR-FTIR spectroscopy

The ingestion of anthropogenic plastic debris by marine wildlife is widespread in the Mediterranean Sea. The endangered status (in the IUCN Red List) of Loggerhead turtle (Caretta caretta, Linnaeus, 1758) is a consequence of its vulnerability. In this study, macro-/meso-plastics (5–170 mm) collected from faeces of twelve loggerhead turtles rescued (live) in the Aeolian Archipelago (Southern Tyrrhenian Sea, Italy) were analyzed by size, weight, shape, color and polymer type through Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR). The defecation rate during hospitalization (7–14 days) varied among turtles (from 0.08 to 0.58). The mean number of plastic expulsions (2.7 ± 1.8 items for turtle) was higher during the 5th day of hospitalization (Kruskal-Wallis test, P = 0.01). However, the mean number of plastic-like items defecated during the common days of hospitalization did not vary among turtles (Kruskal-Wallis test, P > 0.05). All turtles were found to have ingested plastic. A total of 114 debris items were recovered from their faeces, 113 of which were identified as plastic. Their color was mostly white-transparent (64.9%) and light (19.3%). Shape was mainly fragments (52.6%), sheets (38.6%), followed by nylon, net-fragments, elastic plastic, foamed plastic and industrial granules (8.8%). Meso-plastics (5–25 mm) represented 72% of the total number of debris and were found more frequently in turtle with Curved Carapace Length (CCL) ≤ 60 cm (CCL = 30–60 cm, n = 5) than those with CCL >60 cm (CCL = 60–71 cm, n = 7). Plastic items were composed mainly of polyethylene (48.2%) and polypropylene (34.2%). Polypropylene (R2 = 0.95, P < 0.001) and polyisoprene (R2 = 0.45, P = 0.017) were more common in meso-plastics while polyethylene (R2 = 0.44, P < 0.01) in macro-plastics. Finally, high-density polyethylene, polyvinyl chloride, polyamide and polyurethane were also found in some turtles. This study reveals high spreads of plastic contamination in faeces of both turtles with CCL ≤60 cm and CCL >60 cm, particularly vulnerable to the increasing quantity of floating plastic into their foraging sites highlighting the need of further research to associate debris ingestion with turtle diet and their size.

Managing Marine Growth on Historic Maritime Structures: An Assessment of Perceptions and Current Management Practices

Maritime built heritage (e.g., historic harbors, breakwaters, etc.) is found widely along the coastlines of Europe. Due to its age and traditional construction, built heritage may represent important and largely unidentified hotspots of biodiversity in marine and coastal environments. At the same time, marine growth (e.g., seaweed, mussels, barnacles, etc.) found on these structures may provide both deteriorative and protective functions. To ensure future research focusing on the two-way interactions between marine growth and built heritage addresses the concerns of those responsible for their management, attitudes towards the colonization and growth of marine wildlife must first be evaluated. Such attitudes will shape how marine growth is managed at these sites, which in turn may influence biodiversity and built heritage conservation and any associated values. This study assesses how the growth of sessile species and other surface-colonizing organisms is currently perceived and managed by those responsible for maintaining maritime built heritage, with a particular focus on historic structures constructed of natural stone. Responses from a semi-quantitative online questionnaire of harbormasters, coastal engineers, environmental officers, and heritage managers from around the UK (n = 132) were analyzed alongside a series of semi-structured interviews (n = 29). Our results demonstrate that attitudes towards marine growth are generally in agreement among practitioners irrespective of their occupation or the historic maritime structures they are responsible for managing. Perceptions of marine growth are mostly positive, but concerns exist regarding its impacts on maintenance regimes, the condition of mortar, and health and safety. As well as highlighting opportunities for a more integrated approach to biodiversity and built heritage conservation, the concerns identified require further research attention to help address potential barriers and conflicts that may arise in practice.

Variability in Foraging Range and Direction Among Colonies in a Widespread Seabird, the Magellanic Penguin

Most seabirds forage far from land, making them hard to observe when foraging. Satellite tracking of seabirds shows where they come into conflict with human uses of the ocean, and whether they use protected areas. Because tracking data are expensive, data from one colony and/or year are sometimes used to design marine protection for a species across its range. Two assumptions commonly made are that foraging distance increases with colony size and individuals are uniformly distributed around colonies. We tested these assumptions using Magellanic penguinsSpheniscus magellanicusas an example. We used a large tracking dataset of 338 penguins foraging for chicks at 10 colonies in Argentina from 1996 to 2019. Foraging distance increased with population size among colonies, but predicted distances would not cover foraging areas for all colonies. There was no relationship between population size and foraging distance within colony among years for colonies with ten and 23 years of data. Penguins were not uniformly distributed around colonies. Penguins used ~24% (12-40%) of the ocean available within the colony’s maximum foraging distance. We also show that overlap between penguin foraging areas and marine protected areas (MPA) and hydrocarbon concessions varied among colonies partly because of variation in how far offshore penguins forage. Overlap with MPAs was low (0% – 20%) for seven of the ten colonies and high (23% – 100%) for the other three. Overlap with a large area permitted for hydrocarbon exploration (seismic surveys) was relatively high (23% – 81%) for seven colonies where penguins forage offshore. Data from one colony are unlikely to indicate the most effective marine spatial planning for all colonies. Our data show that to be effective, marine planning should consider the temporal and spatial dynamics of ocean conditions and the response of marine wildlife to these changes. Climate variability is predicted to increase, making knowledge of foraging-location variation among colonies and years critical to conservation planning.

Shipping in the north-east Atlantic: Identifying spatial and temporal patterns of change

Maritime traffic is increasing globally, with a four-fold increase in commercial vessel movements between 1992 and 2012. Vessels contribute to noise and air pollution, provide pathways for non-native species, and collide with marine wildlife. While knowledge of shipping trends and potential environmental impacts exists at both local and global levels, key information on vessel density for regional-scale management is lacking. This study presents the first in-depth spatio-temporal analysis of shipping in the north-east Atlantic region, over three years in a five-year period. Densities increased by 34%, including in 73% of Marine Protected Areas. Western Scotland and the Bay of Biscay experienced the largest increases in vessel density, predominantly from small and slow vessels. Given well-documented impacts that shipping can have on the marine environment, it is crucial that this situation continues to be monitored – particularly in areas designated to protect vulnerable species and ecosystems which may already be under pressure.

Bottlenose Dolphin Responses to Boat Traffic Affected by Boat Characteristics and Degree of Compliance to Code of Conduct

Levels of boat traffic in coastal seas have been steadily increasing in many parts of the world, introducing pressures on marine wildlife through disturbance. The appropriate management of human activities is important not only to preserve wildlife, but also for the local communities that depend on ecotourism for employment and their economy. This study presents further insight into bottlenose dolphin (Tursiops truncatus) responses to boats in New Quay Bay (West Wales) within the Cardigan Bay Special Area of Conservation. This region is heavily dependent on wildlife tourism, and marine traffic is regulated through a long-standing Code of Conduct. Based on a long-term dataset spanning the months of April to October and the years 2010–2018, the study found that compliance to a code of human behaviour increased dolphin positive responses towards boats. Dolphin responses to individual named boats and to different boat types were examined in greater detail. Speed boats, small motorboats, and kayaks were found to break the code most often, resulting in higher rates of negative response by dolphins. Visitor passenger boats formed the majority of boat traffic in the area, and showed greater compliance than other general recreational crafts. Suggestions are made for the better protection of the coastal dolphin population, as well as the role that citizen science can play to help achieve this goal through working directly with wildlife trip boats and the recruitment of local observers.

The influence of Lake Okeechobee discharges on Karenia brevis blooms and the effects on wildlife along the central west coast of Florida

Blooms of the dinoflagellate Karenia brevis (K. brevis) are a common occurrence in the Gulf of Mexico, especially along Florida's coast. The blooms produce brevetoxins, potent neurotoxins that are associated with mortalities of marine wildlife. In recent years, K. brevis blooms seem to have become more frequent and intense. The cause of these suspected increases is highly debated, with one suggested explanation being anthropogenic eutrophication. Patient records from the Clinic for the Rehabilitation of Wildlife (CROW) on Sanibel Island, Florida, USA, and K. brevis cell count samples from the west coast of Florida were used to assess trends in red tides and affected wildlife. Flow data from the Okeechobee waterway was used to investigate if discharges from Lake Okeechobee and the Caloosahatchee Estuary, where eutrophication is present, influence red tides along Florida's central west coast. Overall, K. brevis blooms show trends of increasing intensity and duration along Florida's coast between 1954 and 2020 (latest data available). This means the amount of wildlife affected will likely increase in the future, as a linear relationship was found between the number of admissions to CROW and K. brevis densities. Furthermore, water discharges from the Okeechobee waterway (including Lake Okeechobee and the Caloosahatchee Estuary) into the Gulf of Mexico were significantly correlated with K. brevis densities, which suggests that anthropogenic pollution might play a role in the observed increases. Clear correlations were found between K. brevis densities and brevetoxicosis patient numbers admitted, and this was strongest with overall admissions lagging 23 days behind cell counts. This further confirms brevetoxins as the likely cause of their morbidity and supports previous research on brevetoxin retention in the environment. Different species groups had significant correlations with K. brevis cell counts, double-crested cormorants showing the strongest link, and there were significant differences between these groups in lag times. The differences are likely due to their distinct foraging behaviours or susceptibilities to brevetoxins. These findings can help predict future trends in red tides and can guide further research on the effects of discharges on K. brevis blooms.

American oysters as bioindicators of emerging organic contaminants in Florida, United States

Per- and polyfluoroalkyl substances (PFAS) and phthalate esters (PAEs) are emerging contaminants of higher concern due to their wide industrial and commercial use, toxicity, and potential adverse health effects. In this study, we assessed PFAS and PAEs exposure in American oysters collected in three study sites in Florida, USA. Potential physiological effects of these contaminants were assessed by collecting oyster biometric data, calculating condition indices, and assessing oxidative stress levels in these individuals. Finally, a human health risk assessment was conducted based on the concentrations found in the consumable Tampa Bay (TB) oysters. All PFAS and PAEs compounds assessed in this study were detected in at least one oyster in all study sites. Among all locations, ΣPFAS concentration range was 0.611–134.78 ng·g−1 and ΣPAEs <0.328–1021 ng·g−1. Despite the smaller size of Biscayne Bay (BB) oysters, they displayed the highest concentrations of most of the PFAS and PAEs compounds, which is likely associated with population size, and other sources in the area. Condition index (CI) III was smaller in BB oysters, likely indicating a stressed population. Even though BB oysters were the most affected individuals, Marco Island (MI) oysters displayed the highest levels of lipid peroxidation, which can also be associated with environmental factors and decreased food availability. Conversely, TB oysters exhibited the highest levels of hydrogen peroxide, likely indicating a better defense mechanism in TB oysters compared to MI oysters. The human health risk assessment for TB oysters indicated low risk from PFAS and PAEs exposure, but there is no reference dose for other compounds and the human diet is wider than only oysters. Therefore, the risk of contaminant exposure is likely higher. This study demonstrates the value of integrating data on contaminant exposure and physiological responses of bioindicator specimens to better understand how emerging contaminants are affecting marine wildlife.

Removing microplastics from wastewater using leading-edge treatment technologies: a solution to microplastic pollution-a review.

Microplastics (MPs) in environmental studies have revealed that public sewage treatment plants are a common pathway for microplastics to reach local surroundings. Microplastics are becoming more of a worry, posing a danger to both marine wildlife and humans. These plastic items not only contribute to the macrocosmic proliferation of plastics but also the scattering of microplastics and the concentration of other micropollutant-containing objects, increasing the number of pollutants identified. Microplastics' behavior, movement, transformation, and persistence mechanisms, as well as their mode of action in various wastewater effluent treatment procedures, are still unknown. They are making microplastics made from wastewater a big deal. We know that microplastics enter wastewater treatment facilities (WWTPs), that wastewater is released into the atmosphere, and that this wastewater has been considered to represent a threat to habitats and ground character based on our literature assessment. The basic methods of wastewater and sewage sludge, as well as the treatment procedure and early characterization, are covered throughout the dissection of the problematic scientific conceptualization.

Legacy and emerging flame retardants in sharks from the Western North Atlantic Ocean

Following the discontinuation of commercial polybrominated diphenyl ether (PBDE) mixtures, a variety of alternative flame retardants (FRs) have been developed and employed. To understand the contamination status of these emerging FRs in marine fish and wildlife, we investigated their bioaccumulation in four shark species, including shortfin mako shark (Isurus oxyrhinchus; n = 26), porbeagle (Lamna nasus; n = 4), sandbar shark (Carcharhinus plumbeus; n = 6), and common thresher (Alopias vulpinus; n = 4), from coastal and offshore waters of the western North Atlantic Ocean. Median concentrations of emerging FRs, including dechlorane analogues (i.e., dechlorane plus, Dec-602, −603, and − 604), tetrabromo-o-chlorotoluene (TBCT), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and hexabromobenzene (HBBZ), ranged from 1.4–7.4, 10.2–22.4, 1.0–16.7, and 4.1–17.7 ng/g lipid weight (lw), respectively. Although concentrations of emerging FRs were generally 1–2 orders of magnitude lower than those of legacy FRs (i.e., PBDEs, 312–800 ng/g lw and hexabromocyclododecane or HBCDD, 17.2–99.3 ng/g lw), they were detected in more than 80% of the shark livers. Analysis of available biological data indicated that fork length significantly correlated with the concentrations of ΣPBDEs, HBCDD, ΣDechloranes or TBCT in shortfin mako livers. This indicates that longer-term exposure likely results in elevated FR concentrations in sharks. Our findings suggest likely exposure of western North Atlantic fish and wildlife to several emerging FRs, including dechloranes, BTBPE, HBBZ, and TBCT. Additional studies are needed to better elucidate their potential risks to fish and wildlife as well as the variety of environmental and biological factors influencing these risks.

Drone Observations of Marine Life and Human–Wildlife Interactions off Sydney, Australia

Drones have become popular with the general public for viewing and filming marine life. One amateur enthusiast platform, DroneSharkApp, films marine life in the waters off Sydney, Australia year-round and posts their observations on social media. The drone observations include the behaviours of a variety of coastal marine wildlife species, including sharks, rays, fur seals, dolphins and fish, as well as migratory species such as migrating humpback whales. Given the extensive effort and multiple recordings of the presence, behaviour and interactions of various species with humans provided by DroneSharkApp, we explored its utility for providing biologically meaningful observations of marine wildlife. Using social media posts from the DroneSharkApp Instagram page, a total of 678 wildlife videos were assessed from 432 days of observation collected by a single observer. This included 94 feeding behaviours or events for fur seals (n = 58) and dolphins (n = 33), two feeding events for white sharks and one feeding event for a humpback whale. DroneSharkApp documented 101 interactions with sharks and humans (swimmers and surfers), demonstrating the frequent, mainly innocuous human–shark overlap off some of Australia’s busiest beaches. Finally, DroneSharkApp provided multiple observations of humpback and dwarf minke whales with calves travelling north, indicating calving occurring well south of traditional northern Queensland breeding waters. Collaboration between scientists and citizen scientists such as those involved with DroneSharkApp can greatly and quantitatively increase the biological understanding of marine wildlife data.

Comparing methods for monitoring nest debris using silver gulls as a case study

Global plastics production is increasing exponentially and contributing to significant pollution of the marine environment. Of particular concern is ingestion and entanglement risks for marine wildlife, including when items such as rope are incorporated into nest structures. These events are commonly documented using photographic and visual surveys, and each presents a number of challenges and benefits for species conservation and monitoring. Here we compare an invasive (i.e., removing debris from nests) and non-invasive (i.e., photographs) sampling method for quantifying nest debris using the silver gull (Chroicocephalus novahollandiae) as a case study. Overall, 17 debris items were detected in 9% of gull nests. While the use of photographs to monitor nest debris is increasingly popular, the invasive method detected one additional debris item not identified using photography. We therefore recommend caution for nest debris and other monitoring programs where identifying small or cryptic items may require a high level of skill.

Paralytic shellfish toxins in Alaskan Arctic food webs during the anomalously warm ocean conditions of 2019 and estimated toxin doses to Pacific walruses and bowhead whales

Climate change-related ocean warming and reduction in Arctic sea ice extent, duration and thickness increase the risk of toxic blooms of the dinoflagellate Alexandrium catenella in the Alaskan Arctic. This algal species produces neurotoxins that impact marine wildlife health and cause the human illness known as paralytic shellfish poisoning (PSP). This study reports Paralytic Shellfish Toxin (PST) concentrations quantified in Arctic food web samples that include phytoplankton, zooplankton, benthic clams, benthic worms, and pelagic fish collected throughout summer 2019 during anomalously warm ocean conditions. PSTs (saxitoxin equivalents, STX eq.) were detected in all trophic levels with concentrations above the seafood safety regulatory limit (80 μg STX eq. 100 g−1) in benthic clams collected offshore on the continental shelf in the Beaufort, Chukchi, and Bering Seas. Most notably, toxic benthic clams (Macoma calcarea) were found north of Saint Lawrence Island where Pacific walruses (Odobenus rosmarus) are known to forage for a variety of benthic species, including Macoma. Additionally, fecal samples collected from 13 walruses harvested for subsistence purposes near Saint Lawrence Island during March to May 2019, all contained detectable levels of STX, with fecal samples from two animals (78 and 72 μg STX eq. 100 g−1) near the seafood safety regulatory limit. In contrast, 64% of fecal samples from zooplankton-feeding bowhead whales (n = 9) harvested between March and September 2019 in coastal waters of the Beaufort Sea near Utqiaġvik (formerly Barrow) and Kaktovik were toxin-positive, and those levels were significantly lower than in walruses (max bowhead 8.5 μg STX eq. 100 g−1). This was consistent with the lower concentrations of PSTs found in regional zooplankton prey. Maximum ecologically-relevant daily toxin doses to walruses feeding on clams and bowhead whales feeding on zooplankton were estimated to be 21.5 and 0.7 μg STX eq. kg body weight−1 day−1, respectively, suggesting that walruses had higher PST exposures than bowhead whales. Average and maximum STX doses in walruses were in the range reported previously to cause illness and/or death in humans and humpback whales, while bowhead whale doses were well below those levels. These findings raise concerns regarding potential increases in PST/STX exposure risks and health impacts to Arctic marine mammals as ocean warming and sea ice reduction continue.

Spatiotemporal distribution of paralytic shellfish poisoning (PSP) toxins in Beagle Channel (South America) during 2005–2017

Toxigenic algal blooms have been reported since 1886 in the Beagle Channel, at the southern limit of South America, mainly associated with the occurrence of paralytic shellfish poisoning (PSP) toxins produced by dinoflagellates of the genus Alexandrium. Toxic outbreaks have serious impacts on marine wildlife and ecosystem services, particularly on fisheries and mussel aquaculture. Within the framework of the Shellfish Toxicity Monitoring Program carried out close to Almanza in Beagle Channel eastern coastal waters, here we analyzed the spatiotemporal patterns of PSP toxins in the Magellan mussel Aulacomya ater and the blue mussel Mytilus edulis, measured by the mouse bioassay for 12 years, between 2005 and 2017. PSP outbreaks occurred mostly during summer and their duration was significantly longer than for outbreaks detected during spring and winter. A marked interannual variability in their magnitude was also evident. The largest outbreaks were detected in summers 2010–2011, in extreme warm and low-wind conditions, reaching up to 5600 µg saxitoxin equivalent per 100 g of tissue, causing a closure of shellfish fisheries of up to 200 days. Small scale spatial variability in PSP was also found, the highest values being observed in the main mussel culture areas, and the lowest in the natural mussel beds. PSP toxicities for the Magellan mussel were significantly higher than for the blue mussel. Natural detoxification in mussels from Beagle Channel followed an exponential decay, with mean detoxification rates of 3.5% toxin day−1, lower than those from elsewhere in the world for similar PSP toxin concentrations, which means a longer time to attain concentration limits safe for human consumption. Understanding PSP dynamics is important to avoid large economic losses related to halting mussel production.

Marine conservation tourism and the Giant Pacific Octopus: A SWOT analysis of two public engagement programs and the viability of a hybrid program at the Seattle Aquarium, Washington, USA

Marine conservation requires financial and human capital to effectively function. Tourism activities can provide both, if done responsibly. Marine conservation tourism (MCT) concerns tourist activities involving the engagement with—and the study, protection, and restoration of—marine wildlife and their ecosystems. There are two models that are commonly used: commercial and non-commercial. However, a combined hybrid MCT model may be more effective. To evaluate this potential, SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis was conducted on two representative programs at the Seattle Aquarium dedicated to the conservation of the iconic Giant Pacific Octopus (GPO). Octopus Survey Week is a non-commercial, research-focused program utilizing voluntary assistance of local divers. Octopus Week is a commercial program in which conservation goals are facilitated by visitor fees and donations from aquarium supporters. The study utilized a mixed-methods approach. Data collection (N=86) involved semi-structured interviews and focus groups. SWOT analysis was enhanced with (1) MECE (Mutually Exclusive and Collectively Exhaustive) framework to identify prominent factors or themes, and (2) TOWS (Threats, Opportunities, Weaknesses, and Strengths) analysis to suggest strategies relevant to the SWOT findings. Results show Octopus Survey Week program is viable but not well known. The Octopus Week program is also viable; there is an opportunity here for improvement. Importantly, interviewees would prefer a hybrid program. However, even a hybrid program would face logistical and temporal issues. To increase public interest and participation, it is recommended that the Seattle Aquarium connect them in a more proactive manner. Looking ahead, we hope the field of marine conservation tourism will expand as researchers develop new methods to improve conservation efforts.

#Wildlifeselfies: insights into the ocular consumption of marine wildlife

ABSTRACT Wildlife tourism has experienced a shift from passive observations towards highly interactive encounters between tourists and wild animals. Tourist behaviour is influenced by the pursuit of ‘visual trophies’ for social media. More specifically, the ‘wildlife selfie’ phenomenon, which requires proximity to a plethora of animal species, may contribute to compromised tourist safety and harassment of wildlife. This paper explores the perceptions of swim-with wildlife tour participants regarding wildlife-focused user-generated content such as wildlife selfies in three different commercial encounter settings in the South Pacific. In-depth qualitative interviews and a thematic analysis of the data yielded two prominent themes: Tourists perceived human-wildlife interactions online as ‘a double-edged sword’, identifying animal welfare as a key concern. Such content was found to shape the decision-making processes of tourists and affected tourists’ perceptions, creating unrealistic expectations of wildlife encounters. Further, whale-swim participants were identified as non-selfie-takers/opponents, while seal swimmers and shark divers were somewhat supportive, actively participating in selfie-taking behaviour to provide proof to peers (‘to selfie or not to selfie’). Those findings indicate that a sound monitoring of the constructed human-wildlife relationship in the twenty-first-century media landscape with a focus on guidelines and regulations to ensure tourist safety and animal welfare is required.

Relationships between gene transcription and contaminant concentrations in Baltic ringed seals: A comparison between tissue matrices.

Ringed seals (Pusa hispida) are slowly recovering in the eastern and northern parts of the Baltic Sea after years of hunting pressure and contaminant exposure. Still, consequences of anthropogenic activities such as contaminant exposure and increasing temperatures are stressors that continue to have deleterious effects on their habitat and health. Transcription profiles of seven health-related genes involved in xenobiotic metabolism, endocrine disruption and stress were evaluated in blood, blubber, and liver of Baltic ringed seals in a multi-tissue approach. Selected persistent organic pollutants and total mercury concentrations were measured in blubber and liver, and muscle and liver of these animals, respectively. Concentrations of contaminants varied across tissues on a lipid weight basis but not with sex. mRNA transcript levels for all seven target genes did not vary between sexes or age classes. Transcript levels of thyroid hormone receptor alpha (TRα), retinoic acid receptor alpha (RARα) and heat shock protein 70 (HSP70) correlated with levels of persistent organic pollutants. TRα transcript levels also correlated positively with mercury concentrations in the liver. Of the three tissues assessed in this multi-tissue approach, blubber showed highest transcription levels of aryl hydrocarbon receptor nuclear translocator (ARNT), thyroid stimulating hormone receptor beta (TSHβ), oestrogen receptor alpha (ESR1) and peroxisome proliferator activated receptor alpha (PPARα). The wide range of genes expressed highlights the value of minimally invasive sampling (e.g. biopsies) for assessing health endpoints in free-ranging marine wildlife and the importance of identifying optimal matrices for targeted gene expression studies. This gene transcript profile study has provided baseline information on transcript levels of biomarkers for early on-set health effects in ringed seals and will be a useful guide to assess the impacts of environmental change in Baltic pinnipeds for conservation and management.

Effects of shark tourism on the daily residency and movements of a non-focal pelagic teleost

Marine wildlife tourism is increasing in popularity, with operations targeting a wide range of taxa globally. While previous studies have mostly focused on assessing the effects of provisioning from tourism on focal species, non-focal species that unintentionally feed on supplemental food sources have largely been overlooked. This study improves our understanding of the effects of shark-cage-diving tourism on the movements and behaviours of a non-focal pelagic fish. We used acoustic tracking to determine the effects of shark-cage-diving tourism on the residency and space use of 17 yellowtail kingfish Seriola lalandi at the Neptune Islands, South Australia. We revealed that while cage-diving did not affect the overall or weekly residency and space use of kingfish, daily time spent at the islands and location of kingfish was influenced by the presence of operators. Acoustic attractant did not affect kingfish behaviours, but operators using food-based attractants increased the average time spent at the Neptune Islands by ~27% (from 230.6 ± 6.8 to 293.8 ± 5.5 min). Kingfish were also observed closer to operators using food-based attractants (217 ± 4.82 m from vessel) compared to an acoustic attractant (412 ± 29.5 m from vessel). Our findings identify changes in the daily behaviour of kingfish at the Neptune Islands as a result of food-based attractants from shark-cage-diving, which demonstrates that non-focal large pelagic species can be affected by shark-diving tourism. These effects may lead to long-term effects on the physiological condition and energetic responses of these individuals.

Marine Neurotoxins’ Effects on Environmental and Human Health: An OMICS Overview

Harmful algal blooms (HAB), and the consequent release of toxic metabolites, can be responsible for seafood poisoning outbreaks. Marine wildlife can accumulate these toxins throughout the food chain, which presents a threat to consumers’ health. Some of these toxins, such as saxitoxin (STX), domoic acid (DA), ciguatoxin (CTX), brevetoxin (BTX), tetrodotoxin (TTX), and β-N-methylamino-L-alanine (BMAA), cause severe neurological symptoms in humans. Considerable information is missing, however, notably the consequences of toxin exposures on changes in gene expression, protein profile, and metabolic pathways. This information could lead to understanding the consequence of marine neurotoxin exposure in aquatic organisms and humans. Nevertheless, recent contributions to the knowledge of neurotoxins arise from OMICS-based research, such as genomics, transcriptomics, proteomics, and metabolomics. This review presents a comprehensive overview of the most recent research and of the available solutions to explore OMICS datasets in order to identify new features in terms of ecotoxicology, food safety, and human health. In addition, future perspectives in OMICS studies are discussed.

Behavioural responses of wild Pacific salmon and herring to boat noise

There is growing concern about impacts of ship and small boat noise on marine wildlife. Few studies have quantified impacts of anthropogenic noise on ecologically, economically, and culturally important fish. We conducted open net pen experiments to measure Pacific herring (Clupea pallasii) and juvenile salmon (pink, Oncorhynchus gorbuscha, and chum, Oncorhynchus keta) behavioural response to noise generated by three boats travelling at different speeds. Dose-response curves for herring and salmon estimated 50% probability of eliciting a response at broadband received levels of 123 and 140 dB (re 1 μPa), respectively. Composite responses (yes/no behaviour change) were evaluated. Both genera spent more time exhibiting behaviours consistent with anti-predator response during boat passings. Repeated elicitation of vigilance or anti-predatory responses could result in increased energy expenditure or decreased foraging. These experiments form an important step toward assessing population-level consequences of noise, and its ecological costs and benefits to predators and prey.

Perspectives on the Use of Unmanned Aerial Vehicle Systems as Tools for Small‐Scale Fisheries Research and Management

Unmanned aerial vehicles (UAVs) are increasingly used in marine wildlife research and have rapidly expanded across many scientific disciplines. As recent technological developments have improved the versatility and functionality of UAVs, the potential of these systems for research on small‐scale and artisanal fisheries has grown considerably, although this potential is still underexploited. However, there is growing interest in the application of cost‐effective UAVs for aerial surveys of fishery activities, but few empirical studies have produced reliable findings to aid the development of effective management actions. Common challenges for effective management include funding limitations and problems related to survey design, coverage, and implementation. In this context, aerial devices have the capacity to fill a niche for intensive fine‐scale sampling in which data gathering strategies need to be tailored to specific operational requirements. Detailed documentation and monitoring of harvest processes and fisheries practices by UAVs can provide important insights into fishing gear and techniques (e.g., gillnets and seine nets), the operation of stationary artisanal fishing devices (e.g., traps and tidal fishing weirs), area coverage, fishery territories, and the number of fishers and/or fleet size. Here, we present and discuss the potential use of UAVs for surveying small‐scale fishing activities as a complement to traditional research methods (e.g., fishery‐dependent approaches, such as landing monitoring, electronic logbooks, dealer reports, dockside intercepts, and fishery cruises). We predict that the use of UAV as a fishery survey tool will become increasingly widespread as the technology and associated methods are refined and become more affordable with potential to generate significant advances in fishery management practices.