Freely-available Literature

Currently indexing 4063 freely-available titles

The following titles are freely-available, or include a link to a preprint or postprint.

Rethinking tourism conflict potential within and between groups using participatory mapping

Lechner AM, Verbrugge LNH, Chelliah A, Ang MLi Ern, Raymond CM. Rethinking tourism conflict potential within and between groups using participatory mapping. Landscape and Urban Planning [Internet]. 2020 ;203:103902. Available from: https://www.sciencedirect.com/science/article/pii/S0169204619315853?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Tourism on small tropical islands in the Global South is a balancing act between development to improve local livelihoods and the conservation of fragile coastal and coral ecosystems. The objective of our study is to develop a series of new spatial metrics to support sustainable development through assessing the direction and magnitude of tourism development support and conflict between groups. We surveyed 317 individuals out of an estimated total population of 3300 using public participation GIS (PPGIS) on Tioman Island, Malaysia. Here we present a first example of how nuances in conflict can be articulated spatially across different levels of attitude toward tourism development within and between different segments of the population. Our results suggest that treating a population as homogeneous risks missing place specific development conflicts between segments of the population and locations of agreement where development can be managed sustainably with the support of the community.

Hydrogeochemical processes and long-term effects of sea-level rise in an uplifted atoll island of Minami-Daito, Japan

Yang H, Kagabu M, Okumura A, Shimada J, Shibata T, Pinti DL. Hydrogeochemical processes and long-term effects of sea-level rise in an uplifted atoll island of Minami-Daito, Japan. Journal of Hydrology: Regional Studies [Internet]. 2020 ;31:100716. Available from: https://www.sciencedirect.com/science/article/pii/S2214581820301907?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Study region

An uplifted atoll of Minami-Daito Island, Japan.

Study focus

Major ions and stable isotopes (δ2H and δ18O) of groundwater at fifteen observation wells, surface water at eight representative lakes and one seawater site were measured to unravel the dominant processes controlling the chemistry of water, its spatial distribution and to identify the salinization mechanism caused by long-term sea-level rise.

New hydrological insights for the region

Rainfall is the main source for groundwater and lake water. Evaporation affects both the ion concentration and the stable isotopes of the lake water. Geochemical modeling suggests that freshwater-seawater mixing is the main process increasing concentrations of Na+, Cl, Mg2+, and SO42−, whereas dissolution of calcite and dolomite increases concentrations of Ca2+, Mg2+, and HCO3 in groundwater. Fresh groundwater and lake water (i.e., Cl < 500 mg/L) are largely distributed along a SW-NE direction, but they have been reduced since the 1970s. Sea-level rise causes an increase in the salinity of lake water by flowing through fractures being connected from lakes to the northern coast, then spreading to other lakes through the artificial channels built in the years.

Submarine groundwater discharge: A previously undocumented source of contaminants of emerging concern to the coastal ocean (Sydney, Australia)

McKenzie T, Holloway C, Dulai H, Tucker JP, Sugimoto R, Nakajima T, Harada K, Santos IR. Submarine groundwater discharge: A previously undocumented source of contaminants of emerging concern to the coastal ocean (Sydney, Australia). Marine Pollution Bulletin [Internet]. 2020 ;160:111519. Available from: https://www.sciencedirect.com/science/article/pii/S0025326X20306378?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Submarine groundwater discharge (SGD) is rarely considered as a pathway for contaminants of emerging concern (CECs). Here, we investigated SGD as a source of CECs in Sydney Harbour, Australia. CEC detection frequencies based on presence/absence of a specific compound were >90% for caffeine, carbamazepine, and dioxins, and overall ranged from 25 to 100% in five studied embayments. SGD rates estimated from radium isotopes explained >80% of observed CEC inventories for one or more compounds (caffeine, carbamazepine, dioxins, sulfamethoxazole, fluoroquinolones and ibuprofen) in four out of the five embayments. Radium-derived residence times imply mixing is also an important process for driving coastal inventories of these persistent chemicals. Two compounds (ibuprofen and dioxins) were in concentrations deemed a high risk to the ecosystem. Overall, we demonstrate that SGD can act as a vector for CECs negatively impacting coastal water quality.

Effect of pelagic longline bait type on species selectivity: a global synthesis of evidence

Gilman E, Chaloupka M, Bach P, Fennell H, Hall M, Musyl M, Piovano S, Poisson F, Song L. Effect of pelagic longline bait type on species selectivity: a global synthesis of evidence. Reviews in Fish Biology and Fisheries [Internet]. 2020 ;30(3):535 - 551. Available from: https://link.springer.com/article/10.1007/s11160-020-09612-0
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Fisheries can profoundly affect bycatch species with ‘slow’ life history traits. Managing bait type offers one tool to control species selectivity. Different species and sizes of marine predators have different prey, and hence bait, preferences. This preference is a function of a bait’s chemical, visual, acoustic and textural characteristics and size, and for seabirds the effect on hook sink rate is also important. We conducted a global meta-analysis of existing estimates of the relative risk of capture on different pelagic longline baits. We applied a Bayesian random effects meta-analytic regression modelling approach to estimate overall expected bait-specific catch rates. For blue shark and marine turtles, there were 34% (95% HDI: 4–59%) and 60% (95% HDI: 44–76%) significantly lower relative risks of capture on forage fish bait than squid bait, respectively. Overall estimates of bait-specific relative risk were not significantly different for seven other assessed taxa. The lack of a significant overall estimate of relative capture risk for pelagic shark species combined but significant effect for blue sharks suggests there is species-specific variability in bait-specific catch risk within this group. A qualitative literature review suggests that tunas and istiophorid billfishes may have higher catch rates on squid than fish bait, which conflicts with reducing marine turtle and blue shark catch rates. The findings from this synthesis of quantitative and qualitative evidence support identifying economically viable bycatch management measures with acceptable tradeoffs when multispecies conflicts are unavoidable, and highlight research priorities for global pelagic longline fisheries.

Soundscape of green turtle foraging habitats in Fiji, South Pacific

Papale E, Prakash S, Singh S, Batibasaga A, Buscaino G, Piovano S. Soundscape of green turtle foraging habitats in Fiji, South Pacific Patterson HM. PLOS ONE [Internet]. 2020 ;15(8):e0236628. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236628
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The soundscape features of the marine environment provide crucial information about ecosystem health for many species, and they are defined by the local biological, geophysical, and anthropogenic components. In this study, we investigated the soundscape at green turtle neritic foraging habitats in Fiji, South Pacific, with the aims of characterizing the contribution of each component and of comparing the levels of acoustic pressure among sites with different abundances of sea turtles. Four sites were selected at two islands, and one hydrophone was deployed at each site. Generalized additive models highlighted that sound pressure levels (SPLs) at low frequencies (125–250 Hz) were especially affected by wind conditions, while at higher frequencies (>250 Hz) SPLs were mostly influenced by fish and crustacean acoustic activity. Higher abundances of green turtles were found at sites with the highest levels of SPLs and the highest number of acoustic emissions by fishes and crustaceans but were not related to maximum seagrass and macroalgae coverage, or the highest number of fish. The selected coastal habitats have negligible anthropogenic noise, thus this study informs physiological and behavioral studies of the acoustic signatures that sea turtles might target and provides a baseline against which potential impact of soundscape changes on sea turtle spatial abundance and distribution can be evaluated.

Deep coral habitats of Glacier Bay National Park and Preserve, Alaska

Hartill ÉC, Waller RG, Auster PJ. Deep coral habitats of Glacier Bay National Park and Preserve, Alaska Davies A. PLOS ONE [Internet]. 2020 ;15(8):e0236945. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236945
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Glacier Bay National Park and Preserve (GBNPP) in Southeast Alaska is a system of glaciated fjords with a unique and recent history of deglaciation. As such, it can serve as a natural laboratory for studying patterns of distribution in marine communities with proximity to glacial influence. In order to examine the changes in fjord-based coral communities, underwater photo-quadrats were collected during multipurpose dives with a remotely operated vehicle (ROV) in March of 2016. Ten sites were chosen to represent the geochronological and oceanographic gradients present in GBNPP. Each site was surveyed vertically between 100 and 420 meters depth and photo-quadrats were extracted from the video strip transects for analysis. The ROV was equipped with onboard CTD which recorded environmental data (temperature and salinity), in order to confirm the uniformity of these characteristics at depth across the fjords. The percent cover and diversity of species were lowest near the glaciated heads of the fjords and highest in the Central Channel and at the mouths of the fjords. Diversity is highest where characteristics such as low sedimentation and increased tidal currents are predominant. The diverse communities at the mouths of the fjords and in the Central Channel were dominated by large colonies of the Red Tree Coral, Primnoa pacifica, as well as sponges, brachiopods, multiple species of cnidarians, echinoderms, molluscs and arthropods. The communities at the heads of the fjords were heavily dominated by pioneering species such as brachiopoda, hydrozoan turf, the encrusting stoloniferan coral Sarcodyction incrustans, and smaller colonies of Ppacifica. This research documents a gradient of species dominance from the Central Channel to the heads of the glaciated fjords, which is hypothesized to be driven by a combination of physical and biological factors such as glacial sedimentation, nutrient availability, larval dispersal, and competition.

The motivation for citizens’ involvement in life sciences research is predicted by age and gender

Lakomý M, Hlavová R, Machackova H, Bohlin G, Lindholm M, Bertero MG, Dettenhofer M. The motivation for citizens’ involvement in life sciences research is predicted by age and gender Tran US. PLOS ONE [Internet]. 2020 ;15(8):e0237140. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0237140
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Open Science is an umbrella term encompassing multiple concepts as open access to publications, open data, open education and citizen science that aim to make science more open and transparent. Citizen science, an important facet of Open Science, actively involves non-scientists in the research process, and can potentially be beneficial for multiple actors, such as scientists, citizens, policymakers and society in general. However, the reasons that motivate different segments of the public to participate in research are still understudied. Therefore, based on data gathered from a survey conducted in Czechia, Germany, Italy, Spain, Sweden, and the UK (N = 5,870), this study explores five types of incentives that can motivate individuals to become involved in life sciences research. The results demonstrate that men and younger individuals are more persuaded by extrinsic motives (external benefits or rewards), as compared with women and older people, who are driven by intrinsic motives (that originates from within an individual). This paper shows that specific strata of the population are differentially motivated to engage in research, thereby providing relevant knowledge for effectively designing public involvement activities that target various groups of the public in research projects.

Geographical variation in the diatom communities associated with loggerhead sea turtles (Caretta caretta)

Van de Vijver B, Robert K, Majewska R, Frankovich TA, Panagopoulou A, Bosak S. Geographical variation in the diatom communities associated with loggerhead sea turtles (Caretta caretta) Méléder V. PLOS ONE [Internet]. 2020 ;15(7):e0236513. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236513
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Epizoic diatoms form an important part of micro-epibiota of marine vertebrates such as whales and sea turtles. The present study explores and compares the diversity and biogeography of diatom communities growing on the skin and shell of loggerhead sea turtles (Caretta caretta) from four different localities: Adriatic Sea (Croatia), Ionian Sea (Greece), South Africa and Florida Bay (USA) using both light and scanning electron microscopy. We observed almost 400 diatom taxa belonging to more than 100 genera. Diatom communities from Greece and Croatia showed the highest similarity and were statistically different from those recorded from South Africa and Florida. Part of this variation could be attributed to differences in sampling techniques; however, we believe that geography had an important role. In general, contrary to several previous observations from sea turtles, the presumably exclusively epizoic diatoms contributed less than common benthic taxa to the total diatom flora, which might have been related to the loggerhead feeding behavior. Moreover, skin samples differed from carapace samples in having a distinct diatom composition with a higher proportion of the putative true epizoonts. Our results indicate that epizoic diatom communities differ according to loggerhead geographical location and substrate (skin vs. carapace). The relative abundances of common benthic diatoms and putative exclusive epizoic taxa may inform about sea turtle habitat use or behavior though detailed comparisons among different host species have yet to be performed.

Modeling diadromous fish loss from historical data: Identification of anthropogenic drivers and testing of mitigation scenarios

Merg M-L, Dézerald O, Kreutzenberger K, Demski S, Reyjol Y, Usseglio-Polatera P, Belliard J. Modeling diadromous fish loss from historical data: Identification of anthropogenic drivers and testing of mitigation scenarios Pinheiro HTercio. PLOS ONE [Internet]. 2020 ;15(7):e0236575. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236575
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Diadromous fishes have drastically declined over the last century, especially in Europe. Several authors have highlighted the role of large dams in this decline, but in fact, its causes are potentially multiple and cumulative, including degradation of local environmental conditions and widespread fragmentation of hydrographic networks associated with the pervasive establishment of smaller barriers. Consequently, there is a need to improve the identification and prioritization of the drivers of diadromous species loss in order to identify and apply the most appropriate conservation and restoration measures. In this study, we used both historical sources (from mid-18th to early 20th century) and current data to quantify the long-term loss of diadromous taxa over 555 sites throughout the French river network. Then, we modeled the effects of several anthropogenic pressures (e.g. barriers, water quality, hydrological and river morphological alterations) on diadromous taxon loss. Lastly, we assessed the potential consequences of four different scenarios of anthropogenic pressure reduction. Due to uncertainties in historical sources, some species were grouped into taxa leading to a potential underestimation of actual species extinctions. Despite this limitation, our results showed that the decline in diadromous assemblages is widespread but with contrasting magnitudes depending on site locations. The maximum height and density of barriers appeared as the major factors of taxon loss. Over the scenarios tested, we observed that exclusively improving local conditions have much more limited effects than restoring river continuity. Focusing actions on large dam removal did not show the strongest responses compared to removing medium and small-sized barriers. For effective and sustainable restoration of diadromous fish assemblage, (1) historical occurrences of diadromous fishes should be used as an indicator for assessing recovery, and (2) undertaken measures must be adapted to each basin to target and limit the number of barriers to remove while allowing diadromous fish recovery.

Vessel noise affects routine swimming and escape response of a coral reef fish

Jimenez LVelasquez, Fakan EP, McCormick MI. Vessel noise affects routine swimming and escape response of a coral reef fish Januchowski-Hartley FAndrew. PLOS ONE [Internet]. 2020 ;15(7):e0235742. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235742
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

An increasing number of studies have shown that anthropogenic noise can negatively affect aspects of the anti-predator behaviour of reef fishes, potentially affecting fitness and survival. However, it has been suggested that effects could differ among noise sources. The present study compared two common sources of anthropogenic noise and investigated its effects on behavioural traits critical for fish survival. In a tank-based experiment we examined the effects of noise from 4-stroke motorboats and ships (bulk carriers > 50,000 tonnes) on the routine swimming and escape response of a coral reef fish, the whitetail damselfish (Pomacentrus chrysurus). Both 4-stroke boat and ship noise playbacks affected the fast-start response and routine swimming of whitetail damselfish, however the magnitude of the effects differed. Fish exposed to ship noise moved shorter distances and responded more slowly (higher response latency) to the startle stimulus compared to individuals under the 4-stroke noise treatment. Our study suggests that 4-stroke and ship noise can affect activity and escape response of individuals to a simulated predation threat, potentially compromising their anti-predator behaviour.

Ocean plastic crisis—Mental models of plastic pollution from remote Indonesian coastal communities

Phelan A(Anya), Ross H, Setianto NAndri, Fielding K, Pradipta L. Ocean plastic crisis—Mental models of plastic pollution from remote Indonesian coastal communities Borrelle SBelle. PLOS ONE [Internet]. 2020 ;15(7):e0236149. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236149
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The crisis facing the world’s oceans from plastics is well documented, yet there is little knowledge of the perspectives, experiences and options of the coastal communities facing overwhelming quantities of plastics on their beaches and in their fishing waters. In emerging economies such as those in the Coral Triangle, the communities affected are among the poorest of their countries. To understand the consequences of ocean plastic pollution in coastal regions, through the eyes of local people, this study examines the knowledge, use, disposal and local consequences of single use plastics in remote island communities in two archipelagos of southern Sulawesi, Indonesia. Using mixed methods—a survey of plastic literacy and behaviour, household interviews about purchasing and disposal, and focus group discussions to generate shared mental models—we identify a complex set of factors contributing to extensive plastic leakage into the marine environment. The rising standard of living has allowed people in low resource, remote communities to buy more single-use plastic items than they could before. Meanwhile complex geography and minimal collection services make waste management a difficult issue, and leave the communities themselves to shoulder the impacts of the ocean plastic crisis. Although plastic literacy is low, there is little the coastal communities can do unless presented with better choice architecture both on the supply side and in disposal options. Our results suggest that for such coastal communities improved waste disposal is urgent. Responsible supply chains and non-plastic alternatives are needed. Producers and manufacturers can no longer focus only on low-cost packaged products, without taking responsibility for the outcomes. Without access to biodegradable, environmentally friendly products, and a circular plastic system, coastal communities and surrounding marine ecosystems will continue to be inundated in plastic waste.

Sleuthing with sound: Understanding vessel activity in marine protected areas using passive acoustic monitoring

Kline LR, DeAngelis AI, McBride C, Rodgers GG, Rowell TJ, Smith J, Stanley JA, Read AD, Van Parijs SM. Sleuthing with sound: Understanding vessel activity in marine protected areas using passive acoustic monitoring. Marine Policy [Internet]. 2020 ;120:104138. Available from: https://www.sciencedirect.com/science/article/pii/S0308597X19309005?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Monitoring compliance and enforcing laws are integral to ensuring the success of marine protected areas (MPAs), but traditional monitoring techniques are costly and resource demanding. Three SoundTrap 300 recorders were deployed for one month between 1 July and September 12, 2018 to collect acoustic data in two marine parks off southeastern Australia: one recorder in Cod Grounds Marine Park (CGMP) and two in the Solitary Islands Marine Park National Park Zone (SIMP NPZ). Extractive activities such as fishing are not permitted in these zones. Raven Pro 2.0 was used to analyze data for vessel presence. Transmission loss equations for each site were generated using patrol boat GPS tracks and used to predict if acoustically recorded vessels were inside park boundaries based on received sound levels. In CGMP, 41 vessels were predicted within the park during the recording period; 34 vessels were predicted within the SIMP NPZ. Thursdays and Saturdays were identified as peak days for vessel presence in CGMP while Thursdays were the peak day in the SIMP NPZ. Most vessel activity at both locations took place between 06:00 and 17:00 AEST. Peak vessel presence in CGMP occurred at 09:00 AEST while the peak vessel presence in the SIMP NPZ occurred at 16:00 AEST. Approximately 12.7 h of vessel sounds were recorded within CGMP; approximately 3.8 h of vessel noise were recorded within the SIMP NPZ. Passive acoustic monitoring of vessel patterns in Australian Marine Parks has provided valuable insight to redirect compliance decisions on how to focus surveillance efforts.

High-throughput diagnosis of human pathogens and fecal contamination in marine recreational water

An X-L, Wang J-Y, Pu Q, Li H, Pan T, Li H-Q, Pan F-X, Su J-Q. High-throughput diagnosis of human pathogens and fecal contamination in marine recreational water. Environmental Research [Internet]. 2020 ;190:109982. Available from: https://www.sciencedirect.com/science/article/pii/S0013935120308793?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Waterborne pathogens and their associated diseases are major threats to public health, and surveillance of pathogens and identification of the sources of pollution are imperative for preventing infections. However, simultaneously quantitative detection of multiple pathogens and pollution sources in water environments is the major challenge. In this study, we developed and validated a highly sensitive (mostly >80%) and highly specific (>99%) high-throughput quantitative PCR (HT-qPCR) approach, which could simultaneously quantify 68 marker genes of 33 human pathogens and 23 fecal markers of 10 hosts. The HT-qPCR approach was then successfully used to investigate pathogens and fecal pollution in marine recreational water samples of Xiamen, China. Totally, seven pathogenic marker genes were found in 13 beach bathing waters, which targeted Acanthamoeba spp., Clostridium perfringens, enteropathogenic Escherichia coliKlebsiella pneumoniaeVibrio cholera/V. parahaemolyticus and Legionella spp.. Fecal markers from human and dog were the most frequently detected, indicating human and dog feces were the main contamination in the recreational waters. Nanopore sequencing of full-length 16S rRNA gene revealed that 28 potential human pathogens were detected and electrical conductivity, salinity, oxidation-reduction potential and dissolved oxygen were significantly correlated with the variation in bacterial community. Our results demonstrated that HT-qPCR approach had the potential rapid quantification of microbial contamination, providing useful data for assessment of microbial pathogen associated health risk and development of management practices to protect human health.

Nanoplastics affect moulting and faecal pellet sinking in Antarctic krill (Euphausia superba) juveniles

Bergami E, Manno C, Cappello S, Vannuccini ML, Corsi I. Nanoplastics affect moulting and faecal pellet sinking in Antarctic krill (Euphausia superba) juveniles. Environment International [Internet]. 2020 ;143:105999. Available from: https://www.sciencedirect.com/science/article/pii/S0160412020319541?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Plastic debris has been identified as a potential threat to Antarctic marine ecosystems, however, the impact of nanoplastics (<1 μm) is currently unexplored. Antarctic krill (Euphausia superba) is a keystone species of Southern Ocean pelagic ecosystems, which plays a central role in the Antarctic food webs and carbon (C) cycle. Krill has been shown to rapidly fragment microplastic beads through the digestive system, releasing nanoplastics with unknown toxicological effects. Here we exposed krill juveniles to carboxylic (COOH, anionic) and amino- (NH2, cationic) polystyrene nanoparticles (PS NPs) and we investigated lethal and sub-lethal endpoints after 48 h. The analysis of PS NP suspensions in Antarctic sea water (SW) media showed that PS-COOH formed large agglomerates (1043 ± 121 nm), while PS-NH2 kept their nominal size (56.8 ± 3 nm) during the exposure time. After 48 h, no mortality was found but increase in exuviae production (12.6 ± 1.3%) and reduced swimming activity were observed in juveniles exposed to PS-NH2. The microbial community composition in SW supports the release of krill moults upon PS NP exposure and stimulates further research on the pivotal role of krill in shaping Southern Ocean bacterial assemblages. The presence of fluorescent signal in krill faecal pellets (FPs) confirmed the waterborne ingestion and egestion of PS-COOH at 48 h of exposure. Changes in FP structure and properties were also associated to the incorporation of PS NPs regardless of their surface charge. The effects of PS NPs on krill FP properties were compared to Control 0 h as a reference for full FPs (plastic vs food) and Control 48 h as a reference for more empty-like FPs (plastic vs lack of food). Exposure to PS NPs led to a FP sinking rate comparable to Control 48 h, but significantly lower than Control 0 h (58.40 ± 23.60 m/d and 51.23 ± 28.60 m/d for PS-COOH and PS-NH2; 168.80 ± 74.58 m/d for Control 0 h). Considering the important role played by krill in the food web and C export in the Southern Ocean, the present study provides cues about the potential impact of nanoplastics on Antarctic pelagic ecosystems and their biogeochemical cycles.

Quantifying local coastal stewardship reveals motivations, models and engagement strategies

Turnbull JW, Johnston EL, Kajlich L, Clark GF. Quantifying local coastal stewardship reveals motivations, models and engagement strategies. Biological Conservation [Internet]. 2020 ;249:108714. Available from: https://www.sciencedirect.com/science/article/pii/S0006320720307722?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The human footprint on earth is now so great that we must become environmental stewards. To encourage stewardship and achieve better conservation outcomes, research is needed to connect practice with sound theory, and to empirically measure stewardship so we can identify its predictors and motivators.

In this study, we use mixed methods to develop a new quantitative indicator for local environmental stewardship in a coastal context. We interviewed 111 people in eastern Australia about their knowledge and use of the coast and extracted information on seven generalised stewardship actions. We combined these into a single indicator which allowed us to evaluate and compare stewardship levels between participants and develop quantitative models.

We found that stewardship was predicted by four traits: attraction to marine wildlife, self-identifying as local, size of local social network, and norms regarding informal enforcement. High-stewardship individuals exhibited eco-centric and anthropocentric worldviews and were motivated by a combination of intrinsic and extrinsic factors. We combined these with stewardship actions in a refined model which highlights the importance of people, policy and place in environmental stewardship.

We believe this is the first study to quantify stewardship behaviour and its motivating factors in a broad social-ecological context spanning both terrestrial and marine realms. Our research allows stewardship to be measured, modelled and analysed via a transferable indicator. This enables a deeper understanding of local environmental stewardship and the factors that predict and motivate it and allows us to propose practical strategies to engage people to improve stewardship and conservation outcomes.

Global warming leading to alarming recession of the Arctic sea-ice cover: Insights from remote sensing observations and model reanalysis

Kumar A, Yadav J, Mohan R. Global warming leading to alarming recession of the Arctic sea-ice cover: Insights from remote sensing observations and model reanalysis. Heliyon [Internet]. 2020 ;6(7):e04355. Available from: https://www.sciencedirect.com/science/article/pii/S2405844020311993?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The present study quantifies the magnitude of Arctic sea-ice loss in the boreal summer (July–September), especially in September at different timescales (daily, monthly, annual and decadal). The investigation on the accelerated decline in the Arctic sea-ice was performed using different datasets of passive microwave satellite imagery and model reanalysis. Arctic sea-ice declined rapidly in the boreal summer (-10.2 ± 0.8 %decade−1) during 1979–2018, while, the highest decline in sea-ice extent (SIE) (i.e., 82,300 km2 yr−1/-12.8 ± 1.1 %decade−1) is reported in the month of September. Since late 1979, the SIE recorded the sixth-lowest decline during September 2018 (4.71 million km2). Incidentally, the records of twelve lowest extents in the satellite era occurred in the last twelve years. The loss of SIE and sea-ice concentration (SIC) are attributed to the impacts of land-ocean warming and the northward heat advection into the Arctic Ocean. This has resulted in considerable thinning of sea-ice thickness (SIT) and reduction in the multiyear ice (MYI) for summer 2018. Global and Arctic land-ocean temperatures have increased by ~0.78 °C and ~3.1 °C, respectively, over the past 40 years (1979–2018) while substantial warming rates have been identified in the Arctic Ocean (~3.5 °C in the last 40-year) relative to the Arctic land (~2.8 °C in the last 40-year). The prevailing ocean-atmospheric warming in the Arctic, the SIE, SIC and SIT have reduced, resulting in the decline of the sea-ice volume (SIV) at the rate of -3.0 ± 0.2 (1000 km3 decade−1). Further, it observed that the SIV in September 2018 was three times lower than September 1979. The present study demonstrates the linkages of sea-ice dynamics to ice drifting and accelerated melting due to persistent low pressure, high air-ocean temperatures, supplemented by the coupled ocean-atmospheric forcing.

Maritime boundary disputes: What are they and why do they matter?

Østhagen A. Maritime boundary disputes: What are they and why do they matter?. Marine Policy [Internet]. 2020 ;120:104118. Available from: https://www.sciencedirect.com/science/article/pii/S0308597X20302426?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

When states legalised the maritime domain in the 20th century, the relationship between states and maritime space changed. Since the turn of the millennium, certain global trends have further amplified the role of the oceans in international affairs. This has led to a renewed focus on maritime space, as well as states' rights and responsibilities within this domain, delineated through the concept of a ‘boundary’ at sea. What, in essence, is a maritime boundary? Why do states end up disputing them? Perhaps more important, how do states go about settling such disputes, and how can we better understand the development of the legal and political principles that frame such endeavours? These are the questions examined in this article, which sets out to examine the concept of maritime boundaries and related disputes. Leaning on political science, international law and political geography, it reviews how the idea of a maritime boundary came about; what principles govern how they are drawn; how they at times are resolved; and possible future trends that might impact boundary-making at sea.

Using Structured Decision-Making Tools With Marginalised Fishers to Promote System-Based Fisheries Management Approaches in South Africa

Gammage LCarin, Jarre A. Using Structured Decision-Making Tools With Marginalised Fishers to Promote System-Based Fisheries Management Approaches in South Africa. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00477/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1376892_45_Marine_20200714_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Fishers, and the communities they support face a range of challenges brought on by complexity and uncertainty in their social-ecological systems (SESs). This undermines their ability to achieve sustainability whilst hampering proactive planning and decision-making. To capacitate fishers to apply risk aversion strategies at smaller scales of operation and for managers to apply inclusive management approaches such as the ecosystem approach to fisheries management (EAF), a better understanding of the relationships and interactions in marine SESs must be developed. At the same time, the EAF requires the inclusion of multiple stakeholders, disciplines and objectives into decision-making processes. Previous work in the southern Cape with fishers, identified drivers of change. Building on this previous research, and using causal mapping, fishers mapped out drivers of change in an iterative process in a problem framing exercise which also highlighted hidden drivers of change and feedback loops. To explore the relative importance of key drivers of change with participants, weighted hierarchies as well as a Bayesian Belief Network (BBN) were developed. By identifying and highlighting these hidden system interactions a more integrated systems view has been facilitated, adding to the understanding of this fishery system. Drivers identified in the weighted hierarchy were consistent with those identified in the causal maps and previous research, of interest is the relative weighting attributed to these drivers. Whereas the weighted hierarchies emphasised the political dimensions, group work already indicated the range of perceptions, reflecting the considerable uncertainties in this SES. While methodologically challenging at first, the individual approach behind the BBN construction yielded a better reflection of the diversity of views and a better balance of political, economic and climate dimensions of drivers of change. We show how, by using SDMTs, the most disenfranchised community members can engage meaningfully in a structured process. As structure is crucial to management processes, the research shows that where the appropriate groundwork, capacity building and resourcing takes place, disenfranchised stakeholders can be integrated into formal management processes; fulfilling a key requirement of an EAF.

Regional Movements of Reef Manta Rays (Mobula alfredi) in Seychelles Waters

Peel LR, Stevens GMW, Daly R, Daly CAKeating, Collin SP, Nogués J, Meekan MG. Regional Movements of Reef Manta Rays (Mobula alfredi) in Seychelles Waters. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00558/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1376892_45_Marine_20200714_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The decline in numbers of reef manta rays (Mobula alfredi) throughout their range has highlighted the need for improved information on their spatial ecology in order to design effective conservation strategies for vulnerable populations. To understand their patterns of movement in Seychelles, we used three techniques—archival pop-up satellite tags, acoustic tags, and photo-identification—and focussed on the aggregation at D’Arros Island and St. Joseph Atoll within the Amirantes Group. M. alfredi were photographed within six of the seven Island Groups of Seychelles, with 64% of individuals being resighted at least once between July 2006 and December 2019 over timeframes of 1–3,462 days (9.5 years; median = 1,018 days). Only three individuals from D’Arros Island were resighted at a second aggregation site located more than 200 km away at St. François Atoll during photo-identification surveys. Satellite-tracked M. alfredi (n = 5 tracks; maximum 180 days) remained within the boundary of the Seychelles Exclusive Economic Zone, where they spent the majority of their time (87%) in the upper 50 m of the water column in close proximity to the Amirantes Bank. The inclusion of acoustic tagging data in the models of estimated satellite-track paths significantly reduced the errors associated with the geolocation positions derived from archived light level data. The insights gained into the patterns of horizontal and vertical movements of M. alfredi using this multi-technique approach highlight the significance of D’Arros Island and St. Joseph Atoll, and the wider Amirantes Group, to M. alfredi in Seychelles, and will benefit future conservation efforts for this species within Seychelles and the broader Western Indian Ocean.

Plastic Ingestion in Sardines (Sardinops sagax) From Frenchman Bay, Western Australia, Highlights a Problem in a Ubiquitous Fish

Crutchett T, Paterson H, Ford BM, Speldewinde P. Plastic Ingestion in Sardines (Sardinops sagax) From Frenchman Bay, Western Australia, Highlights a Problem in a Ubiquitous Fish. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00526/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1376892_45_Marine_20200714_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The ingestion of plastic debris has been studied in many marine fish species, although comparisons between species can be difficult due to factors thought to influence ingestion rates, such as habitat preference, feeding behaviours and trophic level. Sardines are found internationally in many coastal environments and represent a potential sentinel species for monitoring and comparing marine plastic exposure rates. We conducted a pilot study, examining the rate of plastic ingestion in 27 commercially caught sardines (Sardinops sagax) from a low populated coastal region of Western Australia. A total of 251 potentially anthropogenic particles were extracted by chemical digestion of the gastrointestinal tract and classified visually. Fibres were the dominant type of material recovered (82.9%), with both yellow (39.8%) and black (32.7%) coloured particles commonly observed. A subset of 64 particles (25.5%), were subject to Fourier transform infrared (FTIR) spectroscopy to identify polymer composition. This chemical characterisation identified seven plastic items (polypropylene, nylon and polyethylene) and a variety of cellulose-based material that was further examined and classified as natural or semi-synthetic. The mean plastic ingestion rate was 0.3 ± 0.4 particles per fish, suggesting Western Australian sardines ingest relatively low concentrations of plastic when compared to international sardine populations examined using similar methodologies. Despite comparatively low concentrations, plastic and semi-synthetic material are still being ingested by sardines from a low populated coastal region demonstrating the ubiquitous nature of the marine debris problem.

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