Freely-available Literature

Currently indexing 4413 freely-available titles

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

Wind Sea Algae Workshop Report

Trent DJonathan, Lange PLene, Hu PQiang, Lindblad PPeter, Averner DMel. Wind Sea Algae Workshop Report. Lolland, Denmark: International Conference on Offshore Algae for Biofuels and Beyond; 2009.
Freely available?: 
Yes
Summary available?: 
No
Type: Report

It has been known for decades that algae, in particular microalgae, have the potential to be used as a sustainable, carbon-neutral source of biofuels.1 From 1978-1996 the US Department of Energy (DOE) investigated the use of microalgae as a source of oil as well as biomass, hydrogen, hydrocarbons, alcohols, carbohydrates, methane, and syngas. This DOE algae program (The Aquatic Species Program) ended in 1996 for three reasons: 1) the DOE predicted that the cost of petroleum would remain relatively flat for at least 20 years (1996-2016), 2) that algal biodiesel could not compete with such cheap petroleum prices supported by a highly subsidized corporate infrastructure, and 3) there were many formidable technical challenges associated with growing the large quantities of algae needed for fuels. DOE was wrong about their predicted price of oil (Fig. 1).

Within three years the price of oil began to rise and within ten years it was >5 times the “flat” value the DOE had predicted. By 2009, the global reserves of petroleum are reaching their previously predicted limits,2 the largest remaining reserves of oil remain in politically unstable countries, and, most importantly, the increased burning of petroleum, impacting global climate, is of growing concern.3 Indeed, all things considered the price (in many senses) for the continued use of petroleum is too high. DOE’s prediction about the “price” of petroleum was wrong, could they also have been wrong about the economic and technical challenges preventing algae from becoming the much-needed replacement for petroleum? Considerable efforts are now underway to determine if algae can indeed be cultivated in sufficient quantities and at prices that are relevant for biofuels. Nearly all of these efforts are focused on scaling and improving traditional algae cultivation methods on land, which use shallow ponds (raceways) or large photo-bioreactors (PBRs). There are some non-traditional efforts looking into growing and harvesting algae in natural lakes and in harvesting algae directly from the ocean. Progress is being made, but to date, none of these systems have demonstrated they will be able to reach the quantities. and economics-of-scale for algae to contribute significantly to biofuels. In addition, most of the landbased methods are problematic because they significantly impact the environment--changing natural ecologies and competing for agricultural land and water. Indeed, the amount of freshwater required for replacing evaporated water in raceways and for controlling temperature in closed bioreactors, is in itself prohibitive. The goals of the Wind, Sea, and Algae workshop were to address the problems of large-scale algae cultivation on land by considering the possibilities of moving algae cultivation offshore into the ocean. More specifically, a multidisciplinary group of scientists and engineers from Universities, National Laboratories, and Industry, explored the idea of Offshore Membrane Enclosures for Growing Algae (OMEGA). Participants included experts on macro-algae (seaweeds), who provided background information from their offshore cultivation methods. We considered possibilities for ocean environments in general, and Lolland or more specifically the wind farms off the coast of Lolland, in particular. The program of the three-day workshop included lectures in the morning and breakout sessions in the afternoons. The groups discussed and debated, if offshore microalgae production is feasible, scalable, environmentally acceptable, and cost effective. Both the lectures and the breakout sessions were videotaped. This report includes transcripts of the lectures and discussions, selected and edited by the organizers. We hope this volume will help elucidate the challenges and opportunities of offshore algae cultivation and provide inspiration and guidance for future developments in this field in Lolland’s community test facility and beyond.

Modeling changes in baleen whale seasonal abundance, timing of migration, and environmental variables to explain the sudden rise in entanglements in California

Ingman K, Hines E, Mazzini PLF, R. Rockwood C, Nur N, Jahncke J. Modeling changes in baleen whale seasonal abundance, timing of migration, and environmental variables to explain the sudden rise in entanglements in California Li S. PLOS ONE [Internet]. 2021 ;16(4):e0248557. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0248557
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

We document changes in the number of sightings and timing of humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and gray (Eschrichtius robustus) whale migratory phases in the vicinity of the Farallon Islands, California. We hypothesized that changes in the timing of migration off central California were driven by local oceanography, regional upwelling, and basin-scale climate conditions. Using 24 years of daily whale counts collected from Southeast Farallon Island, we developed negative binomial regression models to evaluate trends in local whale sightings over time. We then used linear models to assess trends in the timing of migration, and to identify potential environmental drivers. These drivers included local, regional and basin-scale patterns; the latter included the El Niño Southern Oscillation, the Pacific Decadal Oscillation, and the North Pacific Gyre Oscillation, which influence, wind-driven upwelling, and overall productivity in the California Current System. We then created a forecast model to predict the timing of migration. Humpback whale sightings significantly increased over the study period, but blue and gray whale counts did not, though there was variability across the time series. Date of breeding migration (departure) for all species showed little to no change, whereas date of migration towards feeding areas (arrival) occurred earlier for humpback and blue whales. Timing was significantly influenced by a mix of local oceanography, regional, and basin-scale climate variables. Earlier arrival time without concomitant earlier departure time results in longer periods when blue and humpback whales are at risk of entanglement in the Gulf of the Farallones. We maintain that these changes have increased whale exposure to pot and trap fishery gear off the central California coast during the spring, elevating the risk of entanglements. Humpback entanglement rates were significantly associated with increased counts and early arrival in central California. Actions to decrease the temporal overlap between whales and pot/trap fishing gear, particularly when whales arrive earlier in warm water years, would likely decrease the risk of entanglements.

Fishing for food: Values and benefits associated with coastal infrastructure

Nieman CM, Rudman AN, Chory ML, Murray GD, Fairbanks L, Campbell LM. Fishing for food: Values and benefits associated with coastal infrastructure Seara T. PLOS ONE [Internet]. 2021 ;16(4):e0249725. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0249725
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

While there is substantial literature about the socio-cultural characteristics and values associated with recreational and commercial fisheries in the U.S., studies directed at those who ‘fish for food’—those who depend on consuming their catch to various degrees—are relatively sparse. Using qualitative data collected through 80 semi-structured interviews with fishers in the summer and fall of 2018 in Carteret County, North Carolina, this study aims to better understand the group of recreational fishers who consume their catch by describing social and cultural dimensions and values associated with fishing for food, examining the role of infrastructure in facilitating access to benefits associated with this activity, and considering how knowledge of existing licensing regulations surrounding subsistence license waivers affect this fishing community. Interviews conducted at free public fishing structures in the region revealed that fishers derive a variety of values and benefits from fishing at these sites, including access to recreation, nutrition, a social community, and mental health benefits, which were found to be negatively impacted by Hurricane Florence in September 2018. We also found an informal economy of sharing catch on- and off-site that extends the reach and benefits facilitated by public infrastructure to people beyond those using it directly. Overall, we call for conceptualizations of ‘fishing for food’ that include aspects that go beyond traditional definitions of ‘subsistence’ or ‘recreational’ fishing such as food security, access, and less obvious social and cultural motivations behind the activity. These findings are a compelling rationalization for the creation and maintenance of formal and informal fishing places locally and, by extension, in other coastal areas, given the array of benefits provided by access to these types of locations.

Regulation of apoptosis by Pacific oyster Crassostrea gigas reveals acclimation strategy to CO2 driven acidification

Wang X, Li C, Jia Z, Xu T, Wang Y, Sun M, Han S, Wang X, Qiu L. Regulation of apoptosis by Pacific oyster Crassostrea gigas reveals acclimation strategy to CO2 driven acidification. Ecotoxicology and Environmental Safety [Internet]. 2021 ;217:112235. Available from: https://www.sciencedirect.com/science/article/pii/S0147651321003468?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Ocean acidification (OA) has posed formidable threats to marine calcifiers. In response to elevated CO2 levels, marine calcifiers have developed multiple strategies to survive, such as taking advantage of apoptosis, but its regulation mechanism remains largely unknown. Here, we used the Pacific oyster Crassostrea gigas as model to understand the apoptotic responses and regulation mechanism at short- (7 d) to long-term (56 d) CO2 exposure (pH = 7.50). The apoptosis of hemocytes was significantly induced after short-term treatment (7–21 d) but was suppressed under long-term CO2 exposure (42–56 d). Similarly, caspase-3 and caspase-9 were also increased post short-term exposure and fell back to normal levels after long-term exposure. These data together indicated diverse regulation mechanisms of apoptosis through different exposure periods. Through analysis of the B-cell lymphoma 2 (Bcl-2) family mitochondrial apoptosis regulators, we showed that only CgBcl-XL’s expression kept at high levels after 42- and 56-day CO2 exposure. CgBcl-XL shared sequence, and structural similarity with its mammalian counterpart, and knockdown of CgBcl-XL in hemocytes via RNA interference promoted apoptosis. The protein level of CgBcl-XL was significantly increased after long-term CO2 exposure (28–56 d), and its distribution in hemocytes became more concentrated and dense. Therefore, CgBcl-XL serves as an essential anti-apoptotic protein for tipping the balance of cell apoptosis, which may play a key role in survival under long-term CO2 exposure. These results reveal a potential adaptation strategy of oysters towards OA and the variable environment changes through the modulation of apoptosis.

Seagrass ecosystems of the Pacific Island Countries and Territories: A global bright spot

McKenzie LJ, Yoshida RL, Aini JW, Andréfouët S, Colin PL, Cullen-Unsworth LC, Hughes AT, Payri CE, Rota M, Shaw C, et al. Seagrass ecosystems of the Pacific Island Countries and Territories: A global bright spot. Marine Pollution Bulletin [Internet]. 2021 ;167:112308. Available from: https://www.sciencedirect.com/science/article/pii/S0025326X21003428?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Seagrass ecosystems exist throughout Pacific Island Countries and Territories (PICTs). Despite this area covering nearly 8% of the global ocean, information on seagrass distribution, biogeography, and status remains largely absent from the scientific literature. We confirm 16 seagrass species occur across 17 of the 22 PICTs with the highest number in Melanesia, followed by Micronesia and Polynesia respectively. The greatest diversity of seagrass occurs in Papua New Guinea (13 species), and attenuates eastward across the Pacific to two species in French Polynesia. We conservatively estimate seagrass extent to be 1446.2 km2, with the greatest extent (84%) in Melanesia. We find seagrass condition in 65% of PICTs increasing or displaying no discernible trend since records began. Marine conservation across the region overwhelmingly focuses on coral reefs, with seagrass ecosystems marginalised in conservation legislation and policy. Traditional knowledge is playing a greater role in managing local seagrass resources and these approaches are having greater success than contemporary conservation approaches. In a world where the future of seagrass ecosystems is looking progressively dire, the Pacific Islands appears as a global bright spot, where pressures remain relatively low and seagrass more resilient.

Conservation beyond the existing protected area network is required to improve species and habitat representation in a global biodiversity hotspot

De Alban JDon T, Leong BPo Ian, Venegas-Li R, Connette GM, Jamaludin J, Latt KThinn, Oswald P, Reeder C, Webb EL. Conservation beyond the existing protected area network is required to improve species and habitat representation in a global biodiversity hotspot. Biological Conservation [Internet]. 2021 ;257:109105. Available from: https://www.sciencedirect.com/science/article/pii/S0006320721001579?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Adequate representation of species and habitats is a critical aspect of an effective protected area (PA) network. Here, we evaluate the representation of focal wildlife species and forest types within the existing 11,241-km2 PA network of the Tanintharyi Region in southern Myanmar, a frontier forest landscape and global biodiversity hotspot, and use spatial prioritisation tools to identify additional priority areas for conservation outside the existing network that contribute towards meeting a 30% representation target. Our study showed that the current configuration of the existing PA network underrepresented 32 of 60 threatened wildlife species and 6 of 8 forest types, with mangroves being the least represented. Spatial prioritisation revealed that by protecting an additional 4032 km2 (8.4% of Tanintharyi's land area), 31% of which were adjacent to the existing PA network, the target representation for all wildlife species and forest types can be achieved. Enhancing the effectiveness of the existing network entails modest expansion by establishing additional conservation areas through various area-based conservation strategies, specifically targeting mangrove forests. Large oil palm agribusiness concessions, however, overlapped with almost 12% of priority conservation areas (consisting of additional areas and parts of the existing PA network), thereby competing with conservation interests. Expanding the area of representation will only succeed if the species and their habitats are adequately protected. Efforts therefore must prioritise the involvement and leadership of local communities and reflect local realities in negotiations among stakeholders.

Demographic responses to protection from harvesting in a long-lived marine species

Fernández-Chacón A, Buttay L, Moland E, Knutsen H, Olsen EMoland. Demographic responses to protection from harvesting in a long-lived marine species. Biological Conservation [Internet]. 2021 ;257:109094. Available from: https://www.sciencedirect.com/science/article/pii/S0006320721001464?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Marine protected areas (MPAs) are usually considered to have positive effects on the recovery of over-exploited populations. However, resolving the extent to which MPAs function according to their conservation goals requires that essential demographic information such as individual survival and population size are quantified. To this end, we analyzed a 16-year replicated mark-recapture study on European lobster (Homarus gammarus, n = 8793) conducted at several protected and unprotected sites in southern Norway, quantifying the impact of MPAs on local population dynamics by means of a “before-after control-impact” study approach (BACI). Lobster survival and abundance were estimated by applying multi-state and robust design models to the mark-recapture data. These models revealed underlying positive responses to protection. Annual survival rates and population abundances reached higher values in the MPAs, compared to the unprotected sites (abundance range: MPAs = 96–1172, control areas = 92–747). In general, female survival was higher than male survival (range of survival: male = 0.13–0.75, female = 0.37–0.85), while larger males benefited more from protection compared to smaller males (range of increase in survival after protection: big = 100–125%, small = 55–101%). We also detected regional differences in demographic responses to protection, as not all MPAs showed the same changes in abundance over time. Our results show that MPAs can reach conservation goals by increasing the local survival and abundance of lobster, but they also highlight demographic differences between sexes and geographic areas that are worth considering for the management and design of both current and future MPAs.

First record of plastic debris in the stomach of a hooded seal pup from the Greenland Sea

Pinzone M, Nordøy ES, Eppe G, Malherbe C, Das K, Collard F. First record of plastic debris in the stomach of a hooded seal pup from the Greenland Sea. Marine Pollution Bulletin [Internet]. 2021 ;167:112350. Available from: https://www.sciencedirect.com/science/article/pii/S0025326X21003842?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Plastic debris is globally found around the world and the remote Arctic is no exception. Arctic true seals are sentinel species of marine pollution and represent the link between marine food webs and Arctic apex predators like polar bears and humans. With regard to true seals, ingested macroplastics have never been reported in an Arctic species. We harvested 10 harp seals Pagophilus groenlandicus and 8 hooded seals Cystophora cristata from the breeding grounds in the pack ice of the Greenland Sea. The digestive tract was inspected exclusively for the presence of macroplastics (>5 mm). Two pieces of single-use plastic were found in the stomach of a weaned hooded seal pup. This study indicates that young Arctic marine predators may ingest macroplastics, and therefore may be at risk during their early stages of life due to human caused plastic pollution even in the remote Arctic pack ice.

Opportunities for improving recognition of coastal wetlands in global ecosystem assessment frameworks

Brown CJ, Adame MF, Buelow CA, Frassl MA, Lee SYip, Mackey B, McClure EC, Pearson RM, Rajkaran A, Rayner TS, et al. Opportunities for improving recognition of coastal wetlands in global ecosystem assessment frameworks. Ecological Indicators [Internet]. 2021 ;126:107694. Available from: https://www.sciencedirect.com/science/article/pii/S1470160X21003599?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Vegetated coastal wetlands, including seagrass, saltmarsh and mangroves, are threatened globally, yet the need to avert these losses is poorly recognized in international policy, such as in the Convention on Biological Diversity and the United Nations (UN) Sustainable Development Goals. Identifying the impact of overlooking coastal wetlands in ecosystem assessment frameworks could help prioritize research efforts to fill these gaps. Here, we examine gaps in the recognition of coastal wetlands in globally applicable ecosystem assessments. We address both shortfalls in assessment frameworks when it comes to assessing wetlands, and gaps in data that limit widespread application of assessments. We examine five assessment frameworks that track fisheries, greenhouse gas emissions, ecosystem threats, and ecosystem services. We found that these assessments inform management decisions, but that the functions provided by coastal wetlands are incompletely represented. Most frameworks had sufficient complexity to measure wetland status, but limitations in data meant they were incompletely informed about wetland functions and services. Incomplete representation of coastal wetlands may lead to them being overlooked by research and management. Improving the coverage of coastal wetlands in ecosystem assessments requires improving global scale mapping of wetland trends, developing global-scale indicators of wetland function and synthesis to quantitatively link animal population dynamics to wetland trends. Filling these gaps will help ensure coastal wetland conservation is properly informed to manage them for the outstanding benefits they bring humanity.

Can we enhance ecosystem-based coastal defense by connecting oysters to marsh edges? Analyzing the limits of oyster reef establishment

Fivash GS, Stüben D, Bachmann M, Walles B, van Belzen J, Didderen K, Temmink RJM, Lengkeek W, van der Heide T, Bouma TJ. Can we enhance ecosystem-based coastal defense by connecting oysters to marsh edges? Analyzing the limits of oyster reef establishment. Ecological Engineering [Internet]. 2021 ;165:106221. Available from: https://www.sciencedirect.com/science/article/pii/S0925857421000768?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Nature-based coastal defense schemes commonly value bivalve reefs for i) reducing coastal erosion in the intertidal and for ii) forming fringing reefs near salt marsh edges to protect them against lateral retreat. The capacity for a reef to reduce erosion increases at a higher position in the tidal frame as the lower over-lying water level magnifies the influence of the reef on wave attenuation. Unfortunately, ecological constraints on reef development typically limit their practical application in coastal protection schemes to the lower intertidal, as bivalves grow best with long inundation times. In micro-tidal areas this is a lesser problem, given the close proximity of lower and upper intertidal ecosystems in space. By contrast, in meso- and macro-tidal estuaries, bivalve reefs tend to form hundreds of meters away from existing marshes, nullifying any wave-protective benefits. In this study, we produce evidence that with the assistance of management measures, widespread reef formation is possible on open mudflats, including bordering the marsh edge in meso- and macro-tidal estuaries, where natural reef formation is normally strongly limited.

In four locations throughout the meso- to macro-tidal Dutch Scheldt estuary, we observed the presence of individuals of two major intertidal reef-forming bivalves, Pacific oysters (Crassostrea gigas) and blue mussels (Mytilus edulis), within low-lying Spartina anglica-dominated marshes. As these communities lie well outside of the expected range of reef formation, this observation suggests the existence of mechanisms that extend the habitable range of these bivalves. In a series of field experiments, we first demonstrate how the stabilization of shell-substrate within the marsh promotes successful establishment and adult survival. Secondly, by placing artificial stable substrate in transects from the subtidal up to the marsh edge, we demonstrate that bivalve establishment is possible throughout a much larger range of the intertidal than where natural reefs occur. The effectiveness of stable substrate in stimulating bivalve establishment is likely a consequence of bridging size-dependent thresholds that limit the effective range for natural reef formation on tidal flats. The success of this approach is tempered by a consistent decrease in reef size and growth at higher elevations, suggesting that the optimal reef position for utility in coastal defense lies at an intermediate tidal position, well above the observed range of natural occurrence, but below the maximum achievable upper limit of reef formation. Together this work provides a pathway forward concerning how artificial reefs may be fostered to increase their utility as a nature-based flood defense measure.

Key climate change stressors of marine ecosystems along the path of the East African coastal current

Jacobs ZL, Yool A, Jebri F, Srokosz M, van Gennip S, Kelly SJ, Roberts M, Sauer W, Queirós AM, Osuka KE, et al. Key climate change stressors of marine ecosystems along the path of the East African coastal current. Ocean & Coastal Management [Internet]. 2021 ;208:105627. Available from: https://www.sciencedirect.com/science/article/pii/S0964569121001125?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

For the countries bordering the tropical Western Indian Ocean (TWIO), living marine resources are vital for food security. However, this region has largely escaped the attention of studies investigating potential impacts of future climate change on the marine environment. Understanding how marine ecosystems in coastal East Africa may respond to various climatic stressors is vital for the development of conservation and other ocean management policies that can help to adapt to climate change impacts on natural and associated human systems. Here, we use a high-resolution (1/4°) ocean model, run under a high emission scenario (RCP 8.5) until the end of the 21st century, to identify key regionally important climate change stressors over the East African Coastal Current (EACC) that flows along the coasts of Kenya and Tanzania. We also discuss these stressors in the context of projections from lower resolution CMIP5 models. Our results indicate that the main drivers of dynamics and the associated ecosystem response in the TWIO are different between the two monsoon seasons. Our high resolution model projects weakening of the Northeast monsoon (December–February) winds and slight strengthening of the Southeast monsoon (May–September) winds throughout the course of the 21st century, consistent with CMIP5 models. The projected shallower mixed layers and weaker upwelling during the Northeast Monsoon considerably reduce the availability of surface nutrients and primary production. Meanwhile, primary production during the Southeast monsoon is projected to be relatively stable until the end of the century. In parallel, a widespread warming of up to 5 °C is projected year-round with extreme events such as marine heatwaves becoming more intense and prolonged, with the first year-long event projected to occur as early as the 2030s. This extreme warming will have significant consequences for both marine ecosystems and the coastal populations dependent on these marine resources. These region-specific stressors highlight the importance of dynamic ocean features such as the upwelling systems associated with key ocean currents. This indicates the need to develop and implement a regional system that monitors the anomalous behaviour of such regionally important features. Additionally, this study draws attention to the importance of investment in decadal prediction methods, including high resolution modelling, that can provide information at time and space scales that are more directly relevant to regional management and policy making.

Tracked to protect - Spatiotemporal dynamics of recreational boating in sensitive marine natural areas

Meijles EW, Daams MN, Ens BJ, Heslinga JH, Sijtsma FJ. Tracked to protect - Spatiotemporal dynamics of recreational boating in sensitive marine natural areas. Applied Geography [Internet]. 2021 ;130:102441. Available from: https://www.sciencedirect.com/science/article/pii/S0143622821000576?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

In many coastal areas, high numbers of recreationists may exceed ecological capacities. Careful monitoring of visitor flows is a first prerequisite for coastal area management. We show how AIS ship data can be translated into interpretable information on recreational boats and investigate whether AIS can provide monitoring information when compared to nature conservation policy targets. In the Wadden Sea UNESCO World Heritage Site we used nearly 9 million data points to create spatiotemporal patterns for the 2018 recreation season. We combined this with shipping lanes and bathymetry data and compared the resulting patterns with nature protection regulations. Our results show that most of the traffic is concentrated around tidal channels. We also show that exceeding speed limits is not predominant behaviour, but the effect of speeding on birds and seals might be more severe than the data suggests. We mapped favourite tidal flat moor activities, and observed where this occurs in Marine Protected Areas. We conclude that AIS analysis can provide valuable recreational boating monitoring, relevant to sensitive coastal area management in the entire Dutch Wadden Sea for the full recreational season. Broader integration of AIS with radar data and ecological data can add to the power of using AIS.

Seagrass ecosystem contributions to people's quality of life in the Pacific Island Countries and Territories

McKenzie LJ, Yoshida RL, Aini JW, Andréfouët S, Colin PL, Cullen-Unsworth LC, Hughes AT, Payri CE, Rota M, Shaw C, et al. Seagrass ecosystem contributions to people's quality of life in the Pacific Island Countries and Territories. Marine Pollution Bulletin [Internet]. 2021 ;167:112307. Available from: https://www.sciencedirect.com/science/article/pii/S0025326X21003416?dgcid=raven_sd_search_email
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Seagrass ecosystems provide critical contributions (goods and perceived benefits or detriments) for the livelihoods and wellbeing of Pacific Islander peoples. Through in-depth examination of the contributions provided by seagrass ecosystems across the Pacific Island Countries and Territories (PICTs), we find a greater quantity in the Near Oceania (New Guinea, the Bismarck Archipelago and the Solomon Islands) and western Micronesian (Palau and Northern Marianas) regions; indicating a stronger coupling between human society and seagrass ecosystems. We also find many non-material contributions historically have been overlooked and under-appreciated by decision-makers. Closer cultural connections likely motivate guardianship of seagrass ecosystems by Pacific communities to mitigate local anthropogenic pressures. Regional comparisons also shed light on general and specific aspects of the importance of seagrass ecosystems to Pacific Islanders, which are critical for forming evidence-based policy and management to ensure the long-term resilience of seagrass ecosystems and the contributions they provide.

Interannual Nearshore Habitat Use of Young of the Year White Sharks Off Southern California

Anderson JM, Burns ES, Meese EN, Farrugia TJ, Stirling BS, White CF, Logan RK, O’Sullivan J, Winkler C, Lowe CG. Interannual Nearshore Habitat Use of Young of the Year White Sharks Off Southern California. Frontiers in Marine Science [Internet]. 2021 ;8. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2021.645142/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1599332_45_Marine_20210413_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Young-of-the-year (YOY) and juvenile-stage white sharks may use southern California nearshore beach habitats more extensively than previously known, within meters of some of the most heavily used beaches in the world. Such knowledge forms a critical component of species management and conservation plans, in addition to public safety and risk mitigation planning. We used data derived from a combination of satellite tag locations (13 animals over 3 years) and passive acoustic monitoring (34 animals over 8 years) to examine the occurrence, relative abundance, and residency patterns of YOY white sharks in southern California waters. Our results suggest that southern California contains spatiotemporally dynamic centers of primary nursery habitat. Tagged YOY white sharks formed loose aggregations at “hotspot” locations that were interannually variable, where individuals exhibited temporal fidelity, higher levels of residency, and spatially restricted movements, with multiple YOY individuals simultaneously displaying this behavior. While models of biotic and abiotic variables suggested relative abundance of tagged sharks may be predicted by sea surface temperature, salinity and productivity (chlorophyll-A), these predictors were not consistent across all years of the study. Thus, novel approaches that incorporate technologies to derive high resolution environmental data, paired with more comprehensive telemetry datasets are therefore required to better understand the extrinsic factors that drive habitat selection and residency patterns in juvenile white sharks.

Annotated Video Footage for Automated Identification and Counting of Fish in Unconstrained Seagrass Habitats

Ditria EM, Connolly RM, Jinks EL, Lopez-Marcano S. Annotated Video Footage for Automated Identification and Counting of Fish in Unconstrained Seagrass Habitats. Frontiers in Marine Science [Internet]. 2021 ;8. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2021.629485/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1599332_45_Marine_20210413_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Technological advances are improving the collection, processing and analysis of ecological data. One of these technologies that has been adopted in recent studies by ecologists is computer vision (CV). CV is a rapidly developing area of machine learning that aims to infer image content at the same level humans can by extracting information from pixels (LeCun et al., 2015Weinstein, 2018). CV in ecology has gained much attention as it can quickly and accurately process image from remote video imagery while allowing scientists to monitor both individuals and populations at unprecedented spatial and temporal scales. Automated analysis of imagery through CV has also become more accurate and streamlined with the implementation of deep learning (a subset of machine learning) models that have improved the capacity to processes raw images compared to traditional machine learning methods (LeCun et al., 2015Villon et al., 2016). As the use of camera systems for monitoring fish abundances is common practice in conservation ecology (Gilby et al., 2017Whitmarsh et al., 2017Langlois et al., 2020), deep learning allows for the automated processing of big data from video or images, a step which usually creates a bottleneck when these data must be analyzed manually.

Assessing the Skill of a High-Resolution Marine Biophysical Model Using Geostatistical Analysis of Mesoscale Ocean Chlorophyll Variability From Field Observations and Remote Sensing

Eveleth R, Glover DM, Long MC, Lima ID, Chase AP, Doney SC. Assessing the Skill of a High-Resolution Marine Biophysical Model Using Geostatistical Analysis of Mesoscale Ocean Chlorophyll Variability From Field Observations and Remote Sensing. Frontiers in Marine Science [Internet]. 2021 ;8. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2021.612764/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1599332_45_Marine_20210413_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

High-resolution ocean biophysical models are now routinely being conducted at basin and global-scale, opening opportunities to deepen our understanding of the mechanistic coupling of physical and biological processes at the mesoscale. Prior to using these models to test scientific questions, we need to assess their skill. While progress has been made in validating the mean field, little work has been done to evaluate skill of the simulated mesoscale variability. Here we use geostatistical 2-D variograms to quantify the magnitude and spatial scale of chlorophyll a patchiness in a 1/10th-degree eddy-resolving coupled Community Earth System Model simulation. We compare results from satellite remote sensing and ship underway observations in the North Atlantic Ocean, where there is a large seasonal phytoplankton bloom. The coefficients of variation, i.e., the arithmetic standard deviation divided by the mean, from the two observational data sets are approximately invariant across a large range of mean chlorophyll a values from oligotrophic and winter to subpolar bloom conditions. This relationship between the chlorophyll a mesoscale variability and the mean field appears to reflect an emergent property of marine biophysics, and the high-resolution simulation does poorly in capturing this skill metric, with the model underestimating observed variability under low chlorophyll a conditions such as in the subtropics.

How Fishery Collapses: The Case of Lepidopus caudatus (Pisces: Trichiuridae) in the Strait of Sicily (Central Mediterranean)

Falsone F, Scannella D, Geraci MLuca, Gancitano V, Vitale S, Fiorentino F. How Fishery Collapses: The Case of Lepidopus caudatus (Pisces: Trichiuridae) in the Strait of Sicily (Central Mediterranean). Frontiers in Marine Science [Internet]. 2021 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.584601/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1599332_45_Marine_20210413_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The silver scabbardfish Lepidopus caudatus is a mesopelagic species living on the shelf and slope down to 600 m in temperate seas all around the world. In the Mediterranean, the species is caught mainly by longlines with a marked seasonality. In the early 90s in the Strait of Sicily (Central Mediterranean Sea), a new fishery targeting L. caudatus was developed. This fishery uses an ad hoc pelagic trawl gear called “spatolara.” Vessels using spatolara have increased from 1 in 1993 to 10 in 2007 with a growth of catches of up to 1,200 tons in 2011. Development of this fishery was not regulated by any specific management measures and, due to the progressive reduction of catch to 169 tons, only one vessel was active in 2018. The availability of catch and biomass indices from trawl survey since the beginning of trawling exploitation allowed providing the first assessment of the state of L. caudatus stock in the Central Mediterranean (GFCM Geographical Sub-Area 16) by using data-limited methods. Catch-Maximum Sustainable Yield (CMSY) and Bayesian State Space Schaefer model (BSM) were fitted to landings and abundance indices (2004–2018). The Abundance-Maximum Sustainable Yield model (AMSY) was also applied to survey data from 1994 (1 year after the start of the spatolara fishery) to 2018 to further corroborate the results. BSM prediction of biomass levels was just above 50% of BMSY, whereas AMSY estimated the current stock levels below 50% of BMSY. The BSM was used for forecasting B/BMSY and catches under different fishing scenarios. Although current exploitation was very close to FMSY, more than a decade would be needed to rebuild the stock to biomass levels producing MSY. A faster rebuilding could be achieved by fishing at least 80% of FMSY, with minimal loss in yield over the next 5–8 years. Following the development of a new fishery since the beginning, the study provides a further example of how unregulated exploitation leads to a heavy overfished state of stock and collapse of fishing activities.

Internal Nutrient Loading Controls Macroalgal and Cyanobacterial Succession in a Coastal Lagoon Restored by Managed Realignment of Agricultural Land

Thorsen SW, Holmer M, Quintana CO, Valdemarsen T, Kristensen E. Internal Nutrient Loading Controls Macroalgal and Cyanobacterial Succession in a Coastal Lagoon Restored by Managed Realignment of Agricultural Land. Frontiers in Marine Science [Internet]. 2021 ;8. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2021.649360/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1599332_45_Marine_20210413_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Managed realignment (MR) has been increasingly applied as an adaptation strategy to sea level rise in low-lying coastal areas, but the ecological consequences after flooding agricultural land with seawater are not well known. The restored Gyldensteen Coastal Lagoon represents one of the largest MR projects in Europe to date. The area served as agricultural land for about 150 years before being deliberately flooded with seawater in 2014. This study monitored for 5 years the succession of macroalgae and benthic cyanobacteria driven by changing internal nutrient (DIN = NH4+ + NO2 + NO3, DON = dissolved organic nitrogen, and DIP = PO43–) loadings in the lagoon after flooding. A massive bloom of opportunistic green macroalgae (dominated by Cladophora spp.) occurred during the first year as response to a substantial loading of DIN and DIP from the newly flooded soils. The macroalgal cover was sparse the following years and the species richness increased with lower loading of particularly DIN. A cyanobacterial bloom controlled by declining DIN and steady DIP concentrations in the water dominated the lagoon and covered all solid surfaces 4 years after flooding. Highest macroalgal species richness with dominance of perennial Fucus vesiculosus and Agarophyton vermiculophylla was recorded 5 years after flooding following a temperature-induced stimulation of soil nitrogen transformation, leading to increased water column DON concentrations and DIN:DIP ratios. The lagoon remains therefore at an unstable tipping point where small and random changes in the DIN:DIP ratio control the balance between blooms of benthic cyanobacteria and high macroalgal species richness. Future MR projects involving agricultural land should prepare the soil to prevent algal blooms driven by sustained internal nutrient loading. Particularly P loading should be avoided to minimize the chances for recurrent blooms of benthic cyanobacteria.

Determining the Ecological Status of Benthic Coastal Communities: A Case in an Anthropized Sub-Arctic Area

Dreujou E, Desroy N, Carrière J, de Coeli LTréau, McKindsey CW, Archambault P. Determining the Ecological Status of Benthic Coastal Communities: A Case in an Anthropized Sub-Arctic Area. Frontiers in Marine Science [Internet]. 2021 ;8. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2021.637546/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1599332_45_Marine_20210413_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

With the widespread influence of human activities on marine ecosystems, evaluation of ecological status provides valuable information for conservation initiatives and sustainable development. To this end, many environmental indicators have been developed worldwide and there is a growing need to evaluate their performance by calculating ecological status in a wide range of ecosystems at multiple spatial and temporal scales. This study calculated and contrasted sixteen indicators of ecological status from three methodological categories: abundance measures, diversity parameters and characteristic species. This selection was applied to coastal benthic ecosystems at Sept-Îles (Québec, Canada), an important industrial harbor area in the Gulf of St. Lawrence, and related to habitat parameters (organic matter, grain size fractions, and heavy metal concentrations). Nearly all indicators highlighted a generally good ecological status in the study area, where communities presented an unperturbed profile with high taxa and functional diversities and without the dominance of opportunistic taxa. Some correlations with habitat parameters were detected, especially with heavy metals, and bootstrap analyses indicated quite robust results. This study provides valuable information on the application of environmental indicators in Canadian coastal ecosystems, along with insights on their use for environmental assessments.

“If You Know the Enemy and Know Yourself”: Addressing the Problem of Biological Invasions in Ports Through a New NIS Invasion Threat Score, Routine Monitoring, and Preventive Action Plans

Miralles L, Ibabe A, González M, Garcia-Vazquez E, Borrell YJ. “If You Know the Enemy and Know Yourself”: Addressing the Problem of Biological Invasions in Ports Through a New NIS Invasion Threat Score, Routine Monitoring, and Preventive Action Plans. Frontiers in Marine Science [Internet]. 2021 ;8. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2021.633118/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1599332_45_Marine_20210413_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Invasive alien species (IAS) are currently considered one of the greatest threats to global marine ecosystems. Thus, ships and maritime activity have been identified as the main factors responsible for the vast majority of accidental species translocations around the world, implying that prevention should be the core of environmental port policies. Preventive port strategies should include analyzing risks based on traffic origins and volumes, revising port policies for inspections, estimating probabilities of non-indigenous species (NIS) appearance, monitoring routine species within ports, and finally implementing management plans and focused actions. Here, we conducted a comprehensive NIS prediction analysis for the port of Gijon (northern Spain), one of the largest ports in the south Bay of Biscay, as a case study that can be extrapolated to other international seaports. An extensive bibliographic search (1953–2020) was conducted and we identified 380 species that have been transported through hull fouling and ballast water around the world. We evaluated their likelihood of arriving (from 14 years of traffic data) and becoming established (from habitat suitability and demonstrated impacts and invasion ability) within the Gijon port, creating a new NIS Invasion Threat Score (NIS-ITS). This new index could help to identify target species that are likely invaders for early detection and prevention policies within the port. The results showed that 15 NIS had >90% likelihood of becoming a biological invasion problem in Gijon Port. At the same time, we reported morphological and genetic analysis of biota found in two successive annual monitoring surveys of Gijon port and ships (n = 612 individuals) revealing 18 NIS, including 6 of the NIS predicted from high NIS-ITS. Actually, 80% (12 NIS) of those potentially most dangerous species (NIS-ITS > 90%) have already been detected in the Bay of Biscay area. We propose the use of this new tool for a risk-reduction strategy in ports, based on accurate predictions that help in promoting specific early detection tests and specific monitoring for NIS that have a high chance of establishment. All international seaports can adopt this strategy to address the problem of biological invasions and become “blueports” in line with EU policy.

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