Literature Library

Currently indexing 7886 titles

Evidence of Overfishing in Small-Scale Fisheries in Madagascar

Gough CLA, Dewar KM, Godley BJ, Zafindranosy E, Broderick AC. Evidence of Overfishing in Small-Scale Fisheries in Madagascar. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00317/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Small-scale fisheries are an important source of food, income and cultural identity to millions of people worldwide. Despite many fisher people observing declining catches, a lack of data remains a barrier to understanding the status of small-scale fisheries and their effective management in many places. Where data exist, complex analyses and stock assessments are often beyond the capacity and budgets of local managers. Working with small-scale fisheries in western Madagascar, we analyze landings data to provide a description of the fishery and evaluate the top twenty most commonly caught species for evidence of overfishing. Using length composition data, we use Froese’s three simple rules: Let them spawn, let them grow and let the mega-spawners live, as well as Cope and Punt’s decision tree to infer if spawning biomass is less than target reference points. We then use length-based parameters to calculate fishing mortality and compare with published estimates of natural mortality to assess overfishing (F > M). Over 17,000 fishing trips were registered over a 2-year period (2010–2012), landing just short of 2 million individual fish. Length data were recorded for a sample of over 120,000 individuals. Fish comprised 95% of landings, with the remainder comprised of other groups including crustaceans (mostly shrimp, crab, and lobster), cephalopods, and holothurians. We provide some of the first evidence that fish species caught in the small-scale fisheries of the Menabe region of Madagascar are experiencing overfishing. The most notable result is that for 13 of the 20 most common species, fishing mortality exceeds natural mortality. Many species had a large proportion of individuals (in some cases 100%) being caught before they reached maturity. Very few species were fished at their optimal size, and there were low numbers of large individuals (mega-spawners) in catches. Overfishing in western Madagascar presents a serious threat to the income, food security and well-being of some of the most vulnerable people in the world. The results of this paper support the call for improved management. However, management approaches should take account of overlapping fisheries and be inclusive to ensure the impacts of management do not undermine the rights of small-scale fishers. Further data are needed to better understand the trends and to improve management but should not hinder pragmatic action.

Deep-Sea Debris in the Central and Western Pacific Ocean

Amon DJ, Kennedy BRC, Cantwell K, Suhre K, Glickson D, Shank TM, Rotjan RD. Deep-Sea Debris in the Central and Western Pacific Ocean. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00369/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Marine debris is a growing problem in the world’s deep ocean. The naturally slow biological and chemical processes operating at depth, coupled with the types of materials that are used commercially, suggest that debris is likely to persist in the deep ocean for long periods of time, ranging from hundreds to thousands of years. However, the realized scale of marine debris accumulation in the deep ocean is unknown due to the logistical, technological, and financial constraints related to deep-ocean exploration. Coordinated deep-water exploration from 2015 to 2017 enabled new insights into the status of deep-sea marine debris throughout the central and western Pacific Basin via ROV expeditions conducted onboard NOAA Ship Okeanos Explorer and RV Falkor. These expeditions included sites in United States protected areas and monuments, other Exclusive Economic Zones, international protected areas, and areas beyond national jurisdiction. Metal, glass, plastic, rubber, cloth, fishing gear, and other marine debris were encountered during 17.5% of the 188 dives from 150 to 6,000 m depth. Correlations were observed between deep-sea debris densities and depth, geological features, and distance from human-settled land. The highest densities occurred off American Samoa and the main Hawaiian Islands. Debris, mostly consisting of fishing gear and plastic, were also observed in most of the large-scale marine protected areas, adding to the growing body of evidence that even deep, remote areas of the ocean are not immune from human impacts. Interactions with and impacts on biological communities were noted, though further study is required to understand the full extent of these impacts. We also discuss potential sources and long-term implications of this debris.

Dolphins and Boats: When Is a Disturbance, Disturbing?

New L, Lusseau D, Harcourt R. Dolphins and Boats: When Is a Disturbance, Disturbing?. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00353/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Globally, the exploitation of marine mammals has shifted from hunting to viewing over the last few decades. While refraining from actively killing animals may have a positive effect on marine mammal populations, whale and dolphin watching can induce changes such as displacement from preferred habitat and disruption of foraging that may also have severe fitness costs. Under some circumstances, this non-lethal disturbance may affect populations in a manner similar to directed mortality. Here, we focus on inshore dolphin populations that are known to show short-term behavioral responses to boat approaches. Long-term fitness effects have only been clearly identified in a small number of these populations, and all share certain characteristics, i.e., closed, small and food-limited. This raises the question of importance of context when considering the long-term effects of disturbance, since many dolphin populations may be open, large, and/or free from resource restriction. We explored the effect of disturbance based on the characteristics of populations using the population consequences of disturbance (PCoD) framework. PCoD was developed to link short-term changes in individual behavior and physiology to presumed long-term effects on population dynamics. To ensure our scenarios were biologically plausible, they reflected the ecological context of four well-studied populations of dolphins, Doubtful Sound, New Zealand, Sarasota Bay, United States, Durban Bay, South Africa, and Jervis Bay, Australia, in terms of their size, closure, and food resources. We found that the characteristics of the populations being disturbed are important with regards to the level of disturbance that could be tolerated. Closed populations were most sensitive, while large, open populations with no food limitation appeared to be able to withstand a higher probability of disturbance. This implies that population characteristics should be accounted for when determining the suitability of whale and dolphin watching operations in a given area.

Toward New Ecologically Relevant Markers of Health for Cetaceans

Derous D, Doeschate Mten, Brownlow AC, Davison NJ, Lusseau D. Toward New Ecologically Relevant Markers of Health for Cetaceans. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00367/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Multiple stressors caused by human-induced disturbances can affect the foraging opportunities of cetaceans, potentially depleting their energy stores, and ultimately impact survival and reproductive success. Currently, blubber thickness and lipid composition is used as measure of health and nutritional status in cetaceans. This assumes that blubber functions in the same manner as adipose tissue in terrestrial mammals. However, cetaceans have evolved to have thickened blubber which serves as thermoregulation, buoyancy and energy store. In addition, blubber is composed of several layers and regions that have different physiological functions. We currently lack a clear understanding of how blubber biology contributes to maintaining energy status in cetaceans and several studies show blubber thickness, and composition in some body regions, is an inappropriate measure of health. Before new markers of health can be identified, we need to understand how environmental stressors influence blubber biology and particularly unravel its complex signaling roles with other organs. Currently, we do not understand how changes in energy status drive changes in health in cetaceans, and eventually population dynamics. This review synthesizes recent developments in cetacean blubber biology to propose potential directions to develop novel cetacean health markers.

Cold Seeps in a Warming Arctic: Insights for Benthic Ecology

Åström EKL, Sen A, Carroll ML, Carroll JL. Cold Seeps in a Warming Arctic: Insights for Benthic Ecology. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00244/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Cold-seep benthic communities in the Arctic exist at the nexus of two extreme environments; one reflecting the harsh physical extremes of the Arctic environment and another reflecting the chemical extremes and strong environmental gradients associated with seafloor seepage of methane and toxic sulfide-enriched sediments. Recent ecological investigations of cold seeps at numerous locations on the margins of the Arctic Ocean basin reveal that seabed seepage of reduced gas and fluids strongly influence benthic communities and associated marine ecosystems. These Arctic seep communities are mostly different from both conventional Arctic benthic communities as well as cold-seep systems elsewhere in the world. They are characterized by a lack of large specialized chemo-obligate polychetes and mollusks often seen at non-Arctic seeps, but, nonetheless, have substantially higher benthic abundance and biomass compared to adjacent Arctic areas lacking seeps. Arctic seep communities are dominated by expansive tufts or meadows of siboglinid polychetes, which can reach densities up to >3 × 105 ind.m–2. The enhanced autochthonous chemosynthetic production, combined with reef-like structures from methane-derived authigenic carbonates, provides a rich and complex local habitat that results in aggregations of non-seep specialized fauna from multiple trophic levels, including several commercial species. Cold seeps are far more widespread in the Arctic than thought even a few years ago. They exhibit in situ benthic chemosynthetic production cycles that operate on different spatial and temporal cycles than the sunlight-driven counterpart of photosynthetic production in the ocean’s surface. These systems can act as a spatio-temporal bridge for benthic communities and associated ecosystems that may otherwise suffer from a lack of consistency in food quality from the surface ocean during seasons of low production. As climate change impacts accelerate in Arctic marginal seas, photosynthetic primary production cycles are being modified, including in terms of changes in the timing, magnitude, and quality of photosynthetic carbon, whose delivery to the seabed fuels benthic communities. Furthermore, an increased northward expansion of species is expected as a consequence of warming seas. This may have implications for dispersal and evolution of both chemosymbiotic species as well as for background taxa in the entire realm of the Arctic Ocean basin and fringing seas.

Thermally Variable, Macrotidal Reef Habitats Promote Rapid Recovery From Mass Coral Bleaching

Schoepf V, Jung MU, McCulloch MT, White NE, Stat M, Thomas L. Thermally Variable, Macrotidal Reef Habitats Promote Rapid Recovery From Mass Coral Bleaching. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00245/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Coral reefs are severely threatened by climate change and recurrent mass bleaching events, highlighting the need for a better understanding of the factors driving recovery and resilience both at the community and species level. While temperature variability has been shown to promote coral heat tolerance, it remains poorly understood whether this also influences coral recovery capacity. Similarly, few studies have investigated how the presence of cryptic species influences bleaching and recovery responses. Using an integrated ecological, physiological, and genetic approach (i.e., reef-wide coral health surveys as well as chlorophyll a concentration and cryptic species diversity of Acropora aspera), we examined the recovery of both coral communities and their dominant species from the 2016 mass bleaching event in the macrotidal Kimberley region, NW Australia. We show that recovery of coral communities inhabiting adjacent but environmentally contrasting reef habitats differed dramatically following unprecedented bleaching in 2016. Both intertidal (thermally extreme) and subtidal (thermally moderate) habitats experienced extensive bleaching (72–81%), but subtidal coral communities had a greater percentage of severely bleached corals than the intertidal community (76 versus 53%). Similarly, subtidal A. aspera corals suffered much greater losses of chlorophyll a than intertidal conspecifics (96 versus 46%). The intertidal coral community fully recovered to its prebleaching configuration within 6 months, whereas the adjacent subtidal suffered extensive mortality (68% loss of live coral cover). Despite the presence of three cryptic genetic lineages in the dominant coral species, the physiological response of A. aspera was independent of host cryptic genetic diversity. Furthermore, both intertidal and subtidal A. aspera harbored symbionts in the genus Cladocopium (previously clade C). Our findings therefore highlight the important role of tidally controlled temperature variability in promoting coral recovery capacity. While the underlying physiological and molecular mechanisms require further investigation, we propose that shallow reef environments characterized by strong environmental gradients may generally promote coral resilience to extreme climatic events. Thermally variable reef environments may therefore provide important spatial refugia for coral reefs under rapid climate change.

Dead Cetacean? Beach, Bloat, Float, Sink

Moore MJ, Mitchell GH, Rowles TK, Early G. Dead Cetacean? Beach, Bloat, Float, Sink. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00333/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Variably buoyant, dead Cetacea may float, or sink and later bloat to refloat if ambient temperature and pressure allow sufficient decomposition gas formation and expansion. Mortality can result from acute or chronic disease, fishery entanglement, vessel collision, noxious noises, or toxicant spills. Investigators often face the daunting task of elucidating a complex series of events, in reverse order, from when and where an animal is found, and to diagnose the cause of death. Various scenarios are possible: an animal could die at sea remaining there or floating ashore, or strand on a beach alive, where it dies and, if cast high enough, remain beached to be scavenged or decompose. An animal that rests low on a beach may refloat again, through increased buoyancy from decomposition gas and favorable tides, currents, and wind. Here we review the factors responsible for the different outcomes, and how to recognize the provenance of a cetacean mortality found beached, or floating at sea. In conclusion, only some carcasses strand, or remain floating. Negatively buoyant animals that die at depth, or on the surface, and sink, may never surface, even after decomposition gas accumulation, as in cold, deep waters gas may fail to adequately reduce the density of a carcass, precluding it from returning to the surface.

Automating the Analysis of Fish Abundance Using Object Detection: Optimizing Animal Ecology With Deep Learning

Ditria EM, Lopez-Marcano S, Sievers M, Jinks EL, Brown CJ, Connolly RM. Automating the Analysis of Fish Abundance Using Object Detection: Optimizing Animal Ecology With Deep Learning. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00429/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Aquatic ecologists routinely count animals to provide critical information for conservation and management. Increased accessibility to underwater recording equipment such as action cameras and unmanned underwater devices has allowed footage to be captured efficiently and safely, without the logistical difficulties manual data collection often presents. It has, however, led to immense volumes of data being collected that require manual processing and thus significant time, labor, and money. The use of deep learning to automate image processing has substantial benefits but has rarely been adopted within the field of aquatic ecology. To test its efficacy and utility, we compared the accuracy and speed of deep learning techniques against human counterparts for quantifying fish abundance in underwater images and video footage. We collected footage of fish assemblages in seagrass meadows in Queensland, Australia. We produced three models using an object detection framework to detect the target species, an ecologically important fish, luderick (Girella tricuspidata). Our models were trained on three randomized 80:20 ratios of training:validation datasets from a total of 6,080 annotations. The computer accurately determined abundance from videos with high performance using unseen footage from the same estuary as the training data (F1 = 92.4%, mAP50 = 92.5%) and from novel footage collected from a different estuary (F1 = 92.3%, mAP50 = 93.4%). The computer’s performance in determining abundance was 7.1% better than human marine experts and 13.4% better than citizen scientists in single image test datasets, and 1.5 and 7.8% higher in video datasets, respectively. We show that deep learning can be a more accurate tool than humans at determining abundance and that results are consistent and transferable across survey locations. Deep learning methods provide a faster, cheaper, and more accurate alternative to manual data analysis methods currently used to monitor and assess animal abundance and have much to offer the field of aquatic ecology.

Past and Future Grand Challenges in Marine Ecosystem Ecology

Borja A, Andersen JH, Arvanitidis CD, Basset A, Buhl-Mortensen L, Carvalho S, Dafforn KA, Devlin MJ, Escobar-Briones EG, Grenz C, et al. Past and Future Grand Challenges in Marine Ecosystem Ecology. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00362/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1348443_45_Marine_20200609_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Initial Grand Challenges

Frontiers in Marine Science launched the Marine Ecosystems Ecology (FMARS-MEE) section in 2014, with a paper that identified eight grand challenges for the discipline (Borja, 2014). Since then, this section has published a total of 370 papers, including 336 addressing aspects of those challenges. As editors of the journal, with a wide range of marine ecology expertise, we felt it was timely to evaluate research advances related to those challenges; and to update the scope of the section to reflect the grand challenges we envision for the next 10 years. This output will match with the United Nations (UN) Decade on Oceans Science for Sustainable Development (DOSSD; Claudet et al., 2020), UN Decade of Ecosystems Restoration (DER; Young and Schwartz, 2019), and the UN Sustainable Development Goals (SDGs; Visbeck et al., 2014).

First, we analyzed each published paper and assigned their topic to a maximum of two out of the eight challenges (all information available in Supplementary Table 1). We then extracted the 3–5 most cited papers within each challenge using two criteria: the total number of citations during this 6-year period, and the annual citation rate (i.e., the mean annual number of citations since publication). We then collated the topics covered by this reduced list of papers (Table 1) and summarized the outcomes for each topic. 

150 shades of green: Using the full spectrum of remote sensing reflectance to elucidate color shifts in the ocean

Vandermeulen RA, Mannino A, Craig SE, P. Werdell J. 150 shades of green: Using the full spectrum of remote sensing reflectance to elucidate color shifts in the ocean. Remote Sensing of Environment [Internet]. 2020 ;247:111900. Available from: https://www.sciencedirect.com/science/article/pii/S0034425720302704
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

This article proposes a simple and intuitive classification system by which to define full spectral remote sensing reflectance (Rrs(λ)) data with a quantitative output that enables a more manageable handling of spectral information for aquatic science applications. The weighted harmonic mean of the Rrs(λ) wavelengths outputs an Apparent Visible Wavelength (in units of nanometers), representing a one-dimensional geophysical metric of color that is inherently correlated to spectral shape. This dimensionality reduction of spectral information combined with the output along a continuum of wavelength values offers a robust and user-friendly means to describe and analyze spectral Rrs(λ) in terms of spatial and temporal trends and variability. The uncertainty in the algorithm's estimation of spectral shape is demonstrated on a global scale, in addition to the utility of the algorithm to discern spectral-spatial-temporal trends in the ocean, on a per-pixel basis for the entire 22 year continuous ocean color (SeaWiFS and MODIS-Aqua) time-series. This technique can be applied to datasets of varying multi- and hyper-spectral resolutions, providing continuity between heritage and future satellite sensors, and further enabling an effective means of elucidating similarities or differences in complex spectral signatures within the constraints of two dimensions. This straightforward means of conceptualizing multi-dimensional variability can help maximize the potential of the spectral information embedded in remote sensing data.

The Importance of the Northeastern Gulf of Mexico to Foraging Loggerhead Sea Turtles

Hart KM, Lamont MM, Iverson AR, Smith BJ. The Importance of the Northeastern Gulf of Mexico to Foraging Loggerhead Sea Turtles. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00330/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1334659_45_Marine_20200521_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Identification of high-use foraging sites where imperiled sea turtles are resident remains a globally-recognized conservation priority. In the biodiverse Gulf of Mexico (GoM), recent telemetry studies highlighted post-nesting foraging sites for federally threatened loggerhead turtles (Caretta caretta). Our aim here was to discern loggerhead use of additional northern GoM regions that may serve as high-use foraging sites. Thus, we used satellite tracking and switching state-space modeling to show that the Big Bend region off the northwest Florida coast is a coastal foraging area that supports imperiled adult female loggerhead turtles tracked from different nesting subpopulations. From 2011 to 2016, we satellite-tagged 15 loggerheads that nested on four distinct beaches around the GoM: Dry Tortugas National Park, FL; Everglades National Park, FL; St. Joseph Peninsula, FL; and Gulf Shores, AL. Turtles arrived at their foraging ground in the Big Bend region between June and September and remained resident in their respective foraging sites for an average of 198 tracking days, where they established mean home ranges (95% kernel density estimate) 232.7 km2. Larger home ranges were in deeper water; 50% kernel density estimate centroid values were a mean 26.4 m deep and 52.7 km from shore. The Big Bend region provides a wide area of suitable year-round foraging habitat for loggerheads from at least 3 different nesting subpopulations. Understanding where and when threatened loggerheads forage and remain resident is key for designing both surveys of foraging resources and additional protection strategies that can impact population recovery trajectories for this imperiled species.

Life Cycle Dynamics of a Key Marine Species Under Multiple Stressors

Otto SA, Niiranen S, Blenckner T, Tomczak MT, Müller-Karulis B, Rubene G, Möllmann C. Life Cycle Dynamics of a Key Marine Species Under Multiple Stressors. Frontiers in Marine Science [Internet]. 2020 ;7. Available from: https://www.frontiersin.org/articles/10.3389/fmars.2020.00296/full?utm_source=F-AAE&utm_medium=EMLF&utm_campaign=MRK_1334659_45_Marine_20200521_arts_A
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Identifying key indicator species, their life cycle dynamics and the multiple driving forces they are affected by is an important step in ecosystem-based management. Similarly important is understanding how environmental changes and trophic interactions shape future trajectories of key species with potential implications for ecosystem state and service provision. We here present a statistical modeling framework to assess and quantify cumulative effects on the long-term dynamics of the copepod Pseudocalanus acuspes, a key species in the Baltic Sea. Our model integrates linear and non-linear responses to changes in life stage density, climate and predation pressure as well as stochastic processes. We use the integrated life cycle model to simulate copepod dynamics under a combination of stressor scenarios and to identify conditions under which population responses are potentially mitigated or magnified. Our novel modeling approach reliably captures the historical P. acuspes population dynamics and allows us to identify females in spring and younger copepodites in summer as stages most sensitive to direct and indirect effects of the main environmental stressors, salinity and temperature. Our model simulations furthermore demonstrate that population responses to stressors are dampened through density effects. Multiple stressor interactions were mostly additive except when acting on the same life stage. Here, negative synergistic and positive dampening effects lead to a lower total population size than expected under additive interactions. As a consequence, we found that a favorable increase of oxygen and phosphate conditions together with a reduction in predation pressure by 50% each could counteract the negative effect of a 25% decrease in salinity by only 6%. Ultimately, our simulations suggest that P. acuspes will most certainly decline under a potential freshening of the Baltic Sea and increasing temperatures, which is conditional on the extent of the assumed climate change. Also the planned nutrient reduction strategy and fishery management plan will not necessarily benefit the temporal development of P. acuspes. Moving forward, there is a growing opportunity for using population modeling in cumulative effects assessments. Our modeling framework can help here as simple tool for species with a discrete life cycle to explore stressor interactions and the safe operating space under future climate change.

Using qualitative network models to assess the influence of mussel culture on ecosystem dynamics

Forget NL, Duplisea DE, Sardenne F, McKindsey CW. Using qualitative network models to assess the influence of mussel culture on ecosystem dynamics. Ecological Modelling [Internet]. 2020 ;430:109070. Available from: https://www.sciencedirect.com/science/article/pii/S0304380020301423
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

The expansion of the aquaculture industry in the last several decades has raised concerns about potential ecological impacts of the industry. Bivalve culture, particularly mussel farming, relies on naturally occurring plankton and numerous studies have demonstrated top-down control on phytoplankton, increased nutrients through excretion of metabolic wastes and remineralization of faeces and pseudofaeces, and bottom-up effects on predators and scavengers through mussel fall-off. However, results are inconsistent between studies, and hydrodynamic conditions and nutrient availability are thought to play an important role in the magnitude and the direction of the ecological effects of mussel culture on the surrounding ecosystem. We used qualitative network models (QNMs), to outline a general model that integrates these environmental conditions and (1) evaluated the ability of different model configurations to reproduce known responses to perturbations, (2) analyzed the behaviour of key components to contrasting hydrodynamic and nutrient condition scenarios, and (3) identified the most influential features of the derived scenarios. The model that included uncertain linkages to characterize unknown relationships performed best based on predetermined validation criteria; the addition of semi-quantitative information on the relative strength of certain linkages improved accuracy and sign determinacy of outcomes. The presence of suspended mussel culture negatively affected primary producers, zooplankton and deposit-feeders, and had a positive effect on predators and scavengers, especially in low-energy environments. Hydrodynamic conditions were shown to have a major impact on the response of the community to mussel culture, while nutrient availability had a very minor impact.

Establishing the links between marine ecosystem components, functions and services: An ecosystem service assessment tool

Armoškaitė A, Puriņa I, Aigars J, Strake S, Pakalniete K, Frederiksen P, Schrøder L, Hansen HSten. Establishing the links between marine ecosystem components, functions and services: An ecosystem service assessment tool. Ocean & Coastal Management [Internet]. 2020 ;193:105229. Available from: https://www.sciencedirect.com/science/article/pii/S0964569120301393
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Although the concept of ecosystem services has been in use for many decades, its application for policy support is limited, particularly with respect to marine ecosystems. Gaps in the assessments of ecosystem services supply prevent its empirical application. We advance these assessments by providing an assessment tool, which links marine ecosystem components, functions and services, and graphically represents the assessment process and its results. The tool consists of two parts: (i) a matrix following the ecosystem services cascade structure for quantifying the contribution of ecosystem components in the provision of ecosystem services; (ii) and a linkage diagram for visualising the interactions between the elements. With the aid of the Common International Classification of Ecosystem Services (CICES), the tool was used to assess the relative contribution of a wide range of marine ecosystem components in the supply of ecosystem services in the Latvian marine waters. Results indicate that the tool can be used to assess the impacts of environmental degradation in terms of ecosystem service supply. These impacts could further be valued in socioeconomic terms, as change in the socioeconomic values derived from the use of ecosystem services. The tool provides an opportunity for conducting a holistic assessment of the ecosystem service supply and communicating the results to marine spatial planning practitioners, and increasing their understanding and use of the ecosystem service concept.

Conservation value of a subtropical reef in south-eastern Queensland, Australia, highlighted by citizen-science efforts

Grol MGG, Vercelloni J, Kenyon TM, Bayraktarov E, van den Berg CP, Harris D, Loder JA, Mihaljević M, Rowland PI, Roelfsema CM. Conservation value of a subtropical reef in south-eastern Queensland, Australia, highlighted by citizen-science efforts. Marine and Freshwater Research [Internet]. 2020 . Available from: https://www.publish.csiro.au/MF/MF19170
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Subtropical reefs are important habitats for many marine species and for tourism and recreation. Yet, subtropical reefs are understudied, and detailed habitat maps are seldom available. Citizen science can help fill this gap, while fostering community engagement and education. In this study, 44 trained volunteers conducted an ecological assessment of subtropical Flinders Reef using established Reef Check and CoralWatch protocols. In 2017, 10 sites were monitored to provide comprehensive information on reef communities and to estimate potential local drivers of coral community structure. A detailed habitat map was produced by integrating underwater photos, depth measurements, wave-exposure modelling and satellite imagery. Surveys showed that coral cover ranged from 14% to 67%. Site location and wave exposure explained 47% and 16% respectively, of the variability in coral community composition. Butterflyfishes were the most abundant fish group, with few invertebrates being observed during the surveys. Reef impacts were three times lower than on other nearby subtropical reefs. These findings can be used to provide local information to spatial management and Marine Park planning. To increase the conservation benefits and to maintain the health of Flinders Reef, we recommend expanding the current protection zone from 500- to a 1000-m radius.

Global hotspots for coastal ecosystem-based adaptation

Jones HP, Nickel B, Srebotnjak T, Turner W, Gonzalez-Roglich M, Zavaleta E, Hole DG. Global hotspots for coastal ecosystem-based adaptation Villamayor-Tomas S. PLOS ONE [Internet]. 2020 ;15(5):e0233005. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233005
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Helping the world’s coastal communities adapt to climate change impacts requires evaluating the vulnerability of coastal communities and assessing adaptation options. This includes understanding the potential for ‘natural’ infrastructure (ecosystems and the biodiversity that underpins them) to reduce communities’ vulnerability, alongside more traditional ‘hard’ infrastructure approaches. Here we present a spatially explicit global evaluation of the vulnerability of coastal-dwelling human populations to key climate change exposures and explore the potential for coastal ecosystems to help people adapt to climate change (ecosystem-based adaptation (EbA)). We find that mangroves and coral reefs are particularly well situated to help people cope with current weather extremes, a function that will only increase in importance as people adapt to climate change now and in coming decades. We find that around 30.9 million people living within 2km of the coast are highly vulnerable to tropical storms and sea-level rise (SLR). Mangroves and coral reefs overlap these threats to at least 5.3 and 3.4 million people, respectively, with substantial potential to dissipate storm surges and improve resilience against SLR effects. Significant co-benefits from mangroves also accrue, with 896 million metric tons of carbon stored in their soils and above- and below-ground biomass. Our framework offers a tool for prioritizing ‘hotspots’ of coastal EbA potential for further, national and local analyses to quantify risk reduction and, thereby, guide investment in coastal ecosystems to help people adapt to climate change. In doing so, it underscores the global role that conserving and restoring ecosystems can play in protecting human lives and livelihoods, as well as biodiversity, in the face of climate change.

Passive acoustic methods for tracking the 3D movements of small cetaceans around marine structures

Gillespie D, Palmer L, Macaulay J, Sparling C, Hastie G. Passive acoustic methods for tracking the 3D movements of small cetaceans around marine structures Halliday WDavid. PLOS ONE [Internet]. 2020 ;15(5):e0229058. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0229058
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

A wide range of anthropogenic structures exist in the marine environment with the extent of these set to increase as the global offshore renewable energy industry grows. Many of these pose acute risks to marine wildlife; for example, tidal energy generators have the potential to injure or kill seals and small cetaceans through collisions with moving turbine parts. Information on fine scale behaviour of animals close to operational turbines is required to understand the likely impact of these new technologies. There are inherent challenges associated with measuring the underwater movements of marine animals which have, so far, limited data collection. Here, we describe the development and application of a system for monitoring the three-dimensional movements of cetaceans in the immediate vicinity of a subsea structure. The system comprises twelve hydrophones and software for the detection and localisation of vocal marine mammals. We present data demonstrating the systems practical performance during a deployment on an operational tidal turbine between October 2017 and October 2019. Three-dimensional locations of cetaceans were derived from the passive acoustic data using time of arrival differences on each hydrophone. Localisation accuracy was assessed with an artificial sound source at known locations and a refined method of error estimation is presented. Calibration trials show that the system can accurately localise sounds to 2m accuracy within 20m of the turbine but that localisations become highly inaccurate at distances greater than 35m. The system is currently being used to provide data on rates of encounters between cetaceans and the turbine and to provide high resolution tracking data for animals close to the turbine. These data can be used to inform stakeholders and regulators on the likely impact of tidal turbines on cetaceans.

How to model social-ecological systems? – A case study on the effects of a future offshore wind farm on the local society and ecosystem, and whether social compensation matters

Haraldsson M, Raoux A, Riera F, Hay J, Dambacher JM, Niquil N. How to model social-ecological systems? – A case study on the effects of a future offshore wind farm on the local society and ecosystem, and whether social compensation matters. Marine Policy [Internet]. 2020 ;119:104031. Available from: 10.1016/j.marpol.2020.104031
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Models of social-ecological systems (SES) are acknowledged as an important tool to understand human-nature relations. However, many SES models fail to integrate adequate information from both the human and ecological subsystems. With an example model of a future Offshore Wind Farm development and its effects on both the ecosystem and local human population, we illustrate a method facilitating a “balanced” SES model, in terms of including information from both subsystems. We use qualitative mathematical modeling, which allows to quickly analyze the structure and dynamics of a system without including quantitative data, and therefore to compare alternative system structures based on different understandings of how the system works. By including similar number of system variables in the two subsystems, we balanced the complexity between them. Our analyses show that this complexity is important in order to predict indirect and sometimes counterintuitive effects. We also highlight some conceptually important questions concerning social compensations during developmental projects in general, and wind farms in particular. Our results suggest that the more project holders get involved in various manner in the local socio-ecological system, the more society will benefit as a whole. Increased involvement through e.g. new projects or job-opportunities around the windfarm has the capacity to offset the negative effects of the windfarm on the local community. These benefits are enhanced when there is an overall acceptance and appropriation of the project. We suggest this method as a tool to support the decision-making process and to facilitate discussions between stakeholders, especially among local communities.

Global hotspots for coastal ecosystem-based adaptation

Jones HP, Nickel B, Srebotnjak T, Turner W, Gonzalez-Roglich M, Zavaleta E, Hole DG. Global hotspots for coastal ecosystem-based adaptation Villamayor-Tomas S. PLOS ONE [Internet]. 2020 ;15(5):e0233005. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233005
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Helping the world’s coastal communities adapt to climate change impacts requires evaluating the vulnerability of coastal communities and assessing adaptation options. This includes understanding the potential for ‘natural’ infrastructure (ecosystems and the biodiversity that underpins them) to reduce communities’ vulnerability, alongside more traditional ‘hard’ infrastructure approaches. Here we present a spatially explicit global evaluation of the vulnerability of coastal-dwelling human populations to key climate change exposures and explore the potential for coastal ecosystems to help people adapt to climate change (ecosystem-based adaptation (EbA)). We find that mangroves and coral reefs are particularly well situated to help people cope with current weather extremes, a function that will only increase in importance as people adapt to climate change now and in coming decades. We find that around 30.9 million people living within 2km of the coast are highly vulnerable to tropical storms and sea-level rise (SLR). Mangroves and coral reefs overlap these threats to at least 5.3 and 3.4 million people, respectively, with substantial potential to dissipate storm surges and improve resilience against SLR effects. Significant co-benefits from mangroves also accrue, with 896 million metric tons of carbon stored in their soils and above- and below-ground biomass. Our framework offers a tool for prioritizing ‘hotspots’ of coastal EbA potential for further, national and local analyses to quantify risk reduction and, thereby, guide investment in coastal ecosystems to help people adapt to climate change. In doing so, it underscores the global role that conserving and restoring ecosystems can play in protecting human lives and livelihoods, as well as biodiversity, in the face of climate change.

Preventing shipping accidents: Past, present, and future of waterway risk management with Baltic Sea focus

Kulkarni K, Goerlandt F, Li J, Banda OValdez, Kujala P. Preventing shipping accidents: Past, present, and future of waterway risk management with Baltic Sea focus. Safety Science [Internet]. 2020 ;129:104798. Available from: https://www.sciencedirect.com/science/article/pii/S0925753520301958
Freely available?: 
Yes
Summary available?: 
No
Type: Journal Article

Various national maritime authorities and international organizations show strong interest to implement risk management processes to decision making for shipping accident prevention in waterway areas. There is a recurring need for approaches, models, and tools for identifying, analysing, and evaluating risks of shipping accidents, and for strategies for preventively managing these in (inter-)organizational settings. This article presents a comprehensive review of academic work in this research area, aiming to identify patterns, trends, and gaps, serving as a guide for future research and development, with a particular focus on the Baltic Sea Region. To understand the links between research in the Baltic Sea area and the global community, a bibliometric analysis is performed, focusing on identifying dominant narratives and social networks in the research community. Articles from the Baltic Sea area are subsequently analysed more in-depth, addressing issues like the nature of the academic work done, the risk management processes involved, and the underlying accident theories. From the results, patterns in the historical evolution of the research domain are detected, and insights about current trends gained, which are used to identify future avenues for research.

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