Changes In Coastal Ecosystems Research Articles

Real-world time-travel experiment shows ecosystem collapse due to anthropogenic climate change

Predicting climate impacts is challenging and has to date relied on indirect methods, notably modeling. Here we examine coastal ecosystem change during 13 years of unusually rapid, albeit likely temporary, sea-level rise ( > 10 mm yr−1) in the Gulf of Mexico. Such rates, which may become a persistent feature in the future due to anthropogenic climate change, drove rising water levels of similar magnitude in Louisiana’s coastal wetlands. Measurements of surface-elevation change at 253 monitoring sites show that 87% of these sites are unable to keep up with rising water levels. We find no evidence for enhanced wetland elevation gain through ecogeomorphic feedbacks, where more frequent inundation would lead to enhanced biomass accumulation that could counterbalance rising water levels. We attribute this to the exceptionally rapid sea-level rise during this time period. Under the current climate trajectory (SSP2-4.5), drowning of ~75% of Louisiana’s coastal wetlands is a plausible outcome by 2070.

Forecasting the Coastal Systems State using Mathematical Modelling Based on Satellite Images

Introduction. Coastal systems of Southern Russia are constantly exposed to biotic, abiotic and anthropogenic factors. In this regard, there is a need to develop non-stationary spatially inhomogeneous interconnected mathematical models that make it possible to reproduce various scenarios for the dynamics of biological and geochemical processes in coastal systems. There is also the problem of the practical use of mathematical modelling, namely its equipping with real input data (boundary, initial conditions, information about source functions). An operational source of field information can be data received from artificial Earth satellites. Therefore, the problem arises of identifying phytoplankton populations in images of reservoirs, which, as a rule, have a spotty structure, with low image contrast relative to the background, as well as determining the boundaries of their location.Materials and Methods. This work is based on the correct application of modern mathematical analysis methods, mathematical physics and functional analysis, the theory of difference schemes, as well as methods for solving grid equations. Biogeochemical processes are described based on convection-diffusion-reaction equations. Linearization of the constructed model is carried out on a time grid with step τ. A method for recognizing the boundaries of spotted structures is being developed based on Earth remote sensing data. A combination of methods is considered as image processing algorithms: local binary patterns (LBP) and a two-layer neural network.Results. The developed software-algorithmic tools for space image recognition are presented, based on a combination of methods — local binary patterns (LBP) and neural network technologies, focused on the subsequent input of the obtained initial conditions for the problem of phytoplankton dynamics into a mathematical model. Regarding the necessary mathematical model, a continuous linearized model has been proposed and studied, and on its basis a linearized discrete model of biogeochemical cycles in coastal systems, for which practically acceptable time step values have been established for numerical (predictive) modelling of problems of the dynamics of planktonic populations and biogeochemical cycles, including in the event of death phenomena, which makes it possible to reduce the time of operational forecasting. At the same time, for the constructed discrete model, properties that are practically significant for discrete models are guaranteed to be satisfied: stability, monotonicity and convergence of the difference scheme, which is important for reliable forecasts of adverse and dangerous phenomena.In the process of work, referring to satellite images, which make it possible to obtain the state of coastal systems with high accuracy, initial conditions are entered into the mathematical (computer) model. The model analyzes satellite image data and determines levels of “pollution”, the formation of extinction zones and other factors that may threaten nature.Discussion and Conclusion. Discussion and conclusions. Using this model, it is possible to predict possible changes in coastal ecosystems and develop strategies to protect them. The results obtained make it possible to significantly reduce the time of forecast calculations (by 20−30 %) and increase the likelihood of early detection of unfavorable and dangerous phenomena, such as intense “blooming” of the aquatic environment and the formation of extinction zones in coastal systems.

Unprecedented phytoplankton blooms in autumn/winter in the southern Bohai Sea (China) due to high Yellow River discharge: Implications of extreme rainfall events

The occurrence of abnormal phytoplankton blooms is one of the significant changes in coastal ecosystems due to climate change. However, the underlying mechanism of such blooms remains poorly understood due to the complexity of the system. In this study, the data from numerous observations was used to elucidate the unprecedented phytoplankton blooms in the autumn and winter of 2021 in Laizhou Bay, a typical aquaculture bay in the southern Bohai Sea of China. The abundance of phytoplankton cells increased by more than tenfold in the southern waters compared to that in the same period from 2019 to 2020. The phytoplankton bloom was first observed in winter in the Bohai Sea, with the cell abundance in the southern bay exceeding 108 cells L−1 in December 2021. The diversity and evenness of phytoplankton communities decreased in the southern area. Cerataulina pelagica was the dominant algae, comprising 69 % of the total phytoplankton in October and 99 % in December. In autumn 2021, the largest flood of the Yellow River in recent decades occurred. This was attributed to extreme rainfall events within the river basin. The input of substantial riverine nutrients played a significant role in promoting phytoplankton blooms. Correlation analysis indicated the important cumulative impact of the Yellow River on phytoplankton blooms rather than a direct short-term effect. Numerical modeling results indicated that exceptionally high Yellow River discharge in autumn could significantly affect the entire bay from autumn to the following spring. This study may contribute to understanding the abnormal phytoplankton blooms in coastal waters and provide valuable insights for environmental management in river basins and coastal waters.

Seasonal lipid dynamics of four Arctic bivalves: Implications for their physiological capacities to cope with future changes in coastal ecosystems.

The Arctic is exposed to unprecedented warming, at least three times higher than the global average, which induces significant melting of the cryosphere. Freshwater inputs from melting glaciers will subsequently affect coastal primary production and organic matter quality. However, due to a lack of basic knowledge on the physiology of Arctic organisms, it remains difficult to understand how these future trophic changes will threaten the long-term survival of benthic species in coastal habitats. This study aimed to gain new insights into the seasonal lipid dynamics of four dominant benthic bivalves (Astarte moerchi, Hiatella arctica, Musculus discors, and Mya truncata) collected before and after sea ice break-up in a high-Arctic fjord (Young Sound, NE Greenland). Total lipid content and fatty acid composition of digestive gland neutral lipids were analyzed to assess bivalve energy reserves while the fatty acid composition of gill polar lipids was determined as a biochemical indicator of interspecies variations in metabolic activity and temperature acclimation. Results showed a decrease in lipid reserves between May and August, suggesting that bivalves have only limited access to fresh organic matter until sea ice break-up. The lack of seasonal variation in the fatty acid composition of neutral lipids, especially essential ω3 fatty acids, indicates that no fatty acid transfer from the digestive glands to the gonads occurs between May and August, and therefore, no reproductive investment takes place during this period. Large interspecies differences in gill fatty acid composition were observed, which appear to be related to differences in species life span and metabolic strategies. Such differences in gill fatty acid composition of polar lipids, which generally influence metabolic rates and energy needs, may imply that not all benthic species will be equally sensitive to future changes in primary production and organic matter quality in Arctic coastal habitats.

Tracking climate-change-induced biological invasions by metabarcoding archived natural eDNA samplers

In a time of unprecedented environmental change, understanding the response of organisms and ecosystems to change is paramount1. However, our knowledge of anthropogenic impacts on ecosystems is limited by a lack of standardized retrospective biomonitoring data2. Here, we use a four-decade time series of archived blue mussels to trace spatiotemporal biodiversity change in coastal ecosystems. The filter-feeding mussels, which were initially collected for pollution monitoring, can serve as natural eDNA samplers, carrying an imprint of the surrounding aquatic community at the time of sampling3. By sequencing the preserved DNA, we characterize highly diverse mussel-associated communities and reconstruct the invasion trajectory of an invasive species, the barnacle Austrominius modestus. We quantitatively trace population growth of the invader to the detriment of native taxa and uncover repeated population collapses and reinvasions after cold winters. By providing highly resolved temporal data on community assembly and global warming-driven invasion processes, natural eDNA sampler time series overcome a critical shortfall in our understanding of biodiversity change in the Anthropocene.

Effects of sea cucumber fishing on tropical seagrass productivity

AbstractFishing can drive major ecological change in coastal ecosystems and is typically examined through top‐down trophic impacts. However, the massive removal of biomass can also disrupt key ecological bottom‐up processes, though how these effects shape ecosystems is poorly understood. Here, we examined the ecological roles of two species of commercially exploited sea cucumbers thought to promote primary productivity in nutrient‐poor environments through nutrient provisioning and sediment processing. Using a large‐scale field experiment, we tested whether simulated sea cucumber fishing affected seagrass productivity in a natural system comprising reef and seagrass patches that varied in abundance of vertebrate nutrient providers (i.e., fishes). Our findings were scale‐ and metric‐specific: while we could not detect a change in patch‐level seagrass productivity in response to simulated sea cucumber fishing, individual leaf extension rates were ~15% lower at sites where all sea cucumbers were removed, relative to the highest density, unfished sites. Interestingly, there was no concomitant effect of nutrients from the more abundant reef‐associated fishes, which contribute far more nutrients overall than sea cucumbers. This suggests that sea cucumbers are likely mediating seagrass growth through mechanisms other than direct nutrient provisioning, perhaps through processes associated with sediment processing. Our study demonstrates the potential consequences of under‐regulated and unmonitored sea cucumber fishing on foundation species like seagrasses, while highlighting the importance of taking a community‐based approach to these types of field experiments.

Economic Valuation of Mangrove Ecosystem Services in Sembilang National Park of South Sumatra, Indonesia

An ecosystem services valuation could provide significant improvements for the policy maker to monitor the mangrove ecosystem changes in coastal ecosystems. Therefore, this study aimed to measure the value of ecosystem service in Sembilang National Park (NSP), Banyuasin District, South Sumatra, Indonesia. Data collection used questionnaires and in-depth interviews with the target respondents being fishermen, farmers, and stakeholders who live in the mangrove ecosystem area. The total economic value (TEV) was used as an approach for calculating the various values of the mangrove services. Several methods have been developed to estimate the ecosystem services value. In this study, the market price method, benefits transfer method, replacement method, and travel cost method were applied to estimate the benefit value for provisioning, regulating, supporting, and cultural services. The result showed that the TEV of mangrove ecosystem services with an area of 88,556 ha was IDR 6,961,126,186,194 year-1 (US$ 467,974,555.06 year-1) or IDR 78,607,444 ha-1year-1 (US$ 5,284.5 ha-1year-1). The annual benefit values for provisioning, regulating, supporting, and cultural services were IDR 267,301,712,200, IDR 6,401,520,094,447, IDR 292,120,962,048, and IDR 183,417,500, respectively. The benefit value of regulating services (coastline protection and carbon sequestration) dominated the TEV of mangrove ecosystems in the SNP. To avoid the lost value of these mangrove services, conservation and restoration should receive a high priority in mangrove management and planning in the future. These research results could be used as baseline data for local governments in managing mangrove ecosystems through the establishment of a mangrove working group in South Sumatra Province. Therefore, the novelty of this research resided in the first economic valuation in the SNP using the TEV approach, as illustrated.

Editorial: Consequences of global change in coastal ecosystems from a multidisciplinary perspective

Editorial: Consequences of global change in coastal ecosystems from a multidisciplinary perspective

Persistent eutrophication and hypoxia in the coastal ocean

AbstractCoastal eutrophication and hypoxia remain a persistent environmental crisis despite the great efforts to reduce nutrient loading and mitigate associated environmental damages. Symptoms of this crisis have appeared to spread rapidly, reaching developing countries in Asia with emergences in Southern America and Africa. The pace of changes and the underlying drivers remain not so clear. To address the gap, we review the up-to-date status and mechanisms of eutrophication and hypoxia in global coastal oceans, upon which we examine the trajectories of changes over the 40 years or longer in six model coastal systems with varying socio-economic development statuses and different levels and histories of eutrophication. Although these coastal systems share common features of eutrophication, site-specific characteristics are also substantial, depending on the regional environmental setting and level of social-economic development along with policy implementation and management. Nevertheless, ecosystem recovery generally needs greater reduction in pressures compared to that initiated degradation and becomes less feasible to achieve past norms with a longer time anthropogenic pressures on the ecosystems. While the qualitative causality between drivers and consequences is well established, quantitative attribution of these drivers to eutrophication and hypoxia remains difficult especially when we consider the social economic drivers because the changes in coastal ecosystems are subject to multiple influences and the cause–effect relationship is often non-linear. Such relationships are further complicated by climate changes that have been accelerating over the past few decades. The knowledge gaps that limit our quantitative and mechanistic understanding of the human-coastal ocean nexus are identified, which is essential for science-based policy making. Recognizing lessons from past management practices, we advocate for a better, more efficient indexing system of coastal eutrophication and an advanced regional earth system modeling framework with optimal modules of human dimensions to facilitate the development and evaluation of effective policy and restoration actions.

Quantifying the ecological consequences of climate change in coastal ecosystems

Abstract Few coastal ecosystems remain untouched by direct human activities, and none are unimpacted by anthropogenic climate change. These drivers interact with and exacerbate each other in complex ways, yielding a mosaic of ecological consequences that range from adaptive responses, such as geographic range shifts and changes in phenology, to severe impacts, such as mass mortalities, ecological regime shifts and loss of biodiversity. Identifying the role of climate change in these phenomena requires corroborating evidence from multiple lines of evidence, including laboratory experiments, field observations, numerical models and palaeorecords. Yet few studies can confidently quantify the magnitude of the effect attributable solely to climate change, because climate change seldom acts alone in coastal ecosystems. Projections of future risk are further complicated by scenario uncertainty – that is, our lack of knowledge about the degree to which humanity will mitigate greenhouse-gas emissions, or will make changes to the other ways we impact coastal ecosystems. Irrespective, ocean warming would be impossible to reverse before the end of the century, and sea levels are likely to continue to rise for centuries and remain elevated for millennia. Therefore, future risks to coastal ecosystems from climate change are projected to mirror the impacts already observed, with severity escalating with cumulative emissions. Promising avenues for progress beyond such qualitative assessments include collaborative modelling initiatives, such as model intercomparison projects, and the use of a broader range of knowledge systems. But we can reduce risks to coastal ecosystems by rapidly reducing emissions of greenhouse gases, by restoring damaged habitats, by regulating non-climate stressors using climate-smart conservation actions, and by implementing inclusive coastal-zone management approaches, especially those involving nature-based solutions.

Glacial meltwater determines the balance between autotrophic and heterotrophic processes in a Greenland fjord

Global warming accelerates melting of glaciers and increases the supply of meltwater and associated inorganic particles, nutrients, and organic matter to adjacent coastal seas, but the ecosystem impact is poorly resolved and quantified. When meltwater is delivered by glacial rivers, the potential impact could be a reduction in light and nutrient availability for primary producers while supplying allochthonous carbon for heterotrophic processes, thereby tipping the net community metabolism toward heterotrophy. To test this hypothesis, we determined physical and biogeochemical parameters along a 110-km fjord transect in NE Greenland fjord, impacted by glacial meltwater from the Greenland Ice Sheet. The meltwater is delivered from glacier-fed river outlets in the inner parts of the fjord, creating a gradient in salinity and turbidity. The planktonic primary production was low, 20-45 mg C m-2 d-1, in the more turbid inner half of the fjord, increasing 10-fold to around 350 mg C m-2 d-1 in the shelf waters outside the fjord. Plankton community metabolism was measured at three stations, which displayed a transition from net heterotrophy in the inner fjord to net autotrophy in the coastal shelf waters. Respiration was significantly correlated to turbidity, with a 10-fold increase in the inner turbid part of the fjord. We estimated the changes in meltwater input and sea ice coverage in the area for the last 60 y. The long-term trend and the observed effects demonstrated the importance of freshwater runoff as a key driver of coastal ecosystem change in the Arctic with potential negative consequences for coastal productivity.

Coastal ecological impacts from pumice rafts

An explosive volcanic eruption occurred in the Ogasawara Islands on 13–15 August 2021, bringing unprecedented amounts of floating pumice to the coast of Okinawa Island in the Ryukyu Archipelago, 1300 km west of the volcano, approximately 2 months later. The coast of Okinawa Island, especially along the northern part, is home to many typical subtropical seascapes, including coral reefs and mangrove forests, so the possible impact of the large amount of pumice is attracting attention. Here, we report early evidence of ecosystem changes as a result of large-scale pumice stranding on coastal beaches, in estuaries and mangrove forests and passage across fringing coral reefs. Massive pumice drifts are major obstacles to fishing activities and ship traffic, but short and long-term changes in coastal ecosystems can also occur. The phenomena observed on Okinawa Island can be a preview of coastal impacts for the Kyushu, Shikoku, Honshu Islands, where pumice has subsequently washed ashore.

Occurrence of Fibropapillomatosis in Green Turtles (Chelonia mydas) in Relation to Environmental Changes in Coastal Ecosystems in Texas and Florida: A Retrospective Study.

Simple SummaryIn the last few decades, sea turtles have been threatened by a disease called Fibropapillomatosis. Infection causes the growth of several tumors which can prevent affected turtles from seeing, swimming, and feeding properly, often with lethal outcomes. Fibropapillomatosis was described for the first time in Florida in 1938 and has since then increased and spread worldwide. To this day, there is no strong nor clear evidence on what causes the exacerbation of this disease which is associated with a herpesvirus. There is a consensus, however, that human-driven changes in the sea turtle habitats (i.e., climate change, pollution, urbanization) might play a role in increasing the number and severity of clinical cases. This study intends to explore the role of various possible environmental drivers behind the increased occurrence of this disease. We found that sea temperature, salinity, human population density, and river discharge from the coastline could be important drivers of tumor prevalence. Results from this preliminary work have the potential to offer an important baseline for future research on environmental drivers of Fibropapillomatosis. Fibropapillomatosis is a neoplastic disease of marine turtles, with green turtles (Chelonia mydas) being the most affected species. Fibropapillomatosis causes debilitating tumor growths on soft tissues and internal organs, often with lethal consequences. Disease incidence has been increasing in the last few decades and the reason is still uncertain. The potential viral infectious agent of Fibropapillomatosis, chelonid herpesvirus 5, has been co-evolving with its sea turtle host for millions of years and no major mutation linked with increased disease occurrence has been detected. Hence, frequent outbreaks in recent decades are likely attributable to external drivers such as large-scale anthropogenic changes in the green turtle coastal marine ecosystem. This study found that variations in sea surface temperature, salinity, and nutrient effluent discharge from nearby rivers were correlated with an increased incidence of the disease, substantiating that these may be among the significant environmental drivers impacting Fibropapillomatosis prevalence. This study offers data and insight on the need to establish a baseline of environmental factors which may drive Fibropapillomatosis and its clinical exacerbation. We highlight the multifactorial nature of this disease and support the inclusion of interdisciplinary work in future Fibropapillomatosis research efforts.

The influence of coastal evolution on the paleobiogeography of the bivalve Anomalocardia flexuosa (Linné, 1767) along the southwestern Atlantic Ocean

Anomalocardia flexuosa is a bivalve that inhabits shallow, low hydrodynamics coastal environments of normal to brackish salinity, currently distributed from the Caribbean up to the state of Santa Catarina (∼28°S) in southern Brazil, but its fossil record extends along the southwestern Atlantic up to ∼40°S, in Argentina. Its absence in southern coasts today is attributed to ocean water cooling as a result of Middle-Late Holocene changes in relative influence of the warm waters of the Brazil Current and the cold waters of the Malvinas/Falklands Current, but geomorphologic and stratigraphic data suggest that coastal evolution controlled mainly by glacioeustatic-driven oscillations may have also played a role on the shifts of its distribution. Here we review the past and present distribution of A. flexuosa along southern Brazil, establishing a correlation with the Holocene geological history of this area. The Holocene post glacial marine transgression (PMT) produced a large complex of interconnected coastal lagoons landward of sandy barriers stretching from southern Brazil (state of Rio Grande do Sul) to Argentina, creating a corridor that allowed for the southward dispersion of A. flexuosa. The few available numerical ages indicate that A. flexuosa was established in the northern coastal plain of Rio Grande do Sul around ∼7.1 ka BP, and by ∼5.8 ka BP it had reached the southern plain, facilitated by warmer ocean waters than today and the sea-level highstand of 6–5 ka BP. The combination of cooling, sea-level fall that reduced marine influence, and fluvial inputs of freshwater and sediments, converted most of the lagoon complex into smaller isolated freshwater lakes after ∼4 ka BP, leading to the regional extinction of that species. The fossils of A. flexuosa and other tropical mollusks in middle and late Pleistocene interglacial barrier-lagoon coastal deposits along the southwestern Atlantic suggest that their latitudinal distribution shifted cyclically, driven by glacial-interglacial oscillations of sea-level and temperatures. The understanding of the coastal processes that affected the distribution of A. flexuosa may help assessing how mollusks and other marine species respond to environmental forcings related to sea-level oscillations and climate, thus contributing from a paleobiological perspective for conservation and management efforts under present and future scenarios of changes in coastal ecosystems.

Simplification, not "tropicalization", of temperate marine ecosystems under ocean warming and acidification.

Ocean warming is altering the biogeographical distribution of marine organisms. In the tropics, rising sea surface temperatures are restructuring coral reef communities with sensitive species being lost. At the biogeographical divide between temperate and tropical communities, warming is causing macroalgal forest loss and the spread of tropical corals, fishes and other species, termed "tropicalization". A lack of field research into the combined effects of warming and ocean acidification means there is a gap in our ability to understand and plan for changes in coastal ecosystems. Here, we focus on the tropicalization trajectory of temperate marine ecosystems becoming coral-dominated systems. We conducted field surveys and in situ transplants at natural analogues for present and future conditions under (i) ocean warming and (ii) both ocean warming and acidification at a transition zone between kelp and coral-dominated ecosystems. We show that increased herbivory by warm-water fishes exacerbates kelp forest loss and that ocean acidification negates any benefits of warming for range extending tropical corals growth and physiology at temperate latitudes. Our data show that, as the combined effects of ocean acidification and warming ratchet up, marine coastal ecosystems lose kelp forests but do not gain scleractinian corals. Ocean acidification plus warming leads to overall habitat loss and a shift to simple turf-dominated ecosystems, rather than the complex coral-dominated tropicalized systems often seen with warming alone. Simplification of marine habitats by increased CO2 levels cascades through the ecosystem and could have severe consequences for the provision of goods and services.

Climate-induced species range shift and local adaptation strategies in a temperate marine protected area, Ashizuri-Uwakai National Park, Shikoku Island, western Japan

In temperate seas, expansion of reef-building coral distribution, decline of macroalgal beds, and changes in constituent species for coral communities and/or macroalgal beds mainly due to increase in sea surface temperature have been reported. Not only mitigation but also adaptive responses are important for the measures against climate change. Consideration of adaptive measures depends on local conditions such as the degree of environmental change and industrial structure is necessary when measures are implemented. This study focused on the marine protected area (Ashizuri-Uwakai National Park in Japan) and its surrounding area. This area is characterized by a very large north-south gradient in water temperature and the distribution of corals and macroalgae along it. The purpose of this study is to consider what adaptive measures are suitable for each region and industry in response to changes in coastal ecosystems (coral community and macroalgal bed). Future (assuming the end of this century under RCP2.6 and RCP8.5 scenarios) changes in the potential distribution area of coral, macroalgae, and their consumers were projected using simulated sea surface temperature with a high-spatial resolution. After projecting the coastal ecosystem changes and assessing the contemporary use of coastal ecosystem, we give examples of what specific adaptive measures should be taken in each area for three fields, i.e., biodiversity conservation, fisheries, and tourism. Assuming the 2090s, though drastic changes in coastal ecosystem are not projected compared to the present state under RCP2.6 scenario, as coral distribution shifts north, feeding damage by crown-of-thorn starfish is projected to become a problem. Therefore, expansion of protected areas and promotion of conservation activities are major challenges for coral ecosystem conservation. On the other hand, under RCP8.5 scenario, it is important to take appropriate conservation measures for macroalgae since coral growth becomes difficult to achieve and grazing pressure on macroalgae increases due to extreme elevated water temperature. Moreover, creation of alternate or new tourism resources will be needed. This research represents projected scenarios of coastal ecosystem changes with a high spatial resolution and adaptation measures based on the changes for each municipality.

Impact of the late Cenomanian sea-level rise on the south Tethyan coastal ecosystem in the Middle East (Jordan, Egypt, and Tunisia): A quantitative eco-biostratigraphy approach

Sea-level rise can cause changes in coastal ecosystems. To understand the link between sea-level rise and the coastal ecosystems during the late Cenomanian of the southern Tethys, five exposed sections from three Middle East countries were quantitatively analyzed. The Unitary Association (UA) method allowed a two-fold increase in the resolution of zones compared to the Oppel method. Five UAs were obtained from analyses of both ammonite and benthic fauna. However, they were grouped into 3 UA Zones (UAZ) to enable basin-wide correlation. These zones were linked to one and half 3rd-order depositional cycles. During the Neolobites vibrayeanus/ Calycoceras guerangeri ammonite zone (95.5–94.4 Ma), high-energy shallow subtidal environments were formed by the transgression that followed the global sequence boundary ‘KCe 4’. They were dominated by stationary epifauna and suspension-feeders (mainly oyster bivalves). During highstand, a restricted lagoonal environment prevailed, where oyster bivalves, which have well-known adaptive strategies, were still dominant. No ammonites were recorded in this zone. Upward, the fauna has underwent a major shift, which documents the beginning of a new depositional sequence above a regional sequence boundary ‘KCe 5’ with a gradual increase of hemipelagic organic-rich sediments and planktic/nektic fauna in addition to infaunal deposit-feeders and mobile benthos, which have lived in a deeper subtidal environment (Vascoceras cauvini/Pseudospidoceras pseudonodosides ammonite zone; 94.4–93.8 Ma). This dramatic change in the character of the macrofauna at the Cenomanian/Turonian boundary (maximum flooding of KCe 5) can be attributed to the hydrodynamic changes associated with the eustatic sea-level rise. Therefore, the sea-level-based faunal changes can be integrated in sequence stratigraphic analyses. The geographic reproducibility of the UA mirrors the delay of the transgressive onlap in proximal sections, and thus, can be used to define transgressive and maximum flooding surfaces. This eco-biostratigraphic scheme can be implemented in reliable large-scale correlations.

Seabird colonies as the main source of nutrients for the coastal ecosystems in the Atlantic Islands of Galicia National Park (NW Spain)

Seabirds form large colonies during the reproductive period, producing substantial changes in coastal ecosystems. The present study quantifies the amount of N and P deposited in colonies of yellow-legged gull (Larus michahellis) in the Atlantic Islands of Galicia National Park (AINP). Based on the composition of droppings, the amount of total N (TN), total P (TP) and bioavailable P (Pbio) deposited directly on the area occupied by the colony was determined. In addition, the amount of NH3 released into the atmosphere was also estimated by applying a bioenergetic model. The results indicated that 5.35 t total N, 3.35 t total P and 1.24 t bioavailable P are deposited in the colony annually. The archipelagos that received the greatest amount of nutrients were the Cíes Islands (2.37 t TN y−1, 1.48 t TP y−1, 0.55 t Pbio y−1), Sálvora (1.94 t TN y−1, 1.22 t TP y−1, 0.55 t Pbio y−1) and Ons (1.04 t TN y−1, 0.65 TP y−1, 0.24 t Pbio y−1). Rainwater from the colonies showed higher values of nutrients than in the control plot, possibly also due to gull influence. Therefore, the yellow-legged gull colony seems to be the most important source of nutrients at a local level, exerting a clear influence on the N and P cycles in this National Park. Another aspect worth taking into consideration is that increased N and P bioavailability may have a negative effect on the conservation of rare or threatened habitats and species by promoting the expansion of non-native ruderal species.

Influence of hydrometeorological hazards and sea coast morphodynamics on development of <i>Cephalanthero</i> <i>rubrae-Fagetum</i> (Wolin island, the southern Baltic Sea)

Abstract. Climate changes, sea transgression and sea coast erosion observed today cause dynamic changes in coastal ecosystems. In the elaboration, cause and effect interrelations between abiotic hazards (hydrometeorological conditions and sea coast morphodynamics) and biotic (Cephalanthero rubrae-Fagetum phytocoenosis) components of natural environment have been defined. An up-to-date phytosociological analysis of a very valuable Cephalanthero rubrae-Fagetum site on cliff tableland was conducted in the context of hitherto temporal variability of climatic conditions and the rate of cliff coast recession. Also, the development prognosis of the researched site in the 21st century is provided, with respect to the expected climate changes and cliff's morphodynamics. The conducted research actions revealed the influence of global hazards (e.g. climate changes, sea transgression and sea coast erosion) on changes in the natural environment on regional scale (with the example of the site of Cephalanthero rubrae-Fagetum on a cliff coast of Wolin island in Poland). It has been established that in the 21st century, a relatively larger hazard to the functioning of the researched site is climate changes (i.e. mostly changes in thermal and precipitation conditions) not the sea coast erosion.

Ubiquitous Patchiness in Chlorophyll a Concentration in Coastal Archipelago of Baltic Sea

Productivity and trophic status of aquatic systems is traditionally quantified by chlorophyll a measurements. Environmental conditions and ecological interactions cause variability in chlorophyll a abundance. In coastal ecosystems, shallow and complex bathymetry reduce vertical heterogeneity, but promote horizontal heterogeneity. However, coastal monitoring programs and scientific surveys are primarily focused on the vertical dimension, at the expense of horizontal resolution. Here we demonstrate the spatial patchiness of chlorophyll a in coastal waters. We collected horizontally detailed and extensive in situ chlorophyll a data from the coastal Baltic Sea (SW Finland), covering the ice-free season of an annual cycle. Altogether, more than 200,000 observations were recorded by an automated underway measurement system equipped with an optical sensor connected to a flow-through system. We analyzed the spatial heterogeneity of calibrated chlorophyll a data by using multiple statistical approaches, and quantified the chlorophyll a patches using a rolling average filter. We were able to identify patches and quantify their abundance and size for each of the eleven sampling campaigns. On average, 285 patches, ranging from 0.6 to 3142 m in size, were observed on the 830 km sampling transect. The average size of the patches was 237 (95% CI 226–248) m, most patches being between 10–1000 m. Our results show that patches of chlorophyll a can be effectively identified and quantified by modern in situ optical instrumentation. Such information is both theoretically and practically relevant. First, these results increase our understanding of the overall heterogeneity of the coastal environment. Further, they demonstrate the value of knowing the magnitude and occurrence of chlorophyll a patchiness in accurate detection of changes in coastal ecosystems caused by increased inputs of nutrients.