452 research outputs found
The starfish Mission, an italian perspective
No full textIn questo volume sono raccolti 24 interventi di autorevoli ricercatori, manager, docenti e champions che analizzano in ottica nazionale gli indirizzi della Missione Starfish.
La Missione Starfish rappresenta una delle 5 Missioni pripritarie lanciate dalla Commissione Europea nel 2021.
I temi trattati seguono le priorità indicate nel Report sulla Missione stessa presentato nella Giornata europea della Ricerca 2020 e sono: ecosistemi, decarbonizzazione, inquinamento, governance, gap emozionale e dati. Il tutto nel contesto marino e marittimo e piu' in generale in una visioner olistica che comprenda tutta la idrosfera
Dynamics of biogeochemical properties in temperate coastal areas of freshwater influence: Lessons from the Northern Adriatic Sea (Gulf of Trieste)
No full textHigh spatial and temporal variabilities of biogeochemical properties are prominent features of regions
under freshwater influence as a result of multiple factors. Understanding the ecological functioning of
these ecosystems, which provide important services for humans, is challenging since it requires adequate
observational strategies and efforts.
Multi-years (1999e2006) continuous observations in the northernmost part of the Adriatic Sea (Gulf
of Trieste) allowed us to compute a climatological description of seasonal dynamics of biogeochemical
properties for three relevant sites: a coastal area directly influenced by a river, an off-shore area located
in the centre of the Gulf and a coastal area located far from potential source of external nutrients.
The analysis of the climatologies provides a quantitative corroboration of the conceptual scheme for
biogeochemical and ecological seasonal dynamics of temperate coastal areas under freshwater influence
already proposed in literature, highlighting the role of river input, lateral transport, stratification regime
and interaction with bottom environment as driving factors.
While all areas follow a common pattern of succession of ecological processes, spatial variability
accounts for a significant decrease of the absolute trophic state, and for a phase delay in biogeochemical
dynamics. Results show that spatial heterogeneity is an inherent structural feature of coastal ecosystems,
suggesting that the evaluation of the quality status of coastal ecosystems should be made by using
different reference terms for different sub-areas
Effects of solar irradiance noise on a complex marine trophic web
No full textThe analysis of experimental data of the solar irradiance, collected on the marine surface, clearly highlights the intrinsic stochasticity of such an environmental parameter. Given this result, effects of randomly fluctuating irradiance on the population dynamics of a marine ecosystem are studied on the basis of the stochastic 0-dimensional biogeochemical flux model. The noisy fluctuations of the irradiance are formally described as a multiplicative Ornstein-Uhlenbeck process, that is a self-correlated Gaussian noise. Nonmonotonic behaviours of the variance of the marine populations’ biomass are found with respect to the intensity and the autocorrelation time of the noise source, manifesting a noise-induced transition of the ecosystem to an out-of-equilibrium steady state. Moreover, evidence of noise-induced effects on the organic carbon cycling processes underlying the food web dynamics are highlighted. The reported results clearly show the profound impact the stochastic environmental variables can have on both the populations and the biogeochemistry at the basis of a marine trophic network
Effects of ocean acidification on benthic organisms in the Mediterranean Sea under realistic climatic scenarios: A meta-analysis
No full textOcean acidification is expected to cause significant changes in the marine environment over the coming century. The effects of acidificationonorganisms’ physiology have been studied over the pasttwodecades. However, the experimental findings are not always easily comparable because of differences in experi- mental design, and comparable experimentsdonot always produce similar results. To rigorously integrate the current knowledge, we performed a meta-analysis of published studies focused on benthic organisms in the Mediterranean Sea, both in controlled manipulative experiments and in situ experiments near vent areas. In each experiment, the effect of acidification was calculated as the log-transformed response ratio (LnRR) of experimental versus control conditions. The quantitative results obtained by the meta-analysis highlight: (a) an increase in fleshy algae cover, which may lead to a competitive advantage over calcify- ing macroalgae; (b) a reduction of calcification by both algae and corals; (c) an increase in seagrass shoot density under low pH; and (d) a general increase in the photosynthetic activity of macrophytes
Natural parks and sustainable development: a theoretical study
No full textWe Analyse the role of natural parks in Europe in mediating among diverging interests on the use of natural resources. Using standard economic concepts, we highlight that natural parks provide different types of goods and act as place-based institutions for sustainable developmen
Remarks on the redefinition of system boundaries and model parameterization for downscaling experiments
No full textThe paper discusses problems encountered while implementing a downscaling experiment for testing the potential impacts of changes in temporal precipitation patterns on the biogeochemical properties of the lagoon of Venice. The paper shows how coupling different models implies redefining the boundaries, as well as space and time scales of the systems to be modelled, carefully revising model assumptions and parameterization, and possibly integrating new elements in the model. The paper also details how, in order to account for changes and adaptation in planktonic pools, a structural dynamic model was implemented by linking the kinetic parameters of a pre-existing calibrated functional response to the recent evolution of environmental conditions. Parameterizations of the boundary conditions of rescaled models and of links among models are also discussed
Marine ecosystem models of realistic complexity rarely exhibits significant endogenous non-stationary dynamics
No full textDespite the observation of cyclic and chaotic dynamics in nature, it is still not clear whether this behaviour is inherent to ecological systems or caused by external forcings. Here we explored a set of approximately 210,000 simulations to assess how often a model of realistic complexity exhibits non-stationary dynamics when external perturbations are excluded. Remarkably, less than one third of the population shown non-stationary dynamics and, even when present, fluctuations were rather small. The inherent stability of plankton communities showed to be related to the presence of multiple feedbacks in the food web structure, omnivory, low centre of gravity, and supports the conclusion that food webs of realistic complexity rarely exhibit significant endogenous non-stationary dynamics. Finally, we computed Lyapunov exponents for the non-stationary trajectories, in order to assess in which proportion they were periodic or chaotic, and we concluded that less than 10% of the non-stationary trajectories (3% of the total) showed sensitivities to initial conditions. This further supports the conclusion that complex topology mainly damps endogenous fluctuations in the food web
Long-term changes in a Mediterranean marine ecosystem
No full textIn the Mediterranean Sea, structured and standardized monitoring programs of marine
resources were set only in the last decades, so the analysis of changes in marine
communities over longer time scale has to rely on other sources. In this work, we
used seven decades (1945–2014) of disaggregated landings statistics for the Northern
Adriatic Sea (Mediterranean) to infer changes in the ecosystem. Analysis of landings
composition was enriched with the application of a suite of ecological indicators (e.g.,
trophodynamic indicators, such as the primary production required to sustain the
catches—PPR; size-based indicators, such as the large species indicator—LSI; other
indicators, such as the elasmobranchs-bony fish ratio—E/B ratio). Indicators were further
compared with main ecosystem drivers, i.e., fishing capacity, nutrient loads and climate
change. Species most vulnerable to fishing (i.e., elasmobranchs and large-sized species)
dramatically declined at the beginning of the industrialization of fishery that occurred
right afterwards World War II, as can be inferred by the negative drop of LSI and
E/B ratio in the mid-1950s. However, until the mid-1980s landings and PPR increased
due to improvements in fishing activities (e.g., the introduction of more efficient fishing
gears) increasing fishing capacity, high productivity of the ecosystem. Overall, the effects
of fishing were buffered by an increase in productivity in the period of high nutrient
discharge (up to mid-1980s), while significant changes in fish community structure were
already occurring. From the mid-1980s, a reduction in nutrient load caused a decline
in productivity but the food-web structure was already modified and unable to support,
or recover from, such unbalanced situation, resulting in the collapse of landings. This
collapse is coherent with alternative stable states hypothesis, typical of complex real
systems, that implies drastic interventions that go beyond fisheries management and
include regulation of nutrient release for recovery. The work highlights that, despite poor
capabilities to track species dynamics, landings and applied indicators might help to
shed light on the long-term dynamics of marine communities, thus contributing to place
current situation in an historical framework with potential for supporting management
Recent changes in the marine ecosystems of the northern Adriatic Sea
No full textThis review of studies on long term series on river discharges, oceanographic features, plankton, fish and
benthic compartments, collected since the 1970s revealed significant changes of mechanisms and trophic
structures in the northern Adriatic ecosystems. A gradual increase of eutrophication pressure occurred
during the 1970s until the mid 1980s, followed by a reversal of the trend, particularly marked in the
2000s. This trend was ascribed to the combination of a reduction of the anthropogenic impact, mainly
due to a substantial decrease of the phosphorus loads, and of climatic modifications, resulting in
a decline of atmospheric precipitations and, consequently, of the runoff in the northern Adriatic Sea.
Significant decreases of the phytoplankton abundances were observed after the mid 1980s, concurrently
with changes in the species composition of the communities, with an evident shift toward smaller cells
or organism sizes. Moreover, changes in the zooplankton community were also observed. A decrease of
demersal fishes, top predators and small pelagic fishes was ascribed to both overfishing and a demise of
eutrophication.
Macrozoobenthic communities slowly recovered in the last two decades after the anoxia events of the
1970s and 1980s.
An increasing number of non-autochthonous species has been recorded in the last decades moreover
the increasing seawater temperature facilitated the spreading of thermophilic specie
Cumulative Impact Index for the Adriatic Sea: Accounting for interactions among climate and anthropogenic pressures
No full textAssessing and managing cumulative impacts produced by interactive anthropogenic and natural drivers is a major challenge to achieve the sustainable use of marine spaces in line with the objectives of relevant EU acquis. However, the complexity of the marine environment and the uncertainty linked to future climate and socio-economic scenarios, represent major obstacles for understanding the multiplicity of impacts on the marine ecosystems and to identify appropriate management strategies to be implemented. Going beyond the traditional additive approach for cumulative impact appraisal, the Cumulative Impact Index (CI-Index) proposed in this paper applies advanced Multi-Criteria Decision Analysis techniques to spatially model relationships between interactive climate and anthropogenic pressures, the environmental exposure and vulnerability patterns and the potential cumulative impacts for the marine ecosystems at risk. The assessment was performed based on spatial data characterizing location and vulnerability of 5 relevant marine targets (e.g. seagrasses and coral beds), and the distribution of 17 human activities (e.g. trawling, maritime traffic) during a reference scenario 2000-2015. Moreover, projections for selected physical and biogeochemical parameters (temperature and chlorophyll 'a') for the 2035-2050 timeframe under RCP8.5 scenario, were integrated in the assessment to evaluate index variations due to changing climate conditions. The application of the CI-Index in the Adriatic Sea, showed higher cumulative impacts in the Northern part of the basin and along the Italian continental shelf, where the high concentration of human activities, the seawater temperature conditions and the presence of vulnerable benthic habitats, contribute to increase the overall impact estimate. Moreover, the CI-Index allowed understanding which are the phenomena contributing to synergic pressures creating potential pathways of environmental disturbance for marine ecosystems. Finally, the application in the Adriatic case showed how the output of the CI-Index can provide support to evaluate multi-risk scenarios and to drive sustainable maritime spatial planning and management.Assessing and managing cumulative impacts produced by interactive anthropogenic and natural drivers is a major challenge to achieve the sustainable use of marine spaces in line with the objectives of relevant EU acquis. However, the complexity of the marine environment and the uncertainty linked to future climate and socioeconomic scenarios, represent major obstacles for understanding the multiplicity of impacts on the marine ecosystems and to identify appropriate management strategies to be implemented. Going beyond the traditional additive approach for cumulative impact appraisal, the Cumulative Impact Index (CI-Index) proposed in this paper applies advanced Multi-Criteria Decision Analysis techniques to spatially model relationships between interactive climate and anthropogenic pressures, the environmental exposure and vulnerability patterns and the potential cumulative impacts for the marine ecosystems at risk. The assessment was performed based on spatial data characterizing location and vulnerability of 5 relevant marine targets (e.g. seagrasses and coral beds), and the distribution of 17 human activities (e.g. trawling, maritime traffic) during a reference scenario 2000-2015. Moreover, projections for selected physical and biogeochemical parameters (temperature and chlorophyll 'a') for the 2035-2050 timeframe under RCP8.5 scenario, were integrated in the assessment to evaluate index variations due to changing climate conditions. The application of the CI-Index in the Adriatic Sea, showed higher cumulative impacts in the Northern part of the basin and along the Italian continental shelf, where the high concentration of human activities, the seawater temperature conditions and the presence of vulnerable benthic habitats, contribute to increase the overall impact estimate. Moreover, the CI-Index allowed understanding which are the phenomena contributing to synergic pressures creating potential pathways of environmental disturbance for marine ecosystems. Finally, the application in the Adriatic case showed how the output of the CI-Index can provide support to evaluate multi-risk scenarios and to drive sustainable maritime spatial planning and management. (C) 2019 Elsevier B.V. All rights reserved
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