Alessandra Conversi

Alessandra Conversi
Italian National Research Council | CNR · Institute of Marine Science ISMAR

Ph.D in Oceanography

About

75
Publications
18,186
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,018
Citations
Introduction
Marine regime shifts around the globe: theory, drivers and impacts, compiled and edited by Alessandra Conversi, Chris Möllmann, M. Edwards, C. Folke. Philosophical Transactions B of the Royal Society, 2015. Table of Contents: http://rstb.royalsocietypublishing.org/content/370/1659.toc The 6th March is the 350th anniversary of the first issue of Philosophical Transactions, all Royal Society content is free for all to access during March, see website
Additional affiliations
January 2012 - January 2014
Sir Alister Hardy Foundation for Ocean Science
Position
  • Marie Curie Experienced Fellow
September 2008 - March 2017
University of Plymouth
Position
  • Researcher
January 2007 - present
Italian National Research Council (CNR)
Position
  • Senior Researcher

Publications

Publications (75)
Article
Full-text available
Understanding marine regime shifts is important not only for ecology but also for developing marine management that assures the provision of ecosystem services to humanity. While regime shift theory is well developed, there is still no common understanding on drivers, mechanisms and characteristic of abrupt changes in real marine ecosystems. Based...
Article
Full-text available
Sudden, dramatic, long-lasting shifts in ecosystem structure and function have been increasingly documented in multiple, diverse marine ecosystems around the globe [[1][1]–[21][2]]. Such regime shifts can be explained with theory on nonlinear systems crossing critical thresholds [[2][3],[22][4]].
Article
Full-text available
Regime shifts are characterized by sudden, substantial and temporally persistent changes in the state of an ecosystem. They involve major biological modifications and often have important implications for exploited living resources. In this study, we examine whether regime shifts observed in 11 marine systems from two oceans and three regional seas...
Article
Full-text available
Marine populations are controlled by a series of drivers, pertaining to both the physical environment and the biological environment (trophic predator-prey interactions). There is heated debate over drivers, especially when trying to understand the causes of major ecosystem events termed regime shifts. In this work, we have researched and developed...
Article
Full-text available
Impermanence is an ecological principle¹ but there are times when changes occur nonlinearly as abrupt community shifts (ACSs) that transform the ecosystem state and the goods and services it provides². Here, we present a model based on niche theory³ to explain and predict ACSs at the global scale. We test our model using 14 multi-decadal time serie...
Article
Full-text available
In this review paper, we explore latest results concerning a few key tipping elements of the Earth system in the ocean, cryosphere, and land realms, namely the Atlantic overturning circulation and the subpolar gyre system, the marine ecosystems, the permafrost, the Greenland and Antarctic ice sheets, and in terrestrial resource use systems. All the...
Article
Full-text available
Coastal zones have large social, economic and environmental values. They are more densely populated than the hinterland and concentrate large economic assets, critical infrastructures and human activities such as tourism, fisheries, navigation. Furthermore, coastal oceans are home to a wealth of living marine resources and very productive ecosystem...
Article
Full-text available
Coastal zones have large social, economic and environmental values. They are more densely populated than the hinterland and concentrate large economic assets, critical infrastructures and human activities such as tourism, fisheries, navigation. Furthermore, coastal oceans are home to a wealth of living marine resources and very productive ecosystem...
Preprint
Full-text available
This is the Supplemental Material for the article: Luca Stirnimann, Alessandra Conversi, Simone Marini, 2019. Detection of regime shifts in the environment: testing “STARS” using synthetic and observed time series, ICES Journal of Marine Science, , fsz148, https://doi.org/10.1093/icesjms/fsz148
Article
While marine populations change all the time, sometimes regime shifts involve an entire ecosystem, resulting in crucial and sometimes permanent alterations in the ecosystem trophic web and services. A commonly used method to detect shifts in marine systems is the Sequential t-test Analysis of Regime Shifts (STARS). In this work, we chose to analyse...
Article
Full-text available
Marine plankton abundance and dynamics in the open and interior ocean is still an unknown field. The knowledge of gelatinous zooplankton distribution is especially challenging, because this type of plankton has a very fragile structure and cannot be directly sampled using traditional net based techniques. To overcome this shortcoming, Computer Visi...
Data
Detailed information on the Genetic Programming parameters used in this study. (PDF)
Data
Example of an approximating function produced by the Genetic Programming based approach, and cumulative sums analysis results. (PDF)
Data
Data availability information. (DOCX)
Conference Paper
Full-text available
The GUARD1 system is a low-cost stand-alone instrument for underwater image acquisition and recognition of gelatinous zooplankton. It is designed for installation and autonomous operation on different platforms (e.g. fixed, towed, mobile). Its low cost, small size and low power consumption coupled with a long-life battery pack equipment, make it an...
Article
Full-text available
Pteropods and heteropods (holoplanktonic gastropods) are an important component of the modern oceans; however, detailed information on their distribution in the fossil record is often based on poorly preserved specimens. This study presents the micropaleontological analysis of three exceptionally well-preserved Late Pleistocene marine sediment core...
Article
Full-text available
The general aim of this paper is to present a possible multidisciplinary approach to the problem of connectivity among marine protected areas (MPAs) describing some of the mechanisms and vectors that control the dispersal of propagules among spatially distributed marine communities of MPAs in the Southern Adriatic Sea. A joint approach is described...
Article
Full-text available
The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can be seen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project ("Biodiversity and Ecosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafauna"), we...
Conference Paper
Full-text available
Much is still unknown about marine plankton abundance and dynamics in the open and interior ocean. Especially challenging is the knowledge of gelatinous zooplankton distribution, since it has a very fragile structure and cannot be directly sampled using traditional net based techniques. In the last decades there has been an increasing interest in t...
Article
Full-text available
A comparative study for abundance, biomass and diversity was carried out for the prokaryote, meiofauna and macrofauna communities at three depth stations (1200, 1800 and 2100 m) along the Malta Escarpment (Mediterranean Sea). Our investigation showed a two-fold increase with depth in prokaryote abundance; the contribution of prokaryote biomass to t...
Article
Decadal-scale regime shifts in Northwest Atlantic shelf ecosystems can be remotely forced by climate-associated atmosphere-ocean interactions in the North Atlantic and Arctic Ocean Basins. This remote climate forcing is mediated primarily by basin- and hemispheric-scale changes in ocean circulation. We review and synthesize results from process-ori...
Article
Full-text available
During recent decades, historically unprecedented changes have been observed in the Arctic as climate warming has increased precipitation, river discharge, and glacial as well as sea ice melting. Additionally, shifts in the Arctic’s atmospheric pressure field have altered surface winds, ocean circulation, and freshwater storage in the Beaufort Gyre...
Data
Marine zooplankton must deal with seasonal variations of the upper-ocean environment that are both intense and prolonged compared to their life spans. This leads to large seasonal fluctuations of population size, and strong evolutionary tuning of demographic processes (e.g. reproduction, somatic and population growth, and dormancy) for optimal matc...
Conference Paper
Full-text available
Zooplankton are considered good indicators for understand-ing how oceans are affected by climate change. While climate influence on zooplankton abundance variability is currently accepted, its mechanisms are not understood, and prediction is not yet possible. This paper uti-lizes the Genetic Programming approach to identify which environmental vari...
Article
Full-text available
Abrupt and rapid ecosystem shifts (where major reorganizations of food-web and community structures occur), commonly termed regime shifts, are changes between contrasting and persisting states of ecosystem structure and function. These shifts have been increasingly reported for exploited marine ecosystems around the world from the North Pacific to...
Chapter
Full-text available
The research activity of ISMAR on plankton communities of the Northern Adri-atic Sea is described here. The results derive from data that have been gathered in 40 years of oceanographic cruises. Spatial and temporal variations of abundance and species composition of phytoplankton and zooplankton communities have been studied in relation with meteor...
Article
Full-text available
Regime shifts are abrupt changes encompassing a multitude of physical properties and ecosystem variables, which lead to new regime conditions. Recent investigations focus on the changes in ecosystem diversity and functioning associated to such shifts. Of particular interest, because of the implication on climate drivers, are shifts that occur synch...
Article
Full-text available
A comparative study of biological and physical time series in the eastern and western Mediterranean Sea for the period 1960s to 2005, combined with a literature review, finds that all point out to an abrupt period of change in the late 1980s that involved circulation and pelagic systems. We show, using regime shift detection methods, evidence that...
Article
Full-text available
Plankton are the main food source in the majority of marine ecosystems and have a crucial role in climate change through primary production and the export of carbon to the deep ocean. Understanding how ocean biology and biogeochemical cycles contribute and respond to climate and other global change is a major challenge of high significance for the...
Article
Full-text available
1] Understanding the impact of climate change on zooplankton populations is of major importance, as they represent the basis for higher trophic levels in the marine food web. In this study we analyze the 36-year copepod abundance time series in the Gulf of Trieste, northern Adriatic, to investigate its interannual variability, with particular atten...
Conference Paper
Full-text available
lankton are the main food source in the majority of marine ecosystems and have a crucial role in climate change through primary production and the export of carbon to the deep ocean. Understanding how ocean biology and biogeochemical cycles contribute and respond to climate and other global change is a major challenge of high significance for the f...
Article
Populations of the copepod species Calanus finmarchicus often dominate the springtime biomass and secondary production of shelf ecosystems throughout the North Atlantic Ocean. Recently, it has been hypothesised that interannual to interdecadal fluctuations observed in such populations are driven primarily by climate-associated changes in ocean circ...
Article
Full-text available
In the last decade, the link between plankton and climate variability has been recognized through several studies in the Atlantic and Pacific Oceans. In the Mediterranean Sea such studies have begun more recently. An important question is which climate data sets and variables should be utilized for this analysis. In the case of the Mediterranean Se...
Article
Full-text available
The PIT AGEM project includes bi-monthly water monitoring, platform monitoring, and primary production and biogeochemical characterization of the Gulf of Manfredonia (southern Adriatic Sea). The bi-monthly monitoring consists of continuous, horizontal tracking of surface physico-chemical parameters (temperature, salinity, dissolved oxygen, pH, in v...
Book
Full-text available
A strong association is documented between variability of the North Atlantic Oscillation (NAO) and changes in various trophic levels of the marine ecosystems of the North Atlantic. Examples are presented for phytoplankton, zooplankton, benthos, fish, marine diseases, whales and seabirds. NAO variability is shown to influence abundance, biomass, dis...
Article
The detection of extreme events is of primary importance because they often change the initial conditions of a dynamic system. However, the definition of what constitutes an extreme or exceptional event is unclear; what threshold or which rate of occurrence delineates an anomaly? An alternate and precisely specified type of definition might be an e...
Article
The Continuous Plankton Recorder and the Comprehensive Ocean–Atmosphere Data Set were used to study the temporal dynamics over 30 years of the Calanus finmarchicus surveys in the Gulf of Maine. Changes in Calanus abundance were compared to those in the sea-surface temperature in the Gulf of Maine and in the North Atlantic Oscillation index. Three m...
Article
The main interannual and seasonal signals have been extracted from a multi-decadal data set of zooplankton collected with the Continuous Plankton Recorder in the Gulf of Maine, from January 1961 to December 1991. The monthly abundances of seven species or genera of copepods representing the dominant biomass in the area were considered. The presence...
Article
There is increasing evidence that zooplankton inter-annual variability is related to changes in the physical and atmospheric environments. Here, we analyse and compare the inter-annual variations of zooplankton biomass and of two environmental properties – surface temperature and surface salinity – at Station P, Gulf of Alaska (50°N 145°W). This 19...
Article
Full-text available
To investigate the possibility of climatic influence on the marine biosphere, we analyzed the decadal time series of zooplankton biomass and sea surface temperature (SST) measured at stationP, Gulf of Alaska, during the period 1957-1980. A relationship between the two series is not apparent in the raw data. However, Fourier analysis revealed peaks...
Article
Full-text available
Variations of zooplankton biomass in the ocean occur due to poorly understood interactions between primary and secondary productivity, nutrients and physical factors. Analysis of 24 years (1957–80) of monthly averaged mesozooplankton biomass at Station P in the Gulf of Alaska indicates that its interannual variability is dominated by the Pole Tide...
Article
The concept of Integrated Coastal Management (ICM) is not new, but it is experiencing a renaissance. The author outline the concept and recommend ways in which its application could change the direction of coastal zone management. -after Authors