Pierre Helaouet

Pierre Helaouet
Marine Biological Association of the UK | MBA · CPR survey team and Data managment team

PhD

About

43
Publications
24,879
Reads
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1,924
Citations
Additional affiliations
September 2009 - present
Sir Alister Hardy Foundation for Ocean Science
Position
  • Research Associate

Publications

Publications (43)
Article
Full-text available
Despite evidence from a number of Earth systems that abrupt temporal changes known as regime shifts are important, their nature, scale and mechanisms remain poorly documented and understood. Applying principal component analysis, change-point analysis and a sequential t-test analysis of regime shifts to 72 time series, we confirm that the 1980s reg...
Article
Full-text available
Differences in phenological responses to climate change among species can desynchronise ecological interactions and thereby threaten ecosystem function. To assess these threats, we must quantify the relative impact of climate change on species at different trophic levels. Here, we apply a Climate Sensitivity Profile approach to 10,003 terrestrial a...
Article
Climate change is having a dramatic impact on marine animal and plant communities but little is known of its influence on marine prokaryotes, which represent the largest living biomass in the world oceans and play a fundamental role in maintaining life on our planet. In this study, for the first time to our knowledge, experimental evidence is provi...
Article
Full-text available
Climate change and resource exploitation have been shown to modify the importance of bottom-up and top-down forces in ecosystems. However, the resulting pattern of trophic control in complex food webs is an emergent property of the system and thus unintuitive. We develop a statistical nondeterministic model, capable of modeling complex patterns of...
Article
Full-text available
Integrating food web indicators into ecological status assessments is central to developing effective management measures that can improve degraded ecosystems. This is because they can reveal how ecosystems respond to environmental change that cannot be inferred from studying habitat, species or assemblages alone. However, the substantial investmen...
Article
Full-text available
Plankton form the base of the marine food web and are sensitive indicators of environmental change. Plankton time series are therefore an essential part of monitoring progress towards global biodiversity goals, such as the Convention on Biological Diversity Aichi Targets, and for informing ecosystem-based policy, such as the EU Marine Strategy Fram...
Article
Full-text available
An efficient ocean management for fisheries requires accurate data over large spatial scales. The horizontal gradient of chlorophyll-a (and the derived mesozooplankton habitat) exemplifies a plankton-to-fish index in support of a sustainable ocean management that targets fisheries and ecosystem productivity. The gradient of chlorophyll-a, which exp...
Article
The presence of invasive species in the Mediterranean Sea is much higher than in other European seas, and understanding the reasons behind the range expansion of this invasive species is important for minimising any possible impacts to the already highly pressurised Mediterranean marine ecosystem. In this work, a brief description of sightings of t...
Book
Full-text available
Summary: https://marine.copernicus.eu/news/ocean-state-report-5-summary-now-available Full report: https://www.tandfonline.com/doi/full/10.1080/1755876X.2021.1946240
Preprint
Full-text available
Plankton form the base of the marine food web and are sensitive indicators of environmental change. Plankton time-series are therefore an essential part of monitoring progress towards global biodiversity goals, such as the Convention on Biological Diversity Aichi Targets, and for informing ecosystem-based policy, such as the EU Marine Strategy Fram...
Article
Full-text available
This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Abstract This study evaluates the relationship between both commercial and scientific spatial fisheries data and a new satellite-based estimate o...
Article
Full-text available
Supplementary Information of : Mesoscale productivity fronts and local fishing opportunities in the European Seas. Fish and Fisheries, 00, 1–21. https://doi.org/10.1111/faf.12585
Article
Full-text available
In the North Atlantic, euphausiids (krill) form a major link between primary production and predators including commercially exploited fish. This basin is warming very rapidly, with species expected to shift northwards following their thermal tolerances. Here we show, however, that there has been a 50% decline in surface krill abundance over the la...
Article
Annual plankton succession has been investigated for many decades with hypotheses ranging from abiotic to biotic mechanisms being proposed to explain these recurrent patterns. Here, using data collected by the Continuous Plankton Recorder (CPR) survey and models originating from the MacroEcological Theory on the Arrangement of Life, we investigate...
Article
Full-text available
Extensive changes in plankton ecosystems around the British Isles over the last 60 years, including production, biodiversity and species distributions, have had effects on fisheries production and other marine life. This has been mainly driven by climate variability and ocean warming. These changes include: • Extensive changes in the planktonic eco...
Article
Full-text available
This study investigates the association between an index of mesozooplankton biomass, derived from the Continuous Plankton Recorder survey and satellite-derived productivity fronts in the North Atlantic. While chlorophyll-a content (CHL) is commonly described as a proxy for phytoplankton biomass, the size of productivity fronts estimated from the ho...
Article
In the past, partitions of the global ocean have been commonly carried out using relatively few environmental or biological variables. Although such partitions are undoubtedly useful on a global scale, we show that, at a basin scale, the use of a large number of biological variables greatly improves the accuracy of a partition. We first determined...
Article
Full-text available
Despite evidence from a number of Earth systems that abrupt temporal changes known as regime shifts are important, their nature, scale and mechanisms remain poorly documented and understood. Applying principal component analysis, change-point analysis and a sequential t-test analysis of regime shifts to 72 time series, we confirm that the 1980s reg...
Article
Full-text available
Due to the unprecedented rate at which our climate is changing, the ultimate consequence for many species is likely to be either extinction or migration to an alternate habitat. Certain species might, however, evolve at a rate that could make them resilient to the effects of a rapidly changing environment. This scenario is most likely to apply to s...
Article
Full-text available
The CPR survey records over 500 taxonomic entities and although the number of fish larvae on each sample is counted, they are not routinely identified to species or taxonomic group. The fish larvae project was an ambitious study to identify the fish larvae and transfer the results to a database incorporating the data from an earlier CPR Fish Atlas...
Article
Full-text available
One of the major challenges to understanding population changes in ecology for assessment purposes is the difficulty in evaluating the suitability of an area for a given species. Here we used a new simple approach able to faithfully predict through time the abundance of two key zooplanktonic species by focusing on the relationship between the speci...
Article
Full-text available
Against the backdrop of warming of the Northern Hemisphere it has recently been acknowledged that North Atlantic temperature changes undergo considerable variability over multidecadal periods. The leading component of natural low-frequency temperature variability has been termed the Atlantic Multidecadal Oscillation (AMO). Presently, correlative st...
Data
Full-text available
Long-term changes in Calanus spp abundance in the North East Atlantic. a. Spatial distribution of eigenvector 1 and First Principal Component time-series corresponding with eigenvector 1 for Calanus spp. abundance in the North East Atlantic from 1948. b. Spatial distribution of eigenvector 2 for Calanus spp. abundance in the North East Atlantic fro...
Data
Full-text available
Long-term changes in Phytoplankton Colour in the North East Atlantic. a. Spatial distribution of eigenvector 1 and First Principal Component time-series corresponding with eigenvector 1 for phytoplankton colour in the North East Atlantic from 1948. b. Spatial distribution of eigenvector 2 for phytoplankton colour in the North East Atlantic from 194...
Conference Paper
Full-text available
At the base of the marine foodweb, the free floating plant life of the sea (phytoplankton) provide food for the animal plankton (zooplankton) which in turn provide food for many other marine organisms. The carrying capacity of marine ecosystems in terms of the size of fish resources and recruitment to individual stocks as well as the abundance of m...
Article
Copepods represent the major part of the dry weight of the mesozooplankton in pelagic ecosystems and therefore have a central role in the secondary production of the North Atlantic Ocean. The calanoid copepod species Calanus finmarchicus is the main large copepod in subarctic waters of the North Atlantic, dominating the dry weight of the mesozoopla...
Conference Paper
Full-text available
The CPR survey records over 500 taxonomic entities and although it counts the number of fish larvae on each sample it does not routinely speciate this group. The fish larvae project was an ambitious study to retrospectively re-analyse CPR samples and record and speciate the findings. Throughout the history of the CPR survey something like this had...
Article
Full-text available
Although many studies have debated the theoretical links between physiology, ecological niches and species distribution, few studies have provided evidence for a tight empirical coupling between these concepts at a macroecological scale. We used an ecophysiological model to assess the fundamental niche of a key-structural marine species. We found a...
Thesis
Full-text available
Marine ecosystems show natural fluctuation throughout a large range of spatial and temporal scales. Despite the large amount of study devoted to the North Atlantic Ocean, drivers of those fluctuations remain unclear. By changing global climate, polluting, introducing exotic species, expanding and intensifying land uses and overharvesting biological...
Article
Full-text available
Hutchinson's (1957; Cold Spring Harbour Symp Quant Biol 22:415-427) niche concept is being used increasingly in the context of global change, and is currently applied to many ecological issues including climate change, exotic species invasion and management of endangered species. For both the marine and terrestrial realms, there is a growing need t...
Article
Full-text available
Global climate change is expected to modify the spatial distribution of marine organisms. However, projections of future changes should be based on robust information on the ecological niche of species. This paper presents a macroecological study of the environmental tolerance and ecological niche (sensu Hutchinson 1957, i.e. the field of tolerance...
Article
Centropages typicus is a temperate neritic-coastal species of the North Atlantic Oceans, generally found between the latitudes of the Mediterranean and the Norwegian Sea. Therefore, the species experiences a large number of environments and adjusts its life cycle in response to changes in key abiotic parameters such as temperature. Using data from...

Projects

Projects (4)
Project
INSITE is a major industry-sponsored project with the overall aim of providing stakeholders with the independent scientific evidence-base needed to better understand the influence of man-made structures on the ecosystem of the North Sea. The initial phase, known as the Foundation Phase has secured research funding of £1.8M and is anticipated to have a duration of three years. Further phases will be developed based on the outcomes from the Foundation Phase.