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Fullgrabe L, Grosjean P, Gobert S, Lejeune P, Leduc M, Engels G, Dauby P, Boissery P, Richir J. Zooplankton dynamics in a changing environment: A 13-year survey in the northwestern Mediterranean Sea. MARINE ENVIRONMENTAL RESEARCH 2020; 159:104962. [PMID: 32662424 DOI: 10.1016/j.marenvres.2020.104962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/14/2020] [Accepted: 03/21/2020] [Indexed: 06/11/2023]
Abstract
Dynamics of the subsurface (2-3 m) mesozooplankton (i.e., > 200 μm) in the Bay of Calvi (Corsica, France) were explored, combining time series (2004-2016) of 14 zooplankton groups, wind gusts, water temperature, nitrate and chlorophyll-a. Zooplankton data was obtained through image analysis. While contrasted group-specific seasonal patterns were observed, the most productive zooplankton annual event occurred in April (spring peak), concentrating on average 25% of the total annual abundance. A "typical" year was defined based on the annual succession of different community states, highlighting particular years (2007, 2015 and 2012) mainly characterized by weak spring peak. Environmental influences on the interannual variability of zooplankton were explored and while relationship between chlorophyll-a and zooplankton abundance was unclear, the availability of nutrients (December-March), potentially mediated via the wind regime (October-January) seemed to be essential to the occurrence of the spring peak. Additionally, we observed an influence of temperature, with winter thermal thresholds (between 12.1 °C and 13.4 °C) conditioning the spring peak. Also, the occurrence of lower annual abundances after 2010 was synchronous with the sharp increase of seawater warming trend, especially regarding winter temperature (0.30 °C.year-1). Finally, winter North Atlantic Oscillation (NAO) was found to be correlated to both winter water temperature and spring peak abundance, which suggests large-scale processes to impact regional zooplankton community.
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Affiliation(s)
- Lovina Fullgrabe
- Station de Recherches Sous-marines et Océanographiques STARESO, Calvi, 20260, France; Laboratory of Oceanology, FOCUS, University of Liège, Belgium; Numerical Ecology of Aquatic Systems, Complexys Institute, University of Mons, 7000, Mons, Belgium.
| | - Philippe Grosjean
- Numerical Ecology of Aquatic Systems, Complexys Institute, University of Mons, 7000, Mons, Belgium
| | - Sylvie Gobert
- Station de Recherches Sous-marines et Océanographiques STARESO, Calvi, 20260, France; Laboratory of Oceanology, FOCUS, University of Liège, Belgium
| | - Pierre Lejeune
- Station de Recherches Sous-marines et Océanographiques STARESO, Calvi, 20260, France
| | - Michèle Leduc
- Station de Recherches Sous-marines et Océanographiques STARESO, Calvi, 20260, France
| | - Guyliann Engels
- Numerical Ecology of Aquatic Systems, Complexys Institute, University of Mons, 7000, Mons, Belgium
| | - Patrick Dauby
- Laboratory of Systematics and Animal Diversity, FOCUS, University of Liège, Belgium
| | - Pierre Boissery
- Agence de l'Eau Rhône-Méditerranée-Corse, Délégation de Marseille, 13001, Marseille, France
| | - Jonathan Richir
- Laboratory of Oceanology, FOCUS, University of Liège, Belgium; Chemical Oceanography Unit, FOCUS, University of Liège, Belgium
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Marine environmental DNA biomonitoring reveals seasonal patterns in biodiversity and identifies ecosystem responses to anomalous climatic events. PLoS Genet 2019; 15:e1007943. [PMID: 30735490 PMCID: PMC6368286 DOI: 10.1371/journal.pgen.1007943] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/07/2019] [Indexed: 01/08/2023] Open
Abstract
Marine ecosystems are changing rapidly as the oceans warm and become more acidic. The physical factors and the changes to ocean chemistry that they drive can all be measured with great precision. Changes in the biological composition of communities in different ocean regions are far more challenging to measure because most biological monitoring methods focus on a limited taxonomic or size range. Environmental DNA (eDNA) analysis has the potential to solve this problem in biological oceanography, as it is capable of identifying a huge phylogenetic range of organisms to species level. Here we develop and apply a novel multi-gene molecular toolkit to eDNA isolated from bulk plankton samples collected over a five-year period from a single site. This temporal scale and level of detail is unprecedented in eDNA studies. We identified consistent seasonal assemblages of zooplankton species, which demonstrates the ability of our toolkit to audit community composition. We were also able to detect clear departures from the regular seasonal patterns that occurred during an extreme marine heatwave. The integration of eDNA analyses with existing biotic and abiotic surveys delivers a powerful new long-term approach to monitoring the health of our world's oceans in the context of a rapidly changing climate.
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Gordo O, Barriocanal C, Robson D. Ecological Impacts of the North Atlantic Oscillation (NAO) in Mediterranean Ecosystems. ADVANCES IN GLOBAL CHANGE RESEARCH 2011. [DOI: 10.1007/978-94-007-1372-7_11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Lejeusne C, Chevaldonné P, Pergent-Martini C, Boudouresque CF, Pérez T. Climate change effects on a miniature ocean: the highly diverse, highly impacted Mediterranean Sea. Trends Ecol Evol 2010; 25:250-60. [DOI: 10.1016/j.tree.2009.10.009] [Citation(s) in RCA: 397] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 10/21/2009] [Accepted: 10/27/2009] [Indexed: 10/20/2022]
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Abstract
Ecosystems can alternate suddenly between contrasting persistent states due to internal processes or external drivers. It is important to understand the mechanisms by which these shifts occur, especially in exploited ecosystems. There have been several abrupt marine ecosystem shifts attributed either to fishing, recent climate change or a combination of these two drivers. We show that temperature has been an important driver of the trophodynamics of the North Sea, a heavily fished marine ecosystem, for nearly 50 years and that a recent pronounced change in temperature established a new ecosystem dynamic regime through a series of internal mechanisms. Using an end-to-end ecosystem approach that included primary producers, primary, secondary and tertiary consumers, and detritivores, we found that temperature modified the relationships among species through nonlinearities in the ecosystem involving ecological thresholds and trophic amplifications. Trophic amplification provides an alternative mechanism to positive feedback to drive an ecosystem towards a new dynamic regime, which in this case favours jellyfish in the plankton and decapods and detritivores in the benthos. Although overfishing is often held responsible for marine ecosystem degeneration, temperature can clearly bring about similar effects. Our results are relevant to ecosystem-based fisheries management (EBFM), seen as the way forward to manage exploited marine ecosystems.
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Affiliation(s)
- Richard R Kirby
- University of Plymouth, School of Marine Science and Engineering, Drake Circus, Plymouth PL4 8AA, UK.
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Casini M, Lövgren J, Hjelm J, Cardinale M, Molinero JC, Kornilovs G. Multi-level trophic cascades in a heavily exploited open marine ecosystem. Proc Biol Sci 2008; 275:1793-801. [PMID: 18460432 DOI: 10.1098/rspb.2007.1752] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Anthropogenic disturbances intertwined with climatic changes can have a large impact on the upper trophic levels of marine ecosystems, which may cascade down the food web. So far it has been difficult to demonstrate multi-level trophic cascades in pelagic marine environments. Using field data collected during a 33-year period, we show for the first time a four-level community-wide trophic cascade in the open Baltic Sea. The dramatic reduction of the cod (Gadus morhua) population directly affected its main prey, the zooplanktivorous sprat (Sprattus sprattus), and indirectly the summer biomass of zooplankton and phytoplankton (top-down processes). Bottom-up processes and climate-hydrological forces had a weaker influence on sprat and zooplankton, whereas phytoplankton variation was explained solely by top-down mechanisms. Our results suggest that in order to dampen the occasionally harmful algal blooms of the Baltic, effort should be addressed not only to control anthropogenic nutrient inputs but also to preserve structure and functioning of higher trophic levels.
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Affiliation(s)
- Michele Casini
- Swedish Board of Fisheries, Institute of Marine Research, PO Box 4, 45321 Lysekil, Sweden.
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