Editorial: Phytoplankton dynamics under climate change

Phytoplankton plays an important role in ocean processes, and is well-known to have an enormous positive impact on climate change or more specifically on global warming, by reducing atmospheric CO2 levels through the sinking of produced organic and inorganic matter to the deep ocean (Falkowski, 2012; Beardall and Raven, 2013). However, climate change, with consequences of elevated seawater temperatures and decreased pH levels (Beardall and Raven, 2013), influences phytoplankton dynamics, changing phytoplankton composition, geography and biomass in the oceans (Falkowski and Oliver, 2007; Boyd et al., 2015; Jonkers et al., 2019). Temperature increases could also drive temporal shifts in the onset of the regular annual blooms, their composition, duration and amplitude as well as mismatches in timing between trophic levels (Hinder et al., 2012; Mikaelyan et al., 2015). The overall impact of increased temperature on phytoplankton is not easy to assess due to variable and complex repercussions. For example, increasing temperatures can lead to more stratified waters, especially in summer months, and prevent nutrient replenishment at the ocean surface.info:eu-repo/semantics/publishedVersio

Increased Chlorophyll Levels in the Southern Caspian Sea Following an Invasion of Jellyfish

A significant correlation was observed between satellite derived chlorophyll a (Chl a) concentrations and the biomass of the invasive comb jellyfish Mnemiopsis leidyi in the southern Caspian Sea. By consuming the herbivorous zooplankton, the predatory ctenophore M. leidyi may have caused levels of Chl a to rise to very high values (∼9 mg m−3) in the southern Caspian Sea. There might also be several other factors concurrent with predation effects of M. leidyi influencing Chl a levels in this region, such as eutrophication and climatic changes which play major roles in nutrient, phytoplankton, and zooplankton variations. The decrease in pelagic fishes due to overfishing, natural, and anthropogenic impacts might have provided a suitable environment for M. leidyi to spread throughout this enclosed basin

A basin-wide Black Sea Mnemiopsis leidyi database

A specific marine biological data management tool, the Black Sea Mnemiopsis leidyi database system was created within the European Commission 6th framework Black Sea SCENE project for the Black Sea region and is now being supported by the Permanent Secretariat of the Black Sea Commission. The core team of scientists studying M. leidyi in the Black Sea was brought together and all their available M. leidyi data and metadata were loaded into the common database. This works on the Internet and has a simple user interface. It gives Black Sea scientists the option to load all their corresponding data on the database and to use it as an effective tool to work both with M. leidyi and, in future, with other gelatinous organisms’ data, including another invasive ctenophore Beroe ovata. All loaded metadata and historical data are available to the entire scientific community. More recent data are available to the team members and with some restrictions to other scientists.JRC.H.5-Land Resources Managemen

Author Correction: Floating macrolitter leaked from Europe into the ocean (Nature Sustainability, (2021), 4, 6, (474-483), 10.1038/s41893-021-00722-6)

During the preparation of the Supplementary Data spreadsheet “S. Data 3_Regression data,” the mean and median confidence intervals (CI) of FML (items yr−1) were misplaced in relation to their corresponding river names. The Supplementary Data file has now been updated in the HTML version of the article. This update does not alter the results or conclusions of this article.Correction to: Nature Sustainability https://doi.org/10.1038/s41893-021-00722-6, published online 10 June 2021. During the preparation of the Supplementary Data spreadsheet “S. Data 3_Regression data,” the mean and median confidence intervals (CI) of FML (items yr−1) were misplaced in relation to their corresponding river names. The Supplementary Data file has now been updated in the HTML version of the article. This update does not alter the results or conclusions of this article.Peer reviewe

Floating macro litter in European rivers - top items

The JRC exploratory project RIMMEL provides information about litter, mainly plastic waste, entering the European Seas through river systems. RIMMEL has collected data on riverine floating macro litter inputs to the sea. Data acquisition was based on the Riverine Litter Observation Network (RiLON) activities, which collected data from rivers in the European marine basins over a period of one year (September 2016 – September 2017). Data was collected by visual observations and documented with the JRC Floating Litter Monitoring Application for mobile devices, allowing a harmonized reporting, compatible with the MSFD Master List of Categories for Litter Items. This report includes the Top Items lists of riverine floating macro litter, based on the total amount of litter items identified during RiLON activities and ranked by abundance. Top Items lists have been elaborated considering the whole database for the European Seas and further detailed for each individual European regional sea: Baltic Sea, Black Sea, Mediterranean Sea and North-East Atlantic. The North-East Atlantic and the Mediterranean Sea regions showed similar litter categories in their Top 20 Items. These two regions provided most of the available data, influencing the general Top Items list. In the Black Sea and Baltic Sea regions, where data availability was limited, the Top Items lists showed more differences among the different regions. Overall, the general Top Items list for the European Seas showed a predominance of plastic item categories (artificial polymer materials). As a whole, plastic items made up to 80.8% of all objects, with plastic and polystyrene fragments comprising 45% of the identified items in the database. Additionally, Single Use Plastics such as bottles, cover/packaging and bags were also ranked among the most frequently found floating litter. The similarities in the Top 10 and Top 20 items for the different regions, and the appearance of Single Use Plastics scoring high in the ranking, support the need for common actions against plastic pollution at EU level.JRC.D.2-Water and Marine Resource

A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe

Increased Chlorophyll Levels in the Southern Caspian Sea Following an Invasion of Jellyfish

A significant correlation was observed between satellite derived chlorophyll a (Chl a) concentrations and the biomass of the invasive comb jellyfish Mnemiopsis leidyi in the southern Caspian Sea. By consuming the herbivorous zooplankton, the predatory ctenophore M. leidyi may have caused levels of Chl a to rise to very high values (~9 mg m-3) in the southern Caspian Sea. There might also be several other factors concurrent with predation effects of M. leidyi influencing Chl a levels in this region, such as eutrophication and climatic changes which play major roles in nutrient, phytoplankton and zooplankton variations. The decrease in pelagic fishes due to overfishing, natural and anthropogenic impacts might have provided a suitable environment for M. leidyi to spread throughout this enclosed basin.JRC.H.3-Global environement monitorin

The Qualitative and Quantitative Distribution in Phytoplankton and Zooplankton of Southern Black Sea of Cape Sinop, Turkey in 1999-2000

n the present study, seasonality and composition of phytoplankton and zooplankton were comparatively studied at two stations (one inshore and one offshore) off Sinop, in southern Black Sea during January-May 1999 and March-October 2000. A total 76 genera including 149 species and varieties were identified, of which 46% were dinoflagellates and 34% were diatoms in phytoplankton. Abundance of the genera Emiliana (in January-May 1999), Pseudosolenia and Ceratium (in March-October 2000) were higher than that of the other genera in almost every sampling period. Increased dinoflagellate to diatom ratio reflects more fertile conditions in the southern Black Sea. Abundance and biomass of the total fodder zooplankton the highest values were recorded in February 1999; March 2000. Cladocera and Appendicularia abundance and biomass values were higher in 1999 than 2000. Noctiluca scintillans was the most abundant of zooplankton group with a share of 43% (maximum: 416,925 ind. m-2 in May) in 1999. The second abundant group was Copepoda with 42% (172,981 ind.m-2 in February). Copepods with 78% of abundance and 73% of biomass (maximum: 372,330 ind. m-2 and 15,253 mg.m-2 in March) were the dominant group in 2000. They were followed by the dinoflagellate Noctiluca scintillans with 4.8% (maximum: 24,500 ind.m-2 in June).JRC.G.4-Maritime affair

Phytoplankton distribution in the Caspian Sea during March 2001

Phytoplankton abundance, biomass and species composition of the Caspian Sea were evaluated by using samples collected from the Iranian (southern Caspian Sea) and southern Kazakhstan (eastern Caspian Sea) surface waters in March 2001. A total of 45 taxa were found in the samples (20 diatoms, 17 dinoflagellates amd 8 others). Abundance and biomass of diatoms were high at the eastern stations, while dinoflagellates were dominant in terms of both biomass and abundance in the southern region. Average abundance and biomass were 40000±35000 cell l-1 and 580±690 ug l-1. the mean biomass value found here for the Middle and south Caspian Sea in March are difficult to compare with the past due to limited information, but seems higher than previously registered values. Higher chlorophyll values were also apparent from the SeaWiFS images in 2001 compared to those in 1998. This is suggested to be due to decreased grazing of phytoplankton by zooplankton which is voraciously preyed by the recent invasive ctenophore Mnemiopsis leidyi.JRC.H.5-Rural, water and ecosystem resource

Impact of a New Invader Ctenophore (Mnemiopsis Leidyi) on the Zooplankton Community of the Southern Caspian Sea

The invasive ctenophore Mnemiopsis leidyi (Agassiz) which was transported from the Black Sea into the Caspian Sea at the end of the 1990s, has negatively affected the ecosystem of the Caspian Sea. Zooplankton abundance, biomass and species composition were evaluated on the Iranian coast of the Caspian Sea during 2001-2006. A total of 18 merozooplankton (13 species composed of larvae of benthic animals) and holozooplankton (4 Copepoda and 1 Cladocera) species were identified. The total number of zooplankton species found here was 50% less than in a previous investigation performed in the same region in 1996 before the introduction of M. leidyi into the Caspian Sea. Cladocera species seemed to be highly affected by the invasion of M. leidyi; only one species, Podon polyphemoides, remained in the study area, whereas, 24 Cladocera species were found in the study carried out in 1996. While Copepoda Eurytemora minor, E. grimmi, Calanipeda aquae dulcis and Acartia tonsa were abundant before the M. leidyi invasion, only A. tonsa (copepodites and adults) dominated the inshore and offshore waters after the invasion. The maxima in zooplankton abundance (22,088 ± 24,840 ind.m-3) and biomass (64.1 ± 56.8 mg.m-3) were recorded in December 2001 and August 2004, respectively. The annual mean zooplankton abundance during 2001-2006 was in the range of 3,361- 8,940 ind.m-3 which was 2-5 fold less than the zooplankton abundance in 1996. During 2001-2006, the highest abundance and biomass of M. leidyi were observed during summer-autumn coincident with warm temperatures and generally when abundance of other zooplankton organisms was low.JRC.H.5-Land Resources Managemen