{"title":"A mass occurrence of pteropods (<i>Limacina</i> spp.) drove a pronounced peak in zooplankton biomass in Atlantic water in the Barents Sea in 1994.","authors":"Hein Rune Skjoldal, Espen Bagøien, Monica Bente Martinussen","doi":"10.1093/plankt/fbaf012","DOIUrl":"10.1093/plankt/fbaf012","url":null,"abstract":"<p><p>Zooplankton have been monitored on autumn cruises in the Barents Sea since the late 1980s. The time series shows a pronounced peak in zooplankton biomass in the inflow region of Atlantic water in 1994. The mean biomass was ~ 20 g dry weight m<sup>-2</sup>, which is more than twice the long-term average, and showed an atypical composition with dominance of the small size fraction (<1 mm). Analysis of stored samples revealed that the high biomass event in 1994 was due to a mass occurrence of two species of <i>Limacina</i> pteropods (<i>Limacina retroversa</i> and <i>Limacina helicina</i>) dominated by small juveniles < 1 mm in diameter. High biomass in the Atlantic inflow region also in 1995 was due to a strong but delayed summer generation of the dominant copepod <i>Calanus finmarchicus</i>. Estimated biomass of copepods (from numbers and individual weight by species and stage) was strongly dominated by <i>C. finmarchicus</i> in both years (~90%). The average biomass of <i>Limacina</i> spp. in 1994 was ~ 7 g dw m<sup>-2</sup>, estimated to be mainly in the small fraction, and contributed to the 1994 peak on top of a \"typical\" biomass of <i>C. finmarchicus</i>. The results contribute to a better understanding of the Barents Sea ecosystem.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 2","pages":"fbaf012"},"PeriodicalIF":1.9,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11950534/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143753233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patricio A Díaz, Ángela M Baldrich, Francisco Rodríguez, Manuel Díaz, Gonzalo Álvarez, Iván Pérez-Santos, Camila Schwerter, Camilo Rodríguez-Villegas, Pamela Carbonell, Bárbara Cantarero, Loreto López, Beatriz Reguera
{"title":"<i>Mesodinium-Dinophysis</i> encounters: temporal and spatial constraints on <i>Dinophysis</i> blooms.","authors":"Patricio A Díaz, Ángela M Baldrich, Francisco Rodríguez, Manuel Díaz, Gonzalo Álvarez, Iván Pérez-Santos, Camila Schwerter, Camilo Rodríguez-Villegas, Pamela Carbonell, Bárbara Cantarero, Loreto López, Beatriz Reguera","doi":"10.1093/plankt/fbae068","DOIUrl":"https://doi.org/10.1093/plankt/fbae068","url":null,"abstract":"<p><p>Species of the <i>Dinophysis acuminata</i> complex are the main cause of diarrhetic shellfish poisoning worldwide. These mixotrophs perform photosynthesis with plastids stolen from specific ciliate prey. Current transport models forecast advection of established populations, but modelling bloom development and maintenance also needs to consider the prey (<i>Mesodinium</i> spp.) of <i>Dinophysis</i>. Predator and prey have distinct niches, and <i>Dinophysis</i> bloom success relies on matching prey populations in time and place. During autumn 2019, red tides of <i>Mesodinium rubrum</i> in Reloncaví Fjord, Chile, were not followed by <i>Dinophysis</i> growth<i>.</i> The dynamics of <i>Mesodinium-Dinophysis</i> encounters during this and additional multiscale cases elsewhere are examined. Analogies with some classic predator-prey models (match-mismatch hypothesis; Lasker's stable ocean hypothesis) are explored. Preceding dense populations of <i>Mesodinium</i> do not guarantee <i>Dinophysis</i> blooms if spatial co-occurrence is not accompanied by water column structure, which leads to thin layer formation, as in Lasker's stable ocean hypothesis or if the predator growth season is over. Tracking the frequency of vacuolate <i>Dinophysis</i> cells, irrefutable signal of prey acquisition, with advanced <i>in situ</i> fluid-imaging instruments, is envisaged as a next-generation tool to predict rising <i>Dinophysis</i> populations.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 2","pages":"fbae068"},"PeriodicalIF":1.9,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11910895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143649438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patricia Reglero, Maria Pilar Tugores, Josefin Titelman, Mar Santandreu, Melissa Martin, Rosa Balbin, Diego Alvarez-Berastegui, Asvin P Torres, Nelly Calcina, Laura Leyva, Øyvind Fiksen
{"title":"Bluefin tuna (<i>Thunnus thynnus</i>) larvae exploit rare food sources to break food limitations in their warm oligotrophic environment.","authors":"Patricia Reglero, Maria Pilar Tugores, Josefin Titelman, Mar Santandreu, Melissa Martin, Rosa Balbin, Diego Alvarez-Berastegui, Asvin P Torres, Nelly Calcina, Laura Leyva, Øyvind Fiksen","doi":"10.1093/plankt/fbaf006","DOIUrl":"10.1093/plankt/fbaf006","url":null,"abstract":"<p><p>Tuna spawns in some of the warmest and most oligotrophic areas worldwide. At the same time, starvation is often considered the main source of mortality for fish larvae. Here we assess if plankton availability is sufficient to sustain the high growth potential of tuna (<i>Thunnus thynnus</i>) larvae in a major spawning ground in the warm oligotrophic Mediterranean Sea. We combine field data with a model of larval foraging, growth, and bioenergetics and find that just enough food is available in the warm surface layer to sustain the high growth rate of the larvae. For bluefin tuna, higher temperatures can be beneficial if prey abundance is high, 10 000-27 000 nauplii m<sup>-3</sup>, 14-36 cladocerans m<sup>-3</sup>, 3-7 copepods m<sup>-3</sup>, but critical if not. While nauplii alone may not sustain the growth potential of even the smallest tuna larvae, our model predicts that including some larger copepods or cladocerans in the diet reduces food limitation and can sustain growth even in the warmest years. The combination of clear Mediterranean waters and the occasional copepod or cladocerans alleviates food limitation despite the low zooplankton concentrations in the area. In conclusion, oligotrophic spawning areas allow for fast growth of these foraging efficient larvae, unless temperatures exceed 28°C.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 2","pages":"fbaf006"},"PeriodicalIF":1.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11879179/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143567010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paul C Frost, Kyle DaSilva, Joseph A Frost-Xenopoulos, Wesley S Burr, Catriona L C Jones
{"title":"Effects of phosphorus enrichment on <i>Daphnia</i>-algae interactions in laboratory microcosms.","authors":"Paul C Frost, Kyle DaSilva, Joseph A Frost-Xenopoulos, Wesley S Burr, Catriona L C Jones","doi":"10.1093/plankt/fbaf002","DOIUrl":"10.1093/plankt/fbaf002","url":null,"abstract":"<p><p>We examined the effects of phosphorus (P) on algal biomass and stoichiometry and, subsequently, alterations to zooplankton populations. We modified P supply in microcosms and tracked changes in algal and <i>Daphnia</i> populations, and phosphorus concentrations. Even though we found algal biomass increased over the experiment in low P containers, greater food abundance did not increase <i>Daphnia</i> abundance. In low P containers, a high algal biomass was accompanied with elevated C:P ratios, very low soluble reactive P concentrations and low <i>Daphnia</i> fecundity. High algal C:P ratios and low soluble reactive P concentrations in these microcosms indicated a strong P-limitation of algae and food quality constraints on consumer populations. In high P containers, algal biomass initially increased, which led to an increased <i>Daphnia</i> abundance. In most of the high P microcosms, rapid increases in <i>Daphnia</i> populations led to reduced algal biomass and increased concentrations of soluble reactive P. However, in an outlier high P container, we found a different pattern with elevated algal biomass, low soluble reactive P concentrations and a very large <i>Daphnia</i> population. Our results show that P supplies can strongly affect <i>Daphnia</i>-algae interactions, but the nature of these effects are likely complicated by internal feedbacks that affect the gain and loss of both populations.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 2","pages":"fbaf002"},"PeriodicalIF":1.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11879204/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143567290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David U Hernández-Becerril, Raquel Rodríguez-Martínez, Francisco Varona-Cordero, Martín Merino-Ibarra, Píndaro Díaz-Jaimes, Silvia Pajares
{"title":"Diversity and distribution of the eukaryotic picoplankton in the oxygen minimum zone of the tropical Mexican Pacific.","authors":"David U Hernández-Becerril, Raquel Rodríguez-Martínez, Francisco Varona-Cordero, Martín Merino-Ibarra, Píndaro Díaz-Jaimes, Silvia Pajares","doi":"10.1093/plankt/fbae083","DOIUrl":"10.1093/plankt/fbae083","url":null,"abstract":"<p><p>The ecology of eukaryotic picoplankton in oxygen minimum zones (OMZs) is crucial to understand global primary production, trophic dynamics and plankton diversity. This study analyses picoeukaryotic diversity and distribution patterns along the water column at two locations (slope and oceanic) in the tropical Mexican Pacific OMZ using metabarcoding and flow cytometry. Well-known groups of Chlorophytes (Mamiellophyceae) and Ochrophytes (Chrysophyceae, Dictyochophyceae, Pelagophyceae) occurred in high relative abundances, whereas less-known groups such as Chloropicophyceae and Prasinodermophyta were found in lower abundances. Picoeukaryotic diversity was higher at the lower end of the oxycline (10 μM O<sub>2</sub>) than at the surface and subsurface layers. Differential distributions of picoeukaryotes were also detected along the water column, with almost exclusive communities at each depth. Mamiellophyceae dominated the surface and subsurface layers, whereas Syndiniales (parasitic dinoflagellates), Radiolaria, Ochrophyta, and Sagenista (MArine STramenopiles -MAST groups-) were prevalent at the oxycline. Post-upwelling oceanographic conditions possibly contributed to shape the differences in community composition and distribution. These findings highlight that oxygen concentration is a key factor driving microbial distribution and that oxyclines provide specialized niches that promote high picoplankton diversity and multiple trophic strategies including autotrophy, mixotrophy, heterotrophy and parasitism.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 2","pages":"fbae083"},"PeriodicalIF":1.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11879187/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143567289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Assessing coastal zooplankton in the St. Lawrence estuary: spatio-temporal patterns of taxonomic and functional biodiversity.","authors":"Mélanie Santo, Piero Calosi, Gesche Winkler","doi":"10.1093/plankt/fbae073","DOIUrl":"10.1093/plankt/fbae073","url":null,"abstract":"<p><p>Biodiversity assessment promotes information on the state of an ecosystem. Zooplankton, as a sentinel group at the basis of aquatic food webs, are, thus, an important component to monitor for ecosystem conservation and management. For the first time, we characterized biodiversity of coastal zooplankton along the shallow Northern shoreline of the lower St. Lawrence estuary (LSLE) using an integrated taxonomic and trait-based approach. For 3 years (2019-2021), in July and October, the zooplankton community and environmental parameters were sampled at < 35 m depth. Mesozooplankton were identified at the lowest possible taxonomic level and assigned functional traits. Community structure and diversities revealed high spatio-temporal variations among three different geographic sectors and between seasons, mainly driven by water temperature, Chlorophyll-<i>a</i> concentration and less by salinity. Hotspots of taxonomic and functional diversities occurred in different sectors in the same month, underlining the complementarity of the two approaches. Seasonal shifts in functional diversity hotspots highlight how environmental variability affects biodiversity beyond taxonomic metrics alone. The results of our study in the LSLE establish a first robust baseline to improve our understanding of zooplankton dynamics in the coastal LSLE, to allow future tracking of ongoing change due to the increase of anthropogenic activities and climate changes and to support future monitoring efforts.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 1","pages":"fbae073"},"PeriodicalIF":1.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11781820/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spatio-temporal variability of mesozooplankton distribution along the Canary Current Large Marine Ecosystem: a regional perspective.","authors":"Yassine Goliat, Omar Ettahiri, Tarik Baibai, Nadia Rharbi, Stamatina Isari","doi":"10.1093/plankt/fbae079","DOIUrl":"10.1093/plankt/fbae079","url":null,"abstract":"<p><p>The Canary Current Large Marine Ecosystem (CCLME), extending from Cape Spartel in Morocco to Guinea-Bissau, supports high primary and fisheries productivity driven by permanent or seasonal upwelling activity. During the current study, mesozooplankton and hydrographic sampling were conducted across the CCLME in the spring/summer of 2017 and the autumn/winter of 2019. The total mesozooplankton abundance and dry weight were found to be higher in 2017, partly due to the summer reproduction cycle of diplostracans. A prominent latitudinal gradient was observed in both the mesozooplankton standing stock and assemblage structure closely linked to a significant shift in oceanographic regimes at Cape Blanc (21<sup>°</sup>N). The area south of Cape Blanc, sampled during the upwelling relaxation in both years, was occupied by warmer South Atlantic Central Waters showing elevated mesozooplankton stock with a tropical assemblage structure. In contrast, cooler and more saline waters north of Cape Blanc, a result of the upwelling regime in that area, explained part of the observed variation in mesozooplankton composition among subregions and sampling periods. Our findings indicate that aside from the upwelling activity, spatiotemporal variation of mesoscale processes and topographical features at a subregional level may also shape mesozooplankton stock and assemblage structure in the CCLME.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 1","pages":"fbae079"},"PeriodicalIF":1.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11781819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frédérick Girard, Amélie Garnier, Riley Hughes, Charlie Sarran, Eric Harvey, Beatrix E Beisner
{"title":"Conditions favoring phagotrophy can lead to larger cell sizes in some freshwater mixoplankton.","authors":"Frédérick Girard, Amélie Garnier, Riley Hughes, Charlie Sarran, Eric Harvey, Beatrix E Beisner","doi":"10.1093/plankt/fbae077","DOIUrl":"10.1093/plankt/fbae077","url":null,"abstract":"<p><p>Cell size is a critical regulator of many metabolic processes in protists. We explored whether body size and abundances vary consistently in phytoplankton capable of both autotrophy and heterotrophy (mixoplankton) by manipulating environmental stoichiometric conditions in a mesocosm experiment. We applied two allochthonous subsidy treatments: high C: nutrient ratios (leaves) should favour bacterivory through phagotrophy, while low ratios (insects) should favour autotrophy. We identified three focal mixoplankton taxa, common in our study system and that represented facultative (<i>Cryptomonas</i> sp. and <i>Plagioselmis</i> sp) and more obligate phagotrophs (<i>Ochromonas</i> sp.). <i>Ochromonas</i> was largest in the leaf treatment, which were also associated with larger sizes in <i>Cryptomonas</i> (but not the other cryptophyte). The obligately mixotrophic <i>Ochromonas</i> responded more significantly to conditions favouring phagotrophy than did the facultative phagotrophic cryptophytes. All mixoplankton taxa densities declined with insect subsidies that favour autotrophy. Future research should examine a wider range of mixoplankton under varying ecological conditions.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"47 1","pages":"fbae077"},"PeriodicalIF":1.9,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11781818/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hein Rune Skjoldal, Johanna Myrseth Aarflot, Tor Knutsen, Peter H Wiebe
{"title":"Comparison of WP-2 and MOCNESS plankton samplers for measuring zooplankton biomass in the Barents Sea ecosystem.","authors":"Hein Rune Skjoldal, Johanna Myrseth Aarflot, Tor Knutsen, Peter H Wiebe","doi":"10.1093/plankt/fbae065","DOIUrl":"10.1093/plankt/fbae065","url":null,"abstract":"<p><p>Zooplankton in the Barents Sea has been monitored on an annual autumn survey since the late 1980s, using vertical WP-2 and oblique Multiple Opening and Closing Net and Environmental Sensing System (MOCNESS) tows over the water column. Sampling with MOCNESS is used to describe the vertical distribution and more frequent sampling with WP-2 (~3:1) to describe the horizontal distribution. We use here a large cumulative data set of 874 MOCNESS and 2850 WP-2 stations with data on size-fractioned dry-weight biomass to compare the two zooplankton sampling gears. MOCNESS is consistently collecting more biomass of the large size fraction (>2 mm screen size) by ~20% and less of the small fraction (<1 mm) by ~30% compared to WP-2. This is interpreted to reflect more extrusion of small plankton and less avoidance by larger plankton with the MOCNESS. The data set has been collected by three research vessels. There was a difference in vertical speed in oblique tows of MOCNESS among the ships but no clear effect on volume filtered per unit time. This demonstrates operational consistency and suggests the use of a constant flow factor (distance per flowmeter count) when calculating results over the time series. The issue of calibration of traditional flowmeters on oblique tows needs further examination.</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"46 6","pages":"654-672"},"PeriodicalIF":1.9,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11629780/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142813412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to: Phytoplankton stoichiometry along the salinity gradient under limited nutrient and light supply.","authors":"","doi":"10.1093/plankt/fbae055","DOIUrl":"https://doi.org/10.1093/plankt/fbae055","url":null,"abstract":"<p><p>[This corrects the article DOI: 10.1093/plankt/fbae031.].</p>","PeriodicalId":16800,"journal":{"name":"Journal of Plankton Research","volume":"46 6","pages":"673"},"PeriodicalIF":1.9,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11629779/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142813420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}