Community Gradients in the Scotian Shelf Zooplankton

1983 ◽  
Vol 40 (5) ◽  
pp. 598-611 ◽  
Author(s):  
M. John Tremblay ◽  
John C. Roff
Keyword(s):  
Prey Species ◽  
Group Analysis ◽  
Zooplankton Community ◽  
Calanus Finmarchicus ◽  
Reciprocal Averaging ◽  
Scotian Shelf ◽  
Recurrent Group ◽  
Core Species ◽  
Oithona Similis ◽  
Hydrographic Conditions

The structure of the zooplankton community of the Scotian Shelf was investigated during eight cruises between August 1978 and September 1980. An inshore–offshore community gradient correlated with temperature, salinity, and distance to shore was the strongest pattern revealed by reciprocal averaging. Zooplankton taxa were grouped as inshore (characterized by Arctic species), intermediate (the dominant shelf species), or offshore (expatriate species) on the basis of reciprocal averaging results and correlations with environmental variables. Recurrent group analysis revealed a pattern consistent with that of reciprocal averaging. A shelf recurrent group was always present, dominated by the "core" species: Calanus finmarchicus, Metridia lucens, Pseudocalanus minutus, Oithona similis, and Limacina retroversa; related shelf edge/slope groups were also present. Substantial differences between cruises were apparent in both reciprocal averaging and recurrent group analysis results and appeared to be related to aperiodic changes in hydrographic conditions. Aperiodic incursions of slope water may represent an energy supplement (as nutrients or zooplankton prey species) or an energy loss if expatriate species exploit the shelf community.

Recurrent groups of zooplankton in the Bay of Fundy and southwest Nova Scotia regions, Canada

1987 ◽  
Vol 65 (10) ◽  
pp. 2400-2405 ◽  
Author(s):  
S. Corey ◽  
W. R. Milne
Keyword(s):  
Nova Scotia ◽  
Group Analysis ◽  
The Other ◽  
Calanus Finmarchicus ◽  
Bay Of Fundy ◽  
Recurrent Group ◽  
Annual Basis ◽  
Core Species ◽  
Zooplankton Communities ◽  
Nova Scotian

Recurrent group analysis of the Bay of Fundy and southwest Nova Scotia regions on 40 species of zooplankton were compared on a seasonal and annual basis. One major recurrent group occurred per region. Six and five core species occurred in the Bay of Fundy and southwest Nova Scotian waters, respectively. Of these core species, Sagitta elegans, Calanus finmarchicus, and Metridia lucens were common to both areas. The interconnection of the Bay of Fundy and southwest Nova Scotia zooplankton communities is relatively strong (75% of core species for either area occurred in the other area in three of the four surveys). All core species were endemic and boreal.

scholarly journals Contribution of Calanus species to the mesozooplankton biomass in the Barents Sea

2017 ◽  
Vol 75 (7) ◽  
pp. 2342-2354 ◽  
Author(s):  
Johanna Myrseth Aarflot ◽  
Hein Rune Skjoldal ◽  
Padmini Dalpadado ◽  
Mette Skern-Mauritzen
Keyword(s):  
Barents Sea ◽  
Zooplankton Community ◽  
Zooplankton Biomass ◽  
Calanus Finmarchicus ◽  
The Arctic ◽  
Arctic Water ◽  
Mesozooplankton Biomass ◽  
The Barents Sea ◽  
Main Driver ◽  
Calanus Species

Abstract Copepods from the genus Calanus are crucial prey for fish, seabirds and mammals in the Nordic and Barents Sea ecosystems. The objective of this study is to determine the contribution of Calanus species to the mesozooplankton biomass in the Barents Sea. We analyse an extensive dataset of Calanus finmarchicus, Calanus glacialis, and Calanus hyperboreus, collected at various research surveys over a 30-year period. Our results show that the Calanus species are a main driver of variation in the mesozooplankton biomass in the Barents Sea, and constitutes around 80% of the total. The proportion of Calanus decreases at low zooplankton biomass, possibly due to a combination of advective processes (low C. finmarchicus in winter) and size selective foraging. Though the Calanus species co-occur in most regions, C. glacialis dominates in the Arctic water masses, while C. finmarchicus dominates in Atlantic waters. The larger C. hyperboreus has considerably lower biomass in the Barents Sea than the other Calanus species. Stages CIV and CV have the largest contribution to Calanus species biomass, whereas stages CI-CIII have an overall low impact on the biomass. In the western area of the Barents Sea, we observe indications of an ongoing borealization of the zooplankton community, with a decreasing proportion of the Arctic C. glacialis over the past 20 years. Atlantic C. finmarchicus have increased during the same period.

Generation Lengths of Some Temperate Marine Copepods: Estimation, Prediction, and Implications

1978 ◽  
Vol 35 (10) ◽  
pp. 1330-1342 ◽  
Author(s):  
I. A. McLaren
Keyword(s):  
Community Dynamics ◽  
Laboratory Data ◽  
Temperature Response ◽  
Life Cycles ◽  
Calanus Finmarchicus ◽  
Published Data ◽  
Temperature Function ◽  
Oithona Similis ◽  
Single Temperature ◽  
Marine Copepods

Only copepodids should be used to trace synchronous cohorts from relative abundance of stages, and only long-lived adults correctly signal new generations from size changes. From extensive published data from Loch Striven, Scotland, life cycles are thus detailed for Pseudocalanus minutus, Microcalanus pygmaeus, Calanus finmarchicus, Centropages hamatus, Temora longicomis, Acartia clausi, and Oithona similis. Generation lengths are also estimated for all but M. pygmaeus from temperatures in nature and from laboratory data on food-satiated development. For stage durations (D) at various temperatures (T), Bělehrádek's temperature function D = a(T − α)−b is used. Temperature response can be about the same throughout a species range. With b fixed, α within a species can be the same for older stages as for embryonic duration, which can thus be used to estimate a for generation length even from a laboratory example at a single temperature. If food-satiated durations are available only for some stages, it can be assumed that other stages are similar (isochronal development). Food-satiated generation lengths predicted thus from the laboratory match those inferred from the Loch Striven samples. Trophic studies may be less revealing than further work on the "intrinsic" determinants of copepod performance. Competition for food should not be assumed in studies of niches and community dynamics of marine copepods. Key words: Copepoda, generation lengths, cohorts, body sizes, prediction, temperature, production, life cycles

Seasonal and spatial distribution of mesozooplankton in a tropical estuary, Nha Phu, South Central Viet Nam

Biologia ◽  
2014 ◽  
Vol 69 (1) ◽  
Author(s):  
Trinh Truong ◽  
Cho Nguyen ◽  
Nguyen-Ngoc Lam ◽  
K. Jensen
Keyword(s):  
Annual Variation ◽  
Zooplankton Community ◽  
The Other ◽  
Viet Nam ◽  
Tropical Estuary ◽  
Zooplankton Species ◽  
South Central ◽  
Stable Conditions ◽  
Hydrographic Conditions ◽  
Euterpina Acutifrons

AbstractThis study provides a description of mesozooplankton (holo- and meroplankton) abundance, biomass and diversity patterns inside and outside a tropical estuary (Nha Phu Estuary, Khanh Hoa, Viet Nam). In total 185 zooplankton species have been recorded during the study period (2009–2010), copepods contribute with the largest share of species (more than 100), Tunicata with 20, Cnidaria with 17 and Chaetognatha with 9 species. At the most species rich site the number of zooplankton species varies between 55 and 123. The number of species and the annual variation in numbers declines towards the head of the estuary (14–37 species). In contrast, the highest numbers of individuals occur in the inner part of NPE. Calanoids that are the most abundant group of the copepods occur in densities up to 28.2 ind. L−1 (Aug. 9). At ‘Outer NPE’ and ‘Outside NPE’ the maximum density of calanoids is 5.8 and 10.7 ind. L−1, respectively. The declining diversity of zooplankton towards the head of the estuary is also supported by various indices (Shannon’s index, Margalef’s index). A cluster analysis on similarity of species supports a clustering of the inner NPE sites vs the other sites. There is a general separation between the dominant copepod species in the inner (Bestiola sp., Acartia pacifica, Pseudodiaptomus incisus) and outer (Paracalanus gracilis, Acrocalanus gibber, Subeucalanus subcrassus, Oithona rigida, Corycaeus andrewsi, Oithona plumifera) part of the estuary though a few species are common in both areas (Paracalanus crassirostris and Euterpina acutifrons). The zooplankton community at the inner NPE is subjected to more variable hydrographic conditions (salinity in particular) than the communities at the other sites where more stable conditions prevail. A short residence time in the inner part of the estuary due to the tide is supposed to impede a strong horizontal structuring of the zooplankton community.

scholarly journals Feeding of Calanus finmarchicus and Oithona similis on the microplankton assemblage in the Irminger Sea, North Atlantic

2008 ◽  
Vol 30 (10) ◽  
pp. 1095-1116 ◽  
Author(s):  
C. Castellani ◽  
X. Irigoien ◽  
D. J. Mayor ◽  
R. P. Harris ◽  
D. Wilson
Keyword(s):  
North Atlantic ◽  
Calanus Finmarchicus ◽  
Oithona Similis ◽  
Irminger Sea

Zooplankton assemblages and hydrography in the spawning area of anchovy (Engraulis anchoita) off Río de la Plata estuary (Argentina - Uruguay)

2002 ◽  
Vol 53 (6) ◽  
pp. 1031 ◽  
Author(s):  
María Delia Viñas ◽  
Rubén M. Negri ◽  
Fernando C. Ramírez ◽  
Daniel Hernández
Keyword(s):  
Size Structure ◽  
Zooplankton Community ◽  
Buenos Aires Province ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
La Plata ◽  
Oithona Similis ◽  
First Feeding ◽  
Plankton Biomass ◽  
Positive Correlations

The massive spawning of anchovy (Engraulis anchoita) in Argentine waters takes place in spring in the coastal sector off the Buenos Aires Province, with the highest concentrations of spawners occurring in front of the Río de la Plata mouth. In October 1995, the size structure, composition and abundance of the zooplankton community was analyzed and related to the hydrography and the abundance of anchovy eggs. Oceanographic conditions were different from the recorded means for the season. A higher proportion of the colder and more saline shelf waters were present in the coastal area and strong haloclines were not observed. High values of plankton biomass were observed in the estuarine frontal area and in the weakly stratified waters of the median shelf. The cluster analysis of the stations gave rise to the formation of coastal (CA), transitional (TA) and shelf (SA) faunistic areas. Mesozooplankton smaller than 1 mm total length (TL) dominated the whole area. The copepods, Paracalanus spp. and Oithona similis, and the cladocerans, Evadne nordmanni and Podon spp., constituted the bulk of this mesozooplankton fraction. Oithona similis was the dominant species in the SA. The copepod, Acartia tonsa (1–2 mm TL), was extremely abundant in the estuarine front (more than 17 600 individuals m–3) followed by appendicularians, members of Pseudocalanidae, anchovy eggs and decapod larvae. Species of Calanidae (Calanoides carinatus and Calanus simillimus), the amphipod hyperiid, Themisto gaudichaudii, and the euphausiid, Euphausia lucens, largely dominated the macrozooplankton (>2 mm TL) in the TA and SA. In the CA, significant positive correlations between the abundance of small copepods (size ranges <1 and 1–2 mm) and anchovy eggs were found. Trophic implications of these findings for first-feeding anchovy larvae were discussed. The adequacy of the TA and SA as feeding ground for adults of anchovy was evaluated.

The distribution of right whales and Zooplankton in the Bay of Fundy, Canada

1989 ◽  
Vol 67 (6) ◽  
pp. 1411-1420 ◽  
Author(s):  
L. D. Murison ◽  
D. E. Gaskin
Keyword(s):  
Gulf Of Maine ◽  
Calanus Finmarchicus ◽  
Eubalaena Glacialis ◽  
Bay Of Fundy ◽  
Scotian Shelf ◽  
Transition Zones ◽  
Right Whale ◽  
Right Whales ◽  
Two Peaks ◽  
Copepod Biomass

Temperature, salinity, density of Zooplankton patches, and the abundance of right whales (Eubalaena glacialis glacialis) were measured concurrently during summer and autumn of 1983 and 1984 over the Grand Manan Basin, outer Bay of Fundy. Right whales appeared to exploit patches of copepods at densities greater than about 820/m3 (170 mg m−3). Patches were composed primarily of stage V Calanus finmarchicus at depths ≥ 100 m during daylight hours. Patch densities were similar in 1983 and 1984. Potential right whale feeding areas increased in extent from late July to October, with at least two peaks of copepod biomass occurring in 1984. Right whales appear to exploit euphausiid patches in the bay only incidentally; the whales departed in 1984 when euphausiid biomass was at a maximum. The topography of the basin, prevailing summer currents, and orientation of transition zones from mixed to stratified water all combine to facilitate accumulation of copepods from the Scotian Shelf and Gulf of Maine in the central lower Bay of Fundy. This area provides an important feeding ground for this stenophagous whale species.

scholarly journals Diets of herring, mackerel, and blue whiting in the Norwegian Sea in relation to Calanus finmarchicus distribution and temperature conditions

2006 ◽  
Vol 63 (1) ◽  
pp. 117-127 ◽  
Author(s):  
Irina Prokopchuk ◽  
Evgeniy Sentyabov
Keyword(s):  
Stomach Content ◽  
Diet Composition ◽  
Pelagic Fish ◽  
Calanus Finmarchicus ◽  
Norwegian Sea ◽  
Main Prey ◽  
Blue Whiting ◽  
Important Prey ◽  
Hydrographic Conditions ◽  
Feeding Area

Abstract Diets of Norwegian spring-spawning herring, mackerel, and blue whiting in the Norwegian Sea are investigated in relation to the distribution of plankton and hydrographic conditions. Fish stomachs and zooplankton samples were collected during summer (June and July) cruises in 2001 and 2002. Calanus finmarchicus was the principal prey of mackerel, accounting for 53–98% of total stomach content by weight. The diet composition of herring varied depending on feeding area and availability of food under various environmental conditions. C. finmarchicus was important prey for herring only in July 2001 (about 77% by weight) in the central part of the sea and in June 2002 (about 82% by weight) near the Lofotens. In July 2002 appendicularians (Oikopleura spp.), amphipods (mainly Parathemisto abissorum), and euphausiids were important in the diet of herring, and at some stations cannibalism was observed. The main prey of blue whiting were amphipods (10–34% by weight), appendicularians (11–34%), and euphausiids (8–47%), as they usually feed deep in the water column, though C. finmarchicus was important, particularly in June 2002, when blue whiting were caught in the upper layers of the sea. Higher water temperatures indirectly affect pelagic fish through accelerated development of their prey and favourable conditions for migration farther north.

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