scholarly journals Spatio-temporal persistence of zooplankton communities in the Gulf of Alaska

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244960
Author(s):  
Brian A. Hoover ◽  
Marisol García-Reyes ◽  
Sonia D. Batten ◽  
Chelle L. Gentemann ◽  
William J. Sydeman
Keyword(s):  
Cold Water ◽  
Gulf Of Alaska ◽  
Trophic Levels ◽  
Zooplankton Abundance ◽  
Ocean Climate ◽  
Distinct Cluster ◽  
Spatial Structuring ◽  
Ocean Conditions ◽  
Spatio Temporal ◽  
Zooplankton Communities

Spatial structuring of mid-trophic level forage communities in the Gulf of Alaska (GoA) is poorly understood, even though it has clear implications for the health of fisheries and marine wildlife populations. Here, we test the hypothesis that summertime (May-August) mesozooplankton communities are spatially-persistent across years of varying ocean conditions, including during the marine heatwave of 2014–2016. We use spatial ordinations and hierarchical clustering of Continuous Plankton Recorder (CPR) sampling over 17 years (2000–2016) to (1) characterize typical zooplankton communities in different regions of the GoA, and (2) investigate spatial structuring relative to variation in ocean temperatures and circulation. Five regional communities were identified, each representing distinct variation in the abundance of 18 primary zooplankton taxa: a distinct cluster of coastal taxa on the continental shelf north of Vancouver Island; a second cluster in the western GoA associated with strong currents and cold water east of Unimak Pass; a shelf break cluster rich in euphausiids found at both the eastern and western margins of the GoA; a broad offshore cluster of abundant pelagic zooplankton in the southern GoA gyre associated with stable temperature and current conditions; and a final offshore cluster exhibiting low zooplankton abundance concentrated along the northeastern arm of the subarctic gyre where ocean conditions are dominated by eddy activity. When comparing years of anomalous warm and cold sea surface temperatures, we observed change in the spatial structure in coastal communities, but little change (i.e., spatial persistence) in the northwestern GoA basin. Whereas previous studies have shown within-region variability in zooplankton communities in response to ocean climate, we highlight both consistency and change in regional communities, with interannual variability in shelf communities and persistence in community structure offshore. These results suggest greater variability in coastal food webs than in the central portion of the GoA, which may be important to energy exchange from lower to upper trophic levels in the mesoscale biomes of this ecosystem.

scholarly journals A novel design for sampling benthic zooplankton communities in disparate Gulf of Alaska habitats using an autonomous deep-water plankton pump

2020 ◽  
Vol 42 (4) ◽  
pp. 457-466
Author(s):  
Rachel E Wilborn ◽  
Christopher N Rooper ◽  
Pam Goddard ◽  
Kresimir Williams ◽  
Rick Towler
Keyword(s):  
Deep Water ◽  
Cold Water ◽  
Larval Fish ◽  
Low Cost ◽  
Benthic Communities ◽  
Gulf Of Alaska ◽  
Design Parameters ◽  
Benthic Habitat ◽  
Pump Design ◽  
Zooplankton Communities

Abstract Deep-water larval fish and zooplankton utilize structurally complex, cold-water coral and sponge (CWCS) habitats as refuges, nurseries and feeding grounds. Fine-scale sampling of these habitats for larval fish and zooplankton has proven difficult. This study implemented a newly designed, autonomous, noninvasive plankton pump sampler that collected large mesozooplankton within 1 m of the seafloor. It was successfully deployed in the western Gulf of Alaska between the Shumagin Islands (~158°W) and Samalga Pass (−170°W), and collected in situ zooplankton from diverse benthic communities (coral, sponge and bare substrates) at depths in excess of 100 m. Key design parameters of the plankton pump were its ability to be deployed from ships of opportunity, be untethered from the vessel during sampling and be deployed and retrieved in high-relief, rocky areas where CWCS are typically present. The plankton pump remains stationary while collecting from the water column, rests within 1 m of the seafloor and captures images of the surrounding habitat and substrate. This plankton pump design is a low-cost, highly portable solution for assessing the role of benthic habitat in the life cycle of mesozooplankton, a linkage that has been relatively underexplored due to the difficulty in obtaining near-bottom samples.

scholarly journals Features of winter zooplankton assemblage in the Central Trough of the Barents Sea

2018 ◽  
Vol 18 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Vladimir Dvoretskiy ◽  
Alexander Dvoretskiy
Keyword(s):  
Barents Sea ◽  
Cold Water ◽  
Sea Water ◽  
Zooplankton Community ◽  
Trophic Levels ◽  
Zooplankton Abundance ◽  
Total Zooplankton ◽  
Transfer Energy ◽  
Commercial Fish ◽  
The Barents Sea

The Barents Sea is a highly productive shelf region. Zooplankton assemblages are a key component of the carbon cycle in Arctic marine ecosystems; they transfer energy from lower trophic levels to higher levels, including larval and young commercial fish. The winter state of the zooplankton community in the Central Through and their slopes (Barents Sea) was investigated in late November 2010. Vertical structure of water layer was characterised by pycnocline located below 80 m. The upper strata were occupied by transformed Atlantic Water, while winter Barents Sea Water with negative temperatures was in the bottom strata. Total zooplankton abundance varied from 162 to 1214 individuals/m3. Biomass ranged from 88 to 799 mg wet mass/m3. Copepods dominated in terms of total zooplankton abundance (average 99%) and biomass (92%). Maximum densities of Calanusfinmarchicus and Calanusglacialis were registered in the frontal zone separating warm and cold water masses. Abundances of Metridialonga and O.similis were highest in cold waters. Three groups of stations differing in terms of the common copepod composition were delineated with cluster analysis. The age structure of Calanusfinmarchicus and Metridialonga was characterised by a prevalence of copepodites IV–V. Total zooplankton abundance and biomass were correlated to water temperature and salinity, suggesting that hydrological conditions were the key driver of spatial variations of the zooplankton communities. High biomass of large copepods suggests potential significance of the investigated region for feeding of young and adult fish.

Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management

2020 ◽  
Vol 637 ◽  
pp. 117-140 ◽  
Author(s):  
DW McGowan ◽  
ED Goldstein ◽  
ML Arimitsu ◽  
AL Deary ◽  
O Ormseth ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Marine Ecosystem ◽  
Gulf Of Alaska ◽  
Data Series ◽  
Limited Information ◽  
Important Species ◽  
Multiple Data ◽  
Spatial And Temporal Dynamics ◽  
Spawning Areas ◽  
Spatio Temporal

Pacific capelin Mallotus catervarius are planktivorous small pelagic fish that serve an intermediate trophic role in marine food webs. Due to the lack of a directed fishery or monitoring of capelin in the Northeast Pacific, limited information is available on their distribution and abundance, and how spatio-temporal fluctuations in capelin density affect their availability as prey. To provide information on life history, spatial patterns, and population dynamics of capelin in the Gulf of Alaska (GOA), we modeled distributions of spawning habitat and larval dispersal, and synthesized spatially indexed data from multiple independent sources from 1996 to 2016. Potential capelin spawning areas were broadly distributed across the GOA. Models of larval drift show the GOA’s advective circulation patterns disperse capelin larvae over the continental shelf and upper slope, indicating potential connections between spawning areas and observed offshore distributions that are influenced by the location and timing of spawning. Spatial overlap in composite distributions of larval and age-1+ fish was used to identify core areas where capelin consistently occur and concentrate. Capelin primarily occupy shelf waters near the Kodiak Archipelago, and are patchily distributed across the GOA shelf and inshore waters. Interannual variations in abundance along with spatio-temporal differences in density indicate that the availability of capelin to predators and monitoring surveys is highly variable in the GOA. We demonstrate that the limitations of individual data series can be compensated for by integrating multiple data sources to monitor fluctuations in distributions and abundance trends of an ecologically important species across a large marine ecosystem.

scholarly journals Fine-scale structures as spots of increased fish concentration in the open ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alberto Baudena ◽  
Enrico Ser-Giacomi ◽  
Donatella D’Onofrio ◽  
Xavier Capet ◽  
Cedric Cotté ◽  
...  
Keyword(s):  
Coherent Structures ◽  
Trophic Levels ◽  
Fish Distribution ◽  
Lagrangian Coherent Structures ◽  
Mesopelagic Fish ◽  
Fine Scale ◽  
Conservation Policies ◽  
Top Predators ◽  
Frontal Zones ◽  
Spatio Temporal

AbstractOceanic frontal zones have been shown to deeply influence the distribution of primary producers and, at the other extreme of the trophic web, top predators. However, the relationship between these structures and intermediate trophic levels is much more obscure. In this paper we address this knowledge gap by comparing acoustic measurements of mesopelagic fish concentrations to satellite-derived fine-scale Lagrangian Coherent Structures in the Indian sector of the Southern Ocean. First, we demonstrate that higher fish concentrations occur more frequently in correspondence with strong Lagrangian Coherent Structures. Secondly, we illustrate that, while increased fish densities are more likely to be observed over these structures, the presence of a fine-scale feature does not imply a concomitant fish accumulation, as other factors affect fish distribution. Thirdly, we show that, when only chlorophyll-rich waters are considered, front intensity modulates significantly more the local fish concentration. Finally, we discuss a model representing fish movement along Lagrangian features, specifically built for mid-trophic levels. Its results, obtained with realistic parameters, are qualitatively consistent with the observations and the spatio-temporal scales analysed. Overall, these findings may help to integrate intermediate trophic levels in trophic models, which can ultimately support management and conservation policies.

scholarly journals Metabarcoding reveals different zooplankton communities in northern and southern areas of the North Sea

2020 ◽  
Author(s):  
Jan Niklas Macher ◽  
Berry B. van der Hoorn ◽  
Katja T. C. A. Peijnenburg ◽  
Lodewijk van Walraven ◽  
Willem Renema
Keyword(s):  
North Sea ◽  
Zooplankton Community ◽  
Taxonomic Diversity ◽  
Molecular Techniques ◽  
Trophic Levels ◽  
List Type ◽  
The North ◽  
Shelf Sea ◽  
The North Sea ◽  
Zooplankton Communities

AbstractZooplankton are key players in marine ecosystems, linking primary production to higher trophic levels. The high abundance and high taxonomic diversity renders zooplankton ideal for biodiversity monitoring. However, taxonomic identification of the zooplankton assemblage is challenging due to its high diversity, subtle morphological differences and the presence of many meroplanktonic species, especially in coastal seas. Molecular techniques such as metabarcoding can help with rapid processing and identification of taxa in complex samples, and are therefore promising tools for identifying zooplankton communities. In this study, we applied metabarcoding of the mitochondrial cytochrome c oxidase I gene to zooplankton samples collected along a latitudinal transect in the North Sea, a shelf sea of the Atlantic Ocean. Northern regions of the North Sea are influenced by inflow of oceanic Atlantic waters, whereas the southern parts are characterised by more coastal waters. Our metabarcoding results indicated strong differences in zooplankton community composition between northern and southern areas of the North Sea, particularly in the classes Copepoda, Actinopterygii (ray-finned fishes) and Polychaeta. We compared these results to the known distributions of species reported in previous studies, and by comparing the abundance of copepods to data obtained from the Continuous Plankton Recorder (CPR). We found that our metabarcoding results are mostly congruent with the reported distribution and abundance patterns of zooplankton species in the North Sea. Our results highlight the power of metabarcoding to rapidly assess complex zooplankton samples, and we suggest that the technique could be used in future monitoring campaigns and biodiversity assessments.HighlightsZooplankton communities are different in northern and southern areas of the North SeaMetabarcoding results are consistent with known species distributions and abundanceMetabarcoding allows for fast identification of meroplanktonic species

scholarly journals Dead zone or oasis in the open ocean? Zooplankton distribution and migration in low-oxygen modewater eddies

2016 ◽  
Vol 13 (6) ◽  
pp. 1977-1989 ◽  
Author(s):  
Helena Hauss ◽  
Svenja Christiansen ◽  
Florian Schütte ◽  
Rainer Kiko ◽  
Miryam Edvam Lima ◽  
...  
Keyword(s):  
Surface Layer ◽  
Dead Zone ◽  
Trophic Levels ◽  
Zooplankton Abundance ◽  
Depth Range ◽  
Calanoid Copepods ◽  
Long Term Effects ◽  
Low Oxygen ◽  
Oxygen Concentrations ◽  
Ocean Deoxygenation

Abstract. The eastern tropical North Atlantic (ETNA) features a mesopelagic oxygen minimum zone (OMZ) at approximately 300–600 m depth. Here, oxygen concentrations rarely fall below 40 µmol O2 kg−1, but are expected to decline under future projections of global warming. The recent discovery of mesoscale eddies that harbour a shallow suboxic (< 5 µmol O2 kg−1) OMZ just below the mixed layer could serve to identify zooplankton groups that may be negatively or positively affected by ongoing ocean deoxygenation. In spring 2014, a detailed survey of a suboxic anticyclonic modewater eddy (ACME) was carried out near the Cape Verde Ocean Observatory (CVOO), combining acoustic and optical profiling methods with stratified multinet hauls and hydrography. The multinet data revealed that the eddy was characterized by an approximately 1.5-fold increase in total area-integrated zooplankton abundance. At nighttime, when a large proportion of acoustic scatterers is ascending into the upper 150 m, a drastic reduction in mean volume backscattering (Sv) at 75 kHz (shipboard acoustic Doppler current profiler, ADCP) within the shallow OMZ of the eddy was evident compared to the nighttime distribution outside the eddy. Acoustic scatterers avoided the depth range between approximately 85 to 120 m, where oxygen concentrations were lower than approximately 20 µmol O2 kg−1, indicating habitat compression to the oxygenated surface layer. This observation is confirmed by time series observations of a moored ADCP (upward looking, 300 kHz) during an ACME transit at the CVOO mooring in 2010. Nevertheless, part of the diurnal vertical migration (DVM) from the surface layer to the mesopelagic continued through the shallow OMZ. Based upon vertically stratified multinet hauls, Underwater Vision Profiler (UVP5) and ADCP data, four strategies followed by zooplankton in response to in response to the eddy OMZ have been identified: (i) shallow OMZ avoidance and compression at the surface (e.g. most calanoid copepods, euphausiids); (ii) migration to the shallow OMZ core during daytime, but paying O2 debt at the surface at nighttime (e.g. siphonophores, Oncaea spp., eucalanoid copepods); (iii) residing in the shallow OMZ day and night (e.g. ostracods, polychaetes); and (iv) DVM through the shallow OMZ from deeper oxygenated depths to the surface and back. For strategy (i), (ii) and (iv), compression of the habitable volume in the surface may increase prey–predator encounter rates, rendering zooplankton and micronekton more vulnerable to predation and potentially making the eddy surface a foraging hotspot for higher trophic levels. With respect to long-term effects of ocean deoxygenation, we expect avoidance of the mesopelagic OMZ to set in if oxygen levels decline below approximately 20 µmol O2 kg−1. This may result in a positive feedback on the OMZ oxygen consumption rates, since zooplankton and micronekton respiration within the OMZ as well as active flux of dissolved and particulate organic matter into the OMZ will decline.

Environmental drivers of a decline in a coastal zooplankton community

2021 ◽  
Author(s):  
Seòna R Wells ◽  
Eileen Bresnan ◽  
Kathryn Cook ◽  
Dafne Eerkes-Medrano ◽  
Margarita Machairopoulou ◽  
...  
Keyword(s):  
Zooplankton Community ◽  
Water Masses ◽  
Environmental Drivers ◽  
High Temporal Resolution ◽  
Monitoring Site ◽  
Zooplankton Abundance ◽  
Offshore Water ◽  
Additive Mixed Models ◽  
Zooplankton Communities

Abstract Major changes in North Atlantic zooplankton communities in recent decades have been linked to climate change but the roles of environmental drivers are often complex. High temporal resolution data is required to disentangle the natural seasonal drivers from additional sources of variability in highly heterogeneous marine systems. Here, physical and plankton abundance data spanning 2003–2017 from a weekly long-term monitoring site on the west coast of Scotland were used to investigate the cause of an increasing decline to approximately -80± 5% in annual average total zooplankton abundance from 2011 to 2017. Generalized additive mixed models (GAMMs), with an autoregressive correlation structure, were used to examine seasonal and inter-annual trends in zooplankton abundance and their relationship with environmental variables. Substantial declines were detected across all dominant taxa, with ∼ 30–70% of the declines in abundance explained by a concurrent negative trend in salinity, alongside the seasonal cycle, with the additional significance of food availability found for some taxa. Temperature was found to drive seasonal variation but not the long-term trends in the zooplankton community. The reduction in salinity had the largest effect on several important taxa. Salinity changes could partly be explained by locally higher freshwater run-off driven by precipitation as well as potential links to changes in offshore water masses. The results highlight that changes in salinity, caused by either freshwater input (expected from climate predictions) or fresher offshore water masses, may adversely impact coastal zooplankton communities and the predators that depend on them.

scholarly journals Ice-on and ice-off dynamics of ciliates and metazooplankton in the Łuczański Canal (Poland)

2020 ◽  
Vol 54 (4) ◽  
pp. 1121-1134
Author(s):  
Krystyna Kalinowska ◽  
Maciej Karpowicz
Keyword(s):  
Field Experiments ◽  
Cold Water ◽  
Ice Cover ◽  
Zooplankton Biomass ◽  
Zooplankton Grazing ◽  
Top Down ◽  
Cover Time ◽  
Trophic Coupling ◽  
Cold Water Temperature ◽  
Zooplankton Communities

Abstract The ciliate–metazooplankton trophic coupling is well documented from both laboratory and field experiments. The knowledge about these relationships during winter ice-covered periods is very scarce. The abundance and composition of planktonic ciliates, rotifers and crustaceans were studied during the ice-covered and ice-free periods in the Łuczański Canal (Masurian Lakeland, Poland). We hypothesised that in winter, rotifers play a major role in the top-down control of ciliates and that ciliate–metazooplankton relationships differ not only between the ice-covered and ice-free periods, but also between ice-covered months. Our study showed that ciliates formed a significant part of zooplankton biomass during the winter ice-covered period when crustaceans occurred in very low abundances. Despite cold water temperature and the presence of ice cover, time was probably a cue that initiates zooplankton development. The ciliate, rotifer and crustacean numbers and biomass, as well as chlorophyll a concentrations, were lower in February than in ice-free periods. In the winter month with ice cover, bottom-up control by resources was more important than top-down control by zooplankton grazing in regulating ciliates. In the spring month with ice cover, crustaceans and rotifers may include ciliates as an important part of their diets. In April, the studied groups of organisms were not related to each other in contrast to the summer, when zooplankton communities were closely related to each other. In autumn, rotifers may play an important role in controlling ciliates. The abundance, composition and ciliate–metazoan relationships can vary considerably not only across seasons, but also across ice-covered months.

scholarly journals Spatially mismatched trophic dynamics: cyclically outbreaking geometrids and their larval parasitoids

2010 ◽  
Vol 6 (4) ◽  
pp. 566-569 ◽  
Author(s):  
Snorre B. Hagen ◽  
Jane U. Jepsen ◽  
Tino Schott ◽  
Rolf A. Ims
Keyword(s):  
Trophic Interactions ◽  
Travelling Waves ◽  
Methodological Approach ◽  
Spatial Dynamics ◽  
Population Cycles ◽  
Trophic Levels ◽  
Trophic Dynamics ◽  
Spatial Mismatch ◽  
Larval Parasitoids ◽  
Spatio Temporal

For trophic interactions to generate population cycles and complex spatio-temporal patterns, like travelling waves, the spatial dynamics must be matched across trophic levels. Here, we propose a spatial methodological approach for detecting such spatial match–mismatch and apply it to geometrid moths and their larval parasitoids in northern Norway, where outbreak cycles and travelling waves occur. We found clear evidence of spatial mismatch, suggesting that the spatially patterned moth cycles in this system are probably ruled by trophic interactions involving other agents than larval parasitoids.

Ocean climate variability links incubation behaviour and fitness in Ancient Murrelets (Synthliboramphus antiquus)

2012 ◽  
Vol 90 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Akiko Shoji ◽  
Motomi Yoneda ◽  
Anthony J. Gaston
Keyword(s):  
Large Scale ◽  
Individual Species ◽  
Haida Gwaii ◽  
Ocean Climate ◽  
Breeding Behaviour ◽  
The North ◽  
Incubation Behaviour ◽  
Ocean Conditions ◽  
Shift Length

Large-scale interannual and decadal variation in ocean conditions, including sea-surface temperature (SST) has been shown to affect the breeding behaviour of marine birds in the North Pacific. However, as individual species respond differently to changing food supplies, our understanding of the role of climate variation in seabirds is limited. To examine the effect of ocean conditions on breeding behaviour, we measured incubation shift lengths of Ancient Murrelet ( Synthliboramphus antiquus (Gmelin, 1789)), a small marine bird with exceptionally long incubation shift length, in seven, nonconsecutive years. We compared variation in shift length with interyear variation in regional SST. Incubation shifts were longer in years when March–May SST was higher. In years with longer shift length, birds have lower reproductive success. Our results suggested that Ancient Murrelets on Haida Gwaii can adjust their incubation patterns by extending their shift length in relation to SST fluctuations during breeding season.

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