Temporal variability in total, micro- and nano-phytoplankton primary production at a coastal site in the Western English Channel

Barnes, Morvan K.; Tilstone, Gavin H.; Suggett, David J.; Widdicombe, Claire E.; Bruun, John; Martinez‐Vicente, Victor; Smyth, Tim

doi:10.1016/j.pocean.2015.04.017

Cited by 32 publications

(28 citation statements)

References 84 publications

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“…A similar seasonal pattern of Chl a and PP has been observed in the temperate Western English Channel (Xie et al, ), Danish waters (Jakobsen & Markager, ; Lyngsgaard et al, ), and the Cantabrian Sea (Calvo‐Díaz et al, ). In the Western English Channel, although the Chl a concentrations are high in the spring, PP during the spring bloom is limited by the low Chl a ‐normalized production rate of Phaeocystis sp., a reflection of the low temperatures at that time of year (Barnes et al, ; Xie et al, ). Lyngsgaard et al () have reported Chl a concentrations in the Baltic Sea transition zone during the spring are higher than at other times of year, whereas C and PP are much lower in spring than in summer.…”

Section: Discussionmentioning

confidence: 99%

Uncoupling of Seasonal Variations Between Phytoplankton Chlorophyll a and Production in the East China Sea

et al. 2019

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Phytoplankton chlorophyll a (Chla), primary production (PP), and nutrient uptake rates are fundamental and important parameters in marine biogeochemical studies. However, the relationships between them are associated with much uncertainty that reflects gaps in basic understanding of ecosystem dynamic. In this study, we simultaneously measured PP and nitrate assimilation (NA) along with estimated concentrations of nutrients, particulate organic carbon concentrations, phytoplankton Chla, pigments, and carbon biomass in the dynamic shelf ecosystems of the East China Sea (ECS) on four cruises during different seasons. There were large spatial gradients of these parameters, and seasonal patterns of phytoplankton Chla and PP varied between water masses. The results of this study and previous work indicated that seasonal variations of Chla and PP were similar in coastal waters but opposite in off‐shelf waters. During summer in off‐shelf waters, there were patches of high PP and NA associated with low Chla concentrations; this pattern was reversed in the winter. We suggest that there is a global tendency for PP and Chla patterns to be out of phase. This asynchrony is reflected mainly in the seasonal variations of C:Chla ratios driven by the combined influences of light, temperature, and nutrients. Stronger grazing pressure by microzooplankton in summer likely contributed to the high production but low biomass in the ECS. The significant correlation between PP and NA suggested that variations of PP in the ECS were driven largely by nitrate uptake, which may be inhibited by high ammonium concentrations in the Changjiang River plume.

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Section: Discussionmentioning

confidence: 99%

Uncoupling of Seasonal Variations Between Phytoplankton Chlorophyll a and Production in the East China Sea

et al. 2019

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“…The physical and biological systems at L4 are strongly influenced by the annual cyclic motion of the Earth and by decadal processes (Smyth et al, 2014). DFSA is a highly accurate and efficient estimation signal analysis approach designed to resolve these cyclic Earth-system processes (Smyth et al, 2014;Barnes et al, 2015;Tarran and Bruun, 2015;Bruun et al, 2017). Here, DFSA was used to construct a predictive dynamic model of the seasonal and decadal properties of how the Oithona spp.…”

Section: Dominant Frequency State Analysismentioning

confidence: 99%

Resilience of the Copepod Oithona similis to Climatic Variability: Egg Production, Mortality, and Vertical Habitat Partitioning

et al. 2020

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There has been an overall decline in copepod populations across the North Atlantic over the past few decades. Reasons for these declines are unclear, and several major species, including the cyclopoid copepod Oithona similis, have maintained stable populations at station L4 in the western English Channel. To identify the factors contributing to this stability, we conducted a 1-year intensive study of O. similis at L4 over 2017-2018, a period of high climatic variability. For context, dominant frequency state analysis was applied to the 30-year L4 time series to derive the baseline dynamics of the Oithona spp. population. The Oithona spp. baseline demonstrated stable densities and a bimodal annual cycle. These dynamics, as well as those of reproductive output and phaenological timings, were upheld in 2017-2018, indicating resilience to climatic variability. During 2017-2018, all life stages of O. similis were relatively scarce in the top 2 m of the water column, despite the presence of abundant food. Naupliar stages occurred predominantly around 10 m depth, with subsequent life stages progressively deeper. We suggest this vertical structuring may represent different trade-offs between feeding and mortality risk between ontogenetic stages. To determine the traits that contribute to population stability, we compare O. similis with the large, biomass-dominant copepod, Calanus helgolandicus. Despite having contrasting functional traits, both species have exhibited strong population stability over the time series. Our results provide evidence that mortality plays a major role in maintaining population dynamics.

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“…However, K. mikimotoi biomass was relatively low during 2010 and, despite the bloom contributing a far lower percentage of the total annual carbon fixation than for 2009, the bloom coincided with the maximum observed daily water column production for 2010. By utilising the absorption-based production model of Barnes et al (2014Barnes et al ( , 2015 produced a longer time-series of production at L4 from 2003 to 2010. In half of those years (2003, 2004, 2005 and 2009), a peak in surface production over 100 mg C m À3 d…”

Section: Effects and Significance Of K Mikimotoimentioning

confidence: 99%

Drivers and effects of Karenia mikimotoi blooms in the western English Channel

Barnes

Tilstone

Smyth

et al. 2015

Progress in Oceanography

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Temporal variability in total, micro- and nano-phytoplankton primary production at a coastal site in the Western English Channel

Cited by 32 publications

References 84 publications

Uncoupling of Seasonal Variations Between Phytoplankton Chlorophyll a and Production in the East China Sea

Uncoupling of Seasonal Variations Between Phytoplankton Chlorophyll a and Production in the East China Sea

Resilience of the Copepod Oithona similis to Climatic Variability: Egg Production, Mortality, and Vertical Habitat Partitioning

Drivers and effects of Karenia mikimotoi blooms in the western English Channel

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