Why Do Phytoplankton Evolve Large Size in Response to Grazing?

Branco, Pedro; Egas, Martijn; Hall, Spencer R.; Huisman, Jef

doi:10.1086/706251

Cited by 27 publications

(29 citation statements)

References 101 publications

(145 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, one of the key differences between our lab experiments and natural waters is that we eliminated the zooplankton community. Hence, our findings support the common idea that size‐dependent grazing by zooplankton plays an important role in the persistence of large phytoplankton species in natural waters (Steiner , Fuchs and Franks ; Branco et al., in press ).…”

Section: Discussionsupporting

confidence: 90%

Stable coexistence of equivalent nutrient competitors through niche differentiation in the light spectrum

Burson

Stomp

Mekkes

et al. 2019

Ecology

Self Cite

View full text Add to dashboard Cite

Niche-based theories and the neutral theory of biodiversity differ in their predictions of how the species composition of natural communities will respond to changes in nutrient availability. This is an issue of major environmental relevance, as many ecosystems have experienced changes in nitrogen (N) and phosphorus (P) due to anthropogenic manipulation of nutrient loading. To understand how changes in N and P limitation may impact community structure, we conducted laboratory competition experiments using a multispecies phytoplankton community sampled from the North Sea. Results showed that picocyanobacteria (Cyanobium sp.) won the competition under N limitation, while picocyanobacteria and nonmotile nanophytoplankton (Nannochloropsis sp.) coexisted at equal abundances under P limitation. Additional experiments using isolated monocultures confirmed that Cyanobium sp. depleted N to lower levels than Nannochloropsis sp., but that both species had nearly identical P requirements, suggesting a potential for neutral coexistence under P-limited conditions. Pairwise competition experiments with the two isolates seemed to support the consistency of these results, but P limitation resulted in stable species coexistence irrespective of the initial conditions rather than the random drift of species abundances predicted by neutral theory. Comparison of the light absorption spectra indicates that coexistence of the two species was stabilized through differential use of the underwater light spectrum. Our results provide an interesting experimental example of modern coexistence theory, where species were equal competitors in one niche dimension but their competitive traits differed in other niche dimensions, thus enabling stable species coexistence on a single limiting nutrient through niche differentiation in the light spectrum.

show abstract

Section: Discussionsupporting

confidence: 90%

Stable coexistence of equivalent nutrient competitors through niche differentiation in the light spectrum

Burson

Stomp

Mekkes

et al. 2019

Ecology

Self Cite

View full text Add to dashboard Cite

show abstract

“…These allelopathic effects can be enhanced by warming ( Felpeto et al, 2019 ) and nutrient-limited conditions ( Fistarol et al, 2005 ). Also, warmer environments and/or low (or limiting) nutrient availability can lead to increased phytoplankton carbon:nutrient stoichiometry, i.e., seston with reduced nutritional quality ( De Senerpont Domis et al, 2014 ), which constitutes an effective defense mechanism against herbivore predators ( Branco et al, 2020 ), and could help explain inverse relationship between temperature and grazing pressure found in temperate, tropical open-ocean and polar coastal ecosystems. A negative relationship between temperature and g :μ may have also arisen from a decrease in microzooplankton biomass with increasing temperature.…”

Section: Discussionmentioning

confidence: 99%

Geographical and Seasonal Thermal Sensitivity of Grazing Pressure by Microzooplankton in Contrasting Marine Ecosystems

Cabrerizo

Marañón

2021

Front. Microbiol.

View full text Add to dashboard Cite

Grazing pressure, estimated as the ratio between microzooplankton grazing and phytoplankton growth rates (g:μ), is a strong determinant of microbial food-web structure and element cycling in the upper ocean. It is generally accepted that g is more sensitive to temperature than μ, but it remains unknown how the thermal dependence (activation energy, Ea) of g:μ varies over spatial and temporal scales. To tackle this uncertainty, we used an extensive literature analysis obtaining 751 paired rate estimates of μ and g from dilution experiments performed throughout the world’s marine environments. On a geographical scale, we found a stimulatory effect of temperature in polar open-ocean (∼0.5 eV) and tropical coastal (∼0.2 eV) regions, and an inhibitory one in the remaining biomes (values between −0.1 and −0.4 eV). On a seasonal scale, the temperature effect on g:μ ratios was stimulatory, particularly in polar environments; however, the large variability existing between estimates resulted in non-significant differences among biomes. We observed that increases in nitrate availability stimulated the temperature dependence of grazing pressure (i.e., led to more positive Ea of g:μ) in open-ocean ecosystems and inhibited it in coastal ones, particularly in polar environments. The percentage of primary production grazed by microzooplankton (∼56%) was similar in all regions. Our results suggest that warming of surface ocean waters could exert a highly variable impact, in terms of both magnitude and direction (stimulation or inhibition), on microzooplankton grazing pressure in different ocean regions.

show abstract

“…The shift in cell size may be related to the pulsed uptake of resources during winter months just prior to the development of the spring bloom that favor small cells relative to larger celled phytoplankton (Lin et al, 2020). As systems become more oligotrophic there tends to be a shift to dominance by picophytoplankton that produces a size-dependent change in food quality associated with low grazing pressure (Branco et al, 2020). For example, it is well known that important secondary producers in the NES, such as Calanus finmarchicus and other large copepods, do not graze on cells less than 10 µm (Marshall and Orr, 1955;Frost, 1972;Bundy et al, 1998).…”

Section: Discussionmentioning

confidence: 99%

Changing Physical Conditions and Lower and Upper Trophic Level Responses on the US Northeast Shelf

et al. 2020

View full text Add to dashboard Cite

Sea surface temperature (SST), salinity, and chlorophyll concentration (CHL) have changed in the US Northeast Shelf ecosystem over recent decades. The changes in these parameters were distinctly marked by change points around the year 2012 resulting in a 0.83 • C increase in SST, a 0.3 PSU increase in salinity, and decrease in CHL in excess of 0.4 mg m −3. Where temperature and salinity shifted in mean level around their respective change points, CHL declined in a more monotonic fashion. Modeled data suggest that the shift in CHL resulted in a greater contribution of picoand nanophytoplankton and a decreased contribution of microphytoplankton to overall CHL. Complementary estimates of the contribution of different phytoplankton functional types suggest a diminished contribution of diatoms to the phytoplankton community. Hence, not only is there evidence of a decline in the overall primary production capacity of the ecosystem, but also evidence of a fundamental change in the size and quality of phytoplankton supporting food webs. Two ecosystem responses to the observed changes in SST, salinity, and CHL were analyzed. Both length and weight at age have declined for a number of species, and both measures of growth appear to be negatively associated with temperature and positively associated with CHL. Biomass of fish and macroinvertebrates has declined in recent years, with a decrease in pelagic species associated with a decrease in CHL, while the decline in demersal species was associated with an increase in temperature. Collectively, these ecosystem changes appear to be the result of the complex interactions of both thermal effects and changes at the base of the food web.

show abstract

Why Do Phytoplankton Evolve Large Size in Response to Grazing?

Cited by 27 publications

References 101 publications

Stable coexistence of equivalent nutrient competitors through niche differentiation in the light spectrum

Stable coexistence of equivalent nutrient competitors through niche differentiation in the light spectrum

Geographical and Seasonal Thermal Sensitivity of Grazing Pressure by Microzooplankton in Contrasting Marine Ecosystems

Changing Physical Conditions and Lower and Upper Trophic Level Responses on the US Northeast Shelf

Contact Info

Product

Resources

About