Phytoplankton composition and biomass under oligotrophic conditions in the Guaymas Basin (Gulf of California)

Main Article Content

Eduardo Millán-Nuñez
Francisco Delgadillo-Hinojosa
Cristian Hakspiel-Segura
Eunise Vanessa Torres-Delgado
Armando Félix-Bermúdez
José Antonio Segovia-Zavala
Víctor Froylán Camacho-Ibar
Albino Munoz-Barbosa


In order to determine the structure and biomass of phytoplankton (picophytoplankton, nanodiatoms, and microdiatoms) under oligotrophic conditions, a study was carried out in the surface layer of the Guaymas Basin, Gulf of California, during the late summer of 2016. This study included the measurement of hydrographic, chemical, and biological variables in the surface layer of the study area. Our results showed a warm, strongly stratified, and nutrient-depleted water column associated with reduced phytoplankton biomass (<1 mg Chla·m–3). The average ratios of N:P (0.55 ± 1.34), N:Si (0.13 ± 0.18), and Fe:N (52.70 ± 29.70) indicate N-limiting conditions. The biomass contribution of phytoplankton groups fluctuated widely by depth level, with predominance of picophytoplankton (85.0 ± 2.7%) at the surface (5 m) and nano-microdiatoms (91.5 ± 5.9%) at the deepest level (35–40 m), adjacent to the thermocline. Diatoms dominated the integrated biomass between the surface and 50-m depth, with an average contribution ~6 times greater than that of picophytoplankton. Despite the ideal conditions for the proliferation of diazotrophs, the presence of Trichodesmium spp. and Richelia intracellularis was very irregular and in relatively low abundances (2,220 ± 1,575 cell·L–1). Our results are especially relevant as they suggest that, under N-limiting conditions, the paradigm of high biomass and large cell dominance in the Gulf of California may be challenged during the summer season.


Download data is not yet available.

Article Details

How to Cite
Millán-Nuñez, E., Delgadillo-Hinojosa, F., Hakspiel-Segura, C., Torres-Delgado, E. V., Félix-Bermúdez, A., Segovia-Zavala, J. A., … Munoz-Barbosa, A. (2023). Phytoplankton composition and biomass under oligotrophic conditions in the Guaymas Basin (Gulf of California). Ciencias Marinas, 49.



Álvarez-Borrego S, Lara-Lara JR. 1991. The physical environment and primary productivity of the Gulf of California. In: Dauphin JP, Simoneit BRT (eds.), The Gulf and Penninsular Province of the Californias. AAPG Memoir 47. McLean (VA): GSW. p. 555-567. DOI:

Bruland KW, Rue EL, Smith GJ. 2001. Iron and macronutrients in California coastal upwelling regimes: implications for diatoms blooms. Limnol Oceanogr. 46(7):1661-1674. DOI:

Chisholm SW. 1992. Phytoplankton size. In: Falkowski PG, Woodhead AD (eds.), Primary Productivity and Biogeochemical Cycles in the Sea. New York (NY): Plenum Press. p. 213-237. DOI:

Cullen JJ. 2015. Subsurface chlorophyll maximum layers: enduring enigma or mystery solved? Annu Rev Mar Sci. 7:207–239. DOI:

Delgadillo-Hinojosa F, Segovia-Zavala JA, Huerta-Diaz MA, Atilano-Silva H. 2006. Influence of geochemical and physical processes on the vertical distribution of manganese in the Gulf of California waters. Deep Sea Res Part I. 53(8):1301-1319. DOI:

Dutkiewicz S, Ward BA, Monteiro F, Follows MJ. 2012. Interconnection of nitrogen fixers and iron in the Pacific Ocean: Theory and numerical simulations. Global Biogeochem Cycles. 26(1):GB1012. DOI:

Edler L. 1979. Recommendations for marine biological studies in the Baltic Sea: Phytoplankton and chlorophyll. Baltic Mar Biol. 5:1-38.

Falkowski PG. 1997. Evolution of the nitrogen cycle and its influence on biological sequestration of CO2 in the oceans. Nature. 387:272-275. DOI:

Félix-Bermúdez A, Delgadillo-Hinojosa F, Torres-Delgado EV, Muñoz-Barbosa A. 2020. Does sea surface temperature affect solubility of iron in mineral dust? The Gulf of California as a case study. J Geophys Res Oceans. 125(9):e2019JC015999. DOI:

Gómez F. 2013. Reinstatement of the dinoflagellate genus Tripos to replace Neoceratium, marine species of Ceratium (Dinophyceae, Alveolata). CICIMAR Oceánides. 28(1):1-22. DOI:

Gordon LI, Jennings JC Jr, Ross AA, Krest JM. 1993. A Suggested protocol for continuous flow automated analysis of seawater nutrients (phosphate, nitrate, nitrite and silicic acid) in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study. WOCE Hydrographic Program Office, Methods Manual WHPO: Oregon State University College of Oceanography. p. 91-100.

Hasle GR. 1978. Using the inverted microscope. In: Sournia A (ed.), Phytoplankton Manual. Paris (France): UNESCO. p. 191-196.

Hernández-Becerril DU. 1987. Vertical distribution of phytoplankton in the central and northern part of the Gulf of California (June 1982). Mar Ecol. 8(3):237-251. DOI:

Jeffrey SW, Humphrey GF. 1975. New spectrophotometric equations for determination chlorophylls a, b, c1 and c2 in higher plants, algae and natural phytoplankton. Biochem Physiol Pflanz. 167(2):191-194. DOI:

Karl DM, Lukas R. 1996. The Hawaii Ocean Time-series (HOT) program: Background, rationale and field implementation. Deep-Sea Res., Part A. 43(2-3):129-156. DOI:

Klausmeier CA, Litchman E. 2001. Algal games: The vertical distribution of phytoplankton in poorly mixed water columns. Limnol Oceanogr. 46(8):1998-2007. DOI:

Latasa M, Cabello AM, Morán XAG, Massana R, Scharek R. 2017. Distribution of phytoplankton groups within the deep chlorophyll maximum. Limnol Oceanogr. 62(2):665-685. DOI:

Lavín MF, Gaxiola-Castro G, Robles JM, Richter K. 1995. Winter water masses and nutrients in the northern Gulf of California. J Geophys Res. 100(C5):8587-8605. DOI:

Maciel-Baltazar E, Hernández-Becerril DU. 2013. Especies de dinoflagelados atecados (Dinophyta) de la costa de Chiapas, sur del Pacífico mexicano = Species of athecate dinoflagellates (Dinophyta) from coasts of Chiapas, southern Mexican Pacific. Rev Biol Mar Oceanogr. 48(2):245-259. DOI:

MacIsaac EA, Stockner JG. 1993. Enumeration of phototrophic picoplankton by autofluorescence microscopy. In: Kemp PF, Sherr BF, Sherr EB, Cole JJ (eds.), Handbook of Methods in Aquatic Microbial Ecology, 1st ed. Boca Raton (FL): CRC Press. p. 187-198. DOI:

Miranda-Alvarez C, González-Silvera A, Santamaría-del-Angel E, López-Calderón J, Godínez VM, Sánchez-Velasco L, Hernández-Walls R. 2020. Phytoplankton pigments and community structure in the northeastern tropical Pacific using HPLC-CHEMTAX analysis. J Oceanogr. 76:91-108. DOI:

Moore LR, Chisholm SW. 1999. Photophysiology of the marine cyanobacterium Prochlorococcus: ecotypic differences among cultured isolates. Limnol Oceanogr. 44(3):628-638. DOI:

Ong LJ, Glazer AN. 1991. Phycoerythrins of marine unicellular cyanobacteria. I. Bilin types and locations and energy transfer pathways in Synechococcus spp. phycoerythrins. J Biol Chem. 266(15):9515-9527. DOI:

Raven JA, Finkel ZV, Irwin AJ. 2005. Picophytoplankton: bottom-up and top down controls on ecology and evolution. Vie et Milieu. 55(3–4):209-215. Robles JM, Marinone SG. 1987. Seasonal and interannual thermohaline variability in the Guaymas Basin of the Gulf of California. Cont Shelf Res. 7(7):715-733. DOI:

Reynolds CS. 1991. Functional morphology and adaptative strategies of freshwater phytoplankton. In: Sandgren C (ed.), Growth and Reproductive Strategies of Freshwater Phytoplankton. Cambridge (MA): Cambridge University Press. p. 388-426. Reynolds CS, Huszar V, Kruk C, Naselli-Flores L, Melo S. 2002. Towards a functional classification of the freshwater phytoplankton. J Plankton Res. 24(5):417428. DOI:

Segovia-Zavala JA, Lares ML, Delgadillo-Hinojosa F, Tovar-Sánchez A, Sañudo-Wilhelmy SA. 2010. Dissolved iron distributions in the central region of the Gulf of California, México. Deep-Sea Res Part I. 57(1):53-64. DOI:

Strathmann RR. 1967. Estimating the organic carbon content of phytoplankton from cell volumen or plasma. Limnol Oceanogr. 12(3):411-418. DOI:

Taylor AG, Landry MR. 2018. Phytoplankton biomass and size structure across trophic gradients in the southern California Current and adjacent ocean ecosystems. Mar Ecol Prog Ser. 592:1-17. DOI:

Torres-Delgado EV, Delgadillo-Hinojosa F, Camacho-Ibar VF, Huerta-Díaz MA, Segovia-Zavala JA, Hernández-Ayón JM, Galindo-Bect S. 2013. Wintertime enrichment of inorganic nutrients in the Ballenas Channel, Gulf of California = Enriquecimiento invernal de nutrientes inorgánicos en el canal de Ballenas, golfo de California. Cienc Mar. 39(2):165-182. DOI:

Valdez-Holguín JE, Álvarez-Borrego S, Trees CC. 1999. Seasonal and spatial characterization of the Gulf of California phytoplankton photosynthetic parameters = Caracterización estacional y espacial de los parámetros fotosintéticos del fitoplacton del golfo de California. Cienc Mar. 25(4):445-467. DOI:

Verity PG, Robertson CY, Tronzo CR, Andrews MG, Nelson JR, Sieracki ME. 1992. Relationships between cell volume and the carbon and nitrogen content of marine photosynthetic nanoplankton. Limnol Oceanogr. 37(7):1434-1446. DOI:

White AE, Prahl FG, Letelier RM, Popp BN. 2007. Summer surface waters in the Gulf of California: Prime habitat for biological N2 fixation. Global Biogeochem Cy. 21(2):GB2017. DOI:

White AE, Foster RA, Benitez-Nelson CR, Masqué P, Verdeny E, Popp BN, Arthur KE, Prahl FG. 2013. Nitrogen fixation in the Gulf of California and the Eastern Tropical North Pacific. Prog Oceanogr. 109:1-17. DOI: