Phytoplankton microscopic observations from the FjordPhyto Citizen Science Project of the 2016-2017 Antarctic season

Study Extent

Samples were taken along the western Antarctic Peninsula during a first survey in February – March 2016 in Neko Harbor and the austral spring-summer 2016-2017, from November to February.

Sampling

Phytoplankton sampling was carried out in the frame of a Citizen Science project, FjordPhyto (www.fjordphyto.org). The samples were collected during Antarctic cruises operated by two tourism companies, G Adventures and Polar Latitudes, both members of the International Association of Antarctic Tour Operators (IAATO). Microscopy samples (120-ml surface seawater fixed in Lugol) were collected from surface waters from an inflatable boat (e.g., a Zodiac) along the Antarctic Peninsula. For further description you can refer to: Mascioni, M., Almandoz, G.O., Cefarelli, A.O., Cusick, A., Ferrario, M.E. and Vernet, M., 2019. Phytoplankton composition and bloom formation in unexplored nearshore waters of the western Antarctic Peninsula. Polar Biology, 42(10), pp.1859-1872. Cusick, A.M., Gilmore, R., Bombosch, A., Mascioni, M., Almandoz, G.O. and Vernet, M., 2020. Polar tourism as an effective research tool. Oceanography, 33(1), pp.50-61.

Quality Control

The quality control of the sampling was carried out by comparing samples taken by citizen scientists and samples taken by scientists on board the cruise ships.

Method steps

1. 1. Microscopy counts For phytoplankton identification, abundance, and carbon biomass estimates by microscopy, surface seawater (0–1 m depth) was collected and preserved by filling pre-rinsed amber HDPE bottles (120 mL) and adding a Lugol’s solution (4% final concentration; Edler and Elbrachter, 2010), which is a less toxic preservation option that stains more fragile organisms. Samples were kept in a cool, dark place until the end of the season, when they were offloaded and sent to Universidad Nacional de La Plata, Argentina, for researchers to analyze (Mascioni et al., 2019, 2023). Cell counts were performed according to Utermöhl (1958) using an inverted optical microscope Leica DMIL LED. Subsamples of 50 mL were left to settle for 24hs in a composite sedimentation chamber. At least 100 cells of the dominant taxa were counted at the maximum amplification (400X) (Lund et al. 1958). The whole chamber bottom was also scanned at 200X to count large and sparse species. The measurement error is <10% with 400 cells counted per sample. Organism abundances are provided in concentrations of cells/liter.
2. 2. Phytoplankton identification During cell counts taxa were mostly identified down to the genus level and in some cases to the level of large groups (e.g., family, order), within which organisms were classified by size. Cell dimensions were measured by using an ocular micrometer. In such cases, closer observation of the samples with specific techniques or electron microscopy allowed the identification of taxa to the genus level and in some cases to the species level. Identification of organisms was carried out by consulting general literature relevant to marine plankton and in particular Antarctica or specific literature where particular taxa are described.

N/A

1. Cosconodiscaceae
   rank: family
2. Cocconeidaceae
   rank: family
3. Cryptista
   rank: phylum
4. Suessiaceae
   rank: family
5. Pyramimonadaceae
   rank: family
6. Dinophyceae
   rank: class
7. Fragilariaceae
   rank: family
8. Eupodiscales
   rank: order
9. Corethraceae
   rank: family
10. Naviculales
    rank: order
11. Chromista
    rank: kingdom
12. Gonyaulacales
    rank: order
13. Coscinodiscophyceae
    rank: class
14. Prorocentrales
    rank: order
15. Bacillariales
    rank: order
16. Dictyochaceae
    rank: family
17. Plantae
    rank: kingdom
18. Haptophyta
    rank: phylum
19. Phaeocystaceae
    rank: family
20. Bacillariophyceae familia incertae sedis
    rank: family
21. Naviculaceae
    rank: family
22. Oxytoxaceae
    rank: family
23. Aphanizomenonaceae
    rank: family
24. Cryptophyceae
    rank: class
25. Thalassionematales
    rank: order
26. Gymnodiniales
    rank: order
27. Pyramimonadophyceae
    rank: class
28. Cyanobacteria
    rank: phylum
29. Protozoa
    rank: kingdom
30. Achnanthales
    rank: order
31. Thalassionemataceae
    rank: family
32. Dinoflagellata
    rank: phylum
33. Pyramimonadales
    rank: order
34. Coscinodiscales
    rank: order
35. Fragilariales
    rank: order
36. Dictyochales
    rank: order
37. Peridiniales familia incertae sedis
    rank: family
38. Eubacteria
    rank: kingdom
39. Oscillatoriales
    rank: order
40. Suessiales
    rank: order
41. Attheyaceae
    rank: family
42. Prorocentraceae
    rank: family
43. Achnanthaceae
    rank: family
44. Pleurosigmataceae
    rank: family
45. Thalassiosirales
    rank: order
46. Licmophoraceae
    rank: family
47. Coccolithophyceae
    rank: class
48. Gyrodiniaceae
    rank: family
49. Bacillariophyceae ordo incertae sedis
    rank: order
50. Peridiniales
    rank: order
51. Oscillatoriaceae
    rank: family
52. Chaetocerotales
    rank: order
53. Protoperidiniaceae
    rank: family
54. Chlorophyta
    rank: phylum
55. Warnowiaceae
    rank: family
56. Dictyochophyceae
    rank: class
57. Biddulphiales
    rank: order
58. Phaeocystales
    rank: order
59. Corethrales
    rank: order
60. Tovelliaceae
    rank: family
61. Bacillariophyceae
    rank: class
62. Plagiotropidaceae
    rank: family
63. Heterocapsaceae
    rank: family
64. Odontellaceae
    rank: family
65. Bacillariophyceae incertae sedis
    rank: class
66. Probosciales
    rank: order
67. Heterokontophyta
    rank: phylum
68. Mediophyceae
    rank: class
69. Chaetocerotaceae
    rank: family
70. Bacillariaceae
    rank: family
71. Nostocales
    rank: order
72. Cyanophyceae
    rank: class
73. Licmophorales
    rank: order
74. Probosciaceae
    rank: family

Samples were taken at numerous locations along the western Antarctic Peninsula between Mikkelsen Harbour (63°S) and Hanusse Bay (near 67°S).