TANE 24, 1978 RECORDS OF MARINE ALGAE FROM THE LEIGH AREA PART III: PHYTOPLANKTON FROM THE WHANG ATE AU HARBOUR by F.J. Taylor and E.G. Durbin* Marine Research Laboratory, University of Auckland, R.D., Leigh (•Present address: Graduate School of Oceanography, University of Rhode Island, Kingston, Rhode Island, U.S.A.) SUMMARY Sixty-eight taxa of phytoplankton identified mainly from quantitative counts made between September, 1967 and May, 1969 are listed with details of their occurrences. INTRODUCTION The Whangateau Harbour is a shallow tidal estuary situated on the north-western side of the Hauraki Gulf, 75km north-west of Auckland. It has been formed by the post-Pleistocene building up of the Tawharanui Peninsula in the south, leaving only a narrow entrance at Ti Point. The harbour lies on partly consolidated sands and muds, with Zostera flats, expanding mangrove areas, and large areas of bare sand. About 98% of the water leaves the harbour between high tide and low tide on the spring tides. This creates an interesting flushing habitat for the plankton, which will be discussed fully elsewhere. One of us (F.J.T.) began taking quantitative phytoplankton samples in the entrance channel in September, 1967. The other (E.G.D.) took over the sampling in March, 1968 and continued until May, 1969. During this latter period four stations were sampled: Station 1 was outside the Harbour in Omaha Bay: Station 2 was in the entrance channel; and Stations 3 and 4 further inside the Harbour. Integrated samples of the water column were taken by a hose-pipe and no net hauls were taken. Consequently the species list is confined to those species present at a concentration greater than 103 cells F1. Relatively little attention was paid to the micro-flagellates, which accounts for the paucity of these records. The nomenclature follows Taylor (1970, 1974a, 1974b). Where more recent name changes have been made the name used in Taylor (he. cit.) has been included in brackets. Some of the identifications made in Durbin (1969) have been corrected or amplified. The genera are listed in alphabetical order within the class, and the species in alphabetical order within the genus. Some of the records have already been published in Taylor (Joe. cit). 219 EUGLENOPHYCEAE Eutreptiella marina da Cunha - Occasional in November and December, 1967. CHRYSOPHYCEAE Dictyocha fibula Ehrenb. sax. fibula - Only recorded in December, 1967. HAPTOPHYCEAE Emiliana huxleyi (Lohm.) Hay & Mohler - Abundant from November to December, 1967 and September to November, 1968 at all stations. BACILLARIOPHYCEAE Amphora lineolata Ehrenb. var. sinensis (A. Schmidt) Cleve - Irregular in low numbers from April to December. Asteromphalus flabellatus (de Brcb) Grev. - Only recorded in August, 1968. Bellerochea malleus (Brightw.) van Heurck f. malleus - Occasional throughout the year. Biddulphia mobiliensis (Bail.) Grun. ex van Heurck - Infrequent in low numbers, but reached 6.3 x 103 cells P in February, 1969 at Station 1. Not recorded at Stations 3 and 4. B. sinensis Grev. — More frequently seen than the preceding species, and found inside the harbour at Station 3 and 4. Chaetoceros compressum Lauder - Only one record: 6.3 x 103 cells T1 at Station 1 on 27 April, 1968. C. curvisetum Cleve - Only one record: 27.2 cells T1 at Station 1 on 1 April, 1968. New record for New Zealand. C. danicum Cleve — Occasional throughout the year, but never in large numbers. C. decipiens Cleve - Frequent in April-May and September, 1968. C. eibenii (Grun.) Meun. ex van Heurck - Only recorded once, 8.4 x 103 cells f at Station 2. C. gracile Schiitt - Frequent from July-October, 1968. New record for New Zealand. C, lorenzianum Grun. - Common from March to May 1968, extending to Station 3 and reaching a maximum concentration of 20.9 x 10 cells T1. C. simile Cleve - Frequent from September to November, 1968 at Stations 1 and 2, but most abundant at 1. C. teres Cleve - Only recorded at Station 2, September, 1967. Coscinodiscus oculus-iridis Ehrenb. - Rarely recorded in August and September. C. wailesii Gran & Angst. - Recorded in April, 1968 and February, 1969, at Stations 1,2 and 3. Cylindrotheca closterium (Ehrenb.) Reiman & Lcwin - Common at all stations from September to May. Dactyliosolen mediterraneus Perag. - Common from September, 1968 to April, 1969, reaching a maximum of 18.9 cells T1, and extending through to Station 4. Diploneis bombus (Ehrenb.) Cleve var. bombus — Low numbers from August to April. Ditylum brightwellii (T. West) Grun. ex van Heurck - Irregular in appearance. Eucampia zoodiacus Ehrenb. - Irregular in appearance, but common when it occurred. Guinardia flaccida (Castr.) Perag. - Only recorded in January and May, 1968. Hemialus hauckii Grun. ex van Heurck - Only recorded once, in March, 1969, but at concentrations of 8.4 — 12.6 x 103 cells 1 . H. sinensis Grev. - Frequent in November and December, 1968. Lauderia borealis Gran - Common from January-July, extending to Station 3. Leptocylindrus danicus Cleve — Common to abundant from September to May, but absent in the winter months. A small form approaching L. minimus was common in November, 1968. Navicula lyra Ehrenb. var. lyra - A littoral species, in nearly every sample, with numbers usually higher at Stations 3 and 4. Nitzschia longissima (de Breb. ex Kiitz.) Ralfs in Pritch - Only recorded once, in April, 1968. N. pseudoseriata Hasle. - Common throughout the year. 220 N. pungens Grun - Only recorded in October, 1967. Paralia sulcata (Ehrenb) Cleve Frequent from March to June, occasional at other times of the year. Phaeodactylon tricornutum Bohl. - Common at all stations throughout the year. Pleurosigma formosum W. Sm. - Irregular throughout the year in low numbers. Podosira stelliger (Bail.) Mann - Frequent to common from September to January, but only at Stations 1 and 2. A concentration of 105 x 103 cells 1 ' was recorded on 22 September, 1968. Pyxidicula cruciata Ehrenb. - Only recorded in November, 1967. Rhizosolenia alata Brightw. f. alata - Frequent in December and January occasional at other times of the year. R. delicatula Cleve - Common from August to May. Associated with Leptocylindrus danicus, and extending to Station 4. R. hebetata Bail. f. semispina (Hensen) Gran - Occasional, September, 1968 - January, 1969. R. imbricata Brightw. var. shrubsolei (Cleve) Schroder - Only recorded in March, 1968, when it was present up to 31.4 x 103 cells f1. R. stolterfothii Perag. - Only recorded in January, 1968. Skeletonema costatum (Grev.) Cleve - Abundant from February to April, 1969, extending through to Station 3. Stauroneis membranacea (Cleve) Hust. - Occasional from October to April. Stephanopyxis turns (Grev. & Arnott) Ralfs. - Only recorded twice, at Station 2 on 22 September, 1967, and at Station 1 on 14 July, 1968, at a concentration of 14.7 \ 103 cells T1. Synedra fulgens (Grev.) W. Sm. - Only recorded in December 1967. Thalassionema nitzschioides (Grun.) Hust. - Only recorded in February and April, but common when it occurred. Thalassiosira eccentricus (Ehrenb.) Cleve (Cosinidiscus eccentricus Ehrenb.) - Occasional throughout the year. T. decipiens (Grun) J«irg - Only recorded in November, 1967. T. hyalina (Grun.) - Common from February to May; irregular throughout the winter. T. rotula Meun. - Only record 90.1 x 103 cells f1 at Station 2 in November, 1967. Thalassiothrix frauenfeldii Grun. - Only recorded in April, 1969. CRYPTOPHYCEAE Rhodomonas baltica Karsten - Only recorded in January, 1968. DINOPHYCEAE Amphidinium sp. 1 - Only seen on 4 December, 1967, the same date as it was found at Goat Island Bay. Ceratium furca (Ehrenb.) Clap. & Lackm. var. furca — Occasional throughout the year, extending to Station 4. C. fusus (Ehrenb.) Dujard. var. fusus - Common from December, 1968 to April 1969, not found at any other time. C. horridum (Cleve) Gran var. horridum — December, 1968 only. C. horridum (Cleve) Gran var. buceros (Zach.) Sournia - Only seen in September and October, 1967. C. tripos (O. F. Mull) Nitzsch var. tripos - September, 1968 only. Cochlodinium sp. - November, 1967 only. The same species as recorded from Goat Island Bay. Dinophysis fortii Pav. - only seen in March and May, 1968. Exuviella marina Cienk. - Only seen in September and October, 1967. Gonyaulax polyedra Stein - Abundant in July and August at all stations. Maximum concentration 67 x 103 cells 1 1 at Station 1. Gymnodinium simplex (Lohm.) Kof. & Swezy - Frequent from October to April at all stations. 221 Peridinium steinii J^rg. - Occasional, especially from May to July, 1968. P. spp. - Unidentified species were found at irregular intervals. Prorocentrum micans Ehrenb. - Only recorded in November and December, 1967. Pyrocystis lunula (Schiitt) - Only seen in March, 1968. REFERENCES Durbin, E.G. 1969: Phytoplankton ecology and productivity in the Whangateau Harbour. MSc Thesis, Auckland University. 175pp. Taylor, F.J. 1970: A preliminary annotated check list of diatoms from New Zealand coastal waters. Transaction!: of the Royal Society of New Zealand, Biological Sciences 12: 154-174. Taylor, F.J. 1974a: A preliminary annotated check list of dinoflagellates, from New Zealand coastal waters. Journal of the Royal Society of New Zealand 4: 193-202. Taylor, F.J. 1974b: A preliminary annotated check list of micro-algae other than diatoms and dinoflagellates from New Zealand coastal waters. Journal of the Royal Society of New Zealand 4: 395-400. 222 .