Zooplankton of Wellington Harbour, New Zealand
July
July
Sea surface temperatures range between 10°C. and 11°C. but slightly lower temperatures are occasionally recorded. Vast numbers of Obelia geniculata medusae and Pleurobrachia pileus still persist and may comprise over 90% of the volume page 24 of one litre or more in some samples. The majority of samples produce a volume of between 50cc and 100cc of plankton. Phialella quadrata was very common in July samples of 1963, but was absent in July of 1961 and 1962. The first evidence of the spring increase in the zooplankton appears in mid-July. Fish eggs are very abundant and fish larvae are now common. As in June Copepoda are abundant. Of the decapods, 18 species are found in July, but these are represented mainly by a few first stage larvae occurring towards the end of the month.