Abstract:
Zooplankton are important grazers of primary production and play a
central role in the transfer of energy from primary producers to higher order
consumers. Zooplankton are sensitive to environmental variability, making them
useful indicators of climate change; importantly, their physiology is strongly
coupled to temperature, they exhibit generally short life cycles and they are
excluded from most pressures associated with commercial fishing. However,
given the diversity of organisms found in the pelagic environment the responses
of different groups of zooplankton to environmental variability are most likely
different. In this study I have investigated the bloom dynamics and trophic
ecology of dominant thaliaceans in Storm Bay: two species of salp (Thalia
democratica and Salpa fusiformis) and two species of doliolid (Dolioletta sp. and
Doliolum sp .). Storm Bay is a region of dynamic oceanography that is influenced
by (i} warm, low nutrient waters from the East Australian Current in the summer,
(ii) cooler, nutrient-rich subantarctic waters in the winter, (iii) the Leeuwin
(Zeehan) Current flowing along the west coast and (iv) flows from the Derwent
Estuary. Key challenges in this study included the fragility of the gelatinous
zooplankton, their unpredictable presence in Storm Bay and the absence of
doliolids during certain years.
