The filamentous green alga Chaetomorpha ligustica (Cladophoraceae, Cladophorales) was recorded covering seagrass meadows at Pāuatahanui Inlet, New Zealand. Species of the genus Chaetomorpha are difficult to identify by their morphologically, and the identification of C. ligustica was confirmed by sequencing the 28S rRNA large subunit providing a high level of confidence in the species designation. In November 2019, we found C....

Seagrass Zostera muelleri has been reported to reproduce mainly asexually in New Zealand. However, a recent study in Tauranga Harbour suggested that flowering might occur more often than previously thought. Here we provide evidence of intertidal seagrass flowering events in six New Zealand estuaries in which it has not before been documented. Further research on seagrass sexual reproduction is desirable as we hypothesise that...

Phosphorus (P) release from sediments accumulating since catchment deforestation, has been linked to algal blooms which have occurred in Lake Wairewa (Canterbury, NZ) for over a century. However, the mechanisms controlling this internal P loading are poorly understood. To address this issue, we investigated sediment P fractions, P release, dissolved oxygen (DO) and pH at the sediment–water interface, and undertook targeted wat...

A field study of Lessonia variegata growing in depths of 8–10 m on the south coast of Wellington, New Zealand investigated morphometric and biomass indices measured on destructively harvested entire algae, rates of blade elongation measured in situ using a blade hole punch technique, and timing of fertility over a 2‐year period. Blade fertility was estimated using a fertility score based on the visual appearance of the reprodu...

The ultraviolet (UV) sensitivity of five species of freshwater zooplankton (three Cladocera, two Copepoda) were investigated. The animals were exposed to varying levels of UV‐radiation in a sunshine‐simulator and the UV doses for 10 and 50% mortality (LD 10 , LD 50 ) were estimated using a dose‐response model. To place these doses in context they were compared with modelled clear‐sky surface UV irradiances in New Zealand. The...

Water column integrated productivity of phytoplankton in three water masses east of New Zealand (Subtropical, Subtropical Convergence, and Subantarctic) varied both seasonally and spatially, ranging across two orders of magnitude. Productivity was highest in spring and autumn, and lowest in winter. Subtropical and Convergence waters were generally more productive than Subantarctic waters, but during summer the 2–3‐fold range o...

Lake Coleridge is a deep monomictic lake in the Southern Alps of New Zealand which is affected by strong adiabatic winds. It receives significant inputs of inorganic suspended solids from rivers diverted into the lake for hydro‐electric generation. External inputs of wind energy and suspended solids to Lake Coleridge were quantified throughout 1 year and their impacts on hydrodynamics and the light climate were analysed. Durin...

The relationship between photosynthesis (P) and light (E) was determined for phytoplankton from the mixed layer and the deep chlorophyll maximum (DCM) at 23 stations off the east coast of New Zealand during February‐March 1995. The stations encompassed three water masses, Sub‐tropical, Sub‐antarctic and the Sub‐tropical Convergence Zone. The light‐saturated rate of photosynthesis (P max ) and slope of the light‐limited portion...