Mass mortality of a dominant kelp (Laminariales) at Goat Island, north-eastern New Zealand

1996 ◽  
Vol 47 (7) ◽  
pp. 907 ◽  
Author(s):  
RG Cole ◽  
RC Babcock
Keyword(s):  
New Zealand ◽  
Marine Reserve ◽  
Kelp Forest ◽  
Austral Summer ◽  
Mass Mortality ◽  
Ecklonia Radiata ◽  
Rocky Reefs ◽  
North Eastern ◽  
Mass Mortalities

In north-eastern New Zealand, monospecific stands of the laminarian Ecklonia radiata occupy rocky reefs at depths below 10 m on exposed shores. In the austral summer of 1992-93, mass mortalities of populations of E. radiata in the Cape Rodney to Okakari Point Marine Reserve near Leigh were recorded, in which 40-100% of the sporophytes at depths greater than 10 m died. Mortality was gradual, beginning with erosion of the laminae and ultimately progressing to the stipes, which eventually decayed. The mortality was first evident in the deepest plants and culminated in the elimination of large areas of kelp forest. The event was not associated with any previously reported mortality agents. Investigations of the effects of the mortality on other organisms are continuing.

Survival and behaviour of juvenile red rock lobster, Jasus edwardsii, on rocky reefs with varying predation pressure and habitat complexity

2008 ◽  
Vol 59 (3) ◽  
pp. 246 ◽  
Author(s):  
K. A. S. Mislan ◽  
Russ C. Babcock
Keyword(s):  
New Zealand ◽  
Kelp Forest ◽  
Predatory Fish ◽  
Rocky Reef ◽  
Rocky Reefs ◽  
Jasus Edwardsii ◽  
Fish Predators ◽  
Two Factors ◽  
Direct And Indirect Impacts ◽  
Indirect Impacts

The role of large predatory fish in coastal communities is generally unknown because of overfishing. In order to understand the direct and indirect impacts of these increased population sizes on coastal food chains, the effect of areas with more fish predators on the survival and behaviour of potential prey was assessed. Juvenile lobsters, Jasus edwardsii (10–20 mm carapace length), were tethered on rocky reefs inside and outside marine reserves in northeastern New Zealand to assess survival under differing predator densities. Since rocky reef habitats in northeastern New Zealand include zones of kelp forest and barren reef, a two-way factorial design was used to determine the effects of predators, habitat, and the interaction of these two factors on juvenile lobster survival. Overall, the results indicated that neither varying large fish density nor varying kelp density had direct impacts on the survival rate of juvenile lobsters. Laboratory manipulations demonstrated behavioural changes by juvenile lobsters such that when a large predatory fish was present, juvenile lobsters spent significantly less time moving, even when separated from the predator by a porous barrier. Thus areas with more fish predators may increase juvenile lobster survival but potentially at the cost of reduced feeding opportunities.

Effect of UVB Irradiation on Cu2+-Binding Organic Ligands and Cu2+ Speciation in Alpine Lake Waters of New Zealand

2005 ◽  
Vol 2 (1) ◽  
pp. 56 ◽  
Author(s):  
Sylvia Sander ◽  
Jonathan P. Kim ◽  
Barry Anderson ◽  
Keith A. Hunter
Keyword(s):  
New Zealand ◽  
Surface Waters ◽  
Natural Waters ◽  
Austral Summer ◽  
Organic Ligands ◽  
Conditional Stability ◽  
Uvb Radiation ◽  
Dissolved Metals ◽  
Conditional Stability Constant ◽  
Uvb Irradiation

Environmental Context. The bioavailability of dissolved metals in natural waters is directly affected by metal-sequestering agents. These agents include soil-derived matter and compounds released by microorganisms, since copper can support or inhibit aquatic microorganisms depending on concentration. During summer the levels of copper increase in surface waters, an effect intuitively attributable to increased ultraviolet light degrading the sequestering agents more effectively, leading to a concurrent release of the metal. This paper shows that the amount of degradation attributable to light is too low to explain the metal release and that a biological influence may instead be responsible. Abstract. The influence of UVB irradiation on the Cu2+ binding by natural organic ligands in six alpine lakes on the South Island, New Zealand, has been investigated using competitive ligand equilibration with salicylaldoxime and detection by cathodic stripping voltammetry (CLE-CSV). During austral summer 2002–2003 the total dissolved Cu ([Cu]T), the concentration of strong Cu2+-binding ligands ([L]T), and their conditional stability constant K´´ were determined in surface samples of all six lakes. All lakes exhibited appreciable concentrations of a strong Cu2+ binding ligand with similar K´´ values and concentrations always exceeding [CuT], thus dominating Cu2+ speciation. Four lakes (Hayes, Manapouri, Wanaka, Te Anau) showed no appreciable trend in [LT] throughout the summer, whereas in Lakes Wakatipu and Hawea [LT] increased steadily throughout this period. Laboratory UVB irradiation of lake water samples using a 400 W mercury lamp with a Pyrex glass filter (λ > 280 nm) showed that Cu2+-binding ligands are destroyed by UVB radiation, causing [L]T to decrease with a rate of –0.588 nmol L–1 h–1 (r2 0.88). From this we calculate that the in situ ligand destruction rate by UVB in summer for surface waters of these lakes is too small to significantly affect [LT], and conclude that variations in ligand concentrations must result from seasonally variable biological factors.

A revision of Vittadinia A.Rich. (Compositae) together with reinstatement of Eurybiopsis DC. and description of a new geunus, Camptacra.

Brunonia ◽  
1982 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
NT Burbidge
Keyword(s):  
New Zealand ◽  
New Genus ◽  
New Caledonia ◽  
Single Species ◽  
New Combinations ◽  
Northern Australia ◽  
New Subgenus ◽  
Eastern Australia ◽  
North Eastern ◽  
Specific Rank

It is reported that Gaudichaud was correct in describing, under Brachycome Cass., three species, B. triloba, B. dentata and B. spathulata. Reference is made to the nomenclatural status of these species in accordance with the results of a revision of Brachycome by Davis (1948). De Candolle erred in transferring the species to Vittadinia A. Rich, for which the New Zealand V. australis is the type. Reasons are given for regarding V. triloba (Gaudich.) DC. as synonymous with V. australis var. dissecta Benth., and the variety is raised to specific rank. Included with V. australis and V. dissecta in Vittadinia s. str. (i.e. in Vittadinia subgenus Vittadinia) are V. cuneata DC. (a name which can be applied to a complex group of taxa widespread in southern and eastern Australia) and a further 17 species of which the following are new: V. cervicularis (with four varieties), V. constricta, V. condyloides, V. decora, V. eremaea, V. humerata, V. nullarborensis, V. pustulata, V. simulans and V. sulcata, while V. gracilis (J. D. Hook.) N. Burbidge and V. australasica (Turcz.) N. Burbidge are new combinations. V. scabra DC. and a group of taxa which have been referred to it or, incorrectly, to V. macrorhiza (DC.) A. Gray have been placed in a new subgenus of Vittadinia under the name Peripleura. Within this subgenus nine species are recognized: V. scabra DC., V, hispidula F. Muell. ex A. Gray (with two varieties), and the new species V. arida, V. bicolor, V. diffusa, V. obovata, V. sericea, V. spechtii (with two varieties) and V. virgata. With the exception of V. australis which is endemic to New Zealand and V. simulans, a New Caledonian species, all are endemic to Australia; however, V. hispidula has been reported for New Caledonia where it is deemed to be an alien and V. gracilis and possibly V. muelleri appear to have become naturalized in New Zealand. V. brachycomoides (F. Muell.) Benth. becomes the type of a new genus, Camptacra, with two species, both distributed in northern and north-eastern Australia. Eurybiopsis DC. is reinstated, with its single species, E. macrorhiza DC., found only in northern Australia.

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