Reproduction in the intertidal limpet Cellana ornata in southern New Zealand

The reproductive cycle of the abundant intertidal limpet Cellana ornata (Dillwyn 1817) was examined over 19 months, covering two breeding periods, on a rocky intertidal platform in southern New Zealand. A gonad index was calculated, and histological sections were used to count the numbers of mature and immature eggs present. Fecundity was estimated using counts of eggs before and after spawning. To determine any variation between sites, the gonad index of limpets at a second site dominated by boulders was examined over 6 months during the second breeding period. C. ornata had a single spawning period annually during summer, with greatest gonad sizes in January‐February. There were significant differences in peak gonad indices between two breeding seasons on the platform. Within the second breeding period, both the timing and magnitude of peak gonad development differed between sites, with lower reproductive output at the boulder site. Fecundity increased with increasing size, but individuals are probably capable of reproducing after their first year on the shore. The life history of this species is discussed in comparison to other limpets in New Zealand.     

Macrobenthic polychaete assemblages of the continental shelf and upper slope off the west coast of the South Island,New Zealand

Polychaete assemblages are described from replicate box‐core samples collected in summer 1983 at 18 stations on the continental shelf and upper slope (28–943 m) off the west coast of the South Island, New Zealand, south‐eastern Tasman Sea (c. 41–43°S, 169–172°E). Three main station groupings were identified by multivariate analysis: (1) inner shelf sandy stations characterised by Prionospio australiensis, Aricidea (Acesta) sp., Magelona cf. dakini, Paraprionospio aff. pinnata, Aglaophamus sp., Heteromastus filiformis, and Magelona sp.; (2) middle to outer shelf muddy stations characterised by Levinsenia cf. gracilis, Prionospio australiensis, Paraprionospio coora, Aglaophamus verrilli, and Auchenoplax mesos; and (3) upper slope sandy mud or mud stations characterised by Prionospio ehlersi. A combination of water depth and sediment clay content provided the best correlation with the biotic pattern. Spionidae was the most abundant family (49% of polychaete individuals), which may reflect the scope for opportunistic species in a shelf environment characterised by a high input of terrigenous sediment and episodic upwelling.     

First identification of the cylindrospermopsin‐producing cyanobacterium Cylindrospermopsis raciborskii in New Zealand

Cylindrospermopsis raciborskii is a planktonic freshwater cyanobacterium that is becoming increasingly prevalent in water bodies worldwide. During a survey of toxic cyanobacteria in New Zealand, C. raciborskii was identified in a sample collected from Lake Waahi (Waikato). This is the first identification of this species in New Zealand. Liquid chromatography‐mass spectrometry and liquid chromatography‐tandem mass spectrometry were used to confirm the presence of the cyanotoxins cylindrospermopsin (CYN) and deoxy‐cylindrospermopsin (do‐CYN). Detection of CYN and do‐CYN demonstrates that C. raciborskii is a now a species of concern in recreational, stock drinking, and potable water supplies in New Zealand.     

Synoptic surveys of lakes Rotorua and Rotoiti

Surface and bottom water samples were collected from 39 widely spaced stations in Lake Rotorua in February 1967 and from 12 stations in Lake Rotoiti in March 1967. In Lake Rotorua, data obtained from these samples showed that small horizontal differences existed between the southern and northern parts of the lake probably related to the higher inflow of plant nutrients at the southern end and to the prevailing southerly wind concentrating phytoplankton populations at the northern end. Lake Rotoiti, which differed from Lake Rotorua in being thermally stratified, showed no important horizontal differences, Vigorous mixing in the strata probably being accomplished by deep seiches except in the shallow western basin of the lake, where the inflow from Lake Rotorua occurs. Serial vertical hauls for a zooplankton survey of Lake Rotoiti were taken from three stations in March 1967. The distribution of zooplankton was complex because diurnal vertical migrations of the animals were combined with horizontal movement of the water layers.     

Developing a conceptual model of marine farming in New Zealand

Survey and Geographic Information System (GIS) data analysis describes the relative influence of biophysical and human variables on site choices made by marine farmers in New Zealand. Community conflicts have grown in importance in determining farm location and different government planning strategies leave distinct signature patterns. Recent legislation empowers local governments to choose among three strategies for future regional aquaculture development. This paper suggests each strategy could result in different spatial outcomes. Simulation modelling of the type described here can provide a better understanding of farmer responses to management approaches and the range of futures that could result from planning choices made today.     

The anatomy of a disaster, an overview of Hurricane Katrina and New Orleans

Hurricane Katrina created the one of the worst natural disaster in the history of the United States, resulting in over 1600 fatalities and $30B in direct economic losses in southern Louisiana. The Louisiana and Mississippi coastlines experienced the highest surge level recorded in North America and Katrina-generated waves in the Gulf of Mexico that equaled the highest previously measured by NOAA buoys. What happened in New Orleans epitomizes the risk of living below sea level in a coastal city, depending on structures that were the result of considerable compromise and piecemeal funding and construction. The Interagency Performance Evaluation Task Force was established to examine the performance of the New Orleans and southeast Louisiana hurricane protection system and provide real-time input to the repairs and rebuilding of the system. In addition to this atypical just-in-time forensic analysis, the task force examined the risk of living in New Orleans prior to and following the repairs to the hurricane protection system. Much of the forensic analysis depended on modeling and simulation of hurricane surge and waves. With virtually all measurement instruments swept away by Katrina, only models and high-water marks were available to recreate the conditions that the structures experienced during the storm. Because of the complexities of the region and the processes involved, simulation of hurricane surge and waves required many fresh ideas and new approaches and these topics, along with new concepts for future planning and design, are the focus of this special issue. Yet, the need to influence the repair and rebuilding of the damaged structures prior to the next hurricane season (roughly 9 months) dictated using existing computational tools that were ready to go. The same modeling and simulation approach was put to work to define the surge and wave hazard New Orleans faces for the future. To put this important body of work in context, this paper provides a broad overview of the entire scope of work of the task force and summarizes its principal findings.     

Private rights,public benefits: Industry-driven seabed protection

New Zealand has a large exclusive economic zone (EEZ) that contains a variety of marine habitats and commercially-important species. The commercial fishing industry operating within New Zealand's EEZ is of significant value to the economy and fisheries resources are managed through the extensive use of Individual Transferable Quotas (ITQs). One of the benefits of ITQs has been to better align some of the private incentives of quota owners with the public interest. These incentives contributed to an initiative proposed by the fishing industry to close large areas of New Zealand's EEZ to protect the seabed from trawling. These closed areas are termed benthic protection areas (BPAs) and protect the benthic biodiversity of about 1.1 million square kilometres of seabed—approximately 30% of New Zealand's EEZ. A significant proportion of New Zealand's known seamounts and active hydrothermal vents are protected by these closed areas. We describe and discuss the criteria used to select BPAs and some of the criticism of this marine protection initiative. We argue that the assignment of strong property rights in fishing resources was an important precondition to an industry initiative that has a significant public benefit. Where private and public interests are well aligned, government can adopt an enabling and facilitation role, ceding direct control of processes in order to get the results the align with the public interest.     

Toxicity in benthic freshwater cyanobacteria (blue‐green algae): First observations in New Zealand

Toxic cyanobacteria have been linked to dog deaths in the Waikanae River (1998) and Mataura River (1999 and 2000), New Zealand. These were Oscillatoria‐like species which formed benthic mats. This is the first time in New Zealand that animal deaths have been linked to toxins from benthic cyanobacteria.