Vol.14 No.1 - March 2006

Contact:
Jim Cooke, Centre Leader
tel: 0-7-856 1744
email: [email protected]
www.niwascience.co.nz/ncwr

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The predatory caddisfly (right) feeds very differently from the filter-feeding blackfly larva (left). Consequently, their contributions to ecosystem functioning are also quite different. (Photos: Mike Scarsbrook, Brian Smith)
How stream animals contribute to ecosystem functioning and the changes that result from sediment input to a stream. (Schematic: Ngaire Phillips)
As Ngaire Phillips explains, what organisms do within an ecosystem is as important as who they are.
Streams are complex, living systems characterised by a one-way flow of water.

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Many hands lighten the load when it comes to counting, measuring, and recording the cockles that have survived in the white mesh cages. The fellowship of hard work is sealed at the end of the day with a welcome cuppa. (Photos: Vonda Cummings, Luca Chiaroni, and Donnelle Fletcher)
The wide sandflats of Whangarei Harbour at low tide, and the white cages containing transplanted cockles.

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Young adult mayfly, Deleatidium species. (Photo: Brian Smith)
The three experimental sites. Figures were produced using TUMONZ
Percent composition of major caddisfly families caught in ridge-top Malaise and light traps. (For more about these traps, see 'How to catch invertebrates'.)
A section of an adult mayfly wing shows the folds and furrows that greatly increase the surface area. The structure resembles the mainsail of a yacht.

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A migratory longfin female eel with pop-up tag attached. (Photo: Don Jellyman)
A tagged eel heads for the sea to begin her journey to the spawning grounds. (Photo: Don Jellyman)
Data from one of the eels tracked in 2001.
Tracks of two of the eels released in May 2000 at Te Waihora, just south of Banks Peninsula.
Don Jellyman explains how high-tech tags are helping to reveal the secret biology of eels at sea.
All 15 species of freshwater eel spawn at sea, although we know with certainty the spawning grounds of only four species.

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Building neural networks to protect shellfish farms
Lisa Tiatia presents a tray of oysters ready for packing at Clevedon Coast Oysters. (Photo: Janice Meadows)
One of the big risks in shellfish aquaculture is that poor water quality can compromise the safety of the product. Mussel and oyster farms are particularly susceptible to episodic contamination of coastal waters when catchments flood or sewage systems overflow.

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Off to a good start with BAYERBoost
Mike Scarsbrook (left) and Sean Gresham examine the contents of a dip net downstream of a former pollution hot spot. (Photo: Colin Scarsbrook)
Sean with net and sample. (Photo: Colin Scarsbrook)
Sean Gresham, who received one of five inaugural BAYERBoost environmental scholarships, writes, 'This summer I have been spending my time at the river, and I'm getting paid for it! BAYER group sponsored me to work on a 10-week environmental research project.

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A SeaWiFS ocean colour image of the striking 1200 km2 bloom (in green) that resulted from adding iron to a patch of subpolar HNLC Pacific waters west of Canada. The international experiment, led by NIWA scientists, took place in July 2002. (Satellite image: Dr Jim Gower, NASA, and Orbimage)
Workshop on iron-enrichment studies
The productivity of the ocean is driven by the carbon fixed during photosynthesis by microscopic plants called phytoplankton. These plants use sunlight and nutrients, such as nitrate, to fuel photosynthesis.

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Going under the ice to measure microbial mats
Underwater photograph of a microbial mat at 8 m depth. We don't know why the microbes form this pinnacled surface, but speculate it could be an adaptation to low light and stagnant water. (Photo: Robin Ellwood)
Ian Hawes (in blue) prepares to go under the ice for further measurements of the microbial mats. The standby-diver helps fit the helmet. The diver's tether (for air supply and voice communication) is coiled in front of the tent. (Photo: Kay Vopel)
US-operated field camp perched above Lake Hoare.

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Mini-jaws: beware the carnivorous sponge
Not much of a threat to the gloved hand, this new species of Abyssocladia was found at the Brothers Seamount, in the southern volcanic Kermadec Arc (northern Bay of Plenty). (Photo: Ashley Rowden)
In February, NIWA hosted Professor Jean Vacelet, Director of Research at CNRS Centre d'Océanologie de Marseille, and the world’s foremost authority on deep-sea carnivorous sponges.

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Brian samples a seepage for caddisflies. (Photo: Martin Haase)
Brian's bugs (from left): adult Hydrobiosis parumbripennis,
immature male pupa of Psilochorema mimicum,
the same male about to emerge from its pupal case. (Photos: Brian Smith)
Water & Atmosphere readers have enjoyed Brian Smith’s close-up photos of aquatic insects for years. Whether he’s clinging to a rockface to sample a freshwater seep, or peering into a dissecting microscope, Brian has focused on caddisflies, mayflies, stoneflies, and their ilk since joining NIWA in 1993.

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A riparian planting at Raglan, designed to improve water quality, buffers both the stream and a wetland area. (Photo: Paula Reeves)
A riparian planting alongside a path in a Christchurch park.(Photo: Paula Reeves)
A narrow planting of Carex and Hebe species, designed to enhance whitebait spawning habitat.

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The Selwyn River at Old South Road crossing during October 2003 and January 2004. (Photos: Scott Larned)
Seasonal abundances of fish along the main stem of Selwyn River between Coalgate and Coes Ford.

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Conrad Pilditch collecting juvenile bivalves in Manukau Harbour. (Photo: Carolyn Lundquist)
The laboratory flume, located at the University of Waikato, Department of Biological Sciences. (Photo: Barry O'Brien)
Sediment cores within the flume, showing juvenile wedge shells (left) and cockles (right) burrowing into the sediment.

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(Photos: Steph Parkyn and Andrew Jenks)
Reasons given for liking photo C the best and photo A the least.
One of the picture frames erected in regional parks by Auckland Regional Council. (Photo: Steph Parkyn)
We restore streams to enhance ecology and biodiversity; but, to be most effective, restoration programmes need buy-in from the locals.

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One of NIWA’s aims with this magazine is to contribute to science education in New Zealand. To this end we distribute Water & Atmosphere without charge to New Zealand high schools. Most of the magazine’s articles are assigned ‘Curriculum Connections’ to indicate which of the NZ NCEA Achievement Standards they can complement as a classroom resource.