Excessive fine sediment (particles

Motivation Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill t...

The management of nutrient inputs into New Zealand waterways is a key focus for environmental agencies, but few North Island studies have examined whether nitrates, phosphates or a combination of nutrients limit periphyton proliferations. The underlying volcanic geology that the Rangitikei River, a large central North Island river, drains would suggest nitrogen (N) as a likely limiting nutrient for periphyton growth. However,...

Twelve Galaxias postvectis (shortjaw kokopu) and four G. fasciatus (banded kokopu) spawning sites were found on the margins of the Katikara Stream, Taranaki, New Zealand. This is the first time G. postvectis spawning sites have been documented. G. fasciatus spawning sites discovered in this study confirm previous observations elsewhere in New Zealand. These spawning sites were all found out of water, variable distances from th...

Invertebrate communities and associated environmental characteristics were monitored at three Pinus radiata and three pasture stream sites in the Pakuratahi and Tamingimingi Stream catchments, New Zealand, respectively, at nine irregular intervals between December 1996 and April 2001. The Pakuratahi sites were logged between May 1998 and September 1999. Following logging the Pakuratahi Stream invertebrate communities changed f...

This study presents a river invertebrate and classification system (RIVPACS) type bioassessment methodology for the Manawatu‐Wanganui region of New Zealand. Aquatic macroinvertebrates and related physico‐chemical data were collected at 127 sites, with minimal human impacts (reference sites) in 2000. The reference sites were classified into five groups based on their macroinvertebrate data using TWINSPAN. These biotic groupings...

Disturbance can be an important determinant of stream benthic invertebrate community structure. Whether this is a result of the direct loss of invertebrates, an alteration to the food base of the community by the disturbance, or a combination of both, is never clear. We examined this question by conducting a disturbance experiment under artificial cover where low light limited periphyton growth and minimised the effect of dist...

Diadromous fish species dominate the New Zealand freshwater fish fauna and make up 15 of the 17 native fish species found on the Taranaki Ring Plain. Trajectories of occurrence in relation to elevation and distance from the sea are described for 11 diadromous and 2 non‐diadromous species using data from the New Zealand Freshwater Fish Database and data collected over the summer of 1997/ 98. Distinctive distributions were found...

To explore whether biotic interactions may be more common in benthic invertebrate communities in stable compared with unstable New Zealand streams, interspecific associations of invertebrate stone assemblages were examined in 10 streams of similar geomorphological character but differing stability. More significant correlations were found than expected by chance at most sites. Stable sites had more negative and positive associ...

A predictive model of fish community composition using a reference condition approach is proposed for the Taranaki region of New Zealand. The model is used to quantify the effects of barriers on the migration of native fish in the region. Occurrence records of fish in streams without migratory barriers (reference sites) obtained from the New Zealand freshwater fish database were used to establish trajectories of occurrence for...