Katharina Anna Doehring

Cawthron Institute | CI · Coastal and Freshwater

In Aotearoa New Zealand, catchment communities have been actively working to restore the health of their rivers, in some cases for many decades. Their knowledge offers a valuable resource that could motivate and empower other groups to do the same, making river restoration more effective at large scales. We spoke to five catchment groups across Aot...

In Aotearoa New Zealand, catchment communities have been actively working to restore the health of their rivers, in some cases for many decades. Their knowledge offers a valuable resource that could motivate and empower other groups to do the same, making river restoration more effective at large scales. We spoke to five catchment groups across Aot...

Worldwide, progress has been made toward managing productive lands more sustainably to improve freshwater health. However, a lack of national guidance for environmental reporting and recording means that it is not possible to quantify consistently which land management actions that help improve water quality have been implemented, where, when, and...

This guidance document supports the Fish passage action plan template. It provides councils with guidance for developing fish passage action plans. The document covers information on overarching freshwater ecosystem objectives and legal requirements and provides background knowledge and considerations specific to the wider fish passage work program...

The fish passage work programme template aims to: • provide a tool to standardise the fish passage action plan steps to identify and document, categorise, prioritise and remediate fish passage barriers, and monitor and maintain fish passage success • provide regional councils (including unitary authorities) with guidance on how to develop region-sp...

Despite several decades of encouraging land management actions to improve water quality on rural land, we are still struggling to accurately quantify what management actions have been implemented, where these actions have been used and the intensity of implementation. This is largely because standardised approaches to recording and reporting of lan...

In New Zealand, streamside fencing is a well-recognised restoration technique for pastoral waterways. However, the response of stream ecosystem function to fencing is not well quantified. We measured the response to fencing of eight variables describing ecosystem function and 11 variables describing physical habitat and water quality at 11 paired s...

Proliferations of the benthic anatoxin-producing cyanobacterium Phormidium are increasing in prevalence in cobble-bed rivers worldwide. This proliferation is of particular concern when rivers are used as sources of drinking water or for recreation. Little is known about the physicochemical variables promoting proliferations, and our existing knowle...

Stream metabolism (gross primary production and ecosystem respiration) is increasingly used to assess waterway health because mean values are responsive to spatial variation in land use, but little is known about how human land use influences the temporal variability of stream metabolism. We investigated daily variation in dissolved O2 (DO) concent...

The mitigating effects of fish passes to aid fish dispersal are well recognised; however, non-sports fish species, juveniles and weak swimmers have mostly been neglected when developing solutions to fish passage issues. We studied the juvenile (fork length, FL <60 mm) swimming ability of a weakly swimming fish species, īnanga (Galaxias maculatus),...

The effects of coastal floodgates on fish distribution are largely unknown. In this study, we used Dual-frequency Identification Sonar (DIDSON) to assess the effect of tidal floodgates on movement of diadromous juvenile galaxiids in a New Zealand estuarine system and test the suitability of DIDSON as a tool for monitoring behaviour of small fish. D...

Alteration of urban streams by culverts is common throughout the world and is known to impede freshwater fish movement. The main objectives were therefore to investigate how different culvert characteristics (e. g. height, length, angle, perched v. non-perched) and habitat variables (e. g. water velocity, riverbed gradient) affect the passage succe...

Ongoing urbanisation in lower stream reaches can adversely affect the ecology of river ecosystems by altering freshwater fish distributions. Diadromous fish species (those that migrate between the sea and freshwater) are particularly affected as unimpeded access to and from the sea is necessary for their life-cycle completion. To investigate the ex...