New special issue on lake resilience

A new special issue of New Zealand Journal of Marine and Freshwater Research, guest edited by Deniz Özkundakci and Moritz K. Lehmann, explores lake ecosystems of New Zealand and the environmental pressures threatening them. These pressures include biological invasions, nutrient runoff and climate change.

In their editorial, Özkundakci and Lehmann explain how the issue has compiled applied research and multidisciplinary frameworks to address the complexity of resilience mechanisms in lake ecosystems and the importance of understanding them.

While lake ecosystems are reasonably resilient to pressures—meaning that when exposed to a threat they are often able to bounce back to a steady or natural state—these environmental pressures have been increasing. Some examples of these threats include warming temperatures, intensification of agriculture and development.

When a lake’s resilience is reduced, there is increased risk of it being pushed to a worse equilibrium. Deteriorated lakes often show poor water quality, lower biodiversity and cyanobacteria blooms, and once deteriorated, they do not respond as well to restoration activities.

In Aotearoa we have great diversity of lake ecosystems, which include the water supplies that we use for power generation, transportation, fisheries, tourism and recreation. Therefore, better understanding of the vulnerability of lakes and how to protect them is increasingly important.

The editorial ‘Lake resilience: concept, observation and management’ includes multi-lake studies to demonstrate the relationship between wide-reaching drivers of lake ecosystem dynamics and functions with local site-specific characteristics.  

It also looks at novel methods to measure specific pressures such as the increase in cyanobacteria abundance and bloom events. These events also have a measurable effect on the health of humans who rely on the lakes.

Maintaining resilience in these environments can be seen as the most effective way to manage ecosystems, as lakes that have been reduced to an undesirable state are often difficult to restore. The various frameworks collated by Özkundakci and Lehmann attempt to demonstrate ecological resilience to understand real world lake management, but also to illustrate the specific challenges involved.

Lehmann is a senior scientist at Xerra Earth Observation Institute with an adjunct position at the University of Waikato. He has a PhD in oceanography from Dalhousie University, Canada, and has worked in both research and consulting until he relocated with his family to New Zealand in 2014. His recent work focuses remote sensing and modelling technologies to address water quality issues in lakes and the coastal ocean. 

Özkundakci is a Freshwater Scientist at Waikato Regional Council and an Associate Editor of New Zealand Journal of Marine and Freshwater Research. His research interests include aquatic ecology in relation to lake biodiversity restoration, ecosystem modelling with an emphasis on water quality issues related to eutrophication, plankton ecology and food web dynamics, and climate impact research on lake dynamics.

This editorial by Deniz Özkundakci and Moritz K. Lehmann introduces the new special issue, ‘Lake resilience: concept, observation and management’,as Volume 53, Issue 4 of New Zealand Journal of Marine and Freshwater Research. The special issue is available at Taylor & Francis Online.