Murky waters make for a murky season.
The Oamaru Blue Penguin Colony has gone from its best breeding season to an average one.
Science and environmental manager Philippa Agnew said a storm in early June disrupted this year’s little penguin (korora) breeding season – and it would not be the last of its kind.
The recent weather event created high waves that raised sediment in the near shore of the ocean, making it murky.
As a result, little penguins were not able to successfully hunt due to poor visibility, venturing further to source food, and parent penguins stopped coming ashore to feed their young, causing the abandonment of nests, Dr Agnew said.
Six weeks after the storm, penguins had started laying in Oamaru again, but there would not be many pairs laying a second clutch this year, Dr Agnew said.
Normally, the season would go uninterrupted and peak around August or September. At this time last year, the colony had 174 breeding pairs – this year it has 48.
Although this year’s “average” season would not have a drastic effect on the Oamaru colony, it would slow the growth of the population in the long term.
Farm run-off was also an ongoing cause of the murky ocean waters, Dr Agnew said.
Normally associated with the deterioration of river quality, farm run-off also had an effect on oceans – and when storms came along, they brought it into suspension, she said.
According to the 2018 report Our Land, New Zealand loses 192 million tonnes of soil every year from erosion. Most of the lost soil resulting in sedimentation is a consequence of natural erosion. However, more than 40% of the soil entering rivers comes from pasture land.
“It’s masses of soil being lost to erosion every year,” Dr Agnew said.
“Sedimentation is a massive issue.”
Dr Agnew predicted with regular storm events, the penguin population would remain stable rather than increase, as it had been.
“They are only doing well where they are protected.”
In the past decade, Dr Agnew had measured a pattern of biennial disruptive weather events – and they were only expected to get worse.
Nation’s Intergovernmental Panel on Climate Change (IPCC) the effects of climate change are worsening globally and it is because of human activity.
As stated in the IPCC’s latest report, New Zealand could expect more droughts and intense storm events. These factors, coupled with an increase in temperature, COconcentration and change in water patterns, would negatively affect water quality.
Deforestation and urbanisation were also contributing factors.
But all was not lost.
“Every little bit helps. Thinking about how we can change our ways to adapt to climate change makes you feel not so scared about it,” Dr Agnew said.