Coastal monitoring of Waikato beaches to get underway

Water sample being collected as part of Waikato Regional Council's beach and estuary monitoring programme.Photo supplied

The summer monitoring programme of Waikato region beaches and estuaries is due to get underway at the end of the month with help from two environmental science university students.

Every year, Waikato Regional Council staff monitor coastal water quality, estuary benthic macrofauna (sediment-dwelling organisms), stream water quality, freshwater fish and water levels of key lakes and wetlands. They're helped during the peak monitoring period by students employed from November to about March.

Much of this testing is part of a council drive to gain better information about what's happening in the region's coastal waters and to make the latest results for the coast, rivers and lakes available to the public on the LAWA website – www.lawa.org.nz – under Can I Swim Here?

The number of faecal bacteria present in the water indicates the likelihood of contracting a disease from many possible pathogens in the water, such as bacteria or viruses.

Seven east coast (Buffalo Beach, Hot Water Beach, Tairua, Pauanui, Whangamatā, Onemana and Whiritoa) and two west coast beaches (Sunset Beach at Port Waikato and Ngarunui near Raglan) are tested to see whether faecal bacteria levels are okay for contact recreation such as swimming and surfing.

Testing is also carried out at estuarine sites – Pepe Inlet at Tairua, Whangamatā Harbour entrance, Whaingaroa Harbour near the motor camp and Maraetai Bay at Port Waikato.

Coastal and marine science team leader Dr Michael Townsend said as a rule, the water quality at Waikato region beaches is generally good for activities like swimming and surfing.

"But people should exercise caution for up to 48 hours following heavy rain, because it flushes contaminants from urban and rural land into waterways, which then make their way to the coast. These contaminants may be present in the water for up to two days after heavy or prolonged rainfall.

"Last summer we recorded two exceedances – at Buffalo Beach and Sunset Beach – and that's likely due to their proximity to large freshwater systems which will have been impacted by heavy rain."

He said providing the public with the best-quality information is important. "So we work together with district councils and Te Whatu Ora – Health New Zealand (Waikato) to identify any results that may have public health implications and then communicate them."

Te Whatu Ora Waikato's Medical Officer of Health, Dr Richard Wall, recommends that where public health warnings are in place, the water at these beaches should be avoided for all recreational use.

"If you do use the water for recreational purposes when a warning sign is in place, then you are potentially exposing yourself to harmful pathogens that can cause illnesses including gastroenteritis, respiratory illnesses, and ear and skin infections," Dr Wall said.

In addition to the coastal water quality testing, during summer the students will be sorting benthic macrofauna (sediment-dwelling organisms such as shellfish and marine worms), samples collected from estuaries and looking at the characteristics of the sediment to evaluate ecological health.