Photo: Dr Michelle Melchior
At the end of the small jetty at Bob's Landing on Lake Karaapiro, what looks like a bed of silt-covered gravel turns out to be something else entirely.
Peering through an underwater viewer to look at the lake bed below, the many small holes dotted around reveal themselves as frill-lined siphons belonging to gold clams.
It should not be a surprise. The edge of the lake is littered with the shells of this invasive clam, and when she scoops a small handful of sediment in the shallows, Dr Michele Melchior collects five without even trying.
Further out, in deeper waters, the clam's preferred habitat here, the numbers are mind-boggling.
"What we've been finding in some spots is that the number of clams can exceed thousands per square metre," Melchior says.
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Michele is a freshwater scientist with Earth Sciences New Zealand in Kirikiriroa Hamilton.
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