In recent years scientists and others have actively raised the profile of shingle beaches and their classification as a type of ‘historically’ rare ecosystem. Shingle beaches are comprised primarily of water-smoothed gravel and cobbles which are usually deposited at these locations by rivers or eroding coastal cliffs.
Adam Forbes, MWH environmental scientist and ecologist based in Hastings, has been involved in ecological valuations and management plans and assessments of environmental effects for a wide range of ecosystems. He has found that the ecosystems of shingle beaches are little understood by those who use them.
“The shingle beaches of Hawke’s Bay are perceived by many people as uneventful, unglamorous areas of little value and lacking the appeal and relative high profile of their sand dune counterparts,” Adam says. “Despite this perception, recreational use abounds including 4WD access, fishing, surfing, dog walking and bonfires – much of it potentially detrimental to the beaches’ ecosystems.”
An example can be seen in the shingle beaches of Hawke’s Bay around the Awatoto, Haumoana and Te Awanga area where studies are revealing that they support a rich diversity of fauna and flora. Ecological values are even greater where these shingle beaches are backed by wetlands, such as those which occur in this area at the Muddy Creek wetland complex and along the back of the beach near Haumoana.
These shingle beaches support localised breeding populations of a wide range of nationally threatened bird species including the endemic black-billed gull, both the banded and black-fronted dotterel, the pied stilt and at least three species of tern. Additionally, many common native and introduced birds add to the biodiversity of this rare ecosystem.
The at-risk spotted skink is at the northernmost extent of its known range in this location and common skink is present in low numbers. Invertebrates are slowly becoming better understood, and recently the Maaminga marrisi, was found in the area, one of only two species of a newly discovered endemic Maamingidae wasp family – currently known only from a small number of sites in New Zealand.
The beaches are home to flora including the commonly occurring ngaio and taupata and several small colonies of the threatened Muehlenbeckia ephedroies. The native shore bindweed with its attractive mauve-coloured trumpet flowers readily colonises shingle areas not disturbed by vehicles.
Adam says: “On face value it is perhaps easy to underestimate the ecological values shingle beaches support. Given the rarity of this ecosystem, along with the diversity of common and threatened flora and fauna found on these beaches, however, the Awatoto, Haumoana and Te Awanga area is surely a prime candidate for carefully planned legal and physical protection. Given the generally high public profile of these sites, opportunities for education can also be realised.”
To better reach its ecological potential, key management actions for this area include legal protection for conservation purposes, further prevention of vehicle access, and more active enforcement of those laws already in place which seek to prevent dogs roaming uncontrolled on the beach. Careful thought should be given to the targets, design and long-term viability of predator control. Further inventory studies would also help to better understand the values in this area and at other shingle beaches regionally and nationally.
MWH has recently led a number of ecological studies, often in collaboration with specialist ecologists, which have contributed to our understanding of the ecological values of this rare habitat type, and some of the urgent management needs.