What's Happening to Our Coastline

Has anyone else noticed the erosion that’s underway around our harbours? Stretches of harbourside that have sat there happily for decades seem to have set off into the sea of late. Any strip where clay is the dominant natural material seems to be actively eroding way faster than it has before.
Has anyone heard their local Regional Council talking about this or are they all lost in the Resource Management Act process or focussing on this month’s fashionably unfashionable non indigenous species?
Why are the mangroves in such a growth spurt and why have the powers that be softened their once hard stance against any culling of mangroves? I’ve heard all sorts of bizarre explanations for the mangrove explosion but none seem sensible to an experienced civil engineer, although increased fertiliser runoff has to have an impact somewhere.
Changes in our bush are taking place without notice. Look at the resurgence of Pongas. At what plant’s expense? Is it their resistance to possums? Who’s watching? I’d like to know.
A friend of mine called me in to look at the loss of material around the island he cares for. The tide is no higher than it used to be. I can vouch for that, as the high water marks on the 100 year old piles under my house haven’t moved, yet very low coastal banks are receding faster than the established plants can handle.
No doubt glib explanations revolving around Kyoto will be offered but give me a break. I’ve often felt that our greatest environmental problem has been erosion of our topsoils into the rivers and thence the seas, but it just doesn’t seem sexy enough for DoC and the usual environmental zealots are more concerned with GE.
Try flying over the Bay of Islands after a heavy rainstorm. The sea is cloudy brown for miles. Surely the fish don’t like processing all that fine material that used to be what passed for topsoil, a treasure we can’t afford to keep losing. The culprits are often the organizations supposed to be the guardians of the environment such as our councils whose tight roading budgets result in unretained scars by the roadsides.
Look around any set of Kiwi hills and you’ll see ugly slashes of clay banks usually by roadsides. No way will our clays stand at steep angles for ever. They shrink and dry and crack through summer then the rains hit them filling the cracks, spalling off chunks that reveal more clay to start the process again. All that stuff washes into our systems. People forget that firm clay is dust when dried out and mud when saturated. It needs the protection of ground cover to insulate it and keep its strength.
Our regional councils worry over the wrong weeds. People in Whangaroa encouraged to spray ginger plant, killed off the free retaining walls holding up their hillsides, then watched them collapse. Ever heard of Prickly Moses? Now there’s a devil of a plant but it’s not hit the naughty list yet.
My friend wants to try some simple fairly agricultural retaining works to protect his coastal fringe. First question he gets is "Have you applied for a resource consent?" That’ll help! What is needed is an enlightened partnership to try a few of these solutions so we can all learn what works.
We need to try a mix of local and imported (yet existing) weeds to resist erosion, rather than heavy handed engineering solutions crafted by the Building Act. Normal weed spraying programs often exacerbate the problem, yet they are recommended to the point of obsession.
An open mind to a mix of native and exotic, weeds and grasses, stuff that may rot like old gum logs rather than everything tanalised is what is needed around our foreshore fringes and to get us all involved in caring for rather than claiming our foreshore. Less talk and more action at the local level will help the environment more than the fun of an international conference. I’m not expecting any MPs to show up with a shovel.
Wayne Brown