Day 8 – March focus on Norfolk Island’s reef

On Norfolk Island, Australian Marine Parks recently issued a notice that came into effect on 15 February 2023:

‘Due to the ongoing issue of storm and groundwater pollution entering the lagoon at Emily and Slaughter Bays, and the important role of herbivorous fish and echinoderms (sea urchins and sea cucumbers) in controlling algal growth, a complete no-take area has been established in these areas, in support of local custom.

‘In recognition of the role that Cemetery Bay plays as a source of echinoderms to the lagoon, it will be a no-take area for sea urchins and sea cucumbers.

‘This decision hasn’t been taken lightly, but our concern for the health of the lagoon means that we need to take every management measure possible to protect the reef.’

As the Marine Park’s statement says, this is in support of local customs, where it was an unwritten rule, or local lore, to not fish inside the reef.

Incredibly, until now, there have been no formal protections for the wildlife in our coral reef lagoons.

My hope is that with these bans in place, in addition to curbing runaway algal growth, there will be an improvement across the reef ecosystem in a number of different species, with knock effects for others. In particular, I am hoping to see rebounding numbers of:

• periwinkles (known locally as hihis – used in traditional dishes, such as pies). In the 1990s these encrusted the rocks at Slaughter Bay, now, to be honest, while they are there, they are thin on the ground. These guys are omnivores, but one service they do is to scrape algae off our rocks.

• sea cucumbers and sea urchins (for all reasons I have raised in earlier articles; I’ve included links here)

• tun snails, all three varieties, that I am sure have been in the sights of some who may not appreciate their importance and role in this small ecosystem (incidentally, tun snails love a diet of sea cucumbers)

• cowries, which used to be in abundance but now are a rare and welcome sighting

• intertidal molluscs (like the ones collected in the 1990s, kept by me all these years, and featured in the image at the top of this post). One of these molluscs is called Bembicium flavescens. It is endemnic and occurs nowhere else. To me they look like little Vietnamese hats, or nón lá.

With regards to the last item, in the 1990s, at the Lone Pine end of Emily Bay there was a low mound – 2 to 3 metres wide and about 10 metres or more long – of tiny shells along the beach there – a death assemblage as it is known in the Earth Sciences – of all different varieties of shells. These have now all but disappeared. What has changed, I wonder.

I am hoping that octopuses, wrasse, and a number of other fish species, will all benefit from these new rules. It’s a shame they were necessary, but they are very welcome.

As Joni Mitchell once sang (and which I seem to hum a lot these days!):

Don’t it always seem to go
That you don’t know what you’ve got ’til it’s gone …

Let’s hope this initiative from Australian Marine Parks is the start of some positive outcomes.

Further reading:

Heroes of the beach – sea cucumbers

The importance of sea urchins