18 NOVEMBER 2005

NEW ZEALAND GAZETTE, No. 194

The classical definition of “littoral zone” when applied to marine environments relates to the
sea-land margin that is influenced by tidal movements: the region between the maximum
spring-tide high water mark and maximum spring-tide low water mark (spanning the region
of largest tidal variation). Eulittoral has been used to define the narrower region of tidal
influence within the littoral zone that is exposed and submerged on a daily basis (irrespective
of maximum tidal range that varies in conjunction with the lunar cycle).

However, like other taiāpure tribunals before us, we rejected this narrow interpretation of
“littoral” as inapplicable to the taiāpure legislative context. His Honour Justice Young
supported this view in his judgment. He said:33

[15] The use of the word littoral is there to emphasise and restrict the words
“coastal waters”. I do not consider, however, it is intended to restrict them to an area
between the high and low level mark as contended for by the appellants. This
interpretation does not fit either with the statutory regime or with the words used in
s174, s175 and s176 referring as they do to areas of “New Zealand fisheries waters”.
The statutory regime is concerned with the management and conservation of fish,
aquatic life and seaweed in the littoral coastal waters and estuarine waters. This
implies sea life beyond the high and low tide mark. The sections of the Fisheries Act
are concerned with littoral coastal waters. The phrase within which littoral sits
contemplates coastal water rather than a tidal area. [Emphasis original]

Witnesses told us that the term sublittoral has been used to describe the biological zone
beneath the region of immediate tidal influence. This is the region of most prolific plant and
animal life and extends from the water surface to the depth of light penetration sufficient to
support growth of large attached foliose plants (macrophytes). Drs Kenneth Grange and John
Zeldis agreed that for the purpose of this application, understanding the term littoral to
include this sublittoral zone made most sense with respect to future fisheries management.
Because this zone contains the greatest biological diversity and abundance it is essential that
it is included in the fishery management area if management practices are to be effective.

There is a precedent for adopting this broader meaning of “littoral” because in the field of
fresh water biology it is accepted that the littoral zone extends from the land/water margin to
the depth at which macrophyte presence ceases.

After considering a number of sources, Dr Kenneth Grange told us:34

It is my interpretation, therefore, that the term “littoral” encompasses the intertidal
area (including the splash zone)[35] and the area that supports the majority of plants in
the subtidal area (where suitable habitat allows plants to grow). The outer (or depth)
limit is where light penetration is insufficient to support plant growth and it may even
extent across the continental shelf…

This definition incorporates the classical littoral, eulittoral and sublittoral zones.

But would the deepest part of Akaroa Harbour be included in this definition? Dr Grange
provided data to show macrophyte distribution to depths of 20m on the rock walls near the
harbour. However, they were not reported as growing on the soft sediment in the middle
region of the outer harbour. Dr Grange contended that their absence probably relates to their
requirement for firm substrates for attachment rather than a lack of light. The outer region of
the harbour to 25 metres depth has not been surveyed for presence/absence of macrophytes,
but Dr Grange argued that water turbidity is lower here and so the depth of light penetration

33 Op.cit. page 10.

34 Statement of evidence, Kenneth Robert Grange, paragraph 10, page 5.

35 The splash zone is where waves splash, which includes areas above the high tide mark.