Brenda and Brent - Trip Diary

There is a lookout just after crossing Wilmot pass. We got our first looks at Doubtful Sound.

The day before it had rained pretty hard down there. Most days it does. Sunny days like today happen about 1 day a month, when the wind comes from the east rather than the west. Today it rained on the east side of the pass, not where we were on the west.

Rain is the main environmental force on the west side of the New Zealand mountains, with yearly rainfall from 7 to 10 metres (depending on who tells you). That is up to 33 feet of rain a year for the metric challenged (myself included).

Not for us though. You can see some blue sky up there - we had a mainly clear sky all day.

The big room just behind Brenda is the dining room. The one on the upper deck is the bridge. There are a few passenger cabins below bridge, but most are down one deck. Some cabins are doubles, some with four bunks in a backpacker style accommodation.

See that blue sky again!

In spite of the large portholes, we spent very little time in the room, preferring the open decks.

These were our first views of native New Zealand trees. In the farming areas we had been cycling through, all native vegetation has been removed - mostly for the fields themselves of course. They then planted European or North American tree species as wind breaks. They also plant introduced species in their gardens, for the most part. In the agricultural areas, vegetation wise we could have been anywhere. (Sadly, most of the birds in those areas are European introductions as well.) (To be fair, it could be that there were no large native trees in the land now used for agriculture - the drier land to the east of the mountains.)

Waterfalls are a part of the beauty of this area.

The plants on the walls hold each other up with their interlocking root systems. Under certain conditions, one can let go and take all its mates along with it. This one probably happened in August 2003 when there was a very strong earthquake in the area - the rain has not yet washed all the remaining top soil from the rocks.

The guides call these events Tree Avalanches or Travalanches.

Looking at the top of the bare area, it could be that the rocks themselves broke away starting this travalanche.

This picture is part of the original - showing only the section where the trees were actually slipping down the rock face. The top of the hill is just visible. It looks like a tree near the top let go, taking out the trees below but leaving an island in the middle. This travalanche did not go all the way to the waterline. The lower section was still moving when I took this picture but stopped soon after.

One of the guides said she had been working on the sound for 4 years and this was the first travalanche she had seen. Hard to say why these trees survived the earthquake in August but decided they had had enough just as we were passing. It had rained pretty hard the previous day, perhaps weakening the root's grip.

This picture shows an old scar which has reached the moss stage.

The trip naturalist, quite a funny guy, said it took about 100 years for the larger trees to come back. My memory must be faulty on that since many of the mature trees look to be a hundred years old themselves. Perhaps he said a thousand years.

The weather continued fine as we cruised through a couple of small islands which were home to some small sea lions (mothers and young, the fathers having headed back out to sea). There was also a colony of terns.

The only danger in the entire area is the sand flea which is actually a fly and is a stinging biter. Most of the bites stung for only a few minutes, but a few on my knuckles itched for several days. As the kayaks got close to shore, the sand fleas were able to feast on the paddlers.

Several of the crew were swimming from the back of the ship, so Brenda and I actually had a very short swim. The water on the surface was only mildly salty and not really cold. We were out in a couple of minutes but some people swam for quite a while.

The fresh water released through the Hydro turbines (normally all the water in Lake Manapouri would flow east, not west into the sound) as well as the rain and the water that falls into the fiord, form a fresh water layer on the surface. Most of the water naturally filters through the tree roots and mosses and is brown - full of tannin. The final factor is the presence of a gravel bar near the mouth left by the last glacier which reduces the amount of salt water that enters the fiord with the tides. This dark fresh water top layer determines the ecology of the fiord - all sea plant life occurs in the top few metres. A similar thing happens in Finlayson Arm near Victoria - the fresh water washes over a layer of salt water that does not get flushed by tidal action, leaving a dead layer below the top few metres.

The possum is the Brush-tailed Possum which was introduced from Australia - they actually farm them, using the fur in combination with wool to make a very warm fabric. The few that escaped have spread all over the country. They are largely plant eaters but will eat young birds and bird eggs. The New Zealand native birds have never faced this kind of predation, so have no natural defenses.

The possums are a serious problem not just for birds. There are so many of them and they eat so much vegetation that they can eat up a forest as fast as it grows. They climb to the tops of the trees and eat the new shoots, preventing the trees from getting very large.

There are large areas in which poison bait is spread to try to eliminate the possum. We saw signs on farm land and in forest areas warning of the poison baits. We saw similar signs in Tasmania, but there the target is the Red Fox which someone introduced in order, they suspect, to have something to hunt. It is interesting that the possums are in balance in Tasmania but out of control here - not that they have any predators either place. It must be that the tree species available here are much better possum food.

As part of the morning ritual, the ship heads for this quite bay and shuts off all on board machines. The quiet -- broken only by bird songs (so there must be a few birds) -- can bring even strong men to tears we are told. Well, this morning the sound of the rain on the ship, on the water, and flowing down the gutters was all we could hear.

It rains so much on the west coast of New Zealand that the tour companies have to encourage tourists by stressing the importance of seeing the west (wet) coast in the rain - the waterfalls are more spectacular during the rain. I suspect this is putting the best face on a rather wet argument. This rainy morning was pretty dreary, especially when compared to the exhilaration of yesterday.

This shipboard poster shows two of the early explorers in the area. Captain James Cook and his naturalist Joseph Banks were the first Europeans in 1770. The pass at the head of the sound was only explored from the other side in by a European in 1897.

When the New Zealand Hydro electric authority decided to divert the water from Lake Manapouri west into the sound to create electricity there was a lot of opposition. The final petition had 250,000 (60,000?) names in a country of fewer than 3 million people.

Adding a lot more fresh water to the Doubtful Sound would completely change the marine environment, especially since the water in Lake Manapouri is relatively clear. More clear (as opposed to tannin rich) fresh water would eliminate the existing marine ecosystems.

There was a compromise which limited the outflow into the sound, and limited the amount they could change the level of the upper lake to about 5 metres. Unlike many hydro reservoirs in Canada, which have their levels change dramatically between the rainy season and the dry season, Lake Manapouri looks much the same year round.