Lake Mapourika – Brown Trout and Quinnat Salmon
Plus Mapourika Salmon Study by Malcolm Flain added 10 February 2022 (scroll down page).
Located 10 km north of Franz Joseph in one of the most beautiful scenic parts of New Zealand. The salmon fishing is variable but there are plenty of big brown trout although you might find them hard to catch.
Though there is good brown trout fishing and sea-run salmon from December to March, the thick bush cover makes access for anglers on foot around the lake difficult. The lake is too dangerous for wading. A small boat or kayak is a worthwhile investment. There are a few clear places where the thread-line angler can cast if you keep a lookout while travelling along State Highway 6. Successful spinners include anything black and gold such as a Toby, small zed spinner, or Tassie Devil. Most trout and salmon are caught near the bottom so your best bet is a slow retrieve.
Lake Mapourika, at 11 square kilometres (7 square miles), is the second-largest lake in the West Coast region after Lake Brunner. The lake bed is 37 metres (120 feet) at its deepest. The lake is carved from an ancient glacier. Perhaps surprisingly Mapourika is not a Maori name. Rather it was the name of a ship that sailed between New Zealand’s West Coast and Australia during the gold rush of the 1800s. In those days it was faster to sail from the West Coast to Australia and back to a New Zealand port than to travel overland by a more direct route.
Salmon were first released into Lake Mapourika as early as 1932. Quinnat salmon run up the Okarito River from the sea into the lake from December to April. Some years the salmon fishing here is very good indeed. Big salmon are also taken by deep trolling. There is also a small population of smaller landlocked salmon present in the lake. Just under 6000 Quinnat salmon fingerlings were released into Lake Mapourika back in 2015.
Like all the West Coast lakes that have dense bush surrounding them the water is tea coloured from rainwater leaching through the vegetation. This makes spotting trout hard work. Spinning and trolling are the preferred fishing methods.
The Okarito River drains Lake Mapourika into the Okarito Lagoon.
Bag Limits and Open Season
The open season for trout and perch fishing in Lake Mapourika (excluding tributaries) is all year. McDonalds Creek at Lake Mapourika is closed to fishing at all times. The minimum length for trout and salmon caught in Lake Mapourika is 250mm. The bag limit in Lake Mapourika is 2 trout and 2 salmon. Bait, fly and spin fishing are all permitted on this lake, as is the case with all waters on the West Coast.
The Open Season for salmon in Lake Mapourika is 1 October to 31 March. Brown trout fishing is permitted all year.
You can download the West Coast Fish & Game Region Access Brochure.
The Department of Conservation Otto/MacDonalds Camp Site is located at the northern end of Lake Mapourika. It has basic facilities only.
Glacier Country Lake Tours vessel at the southern end of Lake Mapourika (no longer operating).
Lake Mapourika Fishing Competition 1995
Though this event took place some time ago many will find it interesting. This fishing competition is still run each year.
Over 130 anglers from all over New Zealand entered the South Westland Lions Club fishing competition held in 1995 at Lake Mapourika.
The organiser of this year’s event, Stan Peterson, said anglers had travelled from Napier, Christchurch, Dunedin, Rakaia, Nelson and all over the West Coast to enter the competition.
The weather was a real mixed bag with everything from sunshine to rain, thunder and lightning. Those who braved the poor conditions on Sunday were well rewarded as this was the time when the winning salmon were caught.
Mr Paterson said that the competition was now in its sixth year and was becoming better known all the time. It was also good to see some old hands at the event, some of whom had attended all six competitions.
A change was made to this year’s competition with the associated social events being held on the lakeshore itself rather than at the Franz Josef village. The picnic area at McDonald’s Creek at the northern end of the lake proved the perfect venue.
The first prize for the heaviest salmon was won by Alistair Climo of Hokitika with a weight of 7.265kg (15.9lb). Alister’s prize was a Yamaha four horsepower outboard motor, sponsored by South Westland Lions Club and McLaren Motors.
In second place was Merv Valenski from Jackson Bay. Merv’s salmon weighed 7.060kg (15.5lb) and won Merv a Yamaha two horsepower outboard motor, also sponsored by South Westland Lions Club and McLaren Motors.
The third prize of a $300 Mobil voucher was won by N.Fegan for his 6.430kg (14.1lb) salmon, sponsored by Mobil Oil New Zealand Ltd.
A salmon weighing 5.960kg (13.1lb) won the fourth prize of an accommodation voucher for two with Scenic Circle hotels South Island wide for James Tisdall.
The fifth prize, a microwave oven, was won by Robert Kirkwood for his salmon weighing 5.725kg (12.5lb), sponsored by South Westland Lions Club and Westpower, Hokitika.
The Milan Arnold trophy for the heaviest salmon overall in the junior section of the competition was won by Quentin Arnold. Quentin’s ﬁsh weighed 4.300kg (9.461b). Quentin’s prize was a trout rod and reel plus an A.S.B. bag, sponsored by Hokitika Cycles and Sports, South Westland Lions Club and A.S.B. Bank – Hokitika.
All ﬁshing competitions have their hard-luck stories. The two “winners” in this category received a “talk about tears” T-shirt. They were Tommy Nolan, who lost his very expensive rod and reel over the side of his boat and Kevin Penrose who managed to hook himself in the head while casting.
South Westland Lions spokesman Allan Cooper welcomed the donation of a new prize for this year’s competition, the Te Koeti Runanga Pounamu Trophy, for the heaviest salmon caught on the ﬁrst day of competition and won by James Tisdall. Mr Copper said that the donation of this trophy reflected the excellent support given to the competition.
Mr Cooper also said that the Lions Club had been able to take a back seat with the organising of this year’s Lake Mapourika fishing competition thanks to the excellent job done by local anglers in putting the project together.
Mr Cooper noted that it would be interesting to analyse the effect of the competition on the local economy and expected that it would be considerable given the large number of visitors regularly attracted to the event. Many who travelled to Lake Mapourika for the fishing competition were so impressed they later returned for family holidays on the Coast.
Other prize winners included: Winner of second place in the Junior Salmon Section was Nathan Blackburn with a fish weighing .335kg. Nathan’s prize was an A.S.B. Bag plus a $25 Voucher, sponsored by A.S.B. Bank – Hokitika and The Tackle Box, Christchurch.
The third prize with a trout weighing .520kg went to D. Blackburn. The prize was a Flask and Pliers plus a $25 Voucher, sponsored by Renton Hardware Ltd, Hokitika and The Tackle Box, Christchurch.
Junior Anglers Fish 1st prize of a Knife, Fork & Spoon set plus a Tackle Box, sponsored by the South Westland Lions Club went to Gerard Williams with a fish weighing 3.080kg.
2nd prize of a Knife, Fork & Spoon set plus a Tackle Box, sponsored by the South Westland Lions Club went to Nathan Blackburn with a ﬁsh weighing 1.670kg.
3rd prize of a Knife, Fork & Spoon set plus a Tackle Box, sponsored by the South Westland Lions Club went to Andy Lash with a ﬁsh weighing 1.670kg.
Heaviest Trout Overall
1st, Phil Crosland, 2.855kg.
2nd, Paul Thompson, 2.420kg.
3rd, Don Fox, 2.190.
The Teams’ Event was won by Ken, Quentin, Sandra and Milan Arnold with a total weight of 12.075kg.
Mapourika Lake Salmon Study
by Malcolm Flain, Fisheries Research Division, MAF. Spring 1982.
Lake Mapourika is one of the few areas on the West Coast of the South Island which has a self-sustaining quinnat salmon population.
In 1974 staff of the Department of Internal Affairs surveyed several West Coast lakes, including Mapourika. Concern was expressed for the continual survival of the salmon in the lake, as spawning counts and angler surveys indicated a small but heavily exploited population. In response to this, internal Affairs placed a total ban on fishing to protect the fishery and allow time for the salmon population to recover.
All salmon populations on the West Coast are found in river systems containing lakes, such as Mapourika, Paringa and Moeraki, which act as reservoirs for the fish which would otherwise be washed straight out to sea by the notorious West Coast floods. They may also offer a stable rearing area for juveniles to grow to a size where they can transfer from fresh to saltwater without the high mortality which occurs when small fry are pushed straight out to sea by
It was surprising to discover from scale readings, however, that the stocks of salmon in Lake Mapourika are resident freshwater fish, even though there is access to the sea by way of the Okarito River and lagoon. However, a proportion of fry does go to sea and return as adults.
An extended freshwater residence is unusual. It does occur in Lakes Coleridge, Wakatipu and Roxburgh but in these lakes, there are physical barriers preventing the fish from leaving. This is not the case in Mapourika and a different explanation is offered for the presence of the resident freshwater population.
Mapourika, like most West Coast lakes, is “tea” coloured and this severely limits light penetration and causes the littoral zone to be shallow. It is 8.3 sq km in area and its greatest depth is 77.6 m. The water is nearly neutral at pH 7.3 and oxygenated throughout. The main spawning stream is Mcdonald’s Creek, which is cold and crystal clear but floods badly on occasions.
From temperature data collected by the Department of Internal Affairs, temperature profiles were drawn for the lake during summer and winter 1974. They also show the limit of plant growth as a line at the depth of four metres observed by divers. This is the main area of fish food production. Also shown is the depth of the 15°C isotherms during summer which is well below the littoral zone.
Salmon have a preferred temperature of 12.5°C and an optimum of 15°C. The winter temperatures for the lake show that all areas of the lake are tolerable to salmon. During summer however the upper 12 m of water is too warm and they are excluded from the main food area, which stops at four metres depth.
During February and through to the end of May, adult lake-resident salmon move into McDonald’s Creek. They do this easily for the creek water which is cold and clear, flows into and down the bed of the lake. The fish, which have a thermal “lid” above them, swim up through this cooler water into McDonald’s Creek to spawn.
The less-dense warm, lake surface water flows out to sea via the Okarito river. This progressively cools as the winter approaches so that it becomes less of a thermal barrier to sea-run fish, which make their appearance on the spawning grounds late in the season and a few are also caught at this time by anglers.
Juvenile salmon emerge from August to the end of November and move into the lake, which has cooled during the winter. Here they feed and grow. From November on they would normally migrate to the sea. However, outflow from the lake into the Okarito river is small and sluggish and is encompassed by a shallow area that, like the lake, is heating up, creating a thermal barrier that tends to hold the juveniles in.
This thermal “lid” thickens as summer progresses, forcing the fish deeper into cooler water and trapping them in the lake. The fish tend to lose the migratory urge until the same time the following year when these events re-occur.
Obviously, some do get out, and this explains why we ‘get some sea-run fish showing evidence of 1, 2 or even 3 years freshwater residence before going to sea. Along with these are found some totally freshwater residents which never found their way out. Because the warmer water extends beyond the littoral zone from mid-May to the beginning of November, the availability of food must decrease.
This is borne out by the slower growth rates of these fish when compared with stocks from other areas, such as Lake Coleridge, where the littoral zone water is suitable for salmon throughout the year. lt also explains why fish are caught at the beginning (October) and end (April) of the angling season but not in the middle. At this time the fish have been forced by the “sinking lid” into cooler, deeper waters.
Marking experiments by Internal Affairs officers have resulted in high recovery rates (in excess of 20%), and indicate that the population is not large. Spawning surveys also point to this conclusion, with as few as 20 fish being counted and only rarely several hundred. It is evident that Mapourika is marginal with regard to its natural salmon run and to improve this situation requires intervention by way of enhancement work.
McDonald’s creek is the most utilised area for spawning but it is unstable. Ideally, provision should be made for stable areas where ova and juvenile fish may safely develop during their most vulnerable growth periods. The most convenient method might be to develop a hatchery facility somewhere and stock the lake with fry.
In addition, the close proximity of McDonald’s creek to the lake outlet is detrimental to the young salmon. When in flood, water from McDonald’s creek passes almost immediately out through the outlet. If a flood occurred at the wrong time of the year juvenile salmon would be swept out to the sea at too early a stage in their development to survive. Relocation of the mouth of McDonald’s creek away from the outflow would help the salmon stock.
Malcolm Flain, FRD, Christchurch.