The exploratory fishing survey ZoNéCo 6 was canied out on board the R.Y. Alis of the IRD (Institut de Recherche pour le Développement) from 1-14 Décember 1998. lts main objective was to show whether commercial fish resources are present at depths between 300 and 800 m on the outer reef slopes of the Fairway-Lansdowne Bank and the Chesterfield Atoll. Two fishing techniques were used, bottom trawling and bottom longlining. The choice of fishing spots was based on both acoustic surveys using a 28 kHz FURUNO FCY 292 and the bathymetric charts produced during the seabed mapping survey ZoNéCo 4 canied out by the R.Y. L'Atalante. The duration of the trip was splitted into 41, l % devoted to transit, 27 % to bathymetry, 22.3 % to fishing and 9,6 % to waste of time due to bad weather conditions. 17 fishing stations were completed of which 9 were trawl hauls and 8 bottom longline sets amounting to a fishing effort close to 5000 hooks. Three trawl stations and 3 longline sets were made on the slopes of the Chesterfield Atoll whilst 6 trawl stations and 5 longline sets were completed on the slopes of the Fairway-Lansdowne Bank. The total catch was 822 kg of which 243 kg were caught with the trawl and 579 kg with the longline. The trawl did not catch any commercial species, shark amounting to 42 % of the catch, bone fishes 40 %, Crustaceans 9 % and Cephalopods 9 %. The average trawl catch rate was 0,6 tonne/km2 (6,06 kg/ha). The only commercial species caught with the longline were « red snappers» Etelis . carbunculus and E coruscans amounting to 211 kg (36,4 % of the total weight) with a catch rate of 4,3 kg/100 hooks. Sharks dominated the catch both in terms of number and weight (320 kg amounting to 55,3 % of the catch). Gnly one Beryx splendens was caught. With the exception of « red snappers », the survey did not show the presence of commercial target resources within the 300-800 m depth range of the prospected area.

Restreint, BERYX 11, BERYX 2, HALICAL 1, HALIPRO 1, HALIPRO 2

The exploratory bottorn trawling survey HALIPRO 2 was carried out from 4 to 28 November 1996 on board the New Zealand research vessel Tangaroa of NIWA (National Institut ofWater and Atrnospheric Research Ltd). It was aimed at identification of deep fishery resources over the Norfolk Ridge and the southern part of the Loyalty Ridge. This zone, the area of which is 73000 square km, was previously rnapped during the seabed rnapping survey ZoNéCo 1. A trawl similar to the one used by the New Zealand commercial deep bottom fishing boats was used. Amongst 35 persons on board, 17 were scientists from different countries with different fields of research. A total of 3755 nautical miles were covered and 106 hauls were made. The environment was studied through temperature and salinity profils down to 1500 m and CUITent records down to 300 ffi. The presence of alfonsino (Beryx splerulens) was confirmed over the summits of the seamounts where this species was exploited by bottom longlining from 1988 to 1991. Hauls made over slopes and plains did not allow the catch of any specimen of orange roughy (Hoplostethus atlanticus). Hard and rough bottoms on the summits and flanks of the seamounts make awkward the use of bottom trawls. HALIPRO 2 showed the high species diversity of the fauna (275 species of fish belonging to 101 families). In particular, 42 different species of shark and ray were collected of which 40% are new to science. Many samples were collected for further analysis. This survey will no doubt remain a perfect exemple of a fruitful collaboration with New Zealand.

HALIPRO 2