Parrish et al.: Nursery habitat in relation to production of Pristipomoides filamentosus 
139 
Interannual fidelity of snapper recruitment to the 
study site was assessed by using 20 video stations in 
the north Kaneohe canyon during 4 surveys in May 
1992, May 1993, September 1993, and June 1994. 
These were designated as “multiyear stations” and 
were compared by using date of survey as a covariate. 
Habitat characteristics 
Slope, substrate type, sediment particle size, and 
proximity to closest known point sources of focused 
coastal drainage (channels through reefs and waste- 
water outfalls) were determined for all areas. The 
effect of slope on snapper abundance was assessed 
by using a GIS slope algorithm with collected 
bathymetry data. At the depths frequented by juve- 
nile snappers, the habitat is typically dominated by 
a featureless expanse of sediment. To test the effect 
of alternative substrates on snapper abundance, 
types of substrate (as identified in video and chro- 
moscope images) were coded as categories: e.g. soft 
sediments, escarpment-type relief (exposed edges of 
shelf, about 3 m high), and hard, even bottom. Video 
drops that recorded alternate substrate, or were 
within a snapper home range (Moffitt and Parrish, 
1996) of such observations, were compared with video 
drops on soft sediment, presumably away from the 
influence of the other substrate. Substrate of adja- 
cent shallower (30-60 m) and deeper (90-120 m) 
habitats, where juveniles have been historically ab- 
sent (F.A. Parrish, 1989; Moffitt and Parrish, 1996), 
were surveyed with a longshore transect of 14 video 
drops in each of the 2 depth ranges. 
Ten bottom grab transects perpendicular to the 
bottom contours, each sampling 3 depths (45, 76, 106 
m), were used to assess a possible relationship be- 
tween snapper abundance and particle sizes in the 
sedimentary habitat. Replicate grabs were taken in 
line with and between the axes of the canyons in each 
area. Samples were wet-sieved into five size catego- 
ries (>2.0, 0.35-2.0, 0.149-0.35, 0.0625-0.149, and 
<0.0625 mm). 
The effect of some notable sources of natural and 
anthropogenic drainage present in each of the three 
canyons was considered. In Kaneohe, bay water 
drains through narrow channels (one in the north 
and one in the south, each with maximum depth of 
-15 m at the seaward end) in the reef during ebb 
tide 3 (Fig. 1, II). In Kailua, increased suspended 
materials are introduced from an island wastewater 
and sewage outfall. 4 * The video index of snapper abun- 
3 Bathen, K. H. 1968. A descriptive study of the physical ocean- 
ography of Kaneohe Bay. Oahu, Hawaii. HIMB Tech. Rep. 14, 
353 p. Univ. Hawaii, 2550 The Mall, Honolulu, HI 96822. 
4 City and County of Honolulu. 1993-1994. Discharge moni- 
toring reports. Environmental Protection Agency form 3320- 
1. Wastewater Division, 650 South King St. Honolulu, HI 
96813. 
Table 1 
Depth, mean daily volume, and suspended load of the east Oahu drainage sources. The Kaneohe channels provide tidal drainage; 
the Kailua discharge is anthropogenic (24 hours). 
Source of discharge 
Discharge 
volume 
(m 3 /day) 
Discharge 
depth 
(m) 
Suspended 
solids 
(kg/day) 
Source 
North Kaneohe channel 
18.5 x 10 6 
0-15 

Bathen' 
South Kaneohe channel 
12.9 x 10 6 
0-15 
— 
Bathen' 
Kailua wastewater outfall 
41,000 
30 
1,000 
City and County of Honolulu 2 
'See Footnote 3 in the main body of the text. 
2 See Footnote 4 in the main body of the text. 
