578 



Fishery Bulletin 88(3). 1990 



SHARK ROCK 



50 

 45 

 4-0 

 35 

 30 

 25 

 20 

 15 

 10 

 5 

 



50 

 45 

 40 

 35 

 30 

 25 

 20 

 15 

 10 

 5 

 



' ' Numbers 

 r^NN Biomass 



JULY 



2400 

 2200 

 2000 

 1800 

 1600 

 1400 

 1200 o 

 1000 ° 



800 

 600 

 400 

 200 

 



o 



I 



o 

 > 



in 



> 



CD Numbers FEBRUARY 



E9 Biomoss 



A^ f\^ i ^i^ 



2 3 4 5 



STATIONS 



2400 -D 



2200 S 



2000 - 

 ■1800 J 



1600 2. 

 ■1400 s 



1200 -^ 



1000 



800 



600 



400 



200 







Figure 2 



Number of conch and conch biomass sampled within a 2.5-m radius 

 circle at Shark Rock, July 1988 and February 1989, at each station. 

 Values are means + SD. 



density between stations 1 and 5 at all sites and dates, 

 except SR station 4. 



A one-way ANOVA and a Newman-Keuls multiple 

 range test were used to test for differences in log 

 transformations of conch density among stations 1-5 

 combining al! sites and dates (CBC-July, SR-July, 

 CBC-February, SR- February). There was a significant 

 difference between stations (F = 22.02, /j<0.0001). 

 Conch densities increased with increasing station 

 number, ranging from 0.42 (±1.38) to 22.4 (±15.8). 

 Newman-Keuls tests showed that the logs of conch den- 

 sity at stations 1 and 2 were significantly different from 

 all other stations, though not from one another, as were 

 stations 4 and 5. Station 3 was significantly different 

 from all other stations (Newman-Keuls, /><0.05). 



Conch biomass patterns 



As with conch density, there was an increase in conch 

 biomass at CBC, from stations 1 to 5. The pattern was 

 strong for both July and February, although the actual 

 biomass values were higher in July at stations 4 and 

 5 than in February. At SR the biomass also increased 

 from stations 1 to 5 (with a slight decrease at station 



4 in July). In July, biomass decreased sharply at sta- 

 tion 6 and 7, while in February the biomass continued 

 to increase at station 6 and decreased at station 7. In 

 July stations 3, 4, and 5 had much higher biomass 

 values than in February. 



After log transformations of the biomass data, a 

 multi-way ANOVA was used again to test for differ- 

 ences or interactions between dates, sites, transects, 

 and stations in conch biomass with transects examined 

 as blocks (Table 5). Where CBC and SR were com- 

 pared, stations 6 and 7 at SR were not used. 



There were no significant interaction terms and no 

 block effects on the ANOVA (p>0.05), therefore the 

 effects of date, site, and station are interpreted direct- 

 ly. As mentioned above, conch biomass at both CBC 

 and SR was higher in July than in February at most 

 stations. Site differences appear to be due to low 

 biomass values in February at SR, especially at stations 

 1-3. Station differences clearly resulted from the in- 

 crease of conch biomass with the increase in station 

 number, at all sites and dates, except SR station 4. 



