364 
Fishery Bulletin 11 7(4) 
Table 1 
Details for smalltooth sawfish (Pristis pectinata) caught and tagged with acoustic 
transmitters in upper Charlotte Harbor, Florida, including in the Peace River, in 2016, 
by tagging date (month/day/year). All individuals received uniquely coded 69-kHz 
acoustic tags. An asterisk indicates an individual that was detected within the array of 
acoustic receivers in the Vemco Positioning System (VPS) along the southern shoreline 
or that spent enough time in the area of the VPS to be analyzed in detail. STL=stretch 
total length. 
Sawfish ID 
number 
Sex 
Date 
tagged 
Date of last 
detection 
STL 
(mm) 
Detected 
by VPS 
Used VPS 
area 
1 
M 
3/8/2016 
1/4/2017 
1432 
* 
2 
F 
3/8/2016 
7/31/2016 
1321 
* 
3 
M 
3/15/2016 
8/20/2016 
1435 
* 
* 
4 
F 
4/22/2016 
4/14/2017 
726 
* 
5 
F 
4/26/2016 
6/11/2016 
952 
6 
M 
4/26/2016 
10/28/2016 
988 
7 
M 
4/26/2016 
5/16/2016 
957 
8 
M 
4/26/2016 
2/18/2017 
1028 
9 
M 
4/26/2016 
7/7/2016 
1001 
10 
M 
4/26/2016 
6/20/2016 
943 
11 
F 
5/9/2016 
6/28/2016 
889 
12 
F 
5/9/2016 
8/5/2016 
1010 
13 
F 
5/9/2016 
4/26/2017 
891 
* 
14 
F 
5/9/2016 
6/27/2016 
903 
* 
15 
M 
5/9/2016 
5/30/2017 
1160 
* 
* 
16 
F 
5/18/2016 
8/23/2016 
1032 
* 
* 
17 
M 
5/18/2016 
3/2/2017 
915 
* 
* 
18 
F 
6/3/2016 
12/5/2016 
1019 
* 
* 
19 
F 
6/28/2016 
12/29/2016 
897 
* 
* 
20 
F 
7/5/2016 
8/15/2016 
1770 
southern shoreline (mostly at night), and 6 sawfish spent 
enough time there to be analyzed in detail. Throughout 
the 153-d study period (27 May-26 October), there were 
115 d (75%) during which the VPS detected at least 1 
sawfish. During 85 d (56%), multiple sawfish were 
detected. 
Positioning system 
The tide model validated water depths recorded in the 
field. Most modeled water depths were within 0.5 m of the 
measured depths, and results from the model indicate that 
the shallowest receiver remained submerged during the 
entire study (receiver depth: 0.1 m; lowest water depths 
were 0.2 m on 4 d in October). Therefore, water level 
should not have affected overall functioning of the array 
of acoustic receivers in the VPS. 
Once the tide model was validated, the relationship 
between the presence of juveniles and tide stage was 
quantified (Fig. 2). Detections of tagged smalltooth sawfish 
occurred during 95 of the 295 flood tide stages (32%) and 
99 of the 296 ebb stages (34%). There was no significant 
difference in median detections per hour along the south¬ 
ern shoreline between flood and ebb tides (Kruskal-Wallis 
test: 77=0.7417, P=0.4). However, there was a significant 
difference in median detections per hour between the first 
and second tide occurrences for both flood (Kruskal-Wallis 
test: 77=63.23, P<0.0001) and ebb (Kruskal-Wallis test: 
77=12.88, P=0.0003) periods. The majority of the first flood 
and first ebb tides occurred at night (75% and 74%, respec¬ 
tively, excluding crepuscular occurrences). 
Habitat polygons created for the major habitat types 
found within the study area provided insight into how 
juveniles used shallow, deep, and oyster habitats, with a 
significant difference in the ratio of observed to expected 
frequencies detected among pooled position estimates 
(likelihood ratio chi-square test: G 2 =3465, P<0.0001, df=2; 
Table 2). 
To explore differences indicated by results from the 
likelihood ratio chi-square tests (Table 2), selection ratios 
were calculated. All but 1 juvenile selected the shallow or 
oyster habitats. This pattern was consistent when ana¬ 
lyzing position data for all 6 sawfish combined, with a 
selection ratio of 3.770 (95% Cl: 2.223-5.317) for shallow 
habitats, 0.828 (95% Cl: 0.726-0.930) for deep habitats, 
and 3.570 (95% Cl: 1.058-6.082) for oyster habitats. 
These data indicate that smalltooth sawfish were select¬ 
ing against the deep habitat type and for shallow and 
