FISHKRY BULLETIN VOL 



T \liLK 3. — Numht*r> (if bcittlenosed dolphins and West Indian manatees entering or leaving the Indian River during the time of the 

 aerial surveys, indicating direction of travel relative to tidal flow 



Dale 



11977) 



Bottlenosed dolphins 



West Indian manatees 



10 Aug 



1 1 Aug 



12 Aug 



13 Aug 



14 Aug 



15 Aug 



Total 



4 adults moving against tide into river through Sebas- 

 tian Inlet 



7 adults 2 calves moving with tide trom river into 

 Sebastian Inlet thence against tide back into river 



1 adult moving against tide into river through Sebas- 

 tian Inlet 











1 luvenile milling within Sebastian Inlet at slack 

 tide 



15 individuals consisting ol 5 moving against tide 

 9 moving both with and against tide and i milling 

 within inlet 



2 adults milling within Fori Pierce Inlet 



2 adults moving against tide into nver through Fort 



Pierce inlet 

 

 1 adult moving with tide from river to ocean through 



Sebastian Inlet 

 1 adult moving with tide from river to ocean through 



Sebastian Inlet 



6 individuals, consisting ol 2 milling withm inlet 2 

 moving against tide, and 2 moving with tide 



T\HLK 4 — Summary of West Indian manatee sightings by day 

 during the six 1-day aerial surveys. August 1977. 



TaHLK 5. — Some estimates of density of bottlenosed dophms, 

 Tursiops sp., in coastal waters of the southeastern United States. 



Reynolds'i. and were consistent with those re- 

 ported from aerial surveys conducted in Texas 

 using similar methodology (Barham et a!.**! (Table 

 5). This consistency and the relatively low var- 

 iance estimates are evidence that this was a 

 realistic estimate of the numbers of dolphins in the 

 rivers during the time of the survey. 



Biittlenosi'd dolphins have been observed to 

 occur as individuals and in groups of over 200 

 animals i Leathfruiind and Platter''). Mean herd 

 sizes iif hdtlleno.sed dolphins off eastern P^lnrida 

 and in {hv C!ulf of Mexico vary considi'iahiy I'nim 

 one area to another- ('ii'oups apparently decrease 



'Odell. D K.. and J, E Reynolds III In press. Distribution 

 and abundance of the bottlenosed dolphin. Tursiitps Iruniiitus. 

 on the west coast of'Florida. Contract Report to the U.S. Marine 

 Mammal Commission. Wash., D.C., 5.5 p. National Technical 

 Information Service. Wash.. DC 



'Barham. E, G . J, C. Sweeny. S. Leatherwood. R. K Beggs. 

 and C. L, Barham, 1978, Aerial census of bottlenosed dol- 

 phins tTursifips truiicatiist in a region of the Texas coast. Un- 

 publ- manuscr,. 34 p. Southwest Fisheries Center. National 

 Marine Fisheries Service. NOAA. P.O, Box 271. La Jolla, CA 

 920.38 



"Leatherwood. S,, and M. F, Platter, 1975, Aerial assess- 

 ment of bottlenosed dolphins off Alabama. Mississippi, and 

 Louisiana, hi D, K, Odell, D. B, Siniff. and G, H. Waring 

 ifditorsi. 7\irsiiips tnmcaliis assessment workshop, p, 49-86, 

 Final Report. U,S, Marine Mammal Commission, Contract 

 MM5AC021 



^Derived trom their Table 10 by computing the product ol mean I 

 (5 43) and mean herd density (0 0497) 



in size with distance from shore lOdell and 

 Reynolds see footnote 7i; tend in coastal waters to 

 be larger in deeper and in open water areas than in 

 shallou embaymenls. lagoons, and marshlands 

 I LeatheiuDod and Platter see footnote 9; Leath- 

 erwood et al. 1978; Shane and Schmidley'"); and 

 tend to fluctuate in size seasonally with little pat- 

 tern discernible i Shane and Schmidley see foot- 

 note lOi. The mean group size observed during this 

 stt-id\- IS. 21 \sas well within the limits reported by 

 all authors for eastern Florida and gulf coast v\a- 

 ters. This and the lack olcorrelation between herd 

 size and herd densit\' lurther suppoi't the reason- 

 ableness of this population estimate (only if the 

 distribution of herd sizes were normal could the 

 inference technically lie made that the two vari- 

 ables were independent (Figure 4ii. 



Because the estimation of variance in total 

 numbers of animals assumes that herd size and 



'".Shane, S, H,, and D, J, Schmidley, In press. Population 

 hiiilogy of .Atlantic bottlenosed dolphins, Tursittpti truncatus, in 

 the .Aransas Pass area of Texas, Contract Report to the U.S. 

 Marine .Mammal Commi.ssion. Wash,, DC. 2.'i8 p. National 

 Technical Inform.itinn .Service. Wash., D.C. 



56 



