484 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Tlie most oominon alfjae iind invertebnites col- 

 lected or recorded from Oyster Pond Kiver 

 (Mass.) are: 



Figure 3. — Locations of mooring sites, oyster leased 

 grounds, and siiat collecting area near Chatham, Mass. 



afternoon the temperature dropped slowly and by 

 6 :00 p.m. it was down to 18.4° C. 



Durino- the '.I years of observations the salinity 

 of tlie water in Oyster Pond River varied from 

 29.23%o to .32.68%o- Since there is no major 

 fresh-water drainage entering tlie river, a Jiori- 

 zontal salinity gradient is absent. The salinity 

 (fig. 4) was higher (;U.00-.S2.(i8) from June 195fi- 

 October 1957 than for the period November 1957- 

 December 1958 (29.28-31.00). 



Dissolved oxygen (fig. 4) was highest during the 

 winter and lowest in tlie smnmer. Most of the 

 readings were at or near 100 percent saturation. 

 The pH varied from 7.(1 to 8.0. ' 



AQUATIC LIFE IN THE RIVER 



The most conspicuous or most abundant animals 

 and plants found on or near the oyster bottoms are 

 various species of algae, Rryozoa, Arthropoda, 

 and Mollusca. All the aninntls species listed in 

 the table are permanent residents of Oyster Pond 

 River with tlie exception of tlie horseshoe crab, 

 L/muIvs poIi/p/iemuK, which enters the ri\er in 

 early spring. After it spawns, polyphennis leaves 

 the river for deeper water. 



^ Ciirrectt'd for salt orror. 



Algae : 



Bnteroniori>ha sp. 

 Gracilaria confervoides 

 Grlffithsia sp. 

 Ceramiiim rubrum 

 Chondria sp. 

 Champia parvula 

 Scythosiphon lomen- 

 taria 



I'ORIFERA : 



Microciona prolifera 



Rryozoa : - 



Memliranipora tenuis 

 Electra liastingsae 

 Callopora aurita 

 Schizoporella unicorn- 

 is 

 Schizoporella biaperta 

 Cryptosula pallasiana 

 Hippodiiilosia ijertusa 

 Microporella ciliata 

 Parasmittina trispino- 

 sa 



Arthropoda : 



I>il)inia emarglnata 

 Carcinides maenas 



Arthropoda — (Continued) 

 Cancer irroratus 

 Neopanopeus texana 

 Panoi)eus herbstii 

 Limulus polypheiuus 



Mollusca : 



Littorina litorea 

 Nassarius obsoletus 

 Urosalpinx cinerea 

 Eupleura candata 

 Bu.sycon canaliculatum 

 Busycon cariea 

 Polinices duplicatus 

 Crepidula fornicata 

 Aequipecten irradians 

 Mercenaria (Venus) 



niercenaria 

 Anomia simplex 

 Crassostrea virginica 

 Mytilus edulis 

 Modiolus demissus 

 Mya arenaria 

 Gennna gemma 



TUNICATA : 



Hotryllus sclilosseri 

 Molgula mauliattensis 



I Alj.'iii' kleiitifiiMl by Pr. Paul S, Galtsoft from material C(il- 

 lectHd cm AiiKUst 7. l!>ril. 



- Br.vozoa identified by Mrs. M. B. Lambert from a sample 

 talien after dredKinR in 5 to S feet of water on July 14, 1953. 



 Several species of oyster predators are i»l)un- 

 dant. Tliese include tlie oyster drills, l' ivs(ili>'ni.r 

 riiteroi and E\i pleura (■(ntdittit. and two species 



32 

 3 I %. 



A S I 



1956 



FiGUliK 4. — Tile average monthly water temi^erature. 

 salinty, and content of dissolved oxygen for Oyster Pond 

 Hivcr. 



