Creaser and Perkins: Distribution, food, and abundance of Pomatomus saltatrix 



495 



correctly identify preserved juvenile bluefish from 

 the laboratory fish collection. 



Study locations 



The primary sampling sites were in the Marsh River 

 (a tributary of the Sheepscot River in Newcastle, 

 Maine) near the confluence of Sherman Lake Outlet 

 and Deer Meadow Brook (Fig. 1A). These sites were 

 selected because juvenile bluefish were consistently 

 captured there in preliminary netting experiments 

 conducted during the summers of 1986-89. The sites 

 are approximately 6.5 km from the confluence of the 

 Marsh River and the Sheepscot River and 34.3 km 

 from the mouth of the Sheepscot River. Marsh banks 

 abut the meandering river and mud flats slope from 

 the base of these banks to the edge of the riverbed. 

 The riverbed is about 46-49 m wide at low tide. 

 The mean tidal range is 1.60 m (U.S. Dep. Commer., 

 1990-91). 



Juvenile bluefish were also obtained from sampling 

 sites at Kennebec Point (Fig. IB) and Merepoint Bay 

 (Fig. 1C). The Kennebec Point site is used routinely 



43°45'N 



44°00'N 



69°35'W 



43°50'N 



70°00'W 



Figure 1 



Sampling locations for juvenile bluefish, Pomatomas saltatrix, in (A 

 Marsh River, (B) Sagadahoc Bay, and (C) Merepoint Bay, Maine. 



by the Division of Benthic and Demersal Fisheries 

 (State of Maine, Dep. of Marine Resources, W. 

 Boothbay Harbor, Maine 04575 ) to monitor biweekly 

 variation in species diversity and abundance; occa- 

 sionally, juvenile bluefish were captured there. The 

 site consists of a sandy beach and a small cove, 1.8 

 km from open ocean. The mean tidal range is 1.37 m 

 (U.S. Dep. Commer., 1990-91). 



Abundant schools of juvenile bluefish and clupeids 

 inhabit the Merepoint Bay site, located in shallow 

 water between the floats at Paul's Marina (Fig. 1C). 

 This site is 16.7 km from open ocean and the tidal 

 range is 1.46 m (U.S. Dep. Commer., 1990-91). 



Sampling gear 



Gill nets were employed to capture juvenile bluefish 

 in the Marsh River for the following reasons. First, 

 the fish were dispersed and sporadic in occurrence 

 and other methods of capture would probably have 

 produced few fish. Swift tidal currents prevented the 

 use of seines at other than low slack water, and a 

 seine requires two operators and frequently only one 

 was available. 



Two sinking gill nets (Sterling 

 Marine Products, Jonesport, Maine 

 04649), measuring 2.4 m in depth 

 and 48.8 m in length, were suspended 

 between stakes driven into the banks 

 of the Marsh River. Ropes suspend- 

 ing these nets bifurcated 4.6 m from 

 the end of each net; one length was 

 attached to the float line and the 

 other to the lead line. Poles measur- 

 ing 2.1 m were positioned between 

 the float and lead lines at each end 

 of each net to prevent the nets from 

 collapsing and twisting during rapid 

 tidal flows at mid-ebb and mid-flood. 

 A window weight (2.4 kg) was at- 

 tached to the lower end of each pole 

 to maintain the net vertically. One 

 net was a variable mesh type con- 

 structed from two 6.1-m panels of 

 each of the following square mesh 

 sizes: 1.27 cm, 1.90 cm, 2.54 cm, and 

 3.18 cm. Individual panels were ran- 

 domly positioned. Additional floats 

 were attached to the float line of 

 these sinking nets so they fished ap- 

 proximately 15-30 cm below the sur- 

 face. This enabled floating debris to 

 pass over the net. The second net was 

 constructed entirely of 1.27-cm square 

 mesh. 



69°45'W 



