FISHERY BULLETIN: VOL. 80, NO. 4 



peratures and spring landings of pink shrimp in 

 North Carolina to determine if temperature 

 could be used as a predictor of landings. Several 

 recent harsh winters (Diaz and Quayle 1980; 

 Ingham 1979) provided an opportunity to com- 

 pare landings over a range of temperatures. This 

 relationship may serve to focus attention on the 

 importance of temperature extremes in under- 

 standing ecosystem productivity. We also ana- 

 lyzed available water and air temperatures to 

 model the annual temperature in the lower New- 

 port River estuary, to compare the weekly mean 

 temperatures of each year with the annual model, 

 and to test the use of air temperature as proxy 

 data for periods when no water temperatures 

 were available. Finally, we examined the effect 

 of local winter rainfall on pink shrimp landings. 



METHODS 



Temperature records were analyzed from the 

 Newport River estuary, which is centrally lo- 

 cated within the North Carolina pink shrimp 

 nursery and fishing grounds, the "Carteret- 

 Onslow Area" of Williams (1955b) (Fig. 1). This 

 estuary, had been the site of several studies con- 

 ducted by our laboratory during which tempera- 

 tures were routinely monitored at one or more 

 locations, but the entire time-series of tempera- 

 ture records had not been analyzed. 



Seawater temperatures were obtained from 

 recordings made at Pivers Island near Beaufort, 

 N.C., at the mouth of the Newport River estuary 

 beginning in 1962. From 1962 until 1968, rec- 

 ords were kept on the island's north channel, and 

 from 1968 to the present, records were kept on 

 the east channel. These locations are <400 m 

 apart. From 1968 to mid-1974, continuous rec- 

 ords either were not kept or were inadvertently 

 lost. Thus, complete continuity from 1962 to 1981 

 was not possible. 



Seawater temperature was recorded continu- 

 ously on 7-d circular charts. Recordings since 

 1974 were calibrated (±0.1°C) with a precision 

 mercury thermometer. The accuracy and preci- 

 sion of pre-1974 records could not be determined. 

 Weekly means from 1962 to mid-1974 were cal- 

 culated by averaging hourly readings during 

 each 7-d cycle. Weekly means from mid-1974 to 

 1981 were calculated by using a compensating 

 polar planimeter. The planimeter method per- 

 mitted rapid integration of the entire weekly 

 temperature record into a single temperature by 

 converting the mean radius of the area encom- 

 passed by the temperature cycle to the equiva- 

 lent weekly mean temperature. 



Daily air temperatures and monthly precipita- 

 tion totals were recorded at the National Weather 

 Service observation station in Morehead City, 

 N.C., 6.2 km west of Pivers Island, and were pub- 



CORE SOUND 



PIVERS ISLAND v Q< 



GUE OUN .»\^ 



77° OO'W h 



Figure 1. — Pink shrimp nursery area 

 (indicated by hatched lines). Pivers 

 Island was point-source of water tem- 

 perature data. 



762 



