National Marine Fisheries Service

About: National Marine Fisheries Service is a government organization based out in Silver Spring, Maryland, United States. It is known for research contribution in the topics: Population & Fisheries management. The organization has 3949 authors who have published 7053 publications receiving 305073 citations. The organization is also known as: NOAA Fisheries & NOAA National Marine Fisheries Service.

Identity and regulation of nutrients limiting phytoplankton production in the shallow estuaries near Beaufort, N.C.

Abstract: Inorganic nutrients limiting phytoplankton production in the shallow estuarine system near Beaufort, N. C., were identified by nutrient enrichment techniques. Nitrogen was the primary limiting nutrient; phosphorus also was limiting at times. Samples receiving a complete enrichment medium plus organic substrates poor or lacking in nitrogen and phosphorus showed no significant increase in relative photosynthesis over unenriched controls, even though there was a significant decrease in the nitrogen and phosphorus concentrations in the enriched samples. This suggested that microbial immobilization of nitrogen and phosphorus during decomposition of organic matter may limit nutrient availability to phytoplankton and in part account for the general paucity of inorganic nutrients present in this shallow system. An estimated 6 x 109 g carbon, 1 x 108 g nitrogen and 2 x 107 g phosphorus enters the estuarine system in the form of partially decayedSpartina alterniflora each year, primarily from September–March. To utilize the readily available fraction of this detrital material estuarine microbes would have to immobilize 2.4 x 107 g nitrogen and 1.6 x 106 g phosphorus. The data also suggested that an annual cycle in nutrient concentration in the estuarine system in part may result from shifts in the equilibrium between microbial immobilization and remineralization.

Valuing Recreation and Amenities at San Diego County Beaches

Abstract: Policymakers and analysts concerned with coastal issues often need economic value information to evaluate policies that affect beach recreation. This paper presents economic values associated with beach recreation in San Diego County generated from a recreation demand model that explains a beach user's choice of which beach to visit. These include estimates of the economic values of a beach day, beach closures, and beach amenities.

Continuous, underway sampling of eggs of Pacific sardine (Sardinops sagax) and northern anchovy (Engraulis mordax) in spring 1996 and 1997 off southern and central California

Abstract: Eggs of the northern anchovy and Pacific sardine were sampled at 3 m depth using the Continuous, Underway Fish Egg Sampler (CUFES) during two cruises off southern and central California in March and April 1996 and 1997. Simultaneous measurements were made of seawater temperature and salinity. Real-time AVHRR satellite images of sea surface temperature were processed onshore and transmitted to the ship at sea. Sardine and anchovy eggs were identified and counted live, at sea, and again ashore, preserved. A total of 2129 CUFES samples were collected during 41 d at sea and contained 62,409 sardine and 15,123 anchovy eggs. Sardine eggs were widespread and abundant in both cruises (mean concentrations: 5.2 and 5.1 eggs m −3 ) at and shoreward of the eastern boundary of the California Current. Anchovy eggs were found primarily inshore in the Southern California Bight and were less abundant (0.4 and 1.0 eggs m −3 , respectively, for the two cruises). Temperature–salinity plots indicated distinct separation of the spawning habitat of these two species and consistency in habitat between cruises in successive years. The distributions of sardine eggs and euphausiids collected by CUFES were complementary in space and time.