Primary producers off the Peruvian coast in summer 2005. Pelagic Resources Assessment Cruise R/V SNP-2, José Olaya

Abstract

In the area from Ilo to Paita, a total of 77 samples were collected using a phytoplankton net (75 µm). Plankton volumes reached a mean value of 0.33 mL/m3 and there were important nuclei within 60 nm off Punta Gobernador and San Juan. Phytoplankton was scarce north and south of the coast and its distribution improved outside 60 nm in Chicama, Chimbote, Callao, and Pisco. Intermediate and early-stage diatoms were prevalent in the ecological succession north of 12°S, and only intermediate-stage species were predominant in the south. Red tide organisms such as Prorocentrum cordatum (Ostenfeld), P. micans Ehrenberg, and Akashiwo sanguinea (Hirasaka) were recorded indistinctly along the coast. The CCW indicator Protoperidinium obtusum (Karsten) was mainly located within 30 nm, except in Chicama, Chimbote, and Chancay where it reached more than 60 nm. Ceratium incisum (Karsten), which is an indicator of Subtropical Surface Waters (SSW) was determined at 120 nm off Punta Falsa