Changes in Fish and Invertebrate
Communities and Detection of
Indicator Species in the beaches of the
Callao During the Period 1997 - 1999

Albertina Kameya, Miguel Lleellish,
Sheila Zacarías, Manuel Bustamante,
Luis Caccha

Instituto del Mar del Perú (IMARPE), Apartado 22,
Callao, Perú, E-mail: akameya@imarpe.gob.pe

The actual concept of indicators of El Niño involves complex responses to seawater physical-chemical changes which have impacts on different biological levels such as individuals, population, communities and biological processes.

Changes of communities of fish and invertebrates at Callao beaches (12°S) were induced by El Niño 1997-98 event. This study was carried out monthly using beach seiner, net curtains and trammel-nets.

The influence of the event was initially evident as drops in captures, which then increased, based on warm water species, during 1998. The values of diversity, calculated from data on abundance collected with the beach seiner, increased during the whole period, varying between 2 and 3.5 bits/ind. A permanency of indicator species of warm waters (49) was observed. 123 species were captured; 87 fish, 25 crustaceans, 9 molluscs and 2 echinoderms.

The return to normal conditions occurred gradually beginning in November 1998, showing a lag of four months in relation to environmental variables.

During 1999, the environmental conditions remained cold, with intensified coastal upwelling in June, favoring some resources of temperate waters. On the other hand, Subtropical Surface Waters were observed very near to the coast (40-100 nm). This explained the presence of the "pelagic swimcrab" Euphylax dovii which was observed, in different coastal areas, especially in the study area.

During 1999, 103 species were captured, among which 74 were fish, 15 crustaceans, 8 molluscs, 5 echinoderms and polychaeta, 43 were warm water species.

There was no significant evidence of an impact of cold periods, however El Niño 1997-1998 periods were observed.