Composition of the zooplankton community, with emphasis in copepods, in Punta Morales, Golfo de Nicoya, Costa Rica

The composition of the mesozooplanktonic community was studied in the Punta Morales estuary, Gulf of Nicoya, Pacific coast of Costa Rica, during 1997. Oblique plankton hauls were performed during high and low tide using a 280 μm mesh screen net equipped with a flowmeter. The community was characterized by holoplanktonic and meroplanktonic organisms. For the holoplanktonic community, the main groups were copepods (80%) and chaetognaths (16%). The most abundant species were the copepods Acartia lilljeborgii and Paracalanus parvus. A. lilljeborgii is a typical estuarine species that maintains high populations in estuarine systems. Meroplankton was represented mainly by crustacean larvae (66%), and icthyoplankton (18%). The dominance of crustacean larvae and icthyoplankton is an evidence of the ecological importance of the Punta Morales zoneSe estudió la composición de la comunidad mezoplanctónica en Punta Morales, Golfo de Nicoya, Pacífico de Costa Rica, en 1997, arrastrando oblicuamente una red de plancton (280 μm, con flujómetro) durante marea alta y baja. La comunidad estuvo caracterizada por la presencia de organismos holo y meroplanctónicos. Los principales grupos holoplanctónicos fueron copépodos (80%) y quetognatos (16%). Las especies más abundantes fueron los copépodos Acartia lilljeborgii y Paracalanus parvus; A. lilljeborgii es una especie estuarina típica que mantiene altas poblaciones en sistemas estuarinos. El meroplancton estuvo representado principalmente por larvas de crustáceos (66%), e ictioplancton (18%). La dominancia de larvas de crustáceos e ictioplancton evidencian la importancia ecológica de la zona de Punta Morales

The Gulf of Nicoya (Costa Rica) Fisheries System: Two Decades of Change

In the early 1990s, ecological and fishery data from the Gulf of Nicoya (Pacific Ocean) were holistically analyzed, and a trophic model was constructed using the Ecopath modeling approach. The results indicated that this tropical estuary, which is a Costa Rican fishery hot spot, was already overexploited by shrimp trawlers and the longline fleet, and recent observations suggest further deteriorations in this system. To evaluate the ecosystem and socioeconomic changes in the Gulf of Nicoya over the last 20 years, the 1993 model was reconstructed with data from 2013 to compare both system states. Although the summary statistics of both states (i.e., 1993 and 2013) suggested that the system maintained its general functionality and even enabled the total harvest to increase by approximately 20%, a more detailed analysis of the levels of the functional groups suggested that the system was further degraded as follows: (1) most shrimp, eel, and catfish species decreased their share in the catches, with severe economic losses for the fishery; (2) of the species that substantially increased their share in the catches, most were short‐lived, low‐value species, such as small pelagic and small demersal fishes; and (3) catches of long‐lived, high‐trophic‐level fish, such as rays, sharks, mackerels, and barracudas, decreased. A picture emerged in which the advancing fishery of low‐trophic‐level species with low economic value enabled the total harvest to increase, while valuable shrimp resources and higher‐trophic‐level species were depleted. These developments caused a tremendous economic loss of approximately 50%