Ecological patterns of macrofauna in sandy beaches of Costa Rica: A Pacific-Caribbean comparison

Autor: Yolanda E. Camacho-García, Jeffrey A. Sibaja-Cordero, Juan Carlos Azofeifa-Solano, Bárbara Alvado-Arranz
Rok vydání: 2019
Předmět:
Zdroj: Estuarine, Coastal and Shelf Science. 223:94-104
ISSN: 0272-7714
Popis: The present study compares the ecological patterns of macrofauna in sandy beaches between the Caribbean and Pacific coasts of Costa Rica. At each beach, the intertidal zone was divided into five strata from low to high tide level. In each stratum, sediment samples (corer area: 20.2 cm2, diameter: 5.07 cm) were collected to analyze the macrofauna. Additionally, grain size composition, total organic matter and carbonates of the sediments were determined. The macrofauna diversity was higher in the Pacific coast (15 taxa, per beach) than in the Caribbean (4 taxa, per beach). The most diverse taxon group was the annelids, followed by arthropods and mollusks. Within the mollusks, the bivalves and the gastropod family Olivellidae were only present in the Pacific coast. Both Caribbean and Pacific coasts had a vertical zonation of taxa distribution from high to low tide level. Typically, the low tide level was populated by several polychaetes, mid littoral by crustacean and mollusks, and the high tidal level was populated by isopods (Cirolanidae). Faunal differences in richness, abundance and composition of assemblages between both coasts can be explained by environmental differences. The tidal range is narrower on the Caribbean (0.5–1.5 m) than the Pacific coast (2–3 m). The slope of the beach is steep in several beaches of the Caribbean, whereas the Pacific has several dissipative beaches with gentle (or flat) slopes. The organic matter was lower (1.00%) in the Caribbean than in the Pacific (2.25%). In the Caribbean coast, the sediment is ∼90% fine sand (500–63 μm), while in the Pacific this fraction was ∼65%, resulting in more heterogeneous sediments in the Pacific. Finally, evidence of change in the abundance and species composition with the latitude in each coast was detected; indicating that these communities are highly variable within a local scale, which could be due to the diversity of sandy beaches and environmental variation that Costa Rica has in both coasts. Our results indicate that beaches with higher number of species or abundance were not necessarily designated as Marine Protected Areas. This information should be considered in the future for the establishment of new Marine Protected Areas.
Databáze: OpenAIRE
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