Metals in Phragmatopoma attenuata Hartman, 1944 (Annelida, Sabellariidae) worm reefs and beach sand, Gulf of Nicoya estuary, Pacific, Costa Rica

PDF

Abstract

Sabellariid annelid polychaete worms build reefs by cementing sand grains in their tubes. In the Gulf of Nicoya estuary, Costa Rica, Phragmatopoma attenuata worms construct reefs on and between rocks used in groins. The objective of this study was to investigate whether these worms select sediment grain sizes and trace metals in the building of their reefs. A total of 12 sand samples were collected (three each from three reefs and three from beach sand) to compare the beach sand to the composition of the sand tubes. Samples were sieved through a series of nested Standard Sieve Series with 2,000 and 62 μm mesh sizes as the upper and lower limits for the sand fractions. A total of 12 metals: Al, Cd, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Sn, and Zn were analyzed by Inductively Coupled Plasma Mass Spectrometry. The results indicate the following decreasing order of concentrations (μg g^-1 dry weight): Al > Fe > Mg > Mn > Cu > Zn > Cr > Ni > Pb > Hg > Sn > Cd. It was concluded that: 1. Metal concentrations were expected for a non-industrialized estuary. 2. P. attenuata worms selected for medium grain size fractions between 300 and 850 μm. 3. Worms also seem to prefer sand containing relatively higher levels of calcium carbonate, cadmium, and manganese when compared to those in beach sand.

Vargas, J., Molina, J., Cambronero, R., & Sibaja-Cordero, J. (2026). Metals in Phragmatopoma attenuata Hartman, 1944 (Annelida, Sabellariidae) worm reefs and beach sand, Gulf of Nicoya estuary, Pacific, Costa Rica. Latin American Journal of Aquatic Research, 54(3). doi:http://dx.doi.org/10.3856/vol54-issue3-fulltext-3334

Copy