Spatial variation of coastal metal contamination and bioaccumulation in multiple intertidal invertebrates

Overview

This study quantified concentrations of eight metals (Al, Cd, Cu, Fe, Li, Ni, Pb, Zn) in eight intertidal invertebrate species across three anthropogenically impacted coastal sites on Tenerife, Canary Islands. The investigation assessed spatial variation in metal bioaccumulation patterns and identified species-specific accumulation profiles.

Methods and approach

Metal concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) in eight intertidal species representing diverse feeding strategies and life histories: the anemone Anemonia viridis, the macroalgae Asparagopsis taxiformis and Dasycladus vermicularis, the gastropod molluscs Micromelo undatus and Phorcus sauciatus and Stramonita haemastoma, the decapod crustaceans Pagurus anachoretus and Palaemon elegans. Sampling occurred at three sites with distinct anthropogenic stressors: El Médano (landfill and urban runoff), Los Silos (submarine outfall), and La Punta del Hidalgo (control site with minimal anthropogenic impact). Concentration data were reported in mg/kg dry weight.

Key Findings

El Médano exhibited the highest metal concentrations across most elements, followed by Los Silos, with La Punta del Hidalgo showing minimal contamination. Species-specific accumulation patterns were evident: M. undatus, P. anachoretus, and P. elegans accumulated elevated Al concentrations, whereas S. haemastoma demonstrated markedly elevated Cd levels. The study generated initial bioaccumulation data for M. undatus, P. anachoretus, and S. haemastoma in the Canary Islands archipelago.

Implications

The spatial heterogeneity in metal concentrations corresponds to proximity and intensity of anthropogenic inputs, supporting the use of this intertidal assemblage for biomonitoring coastal contamination gradients. Species-specific bioaccumulation patterns suggest differential exposure pathways or physiological handling mechanisms, necessitating multi-species approaches in environmental monitoring programs. The first baseline measurements for three species establish a reference point for longitudinal surveillance and risk assessment in island coastal systems.