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Project title

Macroalgal biomonitoring - applying phenolic compounds as biomarkers for metal uptake characteristics in Irish coastal environments

Primary Funding Agency

Environmental Protection Agency

Co-Funding Organisation(s)

n/a

Lead Organisation

National University of Ireland Galway (NUIG)

Lead Applicant

Solene Connan

Project Abstract

Metals occur naturally in seawater at low concentrations and some act as essential micronutrients for marine biota but they become toxic when absorbed or ingested by plants and animals at high concentrations. Despite some recent research on metal contents in seaweeds from Ireland few data exist for Irish coastal and transitional waters. The recent Discussion Document on a National Environmental Monitoring Programme for Transitional Coastal and Marine Waters by the Environmental Protection Agency of Ireland proposes the inclusion of seaweeds in an extended assessment of future monitoring programs for metal concentrations in Ireland and recommends the monitoring of hazardous substances and contaminants including metals by using biomonitoring organisms such as shellfish and seaweeds. Currently no standardised monitoring protocol exists in Ireland although some limited biomonitoring of metals using shellfish has been conducted. In this 3-year project we observed seasonal spatial and inter-site variations in phenolic and metal (copper zinc cadmium chromium) contents and in phenolic composition in the ecologically and economically most important intertidal seaweeds in Ireland Ascophyllum nodosum and Fucus vesiculosus demonstrating their suitability as biomonitors of metal contamination. The experimental approach taken in this project established a quantitative link between physiological responses in intertidal brown seaweeds and phenolic production composition exudation and the potential of phenolics to bind metals under natural environmental conditions. The effect of copper enrichment and its interaction with salinity and the effect of iron and zinc contamination were closely investigated. However neither the intra-cellular phenolic content of the seaweed nor phenolic exudation could be used as biomarkers of metal contamination whereas the cell-wall phenolic content of brown seaweeds seems promising but needs further investigation. This project has produced data on the contaminant status of selected Irish coastal and transitional waters including sites of active seaweed harvesting by the Irish seaweed industry. Finally some recommendations are proposed for the sampling methodology when using seaweeds as biomonitors of metal contamination and some general comments on the utilisation of a series of biomonitors (seaweed animal filter-feeder such as mussels) as well as sediment to characterise the metal contamination of a site in more detail.

Grant Approved

�149,869.80

Research Hub

Healthy Environment

Research Theme

Impacts on Aquatic Ecosystems & Human Health (including Drinking Water)

Start Date

n/a

Initial Projected Completion Date

n/a