Phytoplankton and Algal Blooms

Phytoplankton are possibly the most important group of organisms on the planet as they generate most of the oxygen that we breath. Also, as they convert inorganic nutrients and sunlight into vegetative matter, most marine food chains depend on their presence as a primary food source.

A small proportion of species produce highly potent toxins and the monitoring of these are very important to ensure food safety.

While blooms can provide more food to organisms higher up the food chain, too much phytoplankton can also do harm. Dissolved oxygen becomes rapidly depleted as the phytoplankton die, sink to the bottom and decompose. This can result in the death of other organisms including shellfish, crabs and fish.

Photo of redtide credit: Irish Air Corps

The main groups of Phytoplankton include Diatoms, Dinoflagelates, Coccolithophorids and Micro-Flagellates. Each of these groups has distinguishing features that allow specialists to identify them to species level.

The Marine Institute Phytoplankton Monitoring Programme monitors coastal waters around Ireland for phytoplankton and algal blooms on a year round basis.

The Marine Institute monitors phytoplankton under a national programme which has been in place since the 1980s. During this period, phytoplankton scientists have developed an understanding of phytoplankton populations and dynamics around the Irish coastline.

Sample HAB Bulletin


The PRIMROSE project will develop a web-portal system providing a joint front end for transnational forecasts of harmful events for the aquaculture sector. In addition to the HAB forecasting, PRIMROSE will investigate forecasts models for microbial contamination. Reporting procedures will be standardised, and partly automated for an expert evaluator to have information available to make an accurate forecast.

The Marine Institute are the project lead in PRIMROSE. This project follows on from the successful ASIMUTH project, which delivers weekly HAB’s forecast bulletins to the Irish aquaculture industry.

Further information on the PRIMROSE project is available at


ALERTOX-NET aims to develop a technology driven applied approach to make industries aware of emerging toxin issues stemming from potential environmental change, in order to ensure the delivery of better, safer seafood-products during the occurrence of naturally occurring toxicity in coastal waters.

The Marine Institute are a project partner in ALERTOX-NET

View the ALERTOX-NET website at


Enhanced biorefining methods for the production of marine biotoxins and microalgae fish feed.

MARBioFEED is a three year project supported by the First Call for Transnational Research Projects within the Marine Biotechnology ERA-NET, involving partners from Ireland (Marine Institute), Norway (Norwegian Veterinary Institute), Spain (Spanish Oceanographic Institute and Neoalgae), and Canada (National Research Council).

Project background and aims:

The quality assurance of fish and shellfish for human consumption is of paramount importance in ensuring the marketability of products from this expanding and predominantly rural sector. The global demand for fish is increasing due to an expanding population and the awareness that fish is a healthy food source. With increased pressure on land-based agriculture due to climate change, the potential for sustainable marine sourced food is growing. The industry and regulators rely heavily on analytical reference materials to guarantee safety for human health. This project will involve large-scale algal biotechnology for the production of value added products (marine biotoxin reference materials and fish feed).

Further information on the MARBioFEED project is available at and